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 > _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
