[RFC PATCH 3/7] iio: adc: axp20x-adc: add support for AXP803

From: Icenowy Zheng
Date: Wed Sep 20 2017 - 11:19:06 EST


AXP803 SoC features an ADC part including these channels: GPADC (GPIO0)
and TS pins, PMIC internal temperature sensor, battery voltage, battery
charge/discharge current.

Add support for the battery-related channels and internal temperature
channel in order to allow battery monitoring. The TS and GPADC channels
are complex and will be support after more investigation.

Signed-off-by: Icenowy Zheng <icenowy@xxxxxxx>
---
drivers/iio/adc/axp20x_adc.c | 108 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 108 insertions(+)

diff --git a/drivers/iio/adc/axp20x_adc.c b/drivers/iio/adc/axp20x_adc.c
index 93dd6b80059e..4f0cd98cf6ea 100644
--- a/drivers/iio/adc/axp20x_adc.c
+++ b/drivers/iio/adc/axp20x_adc.c
@@ -28,6 +28,8 @@

#define AXP20X_ADC_EN2_MASK (GENMASK(3, 2) | BIT(7))
#define AXP22X_ADC_EN1_MASK (GENMASK(7, 5) | BIT(0))
+/* TODO: Enable TS and GPADC when supporting them */
+#define AXP803_ADC_EN1_MASK GENMASK(7, 5)

#define AXP20X_GPIO10_IN_RANGE_GPIO0 BIT(0)
#define AXP20X_GPIO10_IN_RANGE_GPIO1 BIT(1)
@@ -95,6 +97,17 @@ enum axp22x_adc_channel_i {
AXP22X_BATT_DISCHRG_I,
};

+enum axp803_adc_channel_v {
+ AXP803_TS_IN = 0,
+ AXP803_GPADC_IN,
+ AXP803_BATT_V,
+};
+
+enum axp803_adc_channel_i {
+ AXP803_BATT_CHRG_I = 2,
+ AXP803_BATT_DISCHRG_I,
+};
+
static struct iio_map axp20x_maps[] = {
{
.consumer_dev_name = "axp20x-usb-power-supply",
@@ -144,6 +157,11 @@ static struct iio_map axp22x_maps[] = {
};

/*
+ * AXP803 shares the same consumer map with AXP22x, as it has no ADC for
+ * VBUS and ACIN inputs either.
+ */
+
+/*
* Channels are mapped by physical system. Their channels share the same index.
* i.e. acin_i is in_current0_raw and acin_v is in_voltage0_raw.
* The only exception is for the battery. batt_v will be in_voltage6_raw and
@@ -197,6 +215,23 @@ static const struct iio_chan_spec axp22x_adc_channels[] = {
AXP20X_BATT_DISCHRG_I_H),
};

+static const struct iio_chan_spec axp803_adc_channels[] = {
+ {
+ .type = IIO_TEMP,
+ .address = AXP288_PMIC_ADC_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(AXP803_BATT_V, "batt_v", IIO_VOLTAGE,
+ AXP20X_BATT_V_H),
+ AXP20X_ADC_CHANNEL(AXP803_BATT_CHRG_I, "batt_chrg_i", IIO_CURRENT,
+ AXP20X_BATT_CHRG_I_H),
+ AXP20X_ADC_CHANNEL(AXP803_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 +278,19 @@ static int axp22x_adc_raw(struct iio_dev *indio_dev,
return IIO_VAL_INT;
}

+static int axp803_adc_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int *val)
+{
+ struct axp20x_adc_iio *info = iio_priv(indio_dev);
+
+ /* All channels on AXP803 are stored on 12 bits. */
+ *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) {
@@ -342,6 +390,31 @@ static int axp22x_adc_scale(struct iio_chan_spec const *chan, int *val,
}
}

+static int axp803_adc_scale(struct iio_chan_spec const *chan, int *val,
+ int *val2)
+{
+ switch (chan->type) {
+ case IIO_VOLTAGE:
+ if (chan->channel != AXP803_BATT_V)
+ return -EINVAL;
+
+ *val = 1;
+ *val2 = 100000;
+ return IIO_VAL_INT_PLUS_MICRO;
+
+ case IIO_CURRENT:
+ *val = 1;
+ return IIO_VAL_INT;
+
+ case IIO_TEMP:
+ *val = 106;
+ return IIO_VAL_INT;
+
+ default:
+ return -EINVAL;
+ }
+}
+
static int axp20x_adc_offset_voltage(struct iio_dev *indio_dev, int channel,
int *val)
{
@@ -425,6 +498,26 @@ static int axp22x_read_raw(struct iio_dev *indio_dev,
}
}

+static int axp803_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 = -2525;
+ return IIO_VAL_INT;
+
+ case IIO_CHAN_INFO_SCALE:
+ return axp803_adc_scale(chan, val, val2);
+
+ case IIO_CHAN_INFO_RAW:
+ return axp803_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)
@@ -472,6 +565,11 @@ static const struct iio_info axp22x_adc_iio_info = {
.driver_module = THIS_MODULE,
};

+static const struct iio_info axp803_adc_iio_info = {
+ .read_raw = axp803_read_raw,
+ .driver_module = THIS_MODULE,
+};
+
static int axp20x_adc_rate(int rate)
{
return AXP20X_ADC_RATE_HZ(rate);
@@ -512,9 +610,19 @@ static const struct axp_data axp22x_data = {
.maps = axp22x_maps,
};

+static const struct axp_data axp803_data = {
+ .iio_info = &axp803_adc_iio_info,
+ .num_channels = ARRAY_SIZE(axp803_adc_channels),
+ .channels = axp803_adc_channels,
+ .adc_en1_mask = AXP803_ADC_EN1_MASK,
+ .adc_en2 = false,
+ .maps = axp22x_maps,
+};
+
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 = "axp803-adc", .driver_data = (kernel_ulong_t)&axp803_data, },
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(platform, axp20x_adc_id_match);
--
2.13.5