Node is being initialized a value that is never read, it is
being written over a few statements into the function with
the return value from call to of_get_child_by_name. Hence
this initialization can be removed. Cleans up clang warning:
drivers/mfd/ti_am335x_tscadc.c:127:22: warning: Value stored
to 'node' during its initialization is never read
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
store the physical address of the device in its priv to use it
for DMA addressing in the client drivers.
Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com>
Acked-for-MFD-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
The regmap structure pointer is named regmap_tscadc, this is not
consistent with other drivers and is redundant, it also contributes
to several checkpatch warnings involving long lines. Rename this.
Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
All functions in this driver reference the same ti_tscadc_dev per device
but use several different names for this structure pointer, this can
be confusing when following the code. Use the name 'tscadc' everywhere.
Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
tscadc_readl and tscadc_writel are single line functions and do not save
use anything, remove these.
Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Fix the code formatting to use the kernel preferred style
of using the actual variables to determine the size using
the sizeof() operator.
Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
In one shot mode, sequencer automatically disables all enabled steps at
the end of each cycle. (both ADC steps and TSC steps) Hence these steps
need not be saved in reg_se_cache for clearing these steps at a later
stage.
Also, when ADC wakes up Sequencer should not be busy executing any of the
config steps except for the charge step. Previously charge step was 1 ADC
clock cycle and hence it was ignored.
TSC steps are always disabled at the end of each conversion cycle, hence
there is no need to explicitly disable TSC steps by writing 0 to REG_SE.
Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
The logic in AFE_Pen_Ctrl bitmask in the CTRL register is different for five
wire versus four or eight wire touschscreens. This patch should fix this for
five-wire touch screens. There should be no change needed here for four and
eight wire tousch screens.
Signed-off-by: Jeff Lance <j-lance1@ti.com>
[bigeasy: keep the change mfd only]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
In the resume path, the ADC invokes am335x_tsc_se_set_cache() with 0 as
the steps argument if continous mode is not in use. This in turn disables
all steps and so the TSC is not working until one ADC sampling is
performed.
This patch fixes it by writing the current cached mask instead of the
passed steps.
Fixes: 7ca6740cd1 ("mfd: input: iio: ti_amm335x: Rework TSC/ADCA
synchronization")
Cc: stable@vger.kernel.org # v3.13+
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
After enabling and disabling ADC continuous mode via sysfs, ts_print_raw
fails to return any data. This is because when ADC is configured for
continuous mode, it disables touch screen steps.These steps are not
re-enabled when ADC continuous mode is disabled. Therefore existing values
of REG_SE needs to be cached before enabling continuous mode and
disabling touch screen steps and enabling ADC steps. The cached value
are to be restored to REG_SE once ADC is disabled.
Fixes: 7ca6740cd1 ("mfd: input: iio: ti_amm335x: Rework TSC/ADC synchronization")
Cc: stable@vger.kernel.org # v3.13+
Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Use devm_ioremap_resource() in order to make the code simpler,
and remove redundant return value check of platform_get_resource()
because the value is checked by devm_ioremap_resource().
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
None of these files are actually using any __init type directives
and hence don't need to include <linux/init.h>. Most are just a
left over from __devinit and __cpuinit removal, or simply due to
code getting copied from one driver to the next.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
The ADC driver always programs all possible ADC values and discards
them except for the value IIO asked for. On the am335x-evm the driver
programs four values and it takes 500us to gather them. Reducing the number
of conversations down to the (required) one also reduces the busy loop down
to 125us.
This leads to another error, namely the FIFOCOUNT register is sometimes
(like one out of 10 attempts) not updated in time leading to EBUSY.
The next read has the FIFOCOUNT register updated.
Checking for the ADCSTAT register for being idle isn't a good choice either.
The problem is that if TSC is used at the same time, the HW completes the
conversation for ADC *and* before the driver noticed it, the HW begins to
perform a TSC conversation and so the driver never seen the HW idle. The
next time we would have two values in the FIFO but since the driver reads
everything we always see the current one.
So instead of polling for the IDLE bit in ADCStatus register, we should
check the FIFOCOUNT register. It should be one instead of zero because we
request one value.
This change in turn leads to another error. Sometimes if TSC & ADC are
used together the TSC starts generating interrupts even if nobody
actually touched the touchscreen. The interrupts seem valid because TSC's
FIFO is filled with values for each channel of the TSC. This condition stops
after a few ADC reads but will occur again. Not good.
On top of this (even without the changes I just mentioned) there is a ADC
& TSC lockup condition which was reported to me by Jeff Lance including the
following test case:
A busy loop of "cat /sys/bus/iio/devices/iio\:device0/in_voltage4_raw"
and a mug on touch screen. With this setup, the hardware will lockup after
something between 20 minutes and it could take up to a couple of hours.
During that lockup, the ADCSTAT register says 0x30 (or 0x70) which means
STEP_ID = IDLE and FSM_BUSY = yes. That means the hardware says that it is
idle and busy at the same time which is an invalid condition.
For all this reasons I decided to rework this TSC/ADC part and add a
handshake / synchronization here:
First the ADC signals that it needs the HW and writes a 0 mask into the
SE register. The HW (if active) will complete the current conversation
and become idle. The TSC driver will gather the values from the FIFO
(woken up by an interrupt) and won't "enable" another conversation.
Instead it will wake up the ADC driver which is already waiting. The ADC
driver will start "its" conversation and once it is done, it will
enable the TSC steps so the TSC will work again.
After this rework I haven't observed the lockup so far. Plus the busy
loop has been reduced from 500us to 125us.
The continues-read mode remains unchanged.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
The update of the SE register in MFD doesn't look right as it has
nothing to do with it. The better place to do it is in TSC driver (which
is already doing it) and in the ADC driver which needs this only in the
continues mode.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
The purpose of reg_se_cache has been defeated. It should avoid the
read-back of the register to avoid the latency and the fact that the
bits are reset to 0 after the individual conversation took place.
The reason why this is required like this to work, is that read-back of
the register removes the bits of the ADC so they do not start another
conversation after the register is re-written from the TSC side for the
update.
To avoid the not required read-back I introduce a "set once" variant which
does not update the cache mask. After the conversation completes, the
bit is removed from the SE register anyway and we don't plan a new
conversation "any time soon". The current set function is renamed to
set_cache to distinguish the two operations.
This is a small preparation for a larger sync-rework.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Since the "recent" changes, am335x_tsc_se_update() has no longer any
users outside of this file so make it local.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Since the addition of continuous sampling mode and shared irq support,
the reg_lock lock can be taken with and without interrupts. This patch
uses the *_irq* variant which should be used in order to avaoid a deadlock.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
The data structure of_match_ptr() protects is always compiled in.
Hence of_match_ptr() is not needed.
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
The ADC clock divider needs to be restored on resume as the register content
is lost when the ADC is powered down
Signed-off-by: Matthias Kaehlcke <matthias@kaehlcke.net>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
The reg_cache variable should be updated with current
steps in the reg_se register. Then the mask should
apply and clear the register. Previously, the reg_cache
can be an old redundant value that isn't updated.
Signed-off-by: Zubair Lutfullah <zubair.lutfullah@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Reg_cache variable is used to lock step enable register
from being accessed and written by both TSC and ADC
at the same time.
However, it isn't updated anywhere in the code at all.
If both TSC and ADC are used, eventually 1FFFF is always
written enabling all 16 steps uselessly causing a mess.
Patch fixes it by correcting the locks and updates the
variable by reading the step enable register
Signed-off-by: Zubair Lutfullah <zubair.lutfullah@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
AFE Pen Ctrl and TouchScreen transistors enabling is not
required when only ADC mode is being used, so check for availability of
TSC driver before accessing control register.
Signed-off-by: Patil, Rachna <rachna@ti.com>
Acked-by: Vaibhav Hiremath <hvaibhav@ti.com>
Signed-off-by: Zubair Lutfullah <zubair.lutfullah@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
ADC is ideally expected to work at a frequency of 3MHz.
The present code had a check, which returned error if the frequency
went below the threshold value. But since AM335x supports various
working frequencies, this check is not required.
Now the code just uses the internal ADC clock divider to set the ADC
frequency w.r.t the sys clock.
Signed-off-by: Patil, Rachna <rachna@ti.com>
Signed-off-by: Zubair Lutfullah <zubair.lutfullah@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
The TSC part allows to specify the input lines. The IIO part assumes
that it usues always the last few, that means if IIO has adc-channels
set to 2 it will use channel 6 and 7. However it might make sense to use
only 6.
This patch changes the device property (which was introduced recently
and was never in an official release) in a way that the user can specify
which of the AIN lines should be used. In Addition to this, the name is
now AINx where x is the channel number i.e. for AIN6 we would have 6.
Prior this, it always started counting at 0 which is confusing. In
addition to this, it also checks for correct step number during reading
and does not rely on proper FIFO depth.
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
TI-adc reads a little better compared to tiadc. And if we add am335x to
it then we have the same naming scheme as the tsc side.
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Fix the mfd device in the case where a subdevice might not be activated.
Signed-off-by: Pantelis Antoniou <panto@antoniou-consulting.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
This patch removes access to platform data mfd_tscadc_board because the
platform is DT only.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Add DT support in the MFD core driver. The node name is "am3359" because
it was tested on this platform.
Signed-off-by: Pantelis Antoniou <panto@antoniou-consulting.com>
Signed-off-by: Patil, Rachna <rachna@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Add DT support for client ADC driver.
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Patil, Rachna <rachna@ti.com>
Signed-off-by: Pantelis Antoniou <panto@antoniou-consulting.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
This patch adds DT support to touch driver. It also provides a binding
document which is used by the MFD and IIO part of the device.
This patch also renames steps_to_configure to coordinate_readouts
because the original name misleads the purpose of the variable.
Signed-off-by: Pantelis Antoniou <panto@antoniou-consulting.com>
Signed-off-by: Patil, Rachna <rachna@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Current code has hard coded value written to
step enable bits. Now the bits are updated based
on how many steps are needed to be configured got
from platform data.
The user needs to take care not to exceed
the count more than 16. While using ADC and TSC
one should take care to set this parameter correctly.
Sebastian added the common lock and moved the code, that manipulates the
steps, from into the mfd module.
Signed-off-by: Patil, Rachna <rachna@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
The mfd driver creates platform data for the child devices and it is the
ti_tscadc_dev struct. This struct is copied for the two devices.
The copy of the structure makes a common lock in this structure a little
less usefull. Therefore the platform data is not a pointer to the
structure and the same structure is used.
While doing the change I noticed that the suspend/resume code assumes
the wrong pointer for ti_tscadc_dev and this has been fixed as well.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
CONFIG_HOTPLUG is going away as an option. As a result, the __dev*
markings need to be removed.
This change removes the use of __devinit, __devexit_p, __devinitdata,
__devinitconst, and __devexit from these drivers.
Based on patches originally written by Bill Pemberton, but redone by me
in order to handle some of the coding style issues better, by hand.
Cc: Bill Pemberton <wfp5p@virginia.edu>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pass on the correct error message from platform_get_irq()
instead of hard coding it to "EINVAL".
Also change label from "err" to "ret" for better
readability and update the same in error path.
Signed-off-by: Patil, Rachna <rachna@ti.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
This patch adds support for TI's ADC driver.
This is a multifunctional device.
Analog input lines are provided on which
voltage measurements can be carried out.
You can have upto 8 input lines.
Signed-off-by: Patil, Rachna <rachna@ti.com>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
This patch converts touchscreen into a MFD client.
All the register definitions, clock initialization,
etc has been moved to MFD core driver.
Signed-off-by: Patil, Rachna <rachna@ti.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Add the mfd core driver which supports touchscreen
and ADC.
With this patch we are only adding infrastructure to
support the MFD clients.
Signed-off-by: Patil, Rachna <rachna@ti.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Colin Ian King