Re: [PATCH v7 0/8] Add PWM and IIO timer drivers for STM32

[Benjamin Gaignard <benjamin.gaignard@linaro.org>]

2017-01-05 15:49 GMT+01:00 Lee Jones <lee.jones@linaro.org>:
> On Thu, 05 Jan 2017, Benjamin Gaignard wrote:
>
>> version 7:
>> - rebase on v4.10-rc2
>> - remove iio_device code from driver and keep only the trigger part
>>
>> version 6:
>> - rename stm32-gptimer in stm32-timers.
>> - change "st,stm32-gptimer" compatible to "st,stm32-timers".
>> - modify "st,breakinput" parameter in pwm part.
>> - split DT patch in 2
>>
>> version 5:
>> - fix comments done on version 4
>> - rebased on kernel 4.9-rc8
>> - change nodes names and re-order then by addresses
>>
>> version 4:
>> - fix comments done on version 3
>> - don't use interrupts anymore in IIO timer
>> - detect hardware capabilities at probe time to simplify binding
>>
>> version 3:
>> - no change on mfd and pwm divers patches
>> - add cross reference between bindings
>> - change compatible to "st,stm32-timer-trigger"
>> - fix attributes access rights
>> - use string instead of int for master_mode and slave_mode
>> - document device attributes in sysfs-bus-iio-timer-stm32
>> - update DT with the new compatible
>>
>> version 2:
>> - keep only one compatible per driver
>> - use DT parameters to describe hardware block configuration:
>>   - pwm channels, complementary output, counter size, break input
>>   - triggers accepted and create by IIO timers
>> - change DT to limite use of reference to the node
>> - interrupt is now in IIO timer driver
>> - rename stm32-mfd-timer to stm32-timers (for general purpose timer)
>>
>> The following patches enable PWM and IIO Timer features for STM32 platforms.
>>
>> Those two features are mixed into the registers of the same hardware block
>> (named general purpose timer) which lead to introduce a multifunctions driver
>> on the top of them to be able to share the registers.
>>
>> In STM32f4 14 instances of timer hardware block exist, even if they all have
>> the same register mapping they could have a different number of pwm channels
>> and/or different triggers capabilities. We use various parameters in DT to
>> describe the differences between hardware blocks
>>
>> The MFD (stm32-timers.c) takes care of clock and register mapping
>> by using regmap. stm32_timers structure is provided to its sub-node to
>> share those information.
>>
>> PWM driver is implemented into pwm-stm32.c. Depending of the instance we may
>> have up to 4 channels, sometime with complementary outputs or 32 bits counter
>> instead of 16 bits. Some hardware blocks may also have a break input function
>> which allows to stop pwm depending of a level, defined in devicetree, on an
>> external pin.
>>
>> IIO timer driver (stm32-timer-trigger.c and stm32-timer-trigger.h) define a list
>> of hardware triggers usable by hardware blocks like ADC, DAC or other timers.
>>
>> The matrix of possible connections between blocks is quite complex so we use
>> trigger names and is_stm32_iio_timer_trigger() function to be sure that
>> triggers are valid and configure the IPs.
>>
>> At run time IIO timer hardware blocks can configure (through "master_mode"
>> IIO device attribute) which internal signal (counter enable, reset,
>> comparison block, etc...) is used to generate the trigger.
>>
>> Benjamin Gaignard (8):
>>   MFD: add bindings for STM32 Timers driver
>>   MFD: add STM32 Timers driver
>>   PWM: add pwm-stm32 DT bindings
>>   PWM: add PWM driver for STM32 plaftorm
>>   IIO: add bindings for STM32 timer trigger driver
>>   IIO: add STM32 timer trigger driver
>>   ARM: dts: stm32: add Timers driver for stm32f429 MCU
>>   ARM: dts: stm32: Enable pwm1 and pwm3 for stm32f469-disco
>
> Any reason why you've dropped all your Acks?
>
> I don't really want to review it again if little is different.
>
> How much MFD related code has changed since the last review?

All my apologies I forgot to add your Acks for MFD parts.

Sorry for that

>
>>  .../ABI/testing/sysfs-bus-iio-timer-stm32          |  29 ++
>>  .../bindings/iio/timer/stm32-timer-trigger.txt     |  23 ++
>>  .../devicetree/bindings/mfd/stm32-timers.txt       |  46 +++
>>  .../devicetree/bindings/pwm/pwm-stm32.txt          |  33 ++
>>  arch/arm/boot/dts/stm32f429.dtsi                   | 275 +++++++++++++
>>  arch/arm/boot/dts/stm32f469-disco.dts              |  28 ++
>>  drivers/iio/Kconfig                                |   1 -
>>  drivers/iio/trigger/Kconfig                        |  10 +
>>  drivers/iio/trigger/Makefile                       |   1 +
>>  drivers/iio/trigger/stm32-timer-trigger.c          | 340 ++++++++++++++++
>>  drivers/mfd/Kconfig                                |  11 +
>>  drivers/mfd/Makefile                               |   2 +
>>  drivers/mfd/stm32-timers.c                         |  80 ++++
>>  drivers/pwm/Kconfig                                |   9 +
>>  drivers/pwm/Makefile                               |   1 +
>>  drivers/pwm/pwm-stm32.c                            | 434 +++++++++++++++++++++
>>  include/linux/iio/timer/stm32-timer-trigger.h      |  62 +++
>>  include/linux/mfd/stm32-timers.h                   |  71 ++++
>>  18 files changed, 1455 insertions(+), 1 deletion(-)
>>  create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-timer-stm32
>>  create mode 100644 Documentation/devicetree/bindings/iio/timer/stm32-timer-trigger.txt
>>  create mode 100644 Documentation/devicetree/bindings/mfd/stm32-timers.txt
>>  create mode 100644 Documentation/devicetree/bindings/pwm/pwm-stm32.txt
>>  create mode 100644 drivers/iio/trigger/stm32-timer-trigger.c
>>  create mode 100644 drivers/mfd/stm32-timers.c
>>  create mode 100644 drivers/pwm/pwm-stm32.c
>>  create mode 100644 include/linux/iio/timer/stm32-timer-trigger.h
>>  create mode 100644 include/linux/mfd/stm32-timers.h
>>
>
> --
> Lee Jones
> Linaro STMicroelectronics Landing Team Lead
> Linaro.org │ Open source software for ARM SoCs
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-- 
Benjamin Gaignard

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