On 25/10/16 17:25, Fabrice Gasnier wrote:
> STM32 ADC may use EXTi signals routed internally as trigger source
> for conversions. Configure them as interrupt to configure this path
> in HW to adc.
> Note: interrupt handler isn't required here, and corresponding interrupt
> can be kept masked at exti controller level.
>
> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@xxxxxx>
> ---
> drivers/iio/adc/stm32/stm32-adc.c | 45 +++++++++++++++++++++++++++++++++++++++
> drivers/iio/adc/stm32/stm32-adc.h | 3 +++
> 2 files changed, 48 insertions(+)
>
> diff --git a/drivers/iio/adc/stm32/stm32-adc.c b/drivers/iio/adc/stm32/stm32-adc.c
> index 25d0307..1a13450 100644
> --- a/drivers/iio/adc/stm32/stm32-adc.c
> +++ b/drivers/iio/adc/stm32/stm32-adc.c
> @@ -482,6 +482,12 @@ static irqreturn_t stm32_adc_common_isr(int irq, void *data)
> return ret;
> }
>
> +static irqreturn_t stm32_adc_exti_handler(int irq, void *data)
> +{
> + /* Exti handler should not be invoqued, and is not used */
invoked.
> + return IRQ_HANDLED;
> +}
> +
> /**
> * stm32_adc_validate_trigger() - validate trigger for stm32 adc
> * @indio_dev: IIO device
> @@ -1051,6 +1057,41 @@ static void stm32_adc_unregister(struct stm32_adc *adc)
> }
> }
>
> +static int stm32_adc_exti_probe(struct stm32_adc_common *common)
> +{
> + int i, irq, ret;
> +
> + common->gpios = devm_gpiod_get_array_optional(common->dev, NULL,
> + GPIOD_IN);
> + if (!common->gpios)
> + return 0;
> +
> + for (i = 0; i < common->gpios->ndescs; i++) {
> + irq = gpiod_to_irq(common->gpios->desc[i]);
> + if (irq < 0) {
> + dev_err(common->dev, "gpio %d to irq failed\n", i);
> + return irq;
> + }
> +
> + ret = devm_request_irq(common->dev, irq, stm32_adc_exti_handler,
> + 0, dev_name(common->dev), common);
> + if (ret) {
> + dev_err(common->dev, "request IRQ %d failed\n", irq);
> + return ret;
> + }
> +
> + /*
> + * gpios are configured as interrupts, so exti trigger path is
> + * configured in HW. But getting interrupts when starting
> + * conversions is unused here, so mask it in on exti
> + * controller by default.
> + */
> + disable_irq(irq);
> + }
> +
> + return 0;
> +}
> +
> int stm32_adc_probe(struct platform_device *pdev)
> {
> struct device_node *np = pdev->dev.of_node, *child;
> @@ -1131,6 +1172,10 @@ int stm32_adc_probe(struct platform_device *pdev)
> goto err_clk_disable;
> }
>
> + ret = stm32_adc_exti_probe(common);
> + if (ret)
> + goto err_clk_disable;
> +
> /* Parse adc child nodes to retrieve master/slave instances data */
> for_each_available_child_of_node(np, child) {
> ret = stm32_adc_register(common, child);
> diff --git a/drivers/iio/adc/stm32/stm32-adc.h b/drivers/iio/adc/stm32/stm32-adc.h
> index 01a0dda..fe3568b 100644
> --- a/drivers/iio/adc/stm32/stm32-adc.h
> +++ b/drivers/iio/adc/stm32/stm32-adc.h
> @@ -23,6 +23,7 @@
> #define __STM32_ADC_H
>
> #include <linux/dmaengine.h>
> +#include <linux/gpio/consumer.h>
> #include <linux/irq_work.h>
>
> /*
> @@ -323,6 +324,7 @@ struct stm32_adc {
> * @aclk: common clock for the analog circuitry
> * @vref: regulator reference
> * @vref_mv: vref voltage (mv)
> + * @gpio_descs: gpio descriptor used to configure EXTi triggers
> * @lock: mutex
> */
> struct stm32_adc_common {
> @@ -335,6 +337,7 @@ struct stm32_adc_common {
> struct clk *aclk;
> struct regulator *vref;
> int vref_mv;
> + struct gpio_descs *gpios;
> struct mutex lock; /* read_raw lock */
> };
>
>
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