[PATCH 03/22] iio: adc: add support for X-Powers AXP20X and AXP22X PMICs ADCs

[Quentin Schulz <quentin.schulz@free-electrons.com>]

The X-Powers AXP20X and AXP22X PMICs have multiple ADCs. They expose the
battery voltage, battery charge and discharge currents, AC-in and VBUS
voltages and currents, 2 GPIOs muxable in ADC mode and PMIC temperature.

This adds support for most of AXP20X and AXP22X ADCs.

Signed-off-by: Quentin Schulz <quentin.schulz@free-electrons.com>
---
 drivers/iio/adc/Kconfig      |  10 +
 drivers/iio/adc/Makefile     |   1 +
 drivers/iio/adc/axp20x_adc.c | 490 +++++++++++++++++++++++++++++++++++++++++++
 include/linux/mfd/axp20x.h   |   4 +
 4 files changed, 505 insertions(+)
 create mode 100644 drivers/iio/adc/axp20x_adc.c

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 38bc319..5c5b51f 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -154,6 +154,16 @@ config AT91_SAMA5D2_ADC
 	  To compile this driver as a module, choose M here: the module will be
 	  called at91-sama5d2_adc.
 
+config AXP20X_ADC
+	tristate "X-Powers AXP20X and AXP22X ADC driver"
+	depends on MFD_AXP20X
+	help
+	  Say yes here to have support for X-Powers power management IC (PMIC)
+	  AXP20X and AXP22X ADC devices.
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called axp20x_adc.
+
 config AXP288_ADC
 	tristate "X-Powers AXP288 ADC driver"
 	depends on MFD_AXP20X
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index d36c4be..f5c28a5 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -16,6 +16,7 @@ obj-$(CONFIG_AD7887) += ad7887.o
 obj-$(CONFIG_AD799X) += ad799x.o
 obj-$(CONFIG_AT91_ADC) += at91_adc.o
 obj-$(CONFIG_AT91_SAMA5D2_ADC) += at91-sama5d2_adc.o
+obj-$(CONFIG_AXP20X_ADC) += axp20x_adc.o
 obj-$(CONFIG_AXP288_ADC) += axp288_adc.o
 obj-$(CONFIG_BCM_IPROC_ADC) += bcm_iproc_adc.o
 obj-$(CONFIG_BERLIN2_ADC) += berlin2-adc.o
diff --git a/drivers/iio/adc/axp20x_adc.c b/drivers/iio/adc/axp20x_adc.c
new file mode 100644
index 0000000..8df972a
--- /dev/null
+++ b/drivers/iio/adc/axp20x_adc.c
@@ -0,0 +1,490 @@
+/* ADC driver for AXP20X and AXP22X PMICs
+ *
+ * Copyright (c) 2016 Free Electrons NextThing Co.
+ *	Quentin Schulz <quentin.schulz@free-electrons.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License version 2 as published by the
+ * Free Software Foundation.
+ *
+ */
+
+#include <linux/completion.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <linux/thermal.h>
+
+#include <linux/iio/iio.h>
+#include <linux/mfd/axp20x.h>
+
+#define AXP20X_ADC_EN1_MASK			GENMASK(7, 0)
+
+#define AXP20X_ADC_EN2_MASK			(GENMASK(3, 2) | BIT(7))
+#define AXP22X_ADC_EN1_MASK			(GENMASK(7, 5) | BIT(0))
+#define AXP20X_ADC_EN2_TEMP_ADC			BIT(7)
+#define AXP20X_ADC_EN2_GPIO0_ADC		BIT(3)
+#define AXP20X_ADC_EN2_GPIO1_ADC		BIT(2)
+
+#define AXP20X_GPIO10_IN_RANGE_GPIO0		BIT(0)
+#define AXP20X_GPIO10_IN_RANGE_GPIO1		BIT(1)
+#define AXP20X_GPIO10_IN_RANGE_GPIO0_VAL(x)	((x) & BIT(0))
+#define AXP20X_GPIO10_IN_RANGE_GPIO1_VAL(x)	(((x) & BIT(0)) << 1)
+
+#define AXP20X_ADC_RATE_MASK			(3 << 6)
+#define AXP20X_ADC_RATE_25HZ			(0 << 6)
+#define AXP20X_ADC_RATE_50HZ			BIT(6)
+#define AXP20X_ADC_RATE_100HZ			(2 << 6)
+#define AXP20X_ADC_RATE_200HZ			(3 << 6)
+
+#define AXP22X_ADC_RATE_100HZ			(0 << 6)
+#define AXP22X_ADC_RATE_200HZ			BIT(6)
+#define AXP22X_ADC_RATE_400HZ			(2 << 6)
+#define AXP22X_ADC_RATE_800HZ			(3 << 6)
+
+#define AXP20X_ADC_CHANNEL(_channel, _name, _type, _reg)	\
+	{							\
+		.type = _type,					\
+		.indexed = 1,					\
+		.channel = _channel,				\
+		.address = _reg,				\
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |	\
+				      BIT(IIO_CHAN_INFO_SCALE),	\
+		.datasheet_name = _name,			\
+	}
+
+#define AXP20X_ADC_CHANNEL_OFFSET(_channel, _name, _type, _reg) \
+	{							\
+		.type = _type,					\
+		.indexed = 1,					\
+		.channel = _channel,				\
+		.address = _reg,				\
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |	\
+				      BIT(IIO_CHAN_INFO_SCALE) |\
+				      BIT(IIO_CHAN_INFO_OFFSET),\
+		.datasheet_name = _name,			\
+	}
+
+struct axp20x_adc_iio {
+	struct iio_dev		*indio_dev;
+	struct regmap		*regmap;
+};
+
+enum axp20x_adc_channel {
+	AXP20X_ACIN_V = 0,
+	AXP20X_ACIN_I,
+	AXP20X_VBUS_V,
+	AXP20X_VBUS_I,
+	AXP20X_TEMP_ADC,
+	AXP20X_GPIO0_V,
+	AXP20X_GPIO1_V,
+	AXP20X_BATT_V,
+	AXP20X_BATT_CHRG_I,
+	AXP20X_BATT_DISCHRG_I,
+	AXP20X_IPSOUT_V,
+};
+
+enum axp22x_adc_channel {
+	AXP22X_TEMP_ADC = 0,
+	AXP22X_BATT_V,
+	AXP22X_BATT_CHRG_I,
+	AXP22X_BATT_DISCHRG_I,
+};
+
+static const struct iio_chan_spec axp20x_adc_channels[] = {
+	AXP20X_ADC_CHANNEL(AXP20X_ACIN_V, "acin_v", IIO_VOLTAGE,
+			   AXP20X_ACIN_V_ADC_H),
+	AXP20X_ADC_CHANNEL(AXP20X_ACIN_I, "acin_i", IIO_CURRENT,
+			   AXP20X_ACIN_I_ADC_H),
+	AXP20X_ADC_CHANNEL(AXP20X_VBUS_V, "vbus_v", IIO_VOLTAGE,
+			   AXP20X_VBUS_V_ADC_H),
+	AXP20X_ADC_CHANNEL(AXP20X_VBUS_I, "vbus_i", IIO_CURRENT,
+			   AXP20X_VBUS_I_ADC_H),
+	AXP20X_ADC_CHANNEL_OFFSET(AXP20X_TEMP_ADC, "temp_adc", IIO_TEMP,
+				  AXP20X_TEMP_ADC_H),
+	AXP20X_ADC_CHANNEL_OFFSET(AXP20X_GPIO0_V, "gpio0_v", IIO_VOLTAGE,
+				  AXP20X_GPIO0_V_ADC_H),
+	AXP20X_ADC_CHANNEL_OFFSET(AXP20X_GPIO1_V, "gpio1_v", IIO_VOLTAGE,
+				  AXP20X_GPIO1_V_ADC_H),
+	AXP20X_ADC_CHANNEL(AXP20X_BATT_V, "batt_v", IIO_VOLTAGE,
+			   AXP20X_BATT_V_H),
+	AXP20X_ADC_CHANNEL(AXP20X_BATT_CHRG_I, "batt_chrg_i", IIO_CURRENT,
+			   AXP20X_BATT_CHRG_I_H),
+	AXP20X_ADC_CHANNEL(AXP20X_BATT_DISCHRG_I, "batt_dischrg_i", IIO_CURRENT,
+			   AXP20X_BATT_DISCHRG_I_H),
+	AXP20X_ADC_CHANNEL(AXP20X_IPSOUT_V, "ipsout_v", IIO_VOLTAGE,
+			   AXP20X_IPSOUT_V_HIGH_H),
+};
+
+static const struct iio_chan_spec axp22x_adc_channels[] = {
+	AXP20X_ADC_CHANNEL_OFFSET(AXP22X_TEMP_ADC, "temp_adc", IIO_TEMP,
+				  AXP22X_TEMP_ADC_H),
+	AXP20X_ADC_CHANNEL(AXP22X_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_read_raw(struct iio_dev *indio_dev,
+			       struct iio_chan_spec const *channel, int *val,
+			       int *val2)
+{
+	struct axp20x_adc_iio *info = iio_priv(indio_dev);
+	int size = 12, ret;
+
+	switch (channel->channel) {
+	case AXP20X_BATT_DISCHRG_I:
+		size = 13;
+	case AXP20X_ACIN_V:
+	case AXP20X_ACIN_I:
+	case AXP20X_VBUS_V:
+	case AXP20X_VBUS_I:
+	case AXP20X_TEMP_ADC:
+	case AXP20X_BATT_V:
+	case AXP20X_BATT_CHRG_I:
+	case AXP20X_IPSOUT_V:
+	case AXP20X_GPIO0_V:
+	case AXP20X_GPIO1_V:
+		ret = axp20x_read_variable_width(info->regmap, channel->address,
+						 size);
+		if (ret < 0)
+			return ret;
+		*val = ret;
+		return IIO_VAL_INT;
+
+	default:
+		return -EINVAL;
+	}
+
+	return -EINVAL;
+}
+
+static int axp22x_adc_read_raw(struct iio_dev *indio_dev,
+			       struct iio_chan_spec const *channel, int *val,
+			       int *val2)
+{
+	struct axp20x_adc_iio *info = iio_priv(indio_dev);
+	int size = 12, ret;
+
+	switch (channel->channel) {
+	case AXP22X_BATT_DISCHRG_I:
+		size = 13;
+	case AXP22X_TEMP_ADC:
+	case AXP22X_BATT_V:
+	case AXP22X_BATT_CHRG_I:
+		ret = axp20x_read_variable_width(info->regmap, channel->address,
+						 size);
+		if (ret < 0)
+			return ret;
+		*val = ret;
+		return IIO_VAL_INT;
+
+	default:
+		return -EINVAL;
+	}
+
+	return -EINVAL;
+}
+
+static int axp20x_adc_scale(int channel, int *val, int *val2)
+{
+	switch (channel) {
+	case AXP20X_ACIN_V:
+	case AXP20X_VBUS_V:
+		*val = 1;
+		*val2 = 700000;
+		return IIO_VAL_INT_PLUS_MICRO;
+
+	case AXP20X_ACIN_I:
+		*val = 0;
+		*val2 = 625000;
+		return IIO_VAL_INT_PLUS_MICRO;
+
+	case AXP20X_VBUS_I:
+		*val = 0;
+		*val2 = 375000;
+		return IIO_VAL_INT_PLUS_MICRO;
+
+	case AXP20X_TEMP_ADC:
+		*val = 100;
+		return IIO_VAL_INT;
+
+	case AXP20X_GPIO0_V:
+	case AXP20X_GPIO1_V:
+		*val = 0;
+		*val2 = 500000;
+		return IIO_VAL_INT_PLUS_MICRO;
+
+	case AXP20X_BATT_V:
+		*val = 1;
+		*val2 = 100000;
+		return IIO_VAL_INT_PLUS_MICRO;
+
+	case AXP20X_BATT_DISCHRG_I:
+	case AXP20X_BATT_CHRG_I:
+		*val = 0;
+		*val2 = 500000;
+		return IIO_VAL_INT_PLUS_MICRO;
+
+	case AXP20X_IPSOUT_V:
+		*val = 1;
+		*val2 = 400000;
+		return IIO_VAL_INT_PLUS_MICRO;
+
+	default:
+		return -EINVAL;
+	}
+
+	return -EINVAL;
+}
+
+static int axp22x_adc_scale(int channel, int *val, int *val2)
+{
+	switch (channel) {
+	case AXP22X_TEMP_ADC:
+		*val = 100;
+		return IIO_VAL_INT;
+
+	case AXP22X_BATT_V:
+		*val = 1;
+		*val2 = 100000;
+		return IIO_VAL_INT_PLUS_MICRO;
+
+	case AXP22X_BATT_DISCHRG_I:
+	case AXP22X_BATT_CHRG_I:
+		*val = 0;
+		*val2 = 500000;
+		return IIO_VAL_INT_PLUS_MICRO;
+
+	default:
+		return -EINVAL;
+	}
+
+	return -EINVAL;
+}
+
+static int axp20x_adc_offset(struct iio_dev *indio_dev, int channel, int *val)
+{
+	struct axp20x_adc_iio *info = iio_priv(indio_dev);
+	int ret, reg;
+
+	switch (channel) {
+	case AXP20X_TEMP_ADC:
+		*val = -1447;
+		return IIO_VAL_INT;
+
+	case AXP20X_GPIO0_V:
+	case AXP20X_GPIO1_V:
+		ret = regmap_read(info->regmap, AXP20X_GPIO10_IN_RANGE, &reg);
+		if (ret < 0)
+			return ret;
+
+		if (channel == AXP20X_GPIO0_V)
+			*val = reg & AXP20X_GPIO10_IN_RANGE_GPIO0;
+		else
+			*val = reg & AXP20X_GPIO10_IN_RANGE_GPIO1;
+
+		*val = !!(*val) * 700000;
+
+		return IIO_VAL_INT;
+
+	default:
+		return -EINVAL;
+	}
+
+	return -EINVAL;
+}
+
+static int axp20x_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:
+		return axp20x_adc_offset(indio_dev, chan->channel, val);
+
+	case IIO_CHAN_INFO_SCALE:
+		return axp20x_adc_scale(chan->channel, val, val2);
+
+	case IIO_CHAN_INFO_RAW:
+		return axp20x_adc_read_raw(indio_dev, chan, val, val2);
+
+	default:
+		return -EINVAL;
+	}
+
+	return -EINVAL;
+}
+
+static int axp22x_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 axp22x_adc_scale(chan->channel, val, val2);
+
+	case IIO_CHAN_INFO_RAW:
+		return axp22x_adc_read_raw(indio_dev, chan, val, val2);
+
+	default:
+		return -EINVAL;
+	}
+
+	return -EINVAL;
+}
+
+static int axp20x_write_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan, int val, int val2,
+			    long mask)
+{
+	struct axp20x_adc_iio *info = iio_priv(indio_dev);
+
+	/*
+	 * The AXP20X PMIC allows the user to choose between 0V and 0.7V offsets
+	 * for (independently) GPIO0 and GPIO1 when in ADC mode.
+	 */
+	if (mask != IIO_CHAN_INFO_OFFSET)
+		return -EINVAL;
+
+	if (chan->channel != AXP20X_GPIO0_V && chan->channel != AXP20X_GPIO1_V)
+		return -EINVAL;
+
+	if (val != 0 && val != 700000)
+		return -EINVAL;
+
+	if (chan->channel == AXP20X_GPIO0_V)
+		return regmap_update_bits(info->regmap, AXP20X_GPIO10_IN_RANGE,
+					  AXP20X_GPIO10_IN_RANGE_GPIO0,
+					  AXP20X_GPIO10_IN_RANGE_GPIO0_VAL(!!val));
+
+	return regmap_update_bits(info->regmap, AXP20X_GPIO10_IN_RANGE,
+				  AXP20X_GPIO10_IN_RANGE_GPIO1,
+				  AXP20X_GPIO10_IN_RANGE_GPIO1_VAL(!!val));
+}
+
+static const struct iio_info axp20x_adc_iio_info = {
+	.read_raw = axp20x_read_raw,
+	.write_raw = axp20x_write_raw,
+	.driver_module = THIS_MODULE,
+};
+
+static const struct iio_info axp22x_adc_iio_info = {
+	.read_raw = axp22x_read_raw,
+	.driver_module = THIS_MODULE,
+};
+
+static const struct of_device_id axp20x_adc_of_match[] = {
+	{ .compatible = "x-powers,axp209-adc", .data = (void *)AXP209_ID, },
+	{ .compatible = "x-powers,axp221-adc", .data = (void *)AXP221_ID, },
+	{ /* sentinel */ },
+};
+
+static int axp20x_probe(struct platform_device *pdev)
+{
+	struct axp20x_adc_iio *info;
+	struct iio_dev *indio_dev;
+	struct axp20x_dev *axp20x_dev;
+	int ret, axp20x_id;
+
+	axp20x_dev = dev_get_drvdata(pdev->dev.parent);
+
+	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*info));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	info = iio_priv(indio_dev);
+	platform_set_drvdata(pdev, indio_dev);
+
+	info->regmap = axp20x_dev->regmap;
+	info->indio_dev = indio_dev;
+	indio_dev->name = dev_name(&pdev->dev);
+	indio_dev->dev.parent = &pdev->dev;
+	indio_dev->dev.of_node = pdev->dev.of_node;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	axp20x_id = (int)of_device_get_match_data(&pdev->dev);
+
+	switch (axp20x_id) {
+	case AXP209_ID:
+		indio_dev->info = &axp20x_adc_iio_info;
+		indio_dev->num_channels = ARRAY_SIZE(axp20x_adc_channels);
+		indio_dev->channels = axp20x_adc_channels;
+
+		/* Enable the ADCs on IP */
+		regmap_write(info->regmap, AXP20X_ADC_EN1, AXP20X_ADC_EN1_MASK);
+
+		/* Enable GPIO0/1 and internal temperature ADCs */
+		regmap_update_bits(info->regmap, AXP20X_ADC_EN2,
+				   AXP20X_ADC_EN2_MASK, AXP20X_ADC_EN2_MASK);
+
+		/* Configure ADCs rate */
+		regmap_update_bits(info->regmap, AXP20X_ADC_RATE,
+				   AXP20X_ADC_RATE_MASK, AXP20X_ADC_RATE_50HZ);
+		break;
+
+	case AXP221_ID:
+		indio_dev->info = &axp22x_adc_iio_info;
+		indio_dev->num_channels = ARRAY_SIZE(axp22x_adc_channels);
+		indio_dev->channels = axp22x_adc_channels;
+
+		/* Enable the ADCs on IP */
+		regmap_write(info->regmap, AXP20X_ADC_EN1, AXP22X_ADC_EN1_MASK);
+
+		/* Configure ADCs rate */
+		regmap_update_bits(info->regmap, AXP20X_ADC_RATE,
+				   AXP20X_ADC_RATE_MASK, AXP22X_ADC_RATE_200HZ);
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	ret = devm_iio_device_register(&pdev->dev, indio_dev);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "could not register the device\n");
+		regmap_write(info->regmap, AXP20X_ADC_EN1, 0);
+		regmap_write(info->regmap, AXP20X_ADC_EN2, 0);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int axp20x_remove(struct platform_device *pdev)
+{
+	struct axp20x_adc_iio *info;
+	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+
+	info = iio_priv(indio_dev);
+	regmap_write(info->regmap, AXP20X_ADC_EN1, 0);
+	regmap_write(info->regmap, AXP20X_ADC_EN2, 0);
+
+	return 0;
+}
+
+static struct platform_driver axp20x_adc_driver = {
+	.driver = {
+		.name = "axp20x-adc",
+		.of_match_table = axp20x_adc_of_match,
+	},
+	.probe = axp20x_probe,
+	.remove = axp20x_remove,
+};
+
+module_platform_driver(axp20x_adc_driver);
+
+MODULE_DESCRIPTION("ADC driver for AXP20X and AXP22X PMICs");
+MODULE_AUTHOR("Quentin Schulz <quentin.schulz@free-electrons.com>");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/mfd/axp20x.h b/include/linux/mfd/axp20x.h
index a4860bc..650c6f6 100644
--- a/include/linux/mfd/axp20x.h
+++ b/include/linux/mfd/axp20x.h
@@ -150,6 +150,10 @@ enum {
 #define AXP20X_VBUS_I_ADC_L		0x5d
 #define AXP20X_TEMP_ADC_H		0x5e
 #define AXP20X_TEMP_ADC_L		0x5f
+
+#define AXP22X_TEMP_ADC_H		0x56
+#define AXP22X_TEMP_ADC_L		0x57
+
 #define AXP20X_TS_IN_H			0x62
 #define AXP20X_TS_IN_L			0x63
 #define AXP20X_GPIO0_V_ADC_H		0x64
-- 
2.9.3