STM32 ADC has external timer trigger sources. Use stm32 timer triggers
API (e.g. is_stm32_timer_trigger()) with local ADC lookup table to
validate a trigger can be used.
This also provides correct trigger selection value (e.g. extsel).
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@xxxxxx>
---
Changes in v2:
- Add comment on dual check to validate trigger (and get extsel)
---
drivers/iio/adc/Kconfig | 2 ++
drivers/iio/adc/stm32-adc.c | 65 +++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 67 insertions(+)
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 33341f4..9a7b090 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -447,6 +447,8 @@ config STM32_ADC_CORE
depends on OF
depends on REGULATOR
select IIO_BUFFER
+ select MFD_STM32_TIMERS
+ select IIO_STM32_TIMER_TRIGGER
select IIO_TRIGGERED_BUFFER
help
Select this option to enable the core driver for STMicroelectronics
diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c
index 1e382b6..87d984b 100644
--- a/drivers/iio/adc/stm32-adc.c
+++ b/drivers/iio/adc/stm32-adc.c
@@ -23,6 +23,7 @@
#include <linux/delay.h>
#include <linux/iio/iio.h>
#include <linux/iio/buffer.h>
+#include <linux/iio/timer/stm32-timer-trigger.h>
#include <linux/iio/trigger.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
@@ -81,6 +82,36 @@ enum stm32_adc_exten {
STM32_EXTEN_HWTRIG_BOTH_EDGES,
};
+/* extsel - trigger mux selection value */
+enum stm32_adc_extsel {
+ STM32_EXT0,
+ STM32_EXT1,
+ STM32_EXT2,
+ STM32_EXT3,
+ STM32_EXT4,
+ STM32_EXT5,
+ STM32_EXT6,
+ STM32_EXT7,
+ STM32_EXT8,
+ STM32_EXT9,
+ STM32_EXT10,
+ STM32_EXT11,
+ STM32_EXT12,
+ STM32_EXT13,
+ STM32_EXT14,
+ STM32_EXT15,
+};
+
+/**
+ * struct stm32_adc_trig_info - ADC trigger info
+ * @name: name of the trigger, corresponding to its source
+ * @extsel: trigger selection
+ */
+struct stm32_adc_trig_info {
+ const char *name;
+ enum stm32_adc_extsel extsel;
+};
+
/**
* stm32_adc_regs - stm32 ADC misc registers & bitfield desc
* @reg: register offset
@@ -176,6 +207,26 @@ struct stm32_adc_chan_spec {
{ STM32F4_ADC_SQR1, GENMASK(19, 15), 15 },
};
+/* STM32F4 external trigger sources for all instances */
+static struct stm32_adc_trig_info stm32f4_adc_trigs[] = {
+ { TIM1_CH1, STM32_EXT0 },
+ { TIM1_CH2, STM32_EXT1 },
+ { TIM1_CH3, STM32_EXT2 },
+ { TIM2_CH2, STM32_EXT3 },
+ { TIM2_CH3, STM32_EXT4 },
+ { TIM2_CH4, STM32_EXT5 },
+ { TIM2_TRGO, STM32_EXT6 },
+ { TIM3_CH1, STM32_EXT7 },
+ { TIM3_TRGO, STM32_EXT8 },
+ { TIM4_CH4, STM32_EXT9 },
+ { TIM5_CH1, STM32_EXT10 },
+ { TIM5_CH2, STM32_EXT11 },
+ { TIM5_CH3, STM32_EXT12 },
+ { TIM8_CH1, STM32_EXT13 },
+ { TIM8_TRGO, STM32_EXT14 },
+ {}, /* sentinel */
+};
+
/**
* STM32 ADC registers access routines
* @adc: stm32 adc instance
@@ -318,6 +369,20 @@ static int stm32_adc_conf_scan_seq(struct iio_dev *indio_dev,
*/
static int stm32_adc_get_trig_extsel(struct iio_trigger *trig)
{
+ int i;
+
+ /* lookup triggers registered by stm32 timer trigger driver */
+ for (i = 0; stm32f4_adc_trigs[i].name; i++) {
+ /**
+ * Checking both stm32 timer trigger type and trig name
+ * should be safe against arbitrary trigger names.
+ */
+ if (is_stm32_timer_trigger(trig) &&
+ !strcmp(stm32f4_adc_trigs[i].name, trig->name)) {
+ return stm32f4_adc_trigs[i].extsel;
+ }
+ }
+
return -EINVAL;
}
--
1.9.1
--
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