linux-toradex.git/drivers/counter/stm32-timer-cnt.c, branch v6.6-rc1

counter: stm32-timer-cnt: Reset TIM_TISEL to its default value in probe

2023-05-09T23:17:17+00:00

The driver assumes that the input selection register (TIM_TISEL) is at
its reset default value. Usually this is the case, but the bootloader
might have modified it.

This bases on a similar patch submitted by Olivier Moysan for pwm-stm32.

Reviewed-by: Fabrice Gasnier 
Signed-off-by: Uwe Kleine-König 
Link: https://lore.kernel.org/r/20230413212339.3611722-1-u.kleine-koenig@pengutronix.de/
Signed-off-by: William Breathitt Gray

counter: Move symbols into COUNTER namespace

2022-09-30T12:32:35+00:00

Counter subsystem symbols are only relevant to counter drivers. A
COUNTER namespace is created to control the availability of these
symbols to modules that import this namespace explicitly.

Cc: Patrick Havelange 
Cc: Jarkko Nikula 
Cc: Oleksij Rempel 
Cc: Pengutronix Kernel Team 
Cc: Kamel Bouhara 
Cc: Fabrice Gasnier 
Cc: Maxime Coquelin 
Cc: Alexandre Torgue 
Acked-by: David Lechner 
Reviewed-by: Jonathan Cameron 
Link: https://lore.kernel.org/r/20220815220321.74161-1-william.gray@linaro.org/
Signed-off-by: William Breathitt Gray 
Link: https://lore.kernel.org/r/8a756df96c24946547a7ece5caa5f654809c5e7f.1664318353.git.william.gray@linaro.org
Signed-off-by: Greg Kroah-Hartman

counter: stm32-timer-cnt: Convert to new counter registration

2021-12-30T16:44:07+00:00

This fixes device lifetime issues where it was possible to free a live
struct device.

Fixes: ad29937e206f ("counter: Add STM32 Timer quadrature encoder")
Reviewed-by: Jonathan Cameron 
Acked-by: William Breathitt Gray 
Signed-off-by: Uwe Kleine-König 
Link: https://lore.kernel.org/r/20211230150300.72196-21-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman

counter: stm32-timer-cnt: Convert to counter_priv() wrapper

2021-12-30T16:44:06+00:00

This is a straight forward conversion to the new counter_priv() wrapper.

Acked-by: Jonathan Cameron 
Acked-by: William Breathitt Gray 
Signed-off-by: Uwe Kleine-König 
Link: https://lore.kernel.org/r/20211230150300.72196-13-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman

counter: Internalize sysfs interface code

2021-10-17T09:52:58+00:00

This is a reimplementation of the Generic Counter driver interface.
There are no modifications to the Counter subsystem userspace interface,
so existing userspace applications should continue to run seamlessly.

The purpose of this patch is to internalize the sysfs interface code
among the various counter drivers into a shared module. Counter drivers
pass and take data natively (i.e. u8, u64, etc.) and the shared counter
module handles the translation between the sysfs interface and the
device drivers. This guarantees a standard userspace interface for all
counter drivers, and helps generalize the Generic Counter driver ABI in
order to support the Generic Counter chrdev interface (introduced in a
subsequent patch) without significant changes to the existing counter
drivers.

Note, Counter device registration is the same as before: drivers
populate a struct counter_device with components and callbacks, then
pass the structure to the devm_counter_register function. However,
what's different now is how the Counter subsystem code handles this
registration internally.

Whereas before callbacks would interact directly with sysfs data, this
interaction is now abstracted and instead callbacks interact with native
C data types. The counter_comp structure forms the basis for Counter
extensions.

The counter-sysfs.c file contains the code to parse through the
counter_device structure and register the requested components and
extensions. Attributes are created and populated based on type, with
respective translation functions to handle the mapping between sysfs and
the counter driver callbacks.

The translation performed for each attribute is straightforward: the
attribute type and data is parsed from the counter_attribute structure,
the respective counter driver read/write callback is called, and sysfs
I/O is handled before or after the driver read/write function is called.

Cc: Jarkko Nikula 
Cc: Patrick Havelange 
Cc: Kamel Bouhara 
Cc: Maxime Coquelin 
Cc: Alexandre Torgue 
Cc: Dan Carpenter 
Acked-by: Syed Nayyar Waris 
Reviewed-by: David Lechner 
Tested-by: David Lechner 
Signed-off-by: William Breathitt Gray 
Reviewed-by: Fabrice Gasnier  # for stm32
Link: https://lore.kernel.org/r/c68b4a1ffb195c1a2f65e8dd5ad7b7c14e79c6ef.1630031207.git.vilhelm.gray@gmail.com
Signed-off-by: Jonathan Cameron

counter: stm32-timer-cnt: Provide defines for slave mode selection

2021-10-17T09:52:46+00:00

The STM32 timer permits configuration of the counter encoder mode via
the slave mode control register (SMCR) slave mode selection (SMS) bits.
This patch provides preprocessor defines for the supported encoder
modes.

Cc: Fabrice Gasnier 
Signed-off-by: William Breathitt Gray 
Reviewed-by: Fabrice Gasnier 
Link: https://lore.kernel.org/r/ad3d9cd7af580d586316d368f74964cbc394f981.1630031207.git.vilhelm.gray@gmail.com
Signed-off-by: Jonathan Cameron

counter: Rename counter_count_function to counter_function

2021-08-09T19:17:36+00:00

The phrase "Counter Count function" is verbose and unintentionally
implies that function is a Count extension. This patch adjusts the
Counter subsystem code to use the more direct "Counter function" phrase
to make the intent of this code clearer.

Cc: Jarkko Nikula 
Cc: Patrick Havelange 
Cc: Oleksij Rempel 
Cc: Kamel Bouhara 
Cc: Maxime Coquelin 
Cc: Alexandre Torgue 
Cc: David Lechner 
Acked-by: Syed Nayyar Waris 
Reviewed-by: Fabrice Gasnier 
Signed-off-by: William Breathitt Gray 
Link: https://lore.kernel.org/r/8268c54d6f42075a19bb08151a37831e22652499.1627990337.git.vilhelm.gray@gmail.com
Signed-off-by: Jonathan Cameron

counter: stm32-timer-cnt: Add const qualifier for actions_list array

2021-06-09T15:32:47+00:00

The struct counter_synapse actions_list member expects a const enum
counter_synapse_action array. This patch adds the const qualifier to the
stm32_synapse_actions to match actions_list.

Cc: Benjamin Gaignard 
Reviewed-by: Fabrice Gasnier 
Signed-off-by: William Breathitt Gray 
Link: https://lore.kernel.org/r/9675edda958ee2ca371d271f46445d3e1934ba82.1623201081.git.vilhelm.gray@gmail.com
Signed-off-by: Jonathan Cameron

counter: stm32-timer-cnt: Add const qualifier for functions_list array

2021-06-09T15:24:39+00:00

The struct counter_count functions_list member expects a const enum
counter_count_function array. This patch adds the const qualifier to the
stm32_count_functions to match functions_list.

Cc: Benjamin Gaignard 
Reviewed-by: Fabrice Gasnier 
Signed-off-by: William Breathitt Gray 
Link: https://lore.kernel.org/r/46a1e7096dd9280d8f241894186b3c903956a55f.1623201081.git.vilhelm.gray@gmail.com
Signed-off-by: Jonathan Cameron

counter: stm32-timer-cnt: fix ceiling miss-alignment with reload register

2021-03-06T16:48:09+00:00

Ceiling value may be miss-aligned with what's actually configured into the
ARR register. This is seen after probe as currently the ARR value is zero,
whereas ceiling value is set to the maximum. So:
- reading ceiling reports zero
- in case the counter gets enabled without any prior configuration,
  it won't count.
- in case the function gets set by the user 1st, (priv->ceiling) is used.

Fix it by getting rid of the cached "priv->ceiling" variable. Rather use
the ARR register value directly by using regmap read or write when needed.
There should be no drawback on performance as priv->ceiling isn't used in
performance critical path.
There's also no point in writing ARR while setting function (sms), so
it can be safely removed.

Fixes: ad29937e206f ("counter: Add STM32 Timer quadrature encoder")
Suggested-by: William Breathitt Gray 
Signed-off-by: Fabrice Gasnier 
Acked-by: William Breathitt Gray 
Cc: 
Link: https://lore.kernel.org/r/1614793789-10346-1-git-send-email-fabrice.gasnier@foss.st.com
Signed-off-by: Jonathan Cameron