iio: adc: stm32: Enable use of stm32 timer triggers

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@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 69e6cc4b40bffa91fdd64cb517b5086d7b57179a..210fa116842bad7718740e974cf5c5dbb20b04b5 100644 (file)
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -500,6 +500,8 @@ 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 1e382b6c142443edb2b84d711a9414fb77f57dab..87d984ba4ef2547b12811880109607af38688834 100644 (file)
--- 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 @@ static const struct stm32_adc_regs stm32f4_sq[STM32_ADC_MAX_SQ + 1] = {
        { 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;
 }