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

[Benjamin Gaignard]

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

-- 
1.9.1