Commit 3a06b284 authored by George Stark's avatar George Stark Committed by Jonathan Cameron
Browse files

iio: adc: meson: support reading from channel 7 mux inputs 



Add IIO channel for all muxed inputs of channel 7.
Meson saradc channel 7 is connected to a mux that can switch input
to well-known sources like Vdd, GND and several Vdd dividers.

Signed-off-by: default avatarGeorge Stark <GNStark@sberdevices.ru>
Reviewed-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230714114010.293440-7-gnstark@sberdevices.ru


Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent b593ce5d

drivers/iio/adc/meson_saradc.c

+75 −2
Original line number Diff line number Diff line
@@ -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;