[PATCH] Proposal for new GPIO API and example implementation for STM32F4 BSP

[Duc Doan]

Hello Karel,

I came up with this solution: making a macro that returns a function
depending on driver/BSP name.

/**
  * @brief Get an GPIO control object.
  *
  * This macro requires BSPs/drivers to correctly implement
  * function <driver_name>_gpio_get_ctrl(void *arg, 
  * rtems_gpio_ctrl_t **out). 
  *
  * @param _driver is the name of the BSP/GPIO driver
  * @param[in] _arg is the void pointer to an argument type
  *        defined by BSP/driver
  * @param[out] _out is the pointer to the pointer to where
  *             the output object will be stored
  */
#define rtems_gpio_get_ctrl(_driver, _arg, _out) \
    _driver##_gpio_get_ctrl( _arg , _out )

In the application code:

rtems_gpio_get_ctrl(stm32f4, GPIOD, &led_ctrl);
rtems_gpio_get_ctrl(stm32f4, GPIOA, &button_ctrl);

What do you think about this?

Best,

Duc Doan

On Sat, 2022-06-25 at 21:46 +0200, Karel Gardas wrote:
> 
> Hello Duc,
> 
> one reminder, your API should be more or less portable. That means
> the 
> example which you produce as a testing example should be API-wise 
> portable between various BSPs. Is that clear?
> 
> I know, I know, sometimes user led 1 on F4 is on different port/pin
> on 
> F7 and then on H7 you get it on even different port/pin, but!
> 
>  > stm32f4_gpio_get_ctrl(GPIOD, &ctrl);
> 
> do you expect this to be called from app running on RPi4 for example?
> Or 
> on beagle bone white? Or on stm32h757i-eval board?
> 
> Please generalize and make that bit portable too.
> 
> Thanks,
> Karel
> 
> On 6/25/22 15:00, Duc Doan wrote:
> > Hello Christian,
> > 
> > I forgot to send the sample code. Here it a code to turn on an LED:
> > 
> > /*****************************************/
> > 
> > // Obtain the pointer to the instance (port D)
> > rtems_gpio_ctrl_t *ctrl;
> > stm32f4_gpio_get_ctrl(GPIOD, &ctrl);
> > 
> > // enable clocks for port D
> > rtems_gpio_initialize(ctrl);
> > 
> > // configure the pin
> > rtems_gpio_set_pin_mode(ctrl, &LED_PIN,
> > RTEMS_GPIO_PINMODE_OUTPUT_PP);
> > rtems_gpio_set_pull(ctrl, &LED_PIN, RTEMS_GPIO_PULLUP);
> > 
> > // output to LED
> > rtems_gpio_write(ctrl, &LED_PIN, RTEMS_GPIO_PIN_SET);
> > 
> > /*****************************************/
> > 
> > Best,
> > 
> > Duc Doan
> > _______________________________________________
> > devel mailing list
> > devel at rtems.org
> > http://lists.rtems.org/mailman/listinfo/devel
>