Commit Graph

294 Commits

Author SHA1 Message Date
Geert Uytterhoeven ff1cab374a serial: sh-sci: Remove cpufreq notifier to fix crash/deadlock
The BSP team noticed that there is spin/mutex lock issue on sh-sci when
CPUFREQ is used.  The issue is that the notifier function may call
mutex_lock() while the spinlock is held, which can lead to a BUG().
This may happen if CPUFREQ is changed while another CPU calls
clk_get_rate().

Taking the spinlock was added to the notifier function in commit
e552de2413 ("sh-sci: add platform device private data"), to
protect the list of serial ports against modification during traversal.
At that time the Common Clock Framework didn't exist yet, and
clk_get_rate() just returned clk->rate without taking a mutex.
Note that since commit d535a2305f ("serial: sh-sci: Require a
device per port mapping."), there's no longer a list of serial ports to
traverse, and taking the spinlock became superfluous.

To fix the issue, just remove the cpufreq notifier:
  1. The notifier doesn't work correctly: all it does is update stored
     clock rates; it does not update the divider in the hardware.
     The divider will only be updated when calling sci_set_termios().
     I believe this was broken back in 2004, when the old
     drivers/char/sh-sci.c driver (where the notifier did update the
     divider) was replaced by drivers/serial/sh-sci.c (where the
     notifier just updated port->uartclk).
     Cfr. full-history-linux commits 6f8deaef2e9675d9 ("[PATCH] sh: port
     sh-sci driver to the new API") and 3f73fe878dc9210a ("[PATCH]
     Remove old sh-sci driver").
  2. On modern SoCs, the sh-sci parent clock rate is no longer related
     to the CPU clock rate anyway, so using a cpufreq notifier is
     futile.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-07 21:08:05 -08:00
Greg Kroah-Hartman f658f21c65 Merge branch 'scif-clk-sck-brg-for-v4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/renesas-drivers into tty-next
Geert writes:

Summary:
  - Clean up the naming of clocks in the sh-sci driver and its DT bindings,
  - Add support for the optional external clock on (H)SCI(F), where this pin
    can serve as a clock input,
  - Add support for the optional clock sources for the Baud Rate
    Generator for External Clock (BRG), as found on some SCIF variants
    and on HSCIF.
2016-01-07 21:04:46 -08:00
Laurent Pinchart 192d367f21 serial: sh-sci: Drop the sci_fck clock fallback
All platforms that used to define an sci_fck clock have now switched to
the fck name. Remove the fallback code.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-17 11:19:12 +01:00
Geert Uytterhoeven 1270f86517 serial: sh-sci: Add support for optional BRG on (H)SCIF
Add support for using the Baud Rate Generator for External Clock (BRG), as
found on some SCIF and HSCIF variants, to provide the sampling clock.
This can improve baud rate range and accuracy.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-17 11:19:00 +01:00
Geert Uytterhoeven 6af27bf299 serial: sh-sci: Add support for optional external (H)SCK input
Add support for using the SCIx clock pin "(H)SCK" as an external clock
input on (H)SCI(F), providing the sampling clock.

Note that this feature is not yet supported on the select SCIFA variants
that also have it (e.g. sh7723, sh7724, and r8a7740).

On (H)SCIF variants with an External Baud Rate Generator (BRG), the
BRG Clock Select Register must be configured for the external clock.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-17 11:18:57 +01:00
Geert Uytterhoeven f4998e55b8 serial: sh-sci: Prepare for multiple sampling clock sources
Refactor the clock and baud rate parameter code to ease adding support
for multiple sampling clock sources.
sci_scbrr_calc() now returns the bit rate error, so it can be compared
to the bit rate error using other sampling clock sources.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-17 11:18:54 +01:00
Geert Uytterhoeven 9ed44bb209 serial: sh-sci: Correct SCIF type on R-Car for BRG
The "renesas,scif" compatible value is currently used for the SCIF
variant in all Renesas SoCs of the R-Car family.  However, the variant
used in the R-Car family is not the common "SH-4(A)" variant, but a
derivative with added "Baud Rate Generator for External Clock" (BRG),
which is also present in sh7734.

Use the family-specific SCIF compatible values for R-Car Gen1, Gen2, and
Gen3 SoCs to differentiate.  The "renesas,scif" compatible value can
still be used as a common denominator for SCIF variants with the
"SH-4(A)" register layout (i.e. ignoring the "Serial Extension Mode
Register" (SCEMR) and the new BRG-specific registers).

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-17 11:18:52 +01:00
Geert Uytterhoeven f443ff80d0 serial: sh-sci: Correct SCIF type on RZ/A1H
The "renesas,scif" compatible value is currently used for the SCIF
variant in all Renesas SoCs of the R-Car and RZ families.  However, the
variant used in the RZ family is not the common "SH-4(A)" variant, but
the "SH-2(A) with FIFO data count register" variant, as it has the
"Serial Extension Mode Register" (SCEMR), just like on sh7203, sh7263,
sh7264, and sh7269.

Use the (already documented) SoC-specific "renesas,scif-r7s72100"
compatible value to differentiate.  The "renesas,scif" compatible value
can still be used as a common denominator for SCIF variants with the
"SH-4(A)" register layout (i.e. ignoring the SCEMR register).
Note that currently both variants are treated the same, but this may
change if support for the SCEMR register is ever added.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-17 11:18:49 +01:00
Geert Uytterhoeven bd2238fb84 serial: sh-sci: Replace struct sci_port_info by type/regtype encoding
Store the encoded port and register types directly in of_device_id.data,
instead of using a pointer to a structure.
This saves memory and simplifies the source code, especially when adding
more compatible entries later.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-17 11:18:47 +01:00
Geert Uytterhoeven b8bbd6b292 serial: sh-sci: Add BRG register definitions
Add register definitions for the Baud Rate Generator for External Clock
(BRG), as found in some SCIF and in HSCIF, including a new regtype for
the "SH-4(A)"-derived SCIF variant with BRG.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-17 11:18:44 +01:00
Geert Uytterhoeven ff8b275f1f serial: sh-sci: Take into account sampling rate for max baud rate
The maximum baud rate depends on the sampling rate.
HSCIF has a variable sampling rate and sets s->sampling_rate to zero,
hence use the minimum sampling rate of 8.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-17 11:18:41 +01:00
Geert Uytterhoeven b4a5c45908 serial: sh-sci: Merge sci_scbrr_calc() and sci_baud_calc_hscif()
For low bit rates, the for-loop that reduces the divider returned by
sci_scbrr_calc() and picks the clock select value may terminate without
finding suitable values, leading to out-of-range divider and clock
select values.
sci_baud_calc_hscif() doesn't suffer from this problem, as it correctly
uses clamp().

Since there are only two relevant differences between HSCIF and other
variants w.r.t. bit rate configuration (fixed vs. variable sample rate,
and an additional factor of two), sci_scbrr_calc() and
sci_baud_calc_hscif() can be merged, fixing the issue with out-of-range
values.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-17 11:18:38 +01:00
Geert Uytterhoeven 6c51332dfc serial: sh-sci: Avoid calculating the receive margin for HSCIF
When assuming D = 0.5 and F = 0, maximizing the receive margin M is
equivalent to maximizing the sample rate N.

Hence there's no need to calculate the receive margin, as we can obtain
the same result by iterating over all possible sample rates in reverse
order, and skipping parameter sets that don't provide a lower bit rate
error.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-17 11:18:35 +01:00
Geert Uytterhoeven 881a7489f4 serial: sh-sci: Improve bit rate error calculation for HSCIF
The algorithm to find the best parameters for the requested bit rate
calculates the relative bit rate error, using "(br * scrate) / 1000".
For small "br * scrate", this has two problems:
  - The quotient may be zero, leading to a division by zero error,
  - This may introduce a large rounding error.
Switch from relative to absolute bit rate error calculation to fix this.

The default baud rate generator values can be removed, as there will
always be one set of values that gives the smallest absolute error.

Print the best set of values when debugging.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-17 11:18:32 +01:00
Geert Uytterhoeven de01e6cd0b serial: sh-sci: Avoid overflow in sci_baud_calc_hscif()
If bps >= 1048576, the multiplication of the predivider and "bps" will
overflow, and both br and err will contain bogus values.
Skip the current and all higher clock select predividers when overflow
is detected.  Simplify the calculations using intermediates while we're
at it.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-17 11:18:29 +01:00
Geert Uytterhoeven 95a2703e36 serial: sh-sci: Make unsigned values in sci_baud_calc_hscif() unsigned
Move the -1 offset of br to the assignment to *brr, so br cannot become
negative anymore, and update the clamp() call. Now all unsigned values
in sci_baud_calc_hscif() can become unsigned.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-17 11:18:27 +01:00
Geert Uytterhoeven f4de472ef2 serial: sh-sci: Convert from clk_get() to devm_clk_get()
Transfer clock cleanup handling to the core device management code.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-17 11:18:24 +01:00
Geert Uytterhoeven a67969b5fd serial: sh-sci: Don't overwrite clock selection in serial_console_write()
Blindly writing the default configuration value into the SCSCR register
may change the clock selection bits, breaking the serial console if the
current driver settings differ from the default settings.

Keep the current clock selection bits to prevent this from happening
on e.g. r8a7791/koelsch when support for the BRG will be added.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-17 11:18:21 +01:00
Geert Uytterhoeven bdcb382697 serial: sh-sci: Drop unused frame_len parameter for sci_baud_calc_hscif()
As F is assumed to be zero in the receive margin formula, frame_len is
not used. Remove it, together with the sci_baud_calc_frame_len() helper
function.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-17 11:18:18 +01:00
Geert Uytterhoeven 495bb47c5d serial: sh-sci: Use existing local variable in sci_parse_dt()
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
2015-12-17 11:18:15 +01:00
Geert Uytterhoeven 2095fc7695 serial: sh-sci: Grammar s/Get ... for/Get ... from/
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-17 11:18:12 +01:00
Geert Uytterhoeven dcafbb47bd serial: sh-sci: Drop useless check for zero sampling_rate
sci_port.sampling_rate is always non-zero, except for HSCIF, which uses
sci_baud_calc_hscif() instead of sci_scbrr_calc().

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-17 11:18:10 +01:00
Laurent Pinchart a9ec81f4ed serial: sh-sci: Drop the interface clock
As no platform defines an interface clock the SCI driver always falls
back to a clock named "peripheral_clk".
  - On SH platforms that clock is the base clock for the SCI functional
    clock and has the same frequency,
  - On ARM platforms that clock doesn't exist, and clk_get() will return
    the default clock for the device.
We can thus make the functional clock mandatory and drop the interface
clock.

EPROBE_DEFER is handled for clocks that may be referenced from DT (i.e.
"fck", and the deprecated "sci_ick").

Cc: devicetree@vger.kernel.org
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
[geert: Handle EPROBE_DEFER, reformat description, break long comment line]
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-17 11:17:51 +01:00
Yoshihiro Shimoda d09959e752 serial: sh-sci: Fix length of scatterlist
This patch fixes an issue that the "length" of scatterlist should be
set using sg_dma_len(). Otherwise, a dmaengine driver cannot work
correctly if CONFIG_NEED_SG_DMA_LENGTH=y.

Fixes: 7b39d90184 (serial: sh-sci: Fix NULL pointer dereference if HIGHMEM is enabled)
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-12 21:42:31 -08:00
Geert Uytterhoeven ff4411296e serial: sh-sci: Add DT support to DMA setup
Add support for obtaining DMA channel information from the device tree.

This requires switching from the legacy sh_dmae_slave structures with
hardcoded channel numbers and the corresponding filter function to:
  1. dma_request_slave_channel_compat(),
       - On legacy platforms, dma_request_slave_channel_compat() uses
	 the passed DMA channel numbers that originate from platform
	 device data,
       - On DT-based platforms, dma_request_slave_channel_compat() will
	 retrieve the information from DT.
  2. and the generic dmaengine_slave_config() configuration method,
     which requires filling in DMA register ports and slave bus widths.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:36:10 +01:00
Muhammad Hamza Farooq e7327c09de serial: sh-sci: Pause DMA engine and get DMA status again
Occasionally, DMA transaction completes _after_ DMA engine is stopped.
Verify if the transaction has not finished before forcing the engine to
stop and push the data

Signed-off-by: Muhammad Hamza Farooq <mfarooq@visteon.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:36:10 +01:00
Muhammad Hamza Farooq 3b963042b6 serial: sh-sci: Do not terminate DMA engine when race condition occurs
When DMA packet completion and timer expiry take place at the same time,
do not terminate the DMA engine, leading by submission of new
descriptors, as the DMA communication hasn't necessarily stopped here.

Signed-off-by: Muhammad Hamza Farooq <mfarooq@visteon.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:36:10 +01:00
Muhammad Hamza Farooq 1d3db608f9 serial: sh-sci: Call dma_async_issue_pending when transaction completes
dmaengine_submit() will not start the DMA operation, it merely adds
it to the pending queue.  If the queue is no longer running, it won't be
restarted until dma_async_issue_pending() is called.

Signed-off-by: Muhammad Hamza Farooq <mfarooq@visteon.com>
[geert: Add more description]
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:36:10 +01:00
Muhammad Hamza Farooq 371cfed311 serial: sh-sci: Redirect port interrupts to CPU _only_ when DMA stops
Since the DMA engine is not stopped everytime rx_timer_fn is called, the
interrupts have to be redirected back to CPU only when incomplete DMA
transaction is handled

Signed-off-by: Muhammad Hamza Farooq <mfarooq@visteon.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:36:10 +01:00
Aleksandar Mitev 9ab7655660 serial: sh-sci: Remove timer on shutdown of port
This prevents DMA timer timeout that can trigger after the port has
been closed.

Signed-off-by: Aleksandar Mitev <amitev@visteon.com>
[geert: Move del_timer_sync() outside spinlock to avoid circular locking
        dependency between rx_timer_fn() and del_timer_sync()]
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:36:10 +01:00
Geert Uytterhoeven 0e5c4b4d15 serial: sh-sci: Stop calling sci_start_rx() from sci_request_dma()
There's no need to call sci_start_rx() from sci_request_dma() when DMA
setup fails, as sci_startup() will call sci_start_rx() anyway.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:36:10 +01:00
Geert Uytterhoeven 756981be74 serial: sh-sci: Submit RX DMA from RX interrupt on (H)SCIF
For DMA receive requests, the driver is only notified by DMA completion
after the whole DMA request has been transferred.  If less data is
received, it will stay stuck until more data arrives.  The driver
handles this by setting up a timer handler from the receive interrupt,
after reception of the first character.

Unlike SCIFA and SCIFB, SCIF and HSCIF don't issue receive interrupts on
reception of individual characters if a receive DMA request is in
progress, so the timer is never set up.

To fix receive DMA on SCIF and HSCIF, submit the receive DMA request
from the receive interrupt handler instead.
In some sense this is similar to the SCIFA/SCIFB behavior, where the
RDRQE (Rx Data Transfer Request Enable) bit is also set from the receive
interrupt handler.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:36:10 +01:00
Geert Uytterhoeven 67f462b069 serial: sh-sci: Get rid of the workqueue to handle receive DMA requests
The receive DMA workqueue function work_fn_rx() handles two things:
  1. Reception of a full buffer on completion of a receive DMA request,
  2. Reception of a partial buffer on receive DMA time-out.
The workqueue is kicked by both the receive DMA completion handler, and
by a timer to handle DMA time-out.

As there are always two receive DMA requests active, it's possible that
the receive DMA completion handler is called a second time before the
workqueue function runs.

As the time-out handler re-enables the receive interrupt, an interrupt
may come in before time-out has been fully handled.

Move part 1 into the receive DMA completion handler, and move part 2
into the receive DMA time-out handler, to fix these race conditions.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:36:10 +01:00
Geert Uytterhoeven e1910fcdb5 serial: sh-sci: Shuffle functions around
This allows to:
  - Remove forward declarations of static functions,
  - Coalesce two sections protected by #ifdef CONFIG_SERIAL_SH_SCI_DMA,
  - Avoid shuffling functions around in the near future,
  - Avoid adding forward declarations in the near future.

No functional changes.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:36:10 +01:00
Geert Uytterhoeven 99dc8e400e serial: sh-sci: Don't call sci_dma_rx_push() if no data has arrived
On receive DMA time-out, avoid calling sci_dma_rx_push() if no data was
transferred by the timed out DMA request.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:33:48 +01:00
Yoshihiro Shimoda 8eadb56d68 serial: sh-sci: Don't kick tx in sci_er_interrupt() when using DMA
If CONFIG_SERIAL_SH_SCI_DMA is enabled, the driver doesn't enable TIE
on SCIF or HSCIF. However, this driver may call sci_tx_interrupt()
in sci_er_interrupt(). After that, the driver cannot care of the
interrupt, and then "irq 109: nobody cared" happens on r8a7791/koelsch
board. This patch fixes the issue.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
[geert] Keep kicking tx when using PIO
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:33:48 +01:00
Geert Uytterhoeven e6403c112f serial: sh-sci: Don't call sci_rx_interrupt() on error when using DMA
The error handler calls sci_rx_interrupt() to drain the receive FIFO if
an error condition happens.

However, if DMA is enabled on SCIFA or SCIFB, this will call
disable_irq_nosync() twice. Due to this imbalance, the receive interrupt
will never be re-enabled, and reception stops forever.

To fix this, restrict draining the FIFO to PIO mode, and just call
sci_receive_chars() directly.

Inspired by a patch from Yoshihiro Shimoda
<yoshihiro.shimoda.uh@renesas.com>.

Reported-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:33:48 +01:00
Yoshihiro Shimoda 7b39d90184 serial: sh-sci: Fix NULL pointer dereference if HIGHMEM is enabled
This patch fixes an issue that this driver causes a NULL pointer
dereference in the following conditions:
 - CONFIG_HIGHMEM and CONFIG_SERIAL_SH_SCI_DMA are enabled
 - This driver runs on the sci_dma_rx_push()

This issue was caused by virt_to_page(buf) in the sci_request_dma()
because this driver didn't check if the "buf" was valid or not.  So,
this patch uses the "buf" from dma_alloc_coherent() as is, not page.

This patch also fixes a WARNING issue in sci_rx_dma_release():

    WARNING: CPU: 0 PID: 1328 at lib/dma-debug.c:1125 check_unmap+0x444/0x848()
    rcar-dmac e6700000.dma-controller: DMA-API: device driver frees DMA memory with different CPU address [device address=0x000000006dd89000] [size=64 bytes] [cpu alloc address=0x000000016189c000] [cpu free address=0x0000000080000000]

    WARNING: CPU: 1 PID: 1 at drivers/base/dma-mapping.c:334 dma_common_free_remap+0x48/0x6c()
    trying to free invalid coherent area:   (null)

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
[geert] Rebased
[geert] Reworded
[geert] Dropped .rx_chunk, as it's always identical to .rx_buf[0]
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:33:48 +01:00
Geert Uytterhoeven ba172c7045 serial: sh-sci: Use incrementing pointers instead of stack array
There's no need to keep all buffer and DMA pointers on the stack.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:33:48 +01:00
Geert Uytterhoeven 47b0e94a67 serial: sh-sci: Use tty_insert_flip_string() for DMA receive
Switch from using tty_buffer_request_room() and looping over
tty_insert_flip_char() to tty_insert_flip_string().
Keep track of buffer overruns in the icount structure, like
serial_core.c does.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:33:48 +01:00
Geert Uytterhoeven 0533502d25 serial: sh-sci: Pass scatterlist to sci_dma_rx_push()
Currently sci_dma_rx_push() has to find the active scatterlist itself,
but in some cases the caller already knows.

Hence let the caller pass the scatterlist, and introduce a helper to
find the active DMA request while we're at it.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:33:48 +01:00
Geert Uytterhoeven 04928b79d2 serial: sh-sci: Fix race condition between RX worker and cleanup
During serial port shutdown, the DMA receive worker function may still
be called after the receive DMA cleanup function has been called.
Fix this race condition between work_fn_rx() and sci_rx_dma_release() by
acquiring the port's spinlock in sci_rx_dma_release().
This requires releasing the spinlock in work_fn_rx() before calling (any
function that may call) sci_rx_dma_release().

Terminate all active receive DMA descriptors to release them, and to
make sure no more completions come in.

Do the same in sci_tx_dma_release() for symmetry, although the serial
upper layer will no longer submit more data at this point of time.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:33:48 +01:00
Kazuya Mizuguchi 0907c1004f serial: sh-sci: Fix exclusion of work_fn_rx and sci_dma_rx_complete
There is a problem when the sci_dma_rx_complete() is processed
before cancel process of work_fn_rx() completes by rx_timer_fn().
This patch locks work_fn_rx().

Signed-off-by: Kazuya Mizuguchi <kazuya.mizuguchi.ks@renesas.com>
Signed-off-by: Yoshihiro Kaneko <ykaneko0929@gmail.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:33:48 +01:00
Geert Uytterhoeven 47aceb927f serial: sh-sci: Do not resubmit DMA descriptors
Resubmission of DMA descriptors is explicitly forbidden by the DMA
engine API.

Hence pass DMA_CTRL_ACK to dmaengine_prep_slave_sg(), and prepare a new
DMA descriptor instead of reusing the old one.
Remove sci_port.desc_rx[], as there's no longer a need to access the
active descriptor.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:33:48 +01:00
Geert Uytterhoeven 658daa95b6 serial: sh-sci: Simplify sci_submit_rx() error handling
Simplify the error handling in sci_submit_rx() by
  - Moving it to the end of the function,
  - Just calling dmaengine_terminate_all() instead of calling
    async_tx_ack() for all already submitted descriptors.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:33:48 +01:00
Geert Uytterhoeven 32f2ce031f serial: sh-sci: Stop acknowledging DMA transmit completions
As dmaengine_prep_slave_sg() is called with the DMA_CTRL_ACK flag set
for DMA transmit requests, there's no need to explicitly acknowledge DMA
transmit requests in the DMA transmit completion callback.

Hence remove the call to async_tx_ack(), and remove the now unused
dma_async_tx_descriptor pointer in the sci_port structure.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:33:48 +01:00
Geert Uytterhoeven 565dd11aa7 serial: sh-sci: Switch to generic DMA residue handling
Convert the SCI driver from the SHDMAE-specific partial DMA transfer
handling to the generic dmaengine residual data framework.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:33:48 +01:00
Geert Uytterhoeven 3e14670c06 serial: sh-sci: Use DMA submission helpers instead of open-coding
Replace open-coded
  - calls to dma_async_tx_descriptor.tx_submit() by calls to the
    dmaengine_submit() helper,
  - dma_cookie_t comparisons by calls to dma_submit_error().

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:33:48 +01:00
Geert Uytterhoeven 2e301474f1 serial: sh-sci: Fix TX buffer mapping leak
The mapped transmit buffer is never unmapped. This leaks quite some
mappings, as the mapping is done in uart_ops.startup(), i.e. every time
the device is opened. Unmap the buffer on device close.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:33:48 +01:00
Geert Uytterhoeven 79904420b7 serial: sh-sci: Switch to dma_map_single() for DMA transmission
Simplify the DMA transmit code by using dma_map_single() instead of
constantly modifying the single-entry scatterlist to match what's
currently being transmitted.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:33:48 +01:00
Geert Uytterhoeven 092248aa32 serial: sh-sci: Use min_t()/max_t() instead of casts
When comparing differently sized types, it's better to use
min_t()/max_t() than adding casts.

Also use "unsigned int" instead of "int", as that's the right type for
the length of an SG entry.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:33:48 +01:00
Geert Uytterhoeven 8e14ba8f8b serial: sh-sci: Use correct device for DMA mapping with IOMMU
To function correctly in the presence of an IOMMU, the DMA buffers must
be managed using the DMA channel's device instead of the platform
device's device.

Make sure to free the DMA memory before releasing the channel, not
after.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:33:48 +01:00
Geert Uytterhoeven b925802026 serial: sh-sci: Handle DMA init failures inside sci_request_dma()
Let sci_request_dma() handle failures to initialize DMA itself.
This way sci_tx_dma_release() and sci_rx_dma_release() don't have to
consider partial initialization, and thus don't need to reset DMA
addresses to DMA_ERROR_CODE, which is not 100% portable access
architectures.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:33:48 +01:00
Geert Uytterhoeven f5835c1d0e serial: sh-sci: Improve comments for DMA timeout calculation
Reformat, grammar improvements, use "ms" instead of "msec".

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:33:48 +01:00
Geert Uytterhoeven beb9487b0c serial: sh-sci: Improve DMA error messages
Make the life of the driver developer/debugger easier:
  - Add __func__ prefix to identical messages,
  - Add DMA directions to messages,
  - Add TX failure messages,
  - Always use "cookie %d" for DMA cookies,
  - "#%d" is reserved for the DMA cookie/descriptor index.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:33:48 +01:00
Yoshihiro Shimoda 908030727b serial: sh-sci: Return IRQ_HANDLED when overrun if detected
This patch fix an issue that the driver may cause "nobody cared" IRQ
when this driver detects the overrun flag only.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:33:48 +01:00
Geert Uytterhoeven e0a12a27e8 serial: sh-sci: Remove bogus sci_handle_fifo_overrun() call on (H)SCIF
Commit 8b6ff84c2d ("serial: sh-sci: Fix R-Car SCIF and HSCIF
overrun handling") added overrun handling for (H)SCIF using the SCLSR
register, but also accidentally added a bogus call to
sci_handle_fifo_overrun() in the receive interrupt path.

Remove it again.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:33:48 +01:00
Geert Uytterhoeven 4205463ce1 serial: sh-sci: Remove useless memory allocation failure printks
Printing an error on memory allocation failures is unnecessary.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:33:48 +01:00
Geert Uytterhoeven d3184e6886 serial: sh-sci: Make sci_regmap[] const
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:33:48 +01:00
Geert Uytterhoeven d56a91e812 serial: sh-sci: Make sci_irq_desc[] const
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:33:48 +01:00
Geert Uytterhoeven f84b6bdcab serial: sh-sci: Improve readability of sampling rate configuration
Reorder sampling_rate assignment for consistency in all cases of the
switch statement.
Avoid using the ternary conditional operator to make it more clear that
the value is overridden by platform data.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:33:48 +01:00
Geert Uytterhoeven b933bd3200 serial: sh-sci: Drop path in reference to serial_core.c
serial_core.c was moved from drivers/serial/ to drivers/tty/serial/ a
while ago. Remove the path to make it move-proof.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:33:48 +01:00
Geert Uytterhoeven 2944a331b7 serial: sh-sci: Use SCSMR_CKS instead of hardcoded literal 3
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:33:48 +01:00
Geert Uytterhoeven 54af5001e1 serial: sh-sci: Use SCIF_DR instead of hardcoded literal 1
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:33:48 +01:00
Geert Uytterhoeven 5da0f46874 serial: sh-sci: Correct SCIF_ERROR_CLEAR for plain SCIF
SCIF_ERROR_CLEAR includes SCIFA_ORER, which exists only on SCIFA/SCIFB
and SCIF on sh7705/sh7720/sh7721.

To fix this:
  1. Remove SCIFA_ORER from the definition of SCIF_ERROR_CLEAR,
  2. During initialization, store the error clear mask to use,
     incorporating the overrun bit only if it applies to the SCxSR
     register.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:33:48 +01:00
Geert Uytterhoeven a1b5b43ffb serial: sh-sci: Replace buggy big #ifdef by runtime logic
The #ifdef logic to clear SCxSR bits using RMW on SCIFA/SCIFB and SCIF
variants with some SCIFA features (sh7705/SH7720/sh7721) has several
drawbacks:
  - It wasn't updated for newer R-Mobile variants (APE6),
  - It doesn't correctly handle SoCs with both SCIF and SCIFA/B (e.g.
    R-Car Gen2, but also legacy sh7723/sh7724),
  - It doesn't play well with ARM multi-platform kernels: on R-Car Gen2,
    SCIF/SCIFA/SCIFB/HSCIF were handled differently, depending on
    whether r8a7740 or sh73a0 support was enabled or not,

Replace the #ifdef logic by runtime logic to fix this.

SCIFA/SCIFB and SCIF on sh7705/sh7720/sh7721 use RMW to clear error
bits, other variants use plain stores, as before.

Note that this changes behavior for SCIFA on sh7723/sh7724 (these SoCs
have both SCIF and SCIFA), which didn't use RMW before.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:33:48 +01:00
Linus Torvalds 8c7febe839 TTY/Serial driver patches for 4.2-rc1
Here's the tty and serial driver patches for 4.2-rc1.
 
 A number of individual driver updates, some code cleanups, and other
 minor things, full details in the shortlog.
 
 All have been in linux-next for a while with no reported issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver updates from Greg KH:
 "Here's the tty and serial driver patches for 4.2-rc1.

  A number of individual driver updates, some code cleanups, and other
  minor things, full details in the shortlog.

  All have been in linux-next for a while with no reported issues"

* tag 'tty-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (152 commits)
  Doc: serial-rs485.txt: update RS485 driver interface
  Doc: tty.txt: remove mention of the BKL
  MAINTAINERS: tty: add serial docs directory
  serial: sprd: check for NULL after calling devm_clk_get
  serial: 8250_pci: Correct uartclk for xr17v35x expansion chips
  serial: 8250_pci: Add support for 12 port Exar boards
  serial: 8250_uniphier: add bindings document for UniPhier UART
  serial: core: cleanup in uart_get_baud_rate()
  serial: stm32-usart: Add STM32 USART Driver
  tty/serial: kill off set_irq_flags usage
  tty: move linux/gsmmux.h to uapi
  doc: dt: add documentation for nxp,lpc1850-uart
  serial: 8250: add LPC18xx/43xx UART driver
  serial: 8250_uniphier: add UniPhier serial driver
  serial: 8250_dw: support ACPI platforms with integrated DMA engine
  serial: of_serial: check the return value of clk_prepare_enable()
  serial: of_serial: use devm_clk_get() instead of clk_get()
  serial: earlycon: Add support for big-endian MMIO accesses
  serial: sirf: use hrtimer for data rx
  serial: sirf: correct the fifo empty_bit
  ...
2015-06-26 15:53:22 -07:00
Yoshinori Sato e4d6f911a7 sh-sci: Get register size from platform device
There is much SCI of SoC having within,
and the register size is also different in everyone.
So get from platform device.

Signed-off-by: Yoshinori Sato <ysato@users.sourceforge.jp>
Acked-by: by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
2015-06-23 13:35:59 +09:00
Yoshinori Sato e1d0be6161 sh-sci: Add h8300 SCI
Signed-off-by: Yoshinori Sato <ysato@users.sourceforge.jp>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
2015-06-23 13:35:48 +09:00
Geert Uytterhoeven 99fb215eea serial: sh-sci: Remove obsolete comment about overrun detection
The code it refers to was removed in commit b545e4f406 ("serial:
sh-sci: Compute overrun_bit without using baud rate algo").

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-10 19:06:39 +02:00
Geert Uytterhoeven afd66db613 serial: sh-sci: Don't set SCLSR bits in the SCxSR error mask
error_mask is the union of all error indicating bits in the SCxSR
register, while overrun_mask may apply to a different register (SCLSR),
depending on the SCI variant.

Hence overrun_mask should only be ORed into error_mask if it applies to
the SCxSR register.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-10 19:06:39 +02:00
Geert Uytterhoeven 2e0842a154 serial: sh-sci: Use the correct register for overrun checks
The various SCI implementations use 3 different methods to signal
overrun errors:
  - Bit SCI_ORER in register SCxSR on SCI,
  - Bit SCIFA_ORER in register SCxSR on SCIFA and SCIFB, and SCIF on
    SH7705/SH7720/SH7721,
  - Bit SCLSR_ORER in (optional!) register SCLSR on (H)SCIF.

However:
  1. sci_handle_fifo_overrun()
       a. handles (H)SCIF and SCIFA/SCIFB only,
       b. treats SCIF on SH7705/SH7720/SH7721 incorrectly,
  2. sci_mpxed_interrupt()
       a. treats SCIF on SH7705/SH7720/SH7721 incorrectly,
       b. ignores that not all SCIFs have the SCLSR register, causing
	  "Invalid register access" WARN()ings.

To fix the above:
  1. Determine and store the correct register enum during
     initialization,
  2. Replace the duplicated buggy switch statements by using the stored
     register enum,
  3. Add the missing existence check to  sci_mpxed_interrupt().

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-10 19:06:39 +02:00
Geert Uytterhoeven 75c249fd7c serial: sh-sci: Replace hardcoded overrun bit values
Add the missing overrun bit definition for (H)SCIF.
Replace overrun_bit by overrun_mask, so we can use the existing
defines instead of hardcoded values.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-10 19:06:39 +02:00
Geert Uytterhoeven c097abc33f serial: sh-sci: Add SCIFA/B SCPCR register definitions
Add the register definitions for the Serial Port Control and Data
Registers on SCIFA/SCIFB, which are needed for RTS/CTS pin control.

Extracted from patches by Magnus Damm <damm+renesas@opensource.se>.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-10 19:06:38 +02:00
Nobuhiro Iwamatsu 5f6d851564 serial: sh-sci: Update calculation of timeout for DMA
The current calculation method in the case of 9600bps, rounding error occurs
has become setting that occur timeout faster than the required time. When we
use 9600bps, 32byte buffer, 10 bit (CS8) and 100 HZ, it becomes 3 jiffies
(30msec). In fact it is necessary 33msec. This updates to the calculation
that are not actually less than the value set by the rounding error.
Also, this is nothing will be calculated value when there is no load. If there
are a lot of case load, overrun error will occur immediately.
This is by the buffer size to be calculated twice the DMA buffer, and add the
change of setting a sufficient time-out value.

Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Signed-off-by: Yoshihiro Kaneko <ykaneko0929@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-26 22:42:27 +01:00
Nobuhiro Iwamatsu cb772fe75f serial: sh-sci: Add overrun handling of SCIFA and SCIFB
SCIFA and SCIFB can detect the overrun, but it does not support.
This adds overrun handling of SCIFA and SCIFB.

Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Signed-off-by: Yoshihiro Kaneko <ykaneko0929@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-26 22:42:27 +01:00
Hisashi Nakamura 8b6ff84c2d serial: sh-sci: Fix R-Car SCIF and HSCIF overrun handling
When fifo overrun happened, the interrupt status refers to
SCLSR register in R-Car SCIF and HSCIF.
Thus, overrun handling takes SCLSR register into account.

Signed-off-by: Hisashi Nakamura <hisashi.nakamura.ak@renesas.com>
Signed-off-by: Yoshihiro Kaneko <ykaneko0929@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:26 -08:00
Yoshihiro Kaneko 51b31f1c6b serial: sh-sci: Use dev_dbg() to log an error message
Since the driver cannot return from overrun error if characters
are output during overrun process, use dev_dbg() instead of
dev_notice() to log the error message of overrun in syslog.

Based on a patch by Hisashi Nakamura.

Signed-off-by: Yoshihiro Kaneko <ykaneko0929@gmail.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:26 -08:00
Sergei Shtylyov cb87634172 sh-sci: extend PM methods
In order to make it possible to restore from hibernation not only in Linux but
also in e.g. U-Boot, we have to use sci_{suspend|remove}() for the PM {freeze|
thaw|restore}() methods.  It's handy to achieve this by using SIMPLE_DEV_PM_OPS()
macro, however we have to annotate sci_{suspend|remove}() with '__maybe_unused'
in order to avoid compilation warnings when CONFIG_PM_SLEEP is undefined.

Based on orignal patch by Mikhail Ulyanov <mikhail.ulyanov@cogentembedded.com>.

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:25 -08:00
Linus Torvalds e6b5be2be4 Driver core patches for 3.19-rc1
Here's the set of driver core patches for 3.19-rc1.
 
 They are dominated by the removal of the .owner field in platform
 drivers.  They touch a lot of files, but they are "simple" changes, just
 removing a line in a structure.
 
 Other than that, a few minor driver core and debugfs changes.  There are
 some ath9k patches coming in through this tree that have been acked by
 the wireless maintainers as they relied on the debugfs changes.
 
 Everything has been in linux-next for a while.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core update from Greg KH:
 "Here's the set of driver core patches for 3.19-rc1.

  They are dominated by the removal of the .owner field in platform
  drivers.  They touch a lot of files, but they are "simple" changes,
  just removing a line in a structure.

  Other than that, a few minor driver core and debugfs changes.  There
  are some ath9k patches coming in through this tree that have been
  acked by the wireless maintainers as they relied on the debugfs
  changes.

  Everything has been in linux-next for a while"

* tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (324 commits)
  Revert "ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries"
  fs: debugfs: add forward declaration for struct device type
  firmware class: Deletion of an unnecessary check before the function call "vunmap"
  firmware loader: fix hung task warning dump
  devcoredump: provide a one-way disable function
  device: Add dev_<level>_once variants
  ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries
  ath: use seq_file api for ath9k debugfs files
  debugfs: add helper function to create device related seq_file
  drivers/base: cacheinfo: remove noisy error boot message
  Revert "core: platform: add warning if driver has no owner"
  drivers: base: support cpu cache information interface to userspace via sysfs
  drivers: base: add cpu_device_create to support per-cpu devices
  topology: replace custom attribute macros with standard DEVICE_ATTR*
  cpumask: factor out show_cpumap into separate helper function
  driver core: Fix unbalanced device reference in drivers_probe
  driver core: fix race with userland in device_add()
  sysfs/kernfs: make read requests on pre-alloc files use the buffer.
  sysfs/kernfs: allow attributes to request write buffer be pre-allocated.
  fs: sysfs: return EGBIG on write if offset is larger than file size
  ...
2014-12-14 16:10:09 -08:00
Nobuhiro Iwamatsu f53297fb99 serial: sh-sci: Change checking for error rate of HSCIF
This changes negative values of error rate to be checked, because these
values are valid as error rate. And this changes in the process of adopting
a value close to 0.

Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-25 17:06:38 -08:00
Wolfram Sang 9144b3cded tty: serial: drop owner assignment from platform_drivers
A platform_driver does not need to set an owner, it will be populated by the
driver core.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-10-20 16:21:45 +02:00
Vinod Koul 2bcd90d56c serial: sh-sci: use dmaengine_terminate_all() API
The drivers should use dmaengine_terminate_all() API instead of
accessing the device_control which will be deprecated soon

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-10-15 21:31:00 +05:30
Nobuhiro Iwamatsu 730c4e782c serial: sh-sci: Add calculation recive margin for HSCIF
When the error of the same bit rate is detected, we will need to select
the recive margin is large. Current code holds the minimum error, it does
not have to check the recive margin. This adds this calculation.

Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-17 18:14:44 -07:00
Nobuhiro Iwamatsu bcb9973a60 serial: sh-sci: Fix range check of bit-rate for HSCIF
If bit-rate calculation result of HSCIF is expect 255 from 0,
driver does not calculate error bit. However, we need to round
the value to calculate error bit in the case of negative value.
This rounds the value of bit-rate using clamp(), and bit-rate is the
case of negative value, it enables the calculation of the error bit.

Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-17 18:14:44 -07:00
Nobuhiro Iwamatsu b7d66397f4 serial: sh-sci: Updated calculation of bit error rate and bit rate
Currently, the decimal point is discarded calculation of BRR.
Therefore, it can not calculate a value close to the correct value.
This patch fixes this problem by using DIV_ROUND_CLOSEST.

Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-17 18:14:44 -07:00
Alexander Shiyan 8b152f1096 serial: treewide: Remove empty implementations of enable_ms()
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-09 17:29:38 -07:00
Linus Torvalds cb15955638 TTY/Serial driver update for 3.15-rc1
Here's the big tty/serial driver update for 3.15-rc1.
 
 Nothing major, a number of serial driver updates and a few tty core
 fixes as well.
 
 All have been in linux-next for a while.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver update from Greg KH:
 "Here's the big tty/serial driver update for 3.15-rc1.

  Nothing major, a number of serial driver updates and a few tty core
  fixes as well.

  All have been in linux-next for a while"

* tag 'tty-3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (71 commits)
  tty/serial: omap: empty the RX FIFO at the end of half-duplex TX
  tty/serial: omap: fix RX interrupt enable/disable in half-duplex TX
  serial: sh-sci: Neaten dev_<level> uses
  serial: sh-sci: Replace hardcoded 3 by UART_PM_STATE_OFF
  serial: sh-sci: Add more register documentation
  serial: sh-sci: Remove useless casts
  serial: sh-sci: Replace printk() by pr_*()
  serial_core: Avoid NULL pointer dereference in uart_close()
  serial_core: Get a reference for port->tty in uart_remove_one_port()
  serial: clps711x: Give a chance to perform useful tasks during wait loop
  serial_core: Grammar s/ports/port's/
  serial_core: Spelling s/contro/control/
  serial: efm32: properly namespace location property
  serial: max310x: Add missing #include <linux/uaccess.h>
  synclink: fix info leak in ioctl
  serial: 8250: Clean up the locking for -rt
  serial: 8250_pci: change BayTrail default uartclk
  serial: 8250_pci: more BayTrail error-free bauds
  serial: sh-sci: Add missing call to uart_remove_one_port() in failure path
  serial_core: Unregister console in uart_remove_one_port()
  ...
2014-04-01 16:55:57 -07:00
Viresh Kumar 0b443ead71 cpufreq: remove unused notifier: CPUFREQ_{SUSPENDCHANGE|RESUMECHANGE}
Two cpufreq notifiers CPUFREQ_RESUMECHANGE and CPUFREQ_SUSPENDCHANGE have
not been used for some time, so remove them to clean up code a bit.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
[rjw: Changelog]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-03-19 14:10:24 +01:00
Joe Perches 9b971cd206 serial: sh-sci: Neaten dev_<level> uses
Add missing newlines and coalesce formats.
Realign arguments.

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-03-17 16:20:49 -07:00
Geert Uytterhoeven d3dfe5d9b4 serial: sh-sci: Replace hardcoded 3 by UART_PM_STATE_OFF
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Acked-by: Simon Horman <horms@verge.net.au>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-03-17 16:20:49 -07:00
Geert Uytterhoeven 26de4f1b2f serial: sh-sci: Add more register documentation
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Acked-by: Simon Horman <horms@verge.net.au>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-03-17 16:20:49 -07:00
Geert Uytterhoeven ff43da00e0 serial: sh-sci: Remove useless casts
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Acked-by: Simon Horman <horms@verge.net.au>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-03-17 16:20:49 -07:00
Geert Uytterhoeven 6c13d5d27c serial: sh-sci: Replace printk() by pr_*()
Make banner const while we're at it

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Acked-by: Simon Horman <horms@verge.net.au>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-03-17 16:20:49 -07:00
Geert Uytterhoeven bf13c9a894 serial: sh-sci: Add missing call to uart_remove_one_port() in failure path
If cpufreq_register_notifier() fails, we have to remove the port added by
sci_probe_single(), which is not done by sci_cleanup_single().

Else the serial port stays active from the point of view of the serial
subsystem, and it may crash when userspace getty is started, or when the
loadable driver module is unloaded.

This was introduced by commit 6dae14216c
("serial: sh-sci: Fix probe error paths").

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-28 16:39:38 -08:00
Jingoo Han 3af4e960b8 serial: sh-sci: Fix cast warning
Fix the following compile warning about cast to pointer from
integer of different size.

drivers/tty/serial/sh-sci.c:2021:19: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-13 09:17:31 -08:00
Bastian Hecht 20bdcab826 serial: sh-sci: Add OF support
Extend the driver to with support for SCIx device tree bindings. A
minimal set of features is supported, additional properties can be added
later should the need to describe more device features arise.

Signed-off-by: Bastian Hecht <hechtb+renesas@gmail.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2013-12-24 21:50:54 +09:00
Laurent Pinchart 89b5c1ab94 serial: sh-sci: Remove platform data mapbase and irqs fields
The fields are not used anymore by board files, remove them.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2013-12-24 21:50:54 +09:00
Laurent Pinchart 878fbb9139 serial: sh-sci: Remove platform data scbrr_algo_id field
The field isn't set by any board, remote it.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2013-12-24 21:50:54 +09:00
Laurent Pinchart ec09c5eb49 serial: sh-sci: Rework baud rate calculation
Computing the baud rate register value requires knowledge of the
hardware sampling rate. This information is currently encoded in a baud
rate calculation algorithm ID passed through platform data. However, it
can be derived from the port type directly in most cases.

Compute the sampling rate internally in the driver if the baud rate
calculation algorithm ID isn't specified, and allow platforms to
override the sampling rate through platform data in special cases (this
is only required for SCIFA ports on sh7723 and sh7724, the reason needs
to be investigated).

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2013-12-24 11:17:53 +09:00
Laurent Pinchart b545e4f406 serial: sh-sci: Compute overrun_bit without using baud rate algo
The overrun bit index is a property of the hardware. It's currently
computed based on a different and unrelated hardware property, the baud
rate calculation algorithm. Compute it using hardware identification
information only.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2013-12-24 11:17:52 +09:00
Laurent Pinchart 520402bbc6 serial: sh-sci: Remove unused GPIO request code
The driver requests at initialization time GPIOs passed through platform
data. No platform makes use of this feature, remove it.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2013-12-24 11:17:50 +09:00
Laurent Pinchart 3ae988d97b serial: sh-sci: Move overrun_bit and error_mask fields out of pdata
None of the fields is ever set by board code, and both of them are set
in the driver at probe time. Move them out of struct plat_sci_port to
struct sci_port.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2013-12-24 11:17:48 +09:00
Laurent Pinchart 1fcc91a607 serial: sh-sci: Support resources passed through platform resources
Memory and IRQ resources are currently passed to the driver through
platform data. Support passing them through the standard platform
resources mechanism instead. This deprecates platform data resources.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2013-12-24 11:17:44 +09:00
Laurent Pinchart bc14e00672 serial: sh-sci: Don't check IRQ in verify port operation
The IRQ number can't be modified by the user as the port is fixed.
There's no need to check the new IRQ number as it will be ignored by the
core.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2013-12-24 11:17:41 +09:00
Laurent Pinchart b6e4a3f18c serial: sh-sci: Set the UPF_FIXED_PORT flag
The base address, IRQ and baud rate generator parent clock rate can't be
changed by userspace. Mark the port as fixed.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2013-12-24 11:17:38 +09:00
Laurent Pinchart b5e17b71c6 serial: sh-sci: Remove duplicate interrupt check in verify port op
The driver checks if the interrupt number is greater than nr_irqs and
returns an error in that case. The same check is already performed by
the caller, remove it.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2013-12-24 11:17:36 +09:00
Laurent Pinchart 6557b1f69e serial: sh-sci: Simplify baud rate calculation algorithms
Rewrite the baud rate register value calculations in easier to read
forms. The computed value isn't modified.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2013-12-24 11:17:33 +09:00
Laurent Pinchart 6db201da25 serial: sh-sci: Remove baud rate calculation algorithm 5
The algorithm isn't used, remove it.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2013-12-24 11:17:30 +09:00
Laurent Pinchart 8fb9631c51 serial: sh-sci: Sort headers alphabetically
This helps locating duplicates.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2013-12-24 11:17:25 +09:00
Laurent Pinchart b016b646e8 serial: sh-sci: Convert to clk_prepare/unprepare
Turn clk_enable() and clk_disable() calls into clk_prepare_enable() and
clk_disable_unprepare() to get ready for the migration to the common
clock framework.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Magnus Damm <damm@opensource.se>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2013-12-14 09:59:31 +09:00
Laurent Pinchart caec70381b serial: sh-sci: Don't enable/disable port from within break timer
The break timer accesses hardware registers and thus requires the port
to be enabled. It currently ensures this by enabling the port at the
beginning of the timer handler, and disabling it at the end. However,
the enable/disable operations call the runtime PM sync functions, which
are not allowed in atomic context. The current situation is thus broken.

This change relies on non-atomic code to enable/disable the port. The
break timer will only be started from the IRQ handler, which already
runs with the port enabled. We just need to ensure that the port won't
be disabled with the timer running, and that's easily done by just
cancelling the timer in the port disable function.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Magnus Damm <damm@opensource.se>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2013-12-14 09:58:12 +09:00
Laurent Pinchart e2afca6988 serial: sh-sci: Fix warnings due to improper casts and printk formats
Use the %zu and %pad printk specifiers to print size_t and dma_addr_t
variables, and cast pointers to uintptr_t instead of unsigned int where
applicable. This fixes warnings on platforms where pointers and/or
dma_addr_t have a different size than int.

Cc: linux-serial@vger.kernel.org
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2013-12-12 22:14:49 +09:00
Vinod Koul 0b3d7d39f5 serial: sh: use DMA_COMPLETE for dma completion status
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2013-10-25 11:16:19 +05:30
Jingoo Han 3ba35baa55 serial: sh-sci: use dev_get_platdata()
Use the wrapper function for retrieving the platform data instead of
accessing dev->platform_data directly

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-02 11:54:13 +08:00
Jingoo Han 574de559c1 serial: use dev_get_platdata()
Use the wrapper function for retrieving the platform data instead of
accessing dev->platform_data directly.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-31 17:56:15 -07:00
Simon Horman d4759ded3b serial: sh-sci: Initialise variables before access in sci_set_termios()
This change addresses two warnings that are flagged by gcc relating to
potential access to the ssr and cks variables while they are uninitialised.

I have addressed this by initialising the values to
the defaults present in sci_baud_calc_hscif().

It is my analysis that cks is always initialised if used
but that without this change ssr may be accessed while uninitialised.

The code altered by this patch was introduced by commit
f303b364b4 ("serial: sh-sci: HSCIF support").

Reported-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2013-06-26 17:41:16 +09:00
Ulrich Hecht f303b364b4 serial: sh-sci: HSCIF support
Adds support for "High Speed Serial Communications Interface with FIFO",
essentially a SCIF with 128-byte FIFOs and more accurate baud rate
generator.

Signed-off-by: Ulrich Hecht <ulrich.hecht@gmail.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2013-06-17 18:09:53 +09:00
Jiri Slaby 2e124b4a39 TTY: switch tty_flip_buffer_push
Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty in many
call sites. Only tty_port will needed and hence no more
tty_port_tty_get in those paths.

Now, the one where most of tty_port_tty_get gets removed:
tty_flip_buffer_push.

IOW we also closed all the races in drivers not using tty_port_tty_get
at all yet.

Also we move tty_flip_buffer_push declaration from include/linux/tty.h
to include/linux/tty_flip.h to all others while we are changing it
anyway.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-15 22:30:15 -08:00
Jiri Slaby 92a19f9cec TTY: switch tty_insert_flip_char
Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty in many
call sites. Only tty_port will needed and hence no more
tty_port_tty_get in those paths.

tty_insert_flip_char is the next one to proceed. This one is used all
over the code, so the patch is huge.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-15 22:21:36 -08:00
Jiri Slaby 227434f898 TTY: switch tty_buffer_request_room to tty_port
Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty pointer in
many call sites. Only tty_port will be needed and hence no more
tty_port_tty_get calls in those paths.

Here we start with tty_buffer_request_room.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-15 22:17:28 -08:00
Bill Pemberton 9671f09921 tty: remove use of __devinit
CONFIG_HOTPLUG is going away as an option so __devinit is no longer
needed.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Cc: Jiri Slaby <jirislaby@gmail.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Lucas Tavares <lucaskt@linux.vnet.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Peter Korsgaard <jacmet@sunsite.dk>
Cc: Tony Prisk <linux@prisktech.co.nz>
Acked-by: Tobias Klauser <tklauser@distanz.ch>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-21 15:22:52 -08:00
Shinya Kuribayashi 33b48e1633 serial: sh-sci: fix possible race cases on SCSCR register accesses
In the previous commit, console write function (serial_console_write)
is changed to disable SCI interrupts while printing console strings.
This introduces possible race cases in the serial startup / shutdown
functions on SMP systems.

This patch fixes the sh-sci in the same way as commit 9ec1882df2
(tty: serial: imx: console write routing is unsafe on SMP, from
Xinyu Chen <xinyu.chen@freescale.com>, 2012-08-27) did.

There could be several consumers of the console,
* the kernel printk
* the init process using /dev/kmsg to call printk to show log
* shell, which opens /dev/console and writes with sys_write()

The shell goes into the normal UART open() and write() system calls,
while the other two go into the console operations.  The open() call
invokes serial startup function (sci_startup), which will write to
the SCSCR register (to enable or disable SCI interrupts) without any
locking.  This will conflict with the console serial function.

Add spinlock protections in sci_startup() and sci_shutdown() properly.

Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi.px@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-15 18:02:51 -08:00
Shinya Kuribayashi 40f70c03e3 serial: sh-sci: add locking to console write function to avoid SMP lockup
Symptom:

When entering the suspend with Android logcat running, printk() call
gets stuck and never returns.  The issue can be observed at printk()s
on nonboot CPUs when going to offline with their interrupts disabled,
and never seen at boot CPU (core0 in our case).

Details:

serial_console_write() lacks of appropriate spinlock handling.

In SMP systems, as long as sci_transmit_chars() is being processed
at one CPU core, serial_console_write() can stuck at the other CPU
core(s), when it tries to access to the same serial port _without_
a proper locking.  serial_console_write() waits for the transmit FIFO
getting empty, while sci_transmit_chars() writes data to the FIFO.

In general, peripheral interrupts are routed to boot CPU (core0) by
Linux ARM standard affinity settings.  SCI(F) interrupts are handled
by core0, so sci_transmit_chars() is processed on core0 as well.

When logcat is running, it writes enormous log data to the kernel at
every moment, forever.  So core0 can repeatedly continue to process
sci_transmit_chars() in its interrupt handler, which eventually makes
the other CPU core(s) stuck at serial_console_write().

Looking at serial/8250.c, this is a known console write lockup issue
with SMP kernels.  Fix the sh-sci driver in the same way 8250.c does.

Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi.px@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-15 18:02:51 -08:00
Takashi Yoshii 8c66d6d2a1 serial: sh-sci: fix common SCIFB regmap definition
About FIFO count, there are two variants of SCIFs which show
a) TX count in upper, RX count in lower byte of FDR register
b) TX count in TFDR register, RX count in RFDR register

Common SCIFB regmap in current source code is defined as "a".
At least 7372 and 73a0 HW manual say their SICFB are "b".

This patch alters the definition to "b", considering the current
one has come from a mistake. The reason is as follows.

The flag SCIFB sh-sci driver means it has 256 byte FIFO.
The count is from 0(empty) to 256(full), that makes 9-bit.
Because FDR is 16-bit register, it can not hold two 9-bits.
That's why, SCIFB can not be "a".

Signed-off-by: Takashi Yoshii <takashi.yoshii.zj@renesas.com>
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi.px@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-15 18:02:51 -08:00
Takashi Yoshii 63f7ad115e serial: sh-sci: mask SCTFDR/RFDR according to fifosize
Current mask 0xff to SCTFDR/RFDR damages SCIFB, because the
registers on SCIFB have 9-bit data (0 to 256).

This patch changes the mask according to port->fifosize.
Though I'm not sure if the mask is really needed (I don't know if
there are variants which have non-zero upper bits), it is safer.

Signed-off-by: Takashi Yoshii <takashi.yoshii.zj@renesas.com>
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi.px@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-15 18:02:37 -08:00
Takashi Yoshii 9d482cc353 serial: sh-sci: support lower baud rate
Support prescaler 1/16 and 1/64, in addition to current 1 and 1/4.

Supporting below 2400bps was dropped long time ago in mainline.
Since then, setting lower rate has been resulting in erroneous
register value, without indicating any errors through API.

This patch adds more prescaler to support lower rates again.
This still doesn't check range, but we won't hit the case because
even 50bps at 48MHz clock is now supported.

Signed-off-by: Takashi Yoshii <takashi.yoshii.zj@renesas.com>
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi.px@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-15 18:02:37 -08:00
Takashi Yoshii 4ffc3cdb64 serial: sh-sci: fix condition test to set SCBRR
SCBRR == 0 is valid value (divide by 1).

Signed-off-by: Takashi Yoshii <takashi.yoshii.zj@renesas.com>
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi.px@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-15 18:02:37 -08:00
Teppei Kamijou 0174e5ca82 serial: sh-sci: console runtime PM support (revisit)
The commit 1ba7622094 (serial: sh-sci: console Runtime PM support,
from Magnus Damm <damm@opensource.se>, 2011-08-03), tried to support
console runtime PM, but unfortunately it didn't work for us for some
reason.  We did not investigated further at that time, instead would
like to propose a different approach.

In Linux tty/serial world, to get console PM work properly, a serial
client driver does not have to maintain .runtime_suspend()/..resume()
calls itself, but can leave console power power management handling to
the serial core driver.

This patch moves the sh-sci driver in that direction.

Notes:

* There is room to optimize console runtime PM more aggressively by
  maintaining additional local runtime PM calls, but as a first step
  having .pm() operation would suffice.

* We still have a couple of direct calls to sci_port_enable/..disable
  left in the driver.  We have to live with them, because they're out
  of serial core's help.

Signed-off-by: Teppei Kamijou <teppei.kamijou.yb@renesas.com>
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi.px@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-15 18:02:36 -08:00
Shinya Kuribayashi 00cadbfd1e Partially revert "serial: sh-sci: console Runtime PM support"
This partially reverts commit 1ba7622094 (serial: sh-sci: console
Runtime PM support, from Magnus Damm <damm@opensource.se>, 2011-08-03).

The generic 'serial_core' can take care of console PM maintenance,
so all (or at least the first thing) we have to do to get console PM
work properly, is to implement uart_ops ->pm() operation in the sh-sci
serial client driver.

This patch partially reverts the commit above, but leaving sci_reset()
change in place, because sci_reset() is already part of another commit
(73c3d53f38 serial: sh-sci: Avoid FIFO clear for MCE toggle.).

A revised version of console PM support follows next.

Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi.px@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-15 18:02:36 -08:00
Shinya Kuribayashi 8807ec6c70 Revert "sh-sci / PM: Use power.irq_safe"
This reverts commit 5a50a01bf0 (sh-sci / PM: Use power.irq_safe, from
Rafael J. Wysocki <rjw@sisk.pl>, 2011-08-24).

In order to get console PM work properly, we should implement uart_ops
->pm() operation, rather than sprinkle band-ading runtime PM calls in
the driver.

Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi.px@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-15 18:02:04 -08:00
Shinya Kuribayashi cee31c52df Revert "sh-sci / PM: Avoid deadlocking runtime PM"
This reverts commit 048be431e4 (sh-sci / PM: Avoid deadlocking runtime
PM, from Rafael J. Wysocki <rjw@sisk.pl>, 2012-03-09).

In order to get console PM work properly, we should implement uart_ops
->pm() operation, rather than sprinkle band-ading runtime PM calls in
the driver.

Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi.px@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-15 18:02:04 -08:00
Paul Mundt 0dd4d5cbe4 sh: Fix up more fallout from pointless ARM __iomem churn.
It was already pointed out how to fix these cases before the offending
patches were merged, but unsurprisingly, that didn't happen. As this
change is entirely superfluous to begin with, simply shut things up by
casting everything away.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2012-10-15 14:08:48 +09:00
Guennadi Liakhovetski 4dc4c51675 serial: sh-sci: fix compilation breakage, when DMA is enabled
A recent commit:

commit d6fa5a4e7a
Author: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
    serial: sh-sci: prepare for conversion to the shdma base library

is not sufficient to update the sh-sci driver to the new shdma driver
layout. This caused compilation breakage, when CONFIG_SERIAL_SH_SCI_DMA
is enabled. This patch trivially fixes the problem by updating the DMA
descriptor manipulation code.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2012-08-01 13:48:54 +09:00
Linus Torvalds c511dc1fb6 Merge branch 'next' of git://git.infradead.org/users/vkoul/slave-dma
Pull slave-dmaengine update from Vinod Koul:
 "This time we have a new dmaengine driver from the tegra folks.  Also
  we have Guennadi's cleanup of sh drivers which incudes a library for
  sh drivers.  And the usual odd fixes in bunch of drivers and some nice
  cleanup of dw_dmac from Andy."

Fix up conflicts in drivers/mmc/host/sh_mmcif.c

* 'next' of git://git.infradead.org/users/vkoul/slave-dma: (46 commits)
  dmaengine: Cleanup logging messages
  mmc: sh_mmcif: switch to the new DMA channel allocation and configuration
  dma: sh: provide a migration path for slave drivers to stop using .private
  dma: sh: use an integer slave ID to improve API compatibility
  dmaengine: shdma: prepare to stop using struct dma_chan::private
  sh: remove unused DMA device pointer from SIU platform data
  ASoC: siu: don't use DMA device for channel filtering
  dmaengine: shdma: (cosmetic) simplify a static function
  dmaengine: at_hdmac: add a few const qualifiers
  dw_dmac: use 'u32' for LLI structure members, not dma_addr_t
  dw_dmac: mark dwc_dump_lli inline
  dma: mxs-dma: Export missing symbols from mxs-dma.c
  dma: shdma: convert to the shdma base library
  ASoC: fsi: prepare for conversion to the shdma base library
  usb: renesas_usbhs: prepare for conversion to the shdma base library
  ASoC: siu: prepare for conversion to the shdma base library
  serial: sh-sci: prepare for conversion to the shdma base library
  mmc: sh_mobile_sdhi: prepare for conversion to the shdma base library
  mmc: sh_mmcif: remove unneeded struct sh_mmcif_dma, prepare to shdma conversion
  dma: shdma: prepare for conversion to the shdma base library
  ...
2012-07-24 17:12:54 -07:00
Guennadi Liakhovetski d6fa5a4e7a serial: sh-sci: prepare for conversion to the shdma base library
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Alan Cox <alan@linux.intel.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-07-13 09:13:08 +05:30
Laurent Pinchart b6c5ef6f6d serial: sh-sci: Make probe fail for ports that exceed the maximum count
The driver supports a maximum number of ports configurable at compile
time. Make sure the probe() method fails when registering a port that
exceeds the maximum instead of returning success without registering the
port.

This fixes a crash at system suspend time, when the driver tried to
suspend a non-registered port using the UART core.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2012-06-13 10:22:10 +09:00
Laurent Pinchart 6dae14216c serial: sh-sci: Fix probe error paths
When probing fails, the driver must not try to cleanup resources that
have not been initialized. Fix this.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2012-06-13 10:22:08 +09:00
Paul Mundt 0e8963de1f serial: sh-sci: Fix for port types without BRI interrupts.
In doing the evt2irq() + muxed vector conversion for various port types
it became apparent that some of the legacy port types will presently
error out due to the irq requesting logic attempting to acquire the
non-existent BRI IRQ. This adds some sanity checks to the request/free
path to ensure that non-existence of a source in itself is not an error.

This should restore functionality for legacy PORT_SCI ports.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2012-05-18 18:21:06 +09:00
Shimoda, Yoshihiro a4e02f6d83 serial: sh-sci: Update break_ctl handling for all SCSPTR-capable regtypes.
This updates the earlier break_ctl support regardless of regtype so long
as the requisite SCSPTR exists. This is the same approach used by
sci_init_pins() for providing a generic solution now that we're able to
detect register capabilities on a per-port basis.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2012-04-12 19:19:21 +09:00
Shimoda, Yoshihiro bbb4ce50f3 serial: sh-sci: modify sci_break_ctl()
SCIF modules which have SCSPTR can output the break signal. Now that we
have a way of determining port features/capabilities, add trivial break
control via SCSPTR support. Tested on sh7757lcr.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2012-04-09 17:39:34 +09:00
Paul Mundt b12bb29f84 serial: sh-sci: use serial_port_in/out vs sci_in/out.
Follows the 8250 change for pretty much the same rationale.

See commit "serial: use serial_port_in/out vs serial_in/out in 8250".

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2012-03-30 19:50:15 +09:00
Linus Torvalds f52b69f86e SuperH updates for 3.4 merge window
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Merge tag 'sh-for-linus' of git://github.com/pmundt/linux-sh

Pull SuperH updates from Paul Mundt.

* tag 'sh-for-linus' of git://github.com/pmundt/linux-sh: (25 commits)
  sh: Support I/O space swapping where needed.
  sh: use set_current_blocked() and block_sigmask()
  sh: no need to reset handler if SA_ONESHOT
  sh: intc: Fix up section mismatch for intc_ack_data
  sh: select ARCH_DISCARD_MEMBLOCK.
  sh: Consolidate duplicate _32/_64 unistd definitions.
  sh: ecovec: switch SDHI controllers to card polling
  sh: Avoid exporting unimplemented syscalls.
  sh: add platform_device for RSPI in setup-sh7757
  SH: pci-sh7780: enable big-endian operation.
  serial: sh-sci: fix a race of DMA submit_tx on transfer
  sh: dma: Collect up CHCR of SH7763, SH7764, SH7780 and SH7785
  sh: dma: Collect up CHCR of SH7723 and SH7730
  sh/next: Fix build fail by asm/system.h in asm/bitops.h
  arch/sh/drivers/dma/{dma-g2,dmabrg}.c: ensure arguments to request_irq and free_irq are compatible
  sh: cpufreq: Wire up scaling_available_freqs support.
  sh: cpufreq: notify about rate rounding fallback.
  sh: cpufreq: Support CPU clock frequency table.
  sh: cpufreq: struct device lookup from CPU topology.
  sh: cpufreq: percpu struct clk accounting.
  ...
2012-03-30 00:09:17 -07:00
Linus Torvalds ef08e78268 Merge branch 'next' of git://git.infradead.org/users/vkoul/slave-dma
Pull slave-dmaengine update from Vinod Koul:
 "This includes the cookie cleanup by Russell, the addition of context
  parameter for dmaengine APIs, more arm dmaengine driver cleanup by
  moving code to dmaengine, this time for imx by Javier and pl330 by
  Boojin along with the usual driver fixes."

Fix up some fairly trivial conflicts with various other cleanups.

* 'next' of git://git.infradead.org/users/vkoul/slave-dma: (67 commits)
  dmaengine: imx: fix the build failure on x86_64
  dmaengine: i.MX: Fix merge of cookie branch.
  dmaengine: i.MX: Add support for interleaved transfers.
  dmaengine: imx-dma: use 'dev_dbg' and 'dev_warn' for messages.
  dmaengine: imx-dma: remove 'imx_dmav1_baseaddr' and 'dma_clk'.
  dmaengine: imx-dma: remove unused arg of imxdma_sg_next.
  dmaengine: imx-dma: remove internal structure.
  dmaengine: imx-dma: remove 'resbytes' field of 'internal' structure.
  dmaengine: imx-dma: remove 'in_use' field of 'internal' structure.
  dmaengine: imx-dma: remove sg member from internal structure.
  dmaengine: imx-dma: remove 'imxdma_setup_sg_hw' function.
  dmaengine: imx-dma: remove 'imxdma_config_channel_hw' function.
  dmaengine: imx-dma: remove 'imxdma_setup_mem2mem_hw' function.
  dmaengine: imx-dma: remove dma_mode member of internal structure.
  dmaengine: imx-dma: remove data member from internal structure.
  dmaengine: imx-dma: merge old dma-v1.c with imx-dma.c
  dmaengine: at_hdmac: add slave config operation
  dmaengine: add context parameter to prep_slave_sg and prep_dma_cyclic
  dmaengine/dma_slave: introduce inline wrappers
  dma: imx-sdma: Treat firmware messages as warnings instead of erros
  ...
2012-03-29 15:34:57 -07:00
Yoshii Takashi 49d4bcaddc serial: sh-sci: fix a race of DMA submit_tx on transfer
When DMA is enabled, sh-sci transfer begins with
 uart_start()
  sci_start_tx()
    if (cookie_tx < 0) schedule_work()
Then, starts DMA when wq scheduled, -- (A)
 process_one_work()
  work_fn_rx()
   cookie_tx = desc->submit_tx()
And finishes when DMA transfer ends, -- (B)
 sci_dma_tx_complete()
  async_tx_ack()
  cookie_tx = -EINVAL
  (possible another schedule_work())

This A to B sequence is not reentrant, since controlling variables
(for example, cookie_tx above) are not queues nor lists. So, they
must be invoked as A B A B..., otherwise results in kernel crash.

To ensure the sequence, sci_start_tx() seems to test if cookie_tx < 0
(represents "not used") to call schedule_work().
But cookie_tx will not be set (to a cookie, also means "used") until
in the middle of work queue scheduled function work_fn_tx().

This gap between the test and set allows the breakage of the sequence
under the very frequently call of uart_start().
Another gap between async_tx_ack() and another schedule_work() results
in the same issue, too.

This patch introduces a new condition "cookie_tx == 0" just to mark
it is "busy" and assign it within spin-locked region to fill the gaps.

Signed-off-by: Takashi Yoshii <takashi.yoshii.zj@renesas.com>
Reviewed-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: stable@vger.kernel.org
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2012-03-28 14:26:05 +09:00
Alexandre Bounine 16052827d9 dmaengine/dma_slave: introduce inline wrappers
Add inline wrappers for device_prep_slave_sg() and device_prep_dma_cyclic()
interfaces to hide new parameter from current users of affected interfaces.
Convert current users to use new wrappers instead of direct calls.
Suggested by Russell King [https://lkml.org/lkml/2012/2/3/269].

Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-03-21 19:20:22 +05:30
Rafael J. Wysocki 048be431e4 sh-sci / PM: Avoid deadlocking runtime PM
The runtime PM of sh-sci devices is enabled when sci_probe() returns,
so the pm_runtime_put_sync() executed by driver_probe_device()
attempts to suspend the device.  Then, in some situations, a
diagnostic message is printed to the console by one of the runtime
suspend routines handling the sh-sci device, which causes synchronous
runtime resume to be started from the device's own runtime suspend
callback.  This causes rpm_resume() to be run eventually, which sees
the RPM_SUSPENDING status set by rpm_suspend() and waits for it to
change.  However, the device's runtime PM status cannot change at
that point, because the routine that has set it waits for the
rpm_suspend() to return.  A deadlock occurs as a result.

To avoid that make sci_init_single() increment the device's
runtime PM usage counter, so that it cannot be suspended by
driver_probe_device().  That counter has to be decremented
eventually, so make sci_startup() do that before starting to
actually use the device and make sci_shutdown() increment it
again before returning to balance the incrementation carried out by
sci_startup().

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Tested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2012-03-09 12:59:44 +09:00
Linus Torvalds 57f2685c16 Merge branch 'next' of git://git.infradead.org/users/vkoul/slave-dma
* 'next' of git://git.infradead.org/users/vkoul/slave-dma: (53 commits)
  ARM: mach-shmobile: specify CHCLR registers on SH7372
  dma: shdma: fix runtime PM: clear channel buffers on reset
  dma/imx-sdma: save irq flags when use spin_lock in sdma_tx_submit
  dmaengine/ste_dma40: clear LNK on channel startup
  dmaengine: intel_mid_dma: remove legacy pm interface
  ASoC: mxs: correct 'direction' of device_prep_dma_cyclic
  dmaengine: intel_mid_dma: error path fix
  dmaengine: intel_mid_dma: locking and freeing fixes
  mtd: gpmi-nand: move to dma_transfer_direction
  mtd: fix compile error for gpmi-nand
  mmc: mxs-mmc: fix the dma_transfer_direction migration
  dmaengine: add DMA_TRANS_NONE to dma_transfer_direction
  dma: mxs-dma: Don't use CLKGATE bits in CTRL0 to disable DMA channels
  dma: mxs-dma: make mxs_dma_prep_slave_sg() multi user safe
  dma: mxs-dma: Always leave mxs_dma_init() with the clock disabled.
  dma: mxs-dma: fix a typo in comment
  DMA: PL330: Remove pm_runtime_xxx calls from pl330 probe/remove
  video i.MX IPU: Fix display connections
  i.MX IPU DMA: Fix wrong burstsize settings
  dmaengine/ste_dma40: allow fixed physical channel
  ...

Fix up conflicts in drivers/dma/{Kconfig,mxs-dma.c,pl330.c}

The conflicts looked pretty trivial, but I'll ask people to verify them.
2012-01-17 18:40:24 -08:00
Paul Mundt 50f0959ad4 serial: sh-sci: Handle GPIO function requests.
This adds initial support for requesting the various GPIO functions
necessary for certain ports. This just plugs in dumb request/free logic,
but serves as a building block for migrating off of the ->init_pins mess
to a wholly gpiolib backed solution (primarily parts with external
RTS/CTS pins, but will also allow us to clean up RXD pin testing).

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2011-12-02 20:09:48 +09:00
Paul Mundt 73c3d53f38 serial: sh-sci: Avoid FIFO clear for MCE toggle.
When toggling the MCE support we don't want to concern ourselves with the
FIFO state, so ensure that the clearing bits are masked out when updating
the MCE state.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2011-12-02 19:02:06 +09:00