[PATCH v2 2/3] iio: adc: stm32: remove const channel names definition

[Fabrice Gasnier]

Remove const array that defines channels. Build channels definition
at probe time, when initializing channels (only for requested ones).
This will ease adding differential channels support.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@xxxxxx>
---
Changes in v2:
- Improve val variable names in stm32_adc_chan_init_one()
  definition as suggested by Jonathan.
---
 drivers/iio/adc/stm32-adc.c | 66 ++++++++++-----------------------------------
 1 file changed, 14 insertions(+), 52 deletions(-)

diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c
index 4df32cf..417a894 100644
--- a/drivers/iio/adc/stm32-adc.c
+++ b/drivers/iio/adc/stm32-adc.c
@@ -153,6 +153,8 @@ enum stm32h7_adc_dmngt {
 /* BOOST bit must be set on STM32H7 when ADC clock is above 20MHz */
 #define STM32H7_BOOST_CLKRATE		20000000UL
 
+#define STM32_ADC_CH_MAX		20	/* max number of channels */
+#define STM32_ADC_CH_SZ			5	/* max channel name size */
 #define STM32_ADC_MAX_SQ		16	/* SQ1..SQ16 */
 #define STM32_ADC_MAX_SMP		7	/* SMPx range is [0..7] */
 #define STM32_ADC_TIMEOUT_US		100000
@@ -300,6 +302,7 @@ struct stm32_adc_cfg {
  * @pcsel		bitmask to preselect channels on some devices
  * @smpr_val:		sampling time settings (e.g. smpr1 / smpr2)
  * @cal:		optional calibration data on some devices
+ * @chan_name:		channel name array
  */
 struct stm32_adc {
 	struct stm32_adc_common	*common;
@@ -321,69 +324,28 @@ struct stm32_adc {
 	u32			pcsel;
 	u32			smpr_val[2];
 	struct stm32_adc_calib	cal;
-};
-
-/**
- * struct stm32_adc_chan_spec - specification of stm32 adc channel
- * @type:	IIO channel type
- * @channel:	channel number (single ended)
- * @name:	channel name (single ended)
- */
-struct stm32_adc_chan_spec {
-	enum iio_chan_type	type;
-	int			channel;
-	const char		*name;
+	char			chan_name[STM32_ADC_CH_MAX][STM32_ADC_CH_SZ];
 };
 
 /**
  * struct stm32_adc_info - stm32 ADC, per instance config data
- * @channels:		Reference to stm32 channels spec
  * @max_channels:	Number of channels
  * @resolutions:	available resolutions
  * @num_res:		number of available resolutions
  */
 struct stm32_adc_info {
-	const struct stm32_adc_chan_spec *channels;
 	int max_channels;
 	const unsigned int *resolutions;
 	const unsigned int num_res;
 };
 
-/*
- * Input definitions common for all instances:
- * stm32f4 can have up to 16 channels
- * stm32h7 can have up to 20 channels
- */
-static const struct stm32_adc_chan_spec stm32_adc_channels[] = {
-	{ IIO_VOLTAGE, 0, "in0" },
-	{ IIO_VOLTAGE, 1, "in1" },
-	{ IIO_VOLTAGE, 2, "in2" },
-	{ IIO_VOLTAGE, 3, "in3" },
-	{ IIO_VOLTAGE, 4, "in4" },
-	{ IIO_VOLTAGE, 5, "in5" },
-	{ IIO_VOLTAGE, 6, "in6" },
-	{ IIO_VOLTAGE, 7, "in7" },
-	{ IIO_VOLTAGE, 8, "in8" },
-	{ IIO_VOLTAGE, 9, "in9" },
-	{ IIO_VOLTAGE, 10, "in10" },
-	{ IIO_VOLTAGE, 11, "in11" },
-	{ IIO_VOLTAGE, 12, "in12" },
-	{ IIO_VOLTAGE, 13, "in13" },
-	{ IIO_VOLTAGE, 14, "in14" },
-	{ IIO_VOLTAGE, 15, "in15" },
-	{ IIO_VOLTAGE, 16, "in16" },
-	{ IIO_VOLTAGE, 17, "in17" },
-	{ IIO_VOLTAGE, 18, "in18" },
-	{ IIO_VOLTAGE, 19, "in19" },
-};
-
 static const unsigned int stm32f4_adc_resolutions[] = {
 	/* sorted values so the index matches RES[1:0] in STM32F4_ADC_CR1 */
 	12, 10, 8, 6,
 };
 
+/* stm32f4 can have up to 16 channels */
 static const struct stm32_adc_info stm32f4_adc_info = {
-	.channels = stm32_adc_channels,
 	.max_channels = 16,
 	.resolutions = stm32f4_adc_resolutions,
 	.num_res = ARRAY_SIZE(stm32f4_adc_resolutions),
@@ -394,9 +356,9 @@ struct stm32_adc_info {
 	16, 14, 12, 10, 8,
 };
 
+/* stm32h7 can have up to 20 channels */
 static const struct stm32_adc_info stm32h7_adc_info = {
-	.channels = stm32_adc_channels,
-	.max_channels = 20,
+	.max_channels = STM32_ADC_CH_MAX,
 	.resolutions = stm32h7_adc_resolutions,
 	.num_res = ARRAY_SIZE(stm32h7_adc_resolutions),
 };
@@ -1628,15 +1590,16 @@ static void stm32_adc_smpr_init(struct stm32_adc *adc, int channel, u32 smp_ns)
 }
 
 static void stm32_adc_chan_init_one(struct iio_dev *indio_dev,
-				    struct iio_chan_spec *chan,
-				    const struct stm32_adc_chan_spec *channel,
+				    struct iio_chan_spec *chan, u32 vinp,
 				    int scan_index, u32 smp)
 {
 	struct stm32_adc *adc = iio_priv(indio_dev);
+	char *name = adc->chan_name[vinp];
 
-	chan->type = channel->type;
-	chan->channel = channel->channel;
-	chan->datasheet_name = channel->name;
+	chan->type = IIO_VOLTAGE;
+	chan->channel = vinp;
+	snprintf(name, STM32_ADC_CH_SZ, "in%d", vinp);
+	chan->datasheet_name = name;
 	chan->scan_index = scan_index;
 	chan->indexed = 1;
 	chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
@@ -1699,8 +1662,7 @@ static int stm32_adc_chan_of_init(struct iio_dev *indio_dev)
 					   scan_index, &smp);
 
 		stm32_adc_chan_init_one(indio_dev, &channels[scan_index],
-					&adc_info->channels[val],
-					scan_index, smp);
+					val, scan_index, smp);
 		scan_index++;
 	}
 
-- 
1.9.1