diff mbox

[RESEND,v4,2/9] iio: adc: add support for X-Powers AXP20X and AXP22X PMICs ADCs

Message ID 20170320081653.8884-3-quentin.schulz@free-electrons.com (mailing list archive)
State New, archived
Headers show

Commit Message

Quentin Schulz March 20, 2017, 8:16 a.m. UTC
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>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Reviewed-by: Jonathan Cameron <jic23@kernel.org>
---

v4:
 - added missing space at the beginning of a comment,
 - tidied axp20x_adc_offset_voltage and axp20x_write_raw to use switch case
 instead of if conditions,
 - added MODULE_DEVICE_TABLE for axp20x_adc_id_match for module autoloading,
 - merged two lines in axp20x_remove,

v3:
 - moved from switch to if condition in axp20x_adc_raw and
 axp22x_adc_raw,
 - removed DT support as DT node has been dropped,
   - use of platform_device_id
 - correctly defined the name of the iio device (name used to probe the
 driver),
 - added goto for errors in probe,
 - added iio_map_array_unregister to the remove function,

v2:
 - removed unused defines,
 - changed BIT(x) to 1 << x when describing bits purpose for which 2 <<
 x or 3 << x exists, to be consistent,
 - changed ADC rate defines to macro formulas,
 - reordered IIO channels, now different measures (current/voltage) of
 the same part of the PMIC (e.g. battery), have the same IIO channel in
 their respective IIO type. When a part of the PMIC have only one
 measure, a number is jumped,
 - left IIO channel mapping in DT to use iio_map structure,
 - removed indexing of ADC internal temperature,
 - removed unused iio_dev structure in axp20x_adc_iio,
 - added a structure for data specific to AXP20X or AXP22X PMICs instead
 of using an ID and an if condition when needing to separate the
 behaviour of both,
 - added a comment on batt_chrg_i really being on 12bits rather than
 what the Chinese datasheets say (13 bits),
 - corrected the offset for AXP22X PMIC temperature,
 - set the ADC rate to a value (100Hz) shared by the AXP20X and AXP22X,
 - created macro formulas to compute the ADC rate for each,
 - added a condition on presence of ADC_EN2 reg before setting/resetting
 it,
 - switched from devm_iio_device_unregister to the non-devm function
 because of the need for a remove function,
 - removed some dead code,

 drivers/iio/adc/Kconfig      |  10 +
 drivers/iio/adc/Makefile     |   1 +
 drivers/iio/adc/axp20x_adc.c | 617 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 628 insertions(+)
 create mode 100644 drivers/iio/adc/axp20x_adc.c

Comments

Chen-Yu Tsai March 22, 2017, 4:34 a.m. UTC | #1
Hi,

On Mon, Mar 20, 2017 at 4:16 PM, Quentin Schulz
<quentin.schulz@free-electrons.com> wrote:
> 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>
> Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> Acked-by: Chen-Yu Tsai <wens@csie.org>
> Reviewed-by: Jonathan Cameron <jic23@kernel.org>

This patch seems to depend on commit 4707274714ef ("mfd: axp20x: Correct name
of temperature data ADC registers") currently in the mfd tree.

Jonathan, would it be ok for Lee to take this patch through the mfd tree
as well?


Thanks
ChenYu

P.S. I'm thinking about having MFD_AXP20X imply its various sub-drivers.
Not sure if that was the intended usage of the new imply syntax though.
Jonathan Cameron March 22, 2017, 6:31 a.m. UTC | #2
On 22 March 2017 04:34:45 GMT+00:00, Chen-Yu Tsai <wens@csie.org> wrote:
>Hi,
>
>On Mon, Mar 20, 2017 at 4:16 PM, Quentin Schulz
><quentin.schulz@free-electrons.com> wrote:
>> 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>
>> Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
>> Acked-by: Chen-Yu Tsai <wens@csie.org>
>> Reviewed-by: Jonathan Cameron <jic23@kernel.org>
>
>This patch seems to depend on commit 4707274714ef ("mfd: axp20x:
>Correct name
>of temperature data ADC registers") currently in the mfd tree.
>
>Jonathan, would it be ok for Lee to take this patch through the mfd
>tree
>as well?
Sure.
>
>
>Thanks
>ChenYu
>
>P.S. I'm thinking about having MFD_AXP20X imply its various
>sub-drivers.
>Not sure if that was the intended usage of the new imply syntax though.
Sebastian Reichel March 23, 2017, 9:35 a.m. UTC | #3
Hi,

On Wed, Mar 22, 2017 at 12:34:45PM +0800, Chen-Yu Tsai wrote:
> P.S. I'm thinking about having MFD_AXP20X imply its various sub-drivers.
> Not sure if that was the intended usage of the new imply syntax though.

I think adding "default MFD_AXP20X" to the sub-drivers is cleaner,
as you will not end up with a long list.

-- Sebastian
Chen-Yu Tsai March 23, 2017, 9:52 a.m. UTC | #4
On Thu, Mar 23, 2017 at 5:35 PM, Sebastian Reichel <sre@kernel.org> wrote:
> Hi,
>
> On Wed, Mar 22, 2017 at 12:34:45PM +0800, Chen-Yu Tsai wrote:
>> P.S. I'm thinking about having MFD_AXP20X imply its various sub-drivers.
>> Not sure if that was the intended usage of the new imply syntax though.
>
> I think adding "default MFD_AXP20X" to the sub-drivers is cleaner,
> as you will not end up with a long list.

I'd still need to add imply statements for the various subsystems though,
like regulators, power supplies, extcon, etc..
But I suppose that's cleaner, and fits the original intent of the syntax.

ChenYu
Quentin Schulz March 24, 2017, 7:55 a.m. UTC | #5
Hi,

On 23/03/2017 10:52, Chen-Yu Tsai wrote:
> On Thu, Mar 23, 2017 at 5:35 PM, Sebastian Reichel <sre@kernel.org> wrote:
>> Hi,
>>
>> On Wed, Mar 22, 2017 at 12:34:45PM +0800, Chen-Yu Tsai wrote:
>>> P.S. I'm thinking about having MFD_AXP20X imply its various sub-drivers.
>>> Not sure if that was the intended usage of the new imply syntax though.
>>
>> I think adding "default MFD_AXP20X" to the sub-drivers is cleaner,
>> as you will not end up with a long list.
> 
> I'd still need to add imply statements for the various subsystems though,
> like regulators, power supplies, extcon, etc..
> But I suppose that's cleaner, and fits the original intent of the syntax.
> 

Hum. I don't really understand what you are saying.. Am I supposed to
modify something or, is it okay and we're waiting for Lee to apply on
his tree?

Thanks in advance for clearing it up,

Quentin
Chen-Yu Tsai March 24, 2017, 8:01 a.m. UTC | #6
On Fri, Mar 24, 2017 at 3:55 PM, Quentin Schulz
<quentin.schulz@free-electrons.com> wrote:
> Hi,
>
> On 23/03/2017 10:52, Chen-Yu Tsai wrote:
>> On Thu, Mar 23, 2017 at 5:35 PM, Sebastian Reichel <sre@kernel.org> wrote:
>>> Hi,
>>>
>>> On Wed, Mar 22, 2017 at 12:34:45PM +0800, Chen-Yu Tsai wrote:
>>>> P.S. I'm thinking about having MFD_AXP20X imply its various sub-drivers.
>>>> Not sure if that was the intended usage of the new imply syntax though.
>>>
>>> I think adding "default MFD_AXP20X" to the sub-drivers is cleaner,
>>> as you will not end up with a long list.
>>
>> I'd still need to add imply statements for the various subsystems though,
>> like regulators, power supplies, extcon, etc..
>> But I suppose that's cleaner, and fits the original intent of the syntax.
>>
>
> Hum. I don't really understand what you are saying.. Am I supposed to
> modify something or, is it okay and we're waiting for Lee to apply on
> his tree?
>
> Thanks in advance for clearing it up,
>
> Quentin

I'm just mentioning some follow up tasks I want to do.
The patch is fine and we're waiting for Lee to take it.

ChenYu
diff mbox

Patch

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index d777a97..d15e1bd 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 b11bb57..17899b5 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..11e1771
--- /dev/null
+++ b/drivers/iio/adc/axp20x_adc.c
@@ -0,0 +1,617 @@ 
+/* 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/iio/driver.h>
+#include <linux/iio/machine.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_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			GENMASK(7, 6)
+#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 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 axp_data;
+
+struct axp20x_adc_iio {
+	struct regmap		*regmap;
+	struct axp_data		*data;
+};
+
+enum axp20x_adc_channel_v {
+	AXP20X_ACIN_V = 0,
+	AXP20X_VBUS_V,
+	AXP20X_TS_IN,
+	AXP20X_GPIO0_V,
+	AXP20X_GPIO1_V,
+	AXP20X_IPSOUT_V,
+	AXP20X_BATT_V,
+};
+
+enum axp20x_adc_channel_i {
+	AXP20X_ACIN_I = 0,
+	AXP20X_VBUS_I,
+	AXP20X_BATT_CHRG_I,
+	AXP20X_BATT_DISCHRG_I,
+};
+
+enum axp22x_adc_channel_v {
+	AXP22X_TS_IN = 0,
+	AXP22X_BATT_V,
+};
+
+enum axp22x_adc_channel_i {
+	AXP22X_BATT_CHRG_I = 1,
+	AXP22X_BATT_DISCHRG_I,
+};
+
+static struct iio_map axp20x_maps[] = {
+	{
+		.consumer_dev_name = "axp20x-usb-power-supply",
+		.consumer_channel = "vbus_v",
+		.adc_channel_label = "vbus_v",
+	}, {
+		.consumer_dev_name = "axp20x-usb-power-supply",
+		.consumer_channel = "vbus_i",
+		.adc_channel_label = "vbus_i",
+	}, {
+		.consumer_dev_name = "axp20x-ac-power-supply",
+		.consumer_channel = "acin_v",
+		.adc_channel_label = "acin_v",
+	}, {
+		.consumer_dev_name = "axp20x-ac-power-supply",
+		.consumer_channel = "acin_i",
+		.adc_channel_label = "acin_i",
+	}, {
+		.consumer_dev_name = "axp20x-battery-power-supply",
+		.consumer_channel = "batt_v",
+		.adc_channel_label = "batt_v",
+	}, {
+		.consumer_dev_name = "axp20x-battery-power-supply",
+		.consumer_channel = "batt_chrg_i",
+		.adc_channel_label = "batt_chrg_i",
+	}, {
+		.consumer_dev_name = "axp20x-battery-power-supply",
+		.consumer_channel = "batt_dischrg_i",
+		.adc_channel_label = "batt_dischrg_i",
+	}, { /* sentinel */ }
+};
+
+static struct iio_map axp22x_maps[] = {
+	{
+		.consumer_dev_name = "axp20x-battery-power-supply",
+		.consumer_channel = "batt_v",
+		.adc_channel_label = "batt_v",
+	}, {
+		.consumer_dev_name = "axp20x-battery-power-supply",
+		.consumer_channel = "batt_chrg_i",
+		.adc_channel_label = "batt_chrg_i",
+	}, {
+		.consumer_dev_name = "axp20x-battery-power-supply",
+		.consumer_channel = "batt_dischrg_i",
+		.adc_channel_label = "batt_dischrg_i",
+	}, { /* sentinel */ }
+};
+
+/*
+ * 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
+ * charge current in_current6_raw and discharge current will be in_current7_raw.
+ */
+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),
+	{
+		.type = IIO_TEMP,
+		.address = AXP20X_TEMP_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_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_IPSOUT_V, "ipsout_v", IIO_VOLTAGE,
+			   AXP20X_IPSOUT_V_HIGH_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),
+};
+
+static const struct iio_chan_spec axp22x_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(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_raw(struct iio_dev *indio_dev,
+			  struct iio_chan_spec const *chan, int *val)
+{
+	struct axp20x_adc_iio *info = iio_priv(indio_dev);
+	int size = 12;
+
+	/*
+	 * N.B.:  Unlike the Chinese datasheets tell, the charging current is
+	 * stored on 12 bits, not 13 bits. Only discharging current is on 13
+	 * bits.
+	 */
+	if (chan->type == IIO_CURRENT && chan->channel == AXP20X_BATT_DISCHRG_I)
+		size = 13;
+	else
+		size = 12;
+
+	*val = axp20x_read_variable_width(info->regmap, chan->address, size);
+	if (*val < 0)
+		return *val;
+
+	return IIO_VAL_INT;
+}
+
+static int axp22x_adc_raw(struct iio_dev *indio_dev,
+			  struct iio_chan_spec const *chan, int *val)
+{
+	struct axp20x_adc_iio *info = iio_priv(indio_dev);
+	int size;
+
+	/*
+	 * N.B.: Unlike the Chinese datasheets tell, the charging current is
+	 * stored on 12 bits, not 13 bits. Only discharging current is on 13
+	 * bits.
+	 */
+	if (chan->type == IIO_CURRENT && chan->channel == AXP22X_BATT_DISCHRG_I)
+		size = 13;
+	else
+		size = 12;
+
+	*val = axp20x_read_variable_width(info->regmap, chan->address, size);
+	if (*val < 0)
+		return *val;
+
+	return IIO_VAL_INT;
+}
+
+static int axp20x_adc_scale_voltage(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_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_IPSOUT_V:
+		*val = 1;
+		*val2 = 400000;
+		return IIO_VAL_INT_PLUS_MICRO;
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static int axp20x_adc_scale_current(int channel, int *val, int *val2)
+{
+	switch (channel) {
+	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_BATT_DISCHRG_I:
+	case AXP20X_BATT_CHRG_I:
+		*val = 0;
+		*val2 = 500000;
+		return IIO_VAL_INT_PLUS_MICRO;
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static int axp20x_adc_scale(struct iio_chan_spec const *chan, int *val,
+			    int *val2)
+{
+	switch (chan->type) {
+	case IIO_VOLTAGE:
+		return axp20x_adc_scale_voltage(chan->channel, val, val2);
+
+	case IIO_CURRENT:
+		return axp20x_adc_scale_current(chan->channel, val, val2);
+
+	case IIO_TEMP:
+		*val = 100;
+		return IIO_VAL_INT;
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static int axp22x_adc_scale(struct iio_chan_spec const *chan, int *val,
+			    int *val2)
+{
+	switch (chan->type) {
+	case IIO_VOLTAGE:
+		if (chan->channel != AXP22X_BATT_V)
+			return -EINVAL;
+
+		*val = 1;
+		*val2 = 100000;
+		return IIO_VAL_INT_PLUS_MICRO;
+
+	case IIO_CURRENT:
+		*val = 0;
+		*val2 = 500000;
+		return IIO_VAL_INT_PLUS_MICRO;
+
+	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)
+{
+	struct axp20x_adc_iio *info = iio_priv(indio_dev);
+	int ret;
+
+	ret = regmap_read(info->regmap, AXP20X_GPIO10_IN_RANGE, val);
+	if (ret < 0)
+		return ret;
+
+	switch (channel) {
+	case AXP20X_GPIO0_V:
+		*val &= AXP20X_GPIO10_IN_RANGE_GPIO0;
+		break;
+
+	case AXP20X_GPIO1_V:
+		*val &= AXP20X_GPIO10_IN_RANGE_GPIO1;
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	*val = !!(*val) * 700000;
+
+	return IIO_VAL_INT;
+}
+
+static int axp20x_adc_offset(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan, int *val)
+{
+	switch (chan->type) {
+	case IIO_VOLTAGE:
+		return axp20x_adc_offset_voltage(indio_dev, chan->channel, val);
+
+	case IIO_TEMP:
+		*val = -1447;
+		return IIO_VAL_INT;
+
+	default:
+		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, val);
+
+	case IIO_CHAN_INFO_SCALE:
+		return axp20x_adc_scale(chan, val, val2);
+
+	case IIO_CHAN_INFO_RAW:
+		return axp20x_adc_raw(indio_dev, chan, val);
+
+	default:
+		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 = -2677;
+		return IIO_VAL_INT;
+
+	case IIO_CHAN_INFO_SCALE:
+		return axp22x_adc_scale(chan, val, val2);
+
+	case IIO_CHAN_INFO_RAW:
+		return axp22x_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)
+{
+	struct axp20x_adc_iio *info = iio_priv(indio_dev);
+	unsigned int reg, regval;
+
+	/*
+	 * 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 (val != 0 && val != 700000)
+		return -EINVAL;
+
+	switch (chan->channel) {
+	case AXP20X_GPIO0_V:
+		reg = AXP20X_GPIO10_IN_RANGE_GPIO0;
+		regval = AXP20X_GPIO10_IN_RANGE_GPIO0_VAL(!!val);
+		break;
+
+	case AXP20X_GPIO1_V:
+		reg = AXP20X_GPIO10_IN_RANGE_GPIO1;
+		regval = AXP20X_GPIO10_IN_RANGE_GPIO1_VAL(!!val);
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	return regmap_update_bits(info->regmap, AXP20X_GPIO10_IN_RANGE, reg,
+				  regval);
+}
+
+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 int axp20x_adc_rate(int rate)
+{
+	return AXP20X_ADC_RATE_HZ(rate);
+}
+
+static int axp22x_adc_rate(int rate)
+{
+	return AXP22X_ADC_RATE_HZ(rate);
+}
+
+struct axp_data {
+	const struct iio_info		*iio_info;
+	int				num_channels;
+	struct iio_chan_spec const	*channels;
+	unsigned long			adc_en1_mask;
+	int				(*adc_rate)(int rate);
+	bool				adc_en2;
+	struct iio_map			*maps;
+};
+
+static const struct axp_data axp20x_data = {
+	.iio_info = &axp20x_adc_iio_info,
+	.num_channels = ARRAY_SIZE(axp20x_adc_channels),
+	.channels = axp20x_adc_channels,
+	.adc_en1_mask = AXP20X_ADC_EN1_MASK,
+	.adc_rate = axp20x_adc_rate,
+	.adc_en2 = true,
+	.maps = axp20x_maps,
+};
+
+static const struct axp_data axp22x_data = {
+	.iio_info = &axp22x_adc_iio_info,
+	.num_channels = ARRAY_SIZE(axp22x_adc_channels),
+	.channels = axp22x_adc_channels,
+	.adc_en1_mask = AXP22X_ADC_EN1_MASK,
+	.adc_rate = axp22x_adc_rate,
+	.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, },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(platform, axp20x_adc_id_match);
+
+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_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;
+	indio_dev->dev.parent = &pdev->dev;
+	indio_dev->dev.of_node = pdev->dev.of_node;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	info->data = (struct axp_data *)platform_get_device_id(pdev)->driver_data;
+
+	indio_dev->name = platform_get_device_id(pdev)->name;
+	indio_dev->info = info->data->iio_info;
+	indio_dev->num_channels = info->data->num_channels;
+	indio_dev->channels = info->data->channels;
+
+	/* Enable the ADCs on IP */
+	regmap_write(info->regmap, AXP20X_ADC_EN1, info->data->adc_en1_mask);
+
+	if (info->data->adc_en2)
+		/* 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,
+			   info->data->adc_rate(100));
+
+	ret = iio_map_array_register(indio_dev, info->data->maps);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to register IIO maps: %d\n", ret);
+		goto fail_map;
+	}
+
+	ret = iio_device_register(indio_dev);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "could not register the device\n");
+		goto fail_register;
+	}
+
+	return 0;
+
+fail_register:
+	iio_map_array_unregister(indio_dev);
+
+fail_map:
+	regmap_write(info->regmap, AXP20X_ADC_EN1, 0);
+
+	if (info->data->adc_en2)
+		regmap_write(info->regmap, AXP20X_ADC_EN2, 0);
+
+	return ret;
+}
+
+static int axp20x_remove(struct platform_device *pdev)
+{
+	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+	struct axp20x_adc_iio *info = iio_priv(indio_dev);
+
+	iio_device_unregister(indio_dev);
+	iio_map_array_unregister(indio_dev);
+
+	regmap_write(info->regmap, AXP20X_ADC_EN1, 0);
+
+	if (info->data->adc_en2)
+		regmap_write(info->regmap, AXP20X_ADC_EN2, 0);
+
+	return 0;
+}
+
+static struct platform_driver axp20x_adc_driver = {
+	.driver = {
+		.name = "axp20x-adc",
+	},
+	.id_table = axp20x_adc_id_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");