| Message ID | 1477412722-24061-5-git-send-email-fabrice.gasnier@st.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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@st.com> > --- > 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 */ > }; > >
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 */ + 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 */ };
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@st.com> --- drivers/iio/adc/stm32/stm32-adc.c | 45 +++++++++++++++++++++++++++++++++++++++ drivers/iio/adc/stm32/stm32-adc.h | 3 +++ 2 files changed, 48 insertions(+)