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[v4,6/6] iio: adc: meson: support reading from channel 7 mux inputs

Message ID 20230707153322.114302-7-gnstark@sberdevices.ru (mailing list archive)
State Superseded
Headers show
Series iio: adc: meson: add iio channels to read channel 7 mux inputs | expand

Commit Message

George Stark July 7, 2023, 3:27 p.m. UTC
Add iio channel for every channel 7 mux input.
Meson saradc channel 7 is connected to a mux that can switch channel
input to well-known sources like Vdd, GND and several Vdd dividers.

Signed-off-by: George Stark <GNStark@sberdevices.ru>
---
 drivers/iio/adc/meson_saradc.c | 77 +++++++++++++++++++++++++++++++++-
 1 file changed, 75 insertions(+), 2 deletions(-)

Comments

Andy Shevchenko July 10, 2023, 9:32 a.m. UTC | #1
On Fri, Jul 07, 2023 at 06:27:43PM +0300, George Stark wrote:
> Add iio channel for every channel 7 mux input.

IIO

"...for each muxed input of the channel 7."

> Meson saradc channel 7 is connected to a mux that can switch channel
> input to well-known sources like Vdd, GND and several Vdd dividers.

Make this sentence to be the first in the commit message.

"can switch input" (again, avoid tautology).
diff mbox series

Patch

diff --git a/drivers/iio/adc/meson_saradc.c b/drivers/iio/adc/meson_saradc.c
index 918bd5da3605..2411cc864ccd 100644
--- a/drivers/iio/adc/meson_saradc.c
+++ b/drivers/iio/adc/meson_saradc.c
@@ -163,6 +163,7 @@ 
 #define MESON_SAR_ADC_MAX_FIFO_SIZE				32
 #define MESON_SAR_ADC_TIMEOUT					100 /* ms */
 #define MESON_SAR_ADC_VOLTAGE_AND_TEMP_CHANNEL			6
+#define MESON_SAR_ADC_VOLTAGE_AND_MUX_CHANNEL			7
 #define MESON_SAR_ADC_TEMP_OFFSET				27
 
 /* temperature sensor calibration information in eFuse */
@@ -202,6 +203,19 @@ 
 	.datasheet_name = "TEMP_SENSOR",				\
 }
 
+#define MESON_SAR_ADC_MUX(_chan, _sel) {				\
+	.type = IIO_VOLTAGE,						\
+	.channel = _chan,						\
+	.indexed = 1,							\
+	.address = MESON_SAR_ADC_VOLTAGE_AND_MUX_CHANNEL,		\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |			\
+				BIT(IIO_CHAN_INFO_AVERAGE_RAW),		\
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),		\
+	.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_CALIBBIAS) |	\
+				BIT(IIO_CHAN_INFO_CALIBSCALE),		\
+	.datasheet_name = "SAR_ADC_MUX_"#_sel,				\
+}
+
 enum meson_sar_adc_avg_mode {
 	NO_AVERAGING = 0x0,
 	MEAN_AVERAGING = 0x1,
@@ -234,6 +248,27 @@  enum meson_sar_adc_channel_index {
 	NUM_CHAN_6,
 	NUM_CHAN_7,
 	NUM_CHAN_TEMP,
+	NUM_MUX_0_VSS,
+	NUM_MUX_1_VDD_DIV4,
+	NUM_MUX_2_VDD_DIV2,
+	NUM_MUX_3_VDD_MUL3_DIV4,
+	NUM_MUX_4_VDD,
+};
+
+static enum meson_sar_adc_chan7_mux_sel chan7_mux_values[] = {
+	CHAN7_MUX_VSS,
+	CHAN7_MUX_VDD_DIV4,
+	CHAN7_MUX_VDD_DIV2,
+	CHAN7_MUX_VDD_MUL3_DIV4,
+	CHAN7_MUX_VDD,
+};
+
+static const char * const chan7_mux_names[] = {
+	[CHAN7_MUX_VSS] = "gnd",
+	[CHAN7_MUX_VDD_DIV4] = "0.25vdd",
+	[CHAN7_MUX_VDD_DIV2] = "0.5vdd",
+	[CHAN7_MUX_VDD_MUL3_DIV4] = "0.75vdd",
+	[CHAN7_MUX_VDD] = "vdd",
 };
 
 static const struct iio_chan_spec meson_sar_adc_iio_channels[] = {
@@ -245,6 +280,11 @@  static const struct iio_chan_spec meson_sar_adc_iio_channels[] = {
 	MESON_SAR_ADC_CHAN(NUM_CHAN_5),
 	MESON_SAR_ADC_CHAN(NUM_CHAN_6),
 	MESON_SAR_ADC_CHAN(NUM_CHAN_7),
+	MESON_SAR_ADC_MUX(NUM_MUX_0_VSS, 0),
+	MESON_SAR_ADC_MUX(NUM_MUX_1_VDD_DIV4, 1),
+	MESON_SAR_ADC_MUX(NUM_MUX_2_VDD_DIV2, 2),
+	MESON_SAR_ADC_MUX(NUM_MUX_3_VDD_MUL3_DIV4, 3),
+	MESON_SAR_ADC_MUX(NUM_MUX_4_VDD, 4),
 };
 
 static const struct iio_chan_spec meson_sar_adc_and_temp_iio_channels[] = {
@@ -257,6 +297,11 @@  static const struct iio_chan_spec meson_sar_adc_and_temp_iio_channels[] = {
 	MESON_SAR_ADC_CHAN(NUM_CHAN_6),
 	MESON_SAR_ADC_CHAN(NUM_CHAN_7),
 	MESON_SAR_ADC_TEMP_CHAN(NUM_CHAN_TEMP),
+	MESON_SAR_ADC_MUX(NUM_MUX_0_VSS, 0),
+	MESON_SAR_ADC_MUX(NUM_MUX_1_VDD_DIV4, 1),
+	MESON_SAR_ADC_MUX(NUM_MUX_2_VDD_DIV2, 2),
+	MESON_SAR_ADC_MUX(NUM_MUX_3_VDD_MUL3_DIV4, 3),
+	MESON_SAR_ADC_MUX(NUM_MUX_4_VDD, 4),
 };
 
 struct meson_sar_adc_param {
@@ -295,6 +340,7 @@  struct meson_sar_adc_priv {
 	bool					temperature_sensor_calibrated;
 	u8					temperature_sensor_coefficient;
 	u16					temperature_sensor_adc_val;
+	enum meson_sar_adc_chan7_mux_sel	chan7_mux_sel;
 };
 
 static const struct regmap_config meson_sar_adc_regmap_config_gxbb = {
@@ -311,6 +357,17 @@  static const struct regmap_config meson_sar_adc_regmap_config_meson8 = {
 	.max_register = MESON_SAR_ADC_DELTA_10,
 };
 
+static const struct iio_chan_spec *
+find_channel_by_num(struct iio_dev *indio_dev, int num)
+{
+	int i;
+
+	for (i = 0; i < indio_dev->num_channels; i++)
+		if (indio_dev->channels[i].channel == num)
+			return &indio_dev->channels[i];
+	return NULL;
+}
+
 static unsigned int meson_sar_adc_get_fifo_count(struct iio_dev *indio_dev)
 {
 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
@@ -359,6 +416,8 @@  static void meson_sar_adc_set_chan7_mux(struct iio_dev *indio_dev,
 			   MESON_SAR_ADC_REG3_CTRL_CHAN7_MUX_SEL_MASK, regval);
 
 	usleep_range(10, 20);
+
+	priv->chan7_mux_sel = sel;
 }
 
 static int meson_sar_adc_read_raw_sample(struct iio_dev *indio_dev,
@@ -454,6 +513,15 @@  static void meson_sar_adc_enable_channel(struct iio_dev *indio_dev,
 		regmap_update_bits(priv->regmap,
 				   MESON_SAR_ADC_DELTA_10,
 				   MESON_SAR_ADC_DELTA_10_TEMP_SEL, regval);
+	} else if (chan->address == MESON_SAR_ADC_VOLTAGE_AND_MUX_CHANNEL) {
+		enum meson_sar_adc_chan7_mux_sel sel;
+
+		if (chan->channel == NUM_CHAN_7)
+			sel = CHAN7_MUX_CH7_INPUT;
+		else
+			sel = chan7_mux_values[chan->channel - NUM_MUX_0_VSS];
+		if (sel != priv->chan7_mux_sel)
+			meson_sar_adc_set_chan7_mux(indio_dev, sel);
 	}
 }
 
@@ -1026,7 +1094,8 @@  static int meson_sar_adc_calib(struct iio_dev *indio_dev)
 	meson_sar_adc_set_chan7_mux(indio_dev, CHAN7_MUX_VDD_DIV4);
 	usleep_range(10, 20);
 	ret = meson_sar_adc_get_sample(indio_dev,
-				       &indio_dev->channels[7],
+				       find_channel_by_num(indio_dev,
+							   NUM_MUX_1_VDD_DIV4),
 				       MEAN_AVERAGING, EIGHT_SAMPLES, &value0);
 	if (ret < 0)
 		goto out;
@@ -1034,7 +1103,8 @@  static int meson_sar_adc_calib(struct iio_dev *indio_dev)
 	meson_sar_adc_set_chan7_mux(indio_dev, CHAN7_MUX_VDD_MUL3_DIV4);
 	usleep_range(10, 20);
 	ret = meson_sar_adc_get_sample(indio_dev,
-				       &indio_dev->channels[7],
+				       find_channel_by_num(indio_dev,
+							   NUM_MUX_3_VDD_MUL3_DIV4),
 				       MEAN_AVERAGING, EIGHT_SAMPLES, &value1);
 	if (ret < 0)
 		goto out;
@@ -1061,6 +1131,9 @@  static int read_label(struct iio_dev *indio_dev,
 {
 	if (chan->type == IIO_TEMP)
 		return sprintf(label, "temp-sensor\n");
+	if (chan->type == IIO_VOLTAGE && chan->channel >= NUM_MUX_0_VSS)
+		return sprintf(label, "%s\n",
+			       chan7_mux_names[chan->channel - NUM_MUX_0_VSS]);
 	if (chan->type == IIO_VOLTAGE)
 		return sprintf(label, "channel-%d\n", chan->channel);
 	return 0;