The error message if we cannot retrieve the clock tells us that the
touchscreen controller clock was unavailable. This is wrong, this is the
"main" clock for the hardware block, it is not specific to the
touchscreen and won't change when we will introduce ADC1/magnetic reader
support so let's correct this comment.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20211015081506.933180-34-miquel.raynal@bootlin.com
We need to retrieve the number of wires used by the "secondary" device
(the touchscreen or the magnetic reader). Let's rename tsc_wires to
become tscmag_wires to clarify the fact that this variable can be used
in both situations.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20211015081506.933180-33-miquel.raynal@bootlin.com
While the register list (and names) between ADC0 and ADC1 are pretty
close, the bits inside changed a little bit. To avoid any future
confusion, let's add the TSC prefix when some bits are in a register
that is common to both revisions of the ADC, but are specific to the
am33xx hardware.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20211015081506.933180-32-miquel.raynal@bootlin.com
This bit is common to all devices (ADC, Touchscreen, Magnetic reader) so
make it clear that it can be used from any location by operating a
mechanical rename:
s/CNTRLREG_TSCSSENB/CNTRLREG_SSENB/
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20211015081506.933180-31-miquel.raynal@bootlin.com
Instead of deriving in the probe and in the resume path the value of the
ctrl register, let's do it only once in the probe, save the value of
this register (all but the subsystem enable bit) in the driver's
structure and use it from the resume callback.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20211015081506.933180-23-miquel.raynal@bootlin.com
TI AM335X TRM [1] states that most of the configuration should be set in
the control register in the first place, before actually enabling the
hardware with the subsystem enable bit.
So far only half of the configuration was made in the first step (before
enabling the "subsystem"), which does not make really sense. Also, the
probe and the resume patch were acting differently. Let's harmonize all
this by following these steps:
1/ Configure the CLKDIV register
2/ Configure the CTRL register
3/ Configure the idle configuration
4/ Really enable the device by rewriting the CTRL register with the
subsystem enable bit set.
[1] https://www.ti.com/lit/pdf/spruh73
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20211015081506.933180-22-miquel.raynal@bootlin.com
The idle register is valid no matter if the touchscreen is used or not,
let's always configure it.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20211015081506.933180-21-miquel.raynal@bootlin.com
Keeping the count of tsc_cells and adc_cells is completely redundant, we
can derive this information from other variables. Plus, these variables
are not used anywhere else now. Let's get rid of them.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20211015081506.933180-20-miquel.raynal@bootlin.com
Use the number of touchscreen wires (tsc_wires) instead of the flag
indicating a touchscreen cell (tsc_cell) to mimic the logic from the
probe.
Besides keeping a certain harmony in the driver, the main benefit is
that we are going to simplify the number of entries in the main MFD
structure and tsc_cell can now be removed more easily.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20211015081506.933180-19-miquel.raynal@bootlin.com
So far every sub-cell parameter in this driver was hardcoded: cell name,
cell compatible, specific clock name and desired clock frequency.
As we are about to introduce support for ADC1/magnetic reader, we need a
bit of flexibility. Let's add a driver data structure which will contain
these information.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20211015081506.933180-18-miquel.raynal@bootlin.com
Allocating the driver structure should be done earlier in the probe so
that we can used its members from the beginning.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20211015081506.933180-17-miquel.raynal@bootlin.com
Let's rewrite this on a single line, it does not hurt the readability
and saves a useless temporary variable.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20211015081506.933180-16-miquel.raynal@bootlin.com
There is a single clock available in our node, which is named
"fck". The clock handler then points to adc_tsc_fck but no need to point
directly to it and do a full tree search.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20211015081506.933180-15-miquel.raynal@bootlin.com
The comment misses the main information which is that we assume that a
sample takes 15 ADC clock cycles to be generated. Let's take the
occasion to rework a little bit this comment.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20211015081506.933180-14-miquel.raynal@bootlin.com
Many variables will be updated (renamed, dropped, added) in the upcoming
changes, so let's simplify the style to avoid messing with spaces over
and over again.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20211015081506.933180-12-miquel.raynal@bootlin.com
Goto's jumping to a return statement are not really useful, drop them.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20211015081506.933180-13-miquel.raynal@bootlin.com
Drop the text license and replace it with an equivalent SPDX license tag
identifier which also matches the MODULE_LICENSE(GPL) macro.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20211015081506.933180-10-miquel.raynal@bootlin.com
of_node_put() should be called after a successful of_get_child_by_name().
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20211015081506.933180-9-miquel.raynal@bootlin.com
In the function ti_tscadc_probe(), when get irq failed,
platform_get_irq() logs an error message, so remove
redundant message here.
Signed-off-by: Tang Bin <tangbin@cmss.chinamobile.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.
Deterministic algorithm:
For each file:
If not .svg:
For each line:
If doesn't contain `\bxmlns\b`:
For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`:
If neither `\bgnu\.org/license`, nor `\bmozilla\.org/MPL\b`:
If both the HTTP and HTTPS versions
return 200 OK and serve the same content:
Replace HTTP with HTTPS.
Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
It is possible that platform_get_resource() might return NULL and
therefore code needs to check for this condition before
de-referencing the pointer.
Therefore move the de-referencing of 'res' pointer after
devm_ioremap_resource() which would have checked the validity of the
pointer.
Reported-by: Dan Murphy <dmurphy@ti.com>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Use PLATFORM_DEVID_AUTO to number mfd cells while registering, so that
different instances are uniquely identified. This is required in order
to support registering of multiple instances of same ti_am335x_tscadc IP.
Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
If a child device like touchscreen is wakeup capable, then keep ADC
interface on, so that a touching resistive screen will generate wakeup
event to the system.
Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Currently tscadc MFD is marked as wakeup capable which incorrect
because, its actually touch event by child TSC device that wakes up the
system. Therefore, remove device_init_wakeup() call that marks TSCADC
device as wakeup capable in favor of moving to mark TSC input device as
wakeup capable later.
Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Omit an extra message for a memory allocation failure in this function.
This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
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>
Miquel Raynal