iio: adc: axp20x_adc: add support for AXP813 ADC

The X-Powers AXP813 PMIC is really close to what is already done for
AXP20X/AXP22X.

There are two pairs of bits to set the rate (one for Voltage and Current
measurements and one for TS/GPIO0 voltage measurements) instead of one.

The register to set the ADC rates is different from the one for
AXP20X/AXP22X.

GPIO0 can be used as an ADC (measuring Volts) unlike for AXP22X.

The scales to apply to the different inputs are unlike the ones from
AXP20X and AXP22X.
Signed-off-by: Quentin Schulz <quentin.schulz@free-electrons.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/axp20x_adc.c

@@ -35,8 +35,13 @@
 #define AXP20X_GPIO10_IN_RANGE_GPIO1_VAL(x)	(((x) & BIT(0)) << 1)
 
 #define AXP20X_ADC_RATE_MASK			GENMASK(7, 6)
+#define AXP813_V_I_ADC_RATE_MASK		GENMASK(5, 4)
+#define AXP813_ADC_RATE_MASK			(AXP20X_ADC_RATE_MASK | AXP813_V_I_ADC_RATE_MASK)
 #define AXP20X_ADC_RATE_HZ(x)			((ilog2((x) / 25) << 6) & AXP20X_ADC_RATE_MASK)
 #define AXP22X_ADC_RATE_HZ(x)			((ilog2((x) / 100) << 6) & AXP20X_ADC_RATE_MASK)
+#define AXP813_TS_GPIO0_ADC_RATE_HZ(x)		AXP20X_ADC_RATE_HZ(x)
+#define AXP813_V_I_ADC_RATE_HZ(x)		((ilog2((x) / 100) << 4) & AXP813_V_I_ADC_RATE_MASK)
+#define AXP813_ADC_RATE_HZ(x)			(AXP20X_ADC_RATE_HZ(x) | AXP813_V_I_ADC_RATE_HZ(x))
 
 #define AXP20X_ADC_CHANNEL(_channel, _name, _type, _reg)	\
 	{							\
@@ -95,6 +100,12 @@ enum axp22x_adc_channel_i {
 	AXP22X_BATT_DISCHRG_I,
 };
 
+enum axp813_adc_channel_v {
+	AXP813_TS_IN = 0,
+	AXP813_GPIO0_V,
+	AXP813_BATT_V,
+};
+
 static struct iio_map axp20x_maps[] = {
 	{
 		.consumer_dev_name = "axp20x-usb-power-supply",
@@ -197,6 +208,25 @@ static const struct iio_chan_spec axp22x_adc_channels[] = {
 			   AXP20X_BATT_DISCHRG_I_H),
 };
 
+static const struct iio_chan_spec axp813_adc_channels[] = {
+	{
+		.type = IIO_TEMP,
+		.address = AXP22X_PMIC_TEMP_H,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+				      BIT(IIO_CHAN_INFO_SCALE) |
+				      BIT(IIO_CHAN_INFO_OFFSET),
+		.datasheet_name = "pmic_temp",
+	},
+	AXP20X_ADC_CHANNEL(AXP813_GPIO0_V, "gpio0_v", IIO_VOLTAGE,
+			   AXP288_GP_ADC_H),
+	AXP20X_ADC_CHANNEL(AXP813_BATT_V, "batt_v", IIO_VOLTAGE,
+			   AXP20X_BATT_V_H),
+	AXP20X_ADC_CHANNEL(AXP22X_BATT_CHRG_I, "batt_chrg_i", IIO_CURRENT,
+			   AXP20X_BATT_CHRG_I_H),
+	AXP20X_ADC_CHANNEL(AXP22X_BATT_DISCHRG_I, "batt_dischrg_i", IIO_CURRENT,
+			   AXP20X_BATT_DISCHRG_I_H),
+};
+
 static int axp20x_adc_raw(struct iio_dev *indio_dev,
 			  struct iio_chan_spec const *chan, int *val)
 {
@@ -243,6 +273,18 @@ static int axp22x_adc_raw(struct iio_dev *indio_dev,
 	return IIO_VAL_INT;
 }
 
+static int axp813_adc_raw(struct iio_dev *indio_dev,
+			  struct iio_chan_spec const *chan, int *val)
+{
+	struct axp20x_adc_iio *info = iio_priv(indio_dev);
+
+	*val = axp20x_read_variable_width(info->regmap, chan->address, 12);
+	if (*val < 0)
+		return *val;
+
+	return IIO_VAL_INT;
+}
+
 static int axp20x_adc_scale_voltage(int channel, int *val, int *val2)
 {
 	switch (channel) {
@@ -273,6 +315,24 @@ static int axp20x_adc_scale_voltage(int channel, int *val, int *val2)
 	}
 }
 
+static int axp813_adc_scale_voltage(int channel, int *val, int *val2)
+{
+	switch (channel) {
+	case AXP813_GPIO0_V:
+		*val = 0;
+		*val2 = 800000;
+		return IIO_VAL_INT_PLUS_MICRO;
+
+	case AXP813_BATT_V:
+		*val = 1;
+		*val2 = 100000;
+		return IIO_VAL_INT_PLUS_MICRO;
+
+	default:
+		return -EINVAL;
+	}
+}
+
 static int axp20x_adc_scale_current(int channel, int *val, int *val2)
 {
 	switch (channel) {
@@ -342,6 +402,26 @@ static int axp22x_adc_scale(struct iio_chan_spec const *chan, int *val,
 	}
 }
 
+static int axp813_adc_scale(struct iio_chan_spec const *chan, int *val,
+			    int *val2)
+{
+	switch (chan->type) {
+	case IIO_VOLTAGE:
+		return axp813_adc_scale_voltage(chan->channel, val, val2);
+
+	case IIO_CURRENT:
+		*val = 1;
+		return IIO_VAL_INT;
+
+	case IIO_TEMP:
+		*val = 100;
+		return IIO_VAL_INT;
+
+	default:
+		return -EINVAL;
+	}
+}
+
 static int axp20x_adc_offset_voltage(struct iio_dev *indio_dev, int channel,
 				     int *val)
 {
@@ -425,6 +505,26 @@ static int axp22x_read_raw(struct iio_dev *indio_dev,
 	}
 }
 
+static int axp813_read_raw(struct iio_dev *indio_dev,
+			   struct iio_chan_spec const *chan, int *val,
+			   int *val2, long mask)
+{
+	switch (mask) {
+	case IIO_CHAN_INFO_OFFSET:
+		*val = -2667;
+		return IIO_VAL_INT;
+
+	case IIO_CHAN_INFO_SCALE:
+		return axp813_adc_scale(chan, val, val2);
+
+	case IIO_CHAN_INFO_RAW:
+		return axp813_adc_raw(indio_dev, chan, val);
+
+	default:
+		return -EINVAL;
+	}
+}
+
 static int axp20x_write_raw(struct iio_dev *indio_dev,
 			    struct iio_chan_spec const *chan, int val, int val2,
 			    long mask)
@@ -470,6 +570,10 @@ static const struct iio_info axp22x_adc_iio_info = {
 	.read_raw = axp22x_read_raw,
 };
 
+static const struct iio_info axp813_adc_iio_info = {
+	.read_raw = axp813_read_raw,
+};
+
 static int axp20x_adc_rate(struct axp20x_adc_iio *info, int rate)
 {
 	return regmap_update_bits(info->regmap, AXP20X_ADC_RATE,
@@ -484,6 +588,13 @@ static int axp22x_adc_rate(struct axp20x_adc_iio *info, int rate)
 				  AXP22X_ADC_RATE_HZ(rate));
 }
 
+static int axp813_adc_rate(struct axp20x_adc_iio *info, int rate)
+{
+	return regmap_update_bits(info->regmap, AXP813_ADC_RATE,
+				 AXP813_ADC_RATE_MASK,
+				 AXP813_ADC_RATE_HZ(rate));
+}
+
 struct axp_data {
 	const struct iio_info		*iio_info;
 	int				num_channels;
@@ -515,9 +626,20 @@ static const struct axp_data axp22x_data = {
 	.maps = axp22x_maps,
 };
 
+static const struct axp_data axp813_data = {
+	.iio_info = &axp813_adc_iio_info,
+	.num_channels = ARRAY_SIZE(axp813_adc_channels),
+	.channels = axp813_adc_channels,
+	.adc_en1_mask = AXP22X_ADC_EN1_MASK,
+	.adc_rate = axp813_adc_rate,
+	.adc_en2 = false,
+	.maps = axp22x_maps,
+};
+
 static const struct of_device_id axp20x_adc_of_match[] = {
 	{ .compatible = "x-powers,axp209-adc", .data = (void *)&axp20x_data, },
 	{ .compatible = "x-powers,axp221-adc", .data = (void *)&axp22x_data, },
+	{ .compatible = "x-powers,axp813-adc", .data = (void *)&axp813_data, },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, axp20x_adc_of_match);
@@ -525,6 +647,7 @@ MODULE_DEVICE_TABLE(of, axp20x_adc_of_match);
 static const struct platform_device_id axp20x_adc_id_match[] = {
 	{ .name = "axp20x-adc", .driver_data = (kernel_ulong_t)&axp20x_data, },
 	{ .name = "axp22x-adc", .driver_data = (kernel_ulong_t)&axp22x_data, },
+	{ .name = "axp813-adc", .driver_data = (kernel_ulong_t)&axp813_data, },
 	{ /* sentinel */ },
 };
 MODULE_DEVICE_TABLE(platform, axp20x_adc_id_match);

include/linux/mfd/axp20x.h

@@ -266,6 +266,8 @@ enum axp20x_variants {
 #define AXP288_RT_BATT_V_H		0xa0
 #define AXP288_RT_BATT_V_L		0xa1
 
+#define AXP813_ADC_RATE			0x85
+
 /* Fuel Gauge */
 #define AXP288_FG_RDC1_REG          0xba
 #define AXP288_FG_RDC0_REG          0xbb