Hi Michal
On 09/11/2018 07:51 AM, Michal Simek wrote:
On 10.9.2018 18:11, Patrice Chotard wrote:
This series :
- Add new gpio ops get_alt_function
- Add get_function and get_alt_function support to stm32 gpio driver
- Add get_alt_function test
I went quickly over this series and TBH I am not getting what this is for. It looks like that this is the part of pinmux.
Can you please elaborate more what this is for?
Currently, get_function callback returns the state of a gpio (GPIOF_INPUT, GPIOF_OUTPUT or GPIO_FUNC).
If a pin's state is GPIO_FUNC, it's useful to know which alternate function is selected for debug purpose.
As example, on STM32 SoCs, a pins can be configured as GPIO or also configured with up to 16 alternate function. Using command "gpio", user can retrieve this information as shown below:
STM32MP> gpio state -a
Bank GPIOA: GPIOA0: unused: 0 [ ] GPIOA1: unused: 0 [ ] GPIOA2: unused: 0 [ ] GPIOA3: unused: 0 [ ] GPIOA4: unused: 0 [ ] GPIOA5: unused: 0 [ ] GPIOA6: unused: 0 [ ] GPIOA7: unused: 0 [ ] GPIOA8: func: 9 GPIOA9: func: 10 GPIOA10: unused: 0 [ ] GPIOA11: unused: 0 [ ] GPIOA12: unused: 0 [ ] GPIOA13: output: 1 [x] red.gpios GPIOA14: output: 0 [x] green.gpios GPIOA15: unused: 0 [ ]
It shows that pin 8 and 9 of bank A are configured respectively in alternate function 9 and 10.
Patrice
Thanks, Michal