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>
It somehow looks like the ending bracket belongs to the if statement but
it does belong to the while loop. This patch moves the bracket where it
belongs.
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 driver is missing the iio_buffer_attach() call. As such it will attempt
to free the buffer twice on removal.
Introduced in commit 9e69c9 ("iio: Add reference counting for buffers").
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
ti_adc_dt_ids is always compiled in. Hence of_match_ptr is not
needed.
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
The equivalent of iio_sw_buffer_preenable() is now done in the IIO buffer
core, so there is no need to do this from the driver anymore.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: Zubair Lutfullah <zubair.lutfullah@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Driver is functional without this error case. Cleaned up.
Signed-off-by: Zubair Lutfullah <zubair.lutfullah@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Trigger related headers and variables are not needed
as driver is now based on INDIO_BUFFER_HARDWARE mode
Signed-off-by: Zubair Lutfullah <zubair.lutfullah@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Static is missing in function header. Corrected.
Signed-off-by: Zubair Lutfullah <zubair.lutfullah@gmail.com>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Previously the driver had only one-shot reading functionality.
This patch adds continuous sampling support to the driver.
Continuous sampling starts when buffer is enabled.
HW IRQ wakes worker thread that pushes samples to userspace.
Sampling stops when buffer is disabled by userspace.
Patil Rachna (TI) laid the ground work for ADC HW register access.
Russ Dill (TI) fixed bugs in the driver relevant to FIFOs and IRQs.
I fixed channel scanning so multiple ADC channels can be read
simultaneously and pushed to userspace.
Restructured the driver to fit IIO ABI.
And added INDIO_BUFFER_HARDWARE mode.
Signed-off-by: Zubair Lutfullah <zubair.lutfullah@gmail.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Russ Dill <Russ.Dill@ti.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
12 bit ADC data is stored in 32 bits of storage.
Change from u32 to u16 to reduce wasted memory.
Signed-off-by: Zubair Lutfullah <zubair.lutfullah@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Previously we tried to read data form ADC even before ADC sequencer
finished sampling. This led to wrong samples.
We now wait on ADC status register idle bit to be set.
Signed-off-by: Patil, Rachna <rachna@ti.com>
Signed-off-by: Zubair Lutfullah <zubair.lutfullah@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This set is larger than I would like, partly due to my lack of review
time in the weeks before the merge window and partly because a
couple of large drivers and the subsystem as a whole seem to be
getting a lot more exposure and testing recently.
1) A long term bug in trigger handling gave a double free of the device.
2) Wrong return value handling means offsets are ignored in
iio_convert_raw_to_processed_unlocked.
3) The iio_channel_has_info utility function was incorrectly updated
during the recent info_mask split, this is now fixed.
4) mxs-lradc has a couple of little fixes.
5) A couple of missing .driver_module entries meant that drivers
could be removed from underneath their users.
6) Error path fixes for ad7303 and lis3l02dq.
7) The scale value for presure in the lps331ap driver was out by
a factor of 100.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.20 (GNU/Linux)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=ratf
-----END PGP SIGNATURE-----
Merge tag 'iio-fixes-for-3.11a' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-linus
Jonathan writes:
The first round of IIO fixes for the 3.11 cycle.
This set is larger than I would like, partly due to my lack of review
time in the weeks before the merge window and partly because a
couple of large drivers and the subsystem as a whole seem to be
getting a lot more exposure and testing recently.
1) A long term bug in trigger handling gave a double free of the device.
2) Wrong return value handling means offsets are ignored in
iio_convert_raw_to_processed_unlocked.
3) The iio_channel_has_info utility function was incorrectly updated
during the recent info_mask split, this is now fixed.
4) mxs-lradc has a couple of little fixes.
5) A couple of missing .driver_module entries meant that drivers
could be removed from underneath their users.
6) Error path fixes for ad7303 and lis3l02dq.
7) The scale value for presure in the lps331ap driver was out by
a factor of 100.
Add missing .driver_module of struct iio_info. This prevents the
module from being removed from underneath its users.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Usually we get all the values we wanted but it is possible, that te ADC
unit is busy performing the conversation for the HW events. In that case
-EBUSY is returned and the user may re-call the function.
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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>
The driver programs a threshold of "coordinate_readouts" say 5. The
REG_FIFO0THR registers says it should it be programmed to "threshold
minus one". The driver does not expect just 5 coordinates but 5 * 2 + 2.
Multiplied by two because 5 for X and 5 for Y and plus 2 because we have
two Z.
The whole thing kind of works because It reads the 5 coordinates for X
and Y from FIFO0 and FIFO1 and the last element in each FIFO is ignored
within the loop and read later.
Nothing guaranties that FIFO1 is ready by the time it is read. In fact I
could see that that FIFO1 reaturns for Y channels 8,9, 10, 12, 6 and for
Y channel 7 for Z. The problem is that channel 7 and channel 12 got
somehow mixed up.
The other Problem is that FIFO1 is also used by the IIO part leading to
wrong results if both (tsc & adc) are used.
The patch tries to clean up the whole thing a little:
- Remove the +1 and -1 in REG_STEPCONFIG, REG_STEPDELAY and its counter
part in the for loop. This is just confusing.
- Use only FIFO0 in TSC. The fifo has space for 64 entries so should be
fine.
- Read the whole FIFO in one function and check the channel.
- in case we dawdle around, make sure we only read a multiple of our
coordinate set. On the second interrupt we will cleanup the remaining
enties.
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
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>
This patch provides the members "datasheet_name" and scan_type. This is
the remaining part of the earlier patch where I (bigeasy) removed iio_map
because it is now supplied by the device tree. It also static names as
suggested by Jonathan.
Acked-by: Jonathan Cameron <jic23@kernel.org>
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.
Acked-by: Jonathan Cameron <jic23@kernel.org>
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>
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>
The original info_mask is going away in favour of the broken out versions.
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
cc: Patil, Rachna <rachna@ti.com>
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, 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: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>