Re: [PATCH v8 0/8] Add PWM and IIO timer drivers for STM32

[Lee Jones]

On Wed, 18 Jan 2017, Benjamin Gaignard wrote:

> version 8:
> - rebase on v4.10-rc4
> - fix comments done by Thierry on PWM
> - reword "reg" parameter description
> - change kernel kernel in IIO ABI documentation
> 
> 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
> 
>  .../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          |  35 ++
>  arch/arm/boot/dts/stm32f429.dtsi                   | 275 ++++++++++++++
>  arch/arm/boot/dts/stm32f469-disco.dts              |  28 ++
>  drivers/iio/trigger/Kconfig                        |   9 +
>  drivers/iio/trigger/Makefile                       |   1 +
>  drivers/iio/trigger/stm32-timer-trigger.c          | 342 ++++++++++++++++++
>  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                            | 398 +++++++++++++++++++++
>  include/linux/iio/timer/stm32-timer-trigger.h      |  62 ++++
>  include/linux/mfd/stm32-timers.h                   |  71 ++++
>  17 files changed, 1422 insertions(+)
>  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

Let me know when you have all your Acks.

I would be happy to take this through the MFD tree.

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org â Open source software for ARM SoCs
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