[v14,1/3] iio: adc: mt6370: Add MediaTek MT6370 support

From: ChiaEn Wu <chiaen_wu@richtek.com>

MediaTek MT6370 is a SubPMIC consisting of a single cell battery charger
with ADC monitoring, RGB LEDs, dual channel flashlight, WLED backlight
driver, display bias voltage supply, one general purpose LDO, and the
USB Type-C & PD controller complies with the latest USB Type-C and PD
standards.

Add support for the MT6370 ADC driver for system monitoring, including
charger current, voltage, and temperature.

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: ChiaEn Wu <chiaen_wu@richtek.com>
---

v14
- Revise the scale value of 'VBUSDIV2' in 'mt6370_adc_read_scale()'
  (50 --> 10)
- Revise the return value of 'TEMP_JC' in 'mt6370_adc_read_scale()'
  (return IIO_VAL_FRACTIONAL; --> return IIO_VAL_INT;)
---
 drivers/iio/adc/Kconfig      |  12 ++
 drivers/iio/adc/Makefile     |   1 +
 drivers/iio/adc/mt6370-adc.c | 305 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 318 insertions(+)
 create mode 100644 drivers/iio/adc/mt6370-adc.c

On Tue, 11 Oct 2022 12:05:45 +0800
ChiaEn Wu <peterwu.pub@gmail.com> wrote:

> From: ChiaEn Wu <chiaen_wu@richtek.com>
> 
> MediaTek MT6370 is a SubPMIC consisting of a single cell battery charger
> with ADC monitoring, RGB LEDs, dual channel flashlight, WLED backlight
> driver, display bias voltage supply, one general purpose LDO, and the
> USB Type-C & PD controller complies with the latest USB Type-C and PD
> standards.
> 
> Add support for the MT6370 ADC driver for system monitoring, including
> charger current, voltage, and temperature.
> 
> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
> Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Signed-off-by: ChiaEn Wu <chiaen_wu@richtek.com>

The header is now upstream so applied to the togreg branch of iio.git but
only pushing that out as testing until I can rebase it on rc1.

For now it's based on somewhere random, mid merge window.

Thanks,

Jonathan

> ---
> 
> v14
> - Revise the scale value of 'VBUSDIV2' in 'mt6370_adc_read_scale()'
>   (50 --> 10)
> - Revise the return value of 'TEMP_JC' in 'mt6370_adc_read_scale()'
>   (return IIO_VAL_FRACTIONAL; --> return IIO_VAL_INT;)
> ---
>  drivers/iio/adc/Kconfig      |  12 ++
>  drivers/iio/adc/Makefile     |   1 +
>  drivers/iio/adc/mt6370-adc.c | 305 +++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 318 insertions(+)
>  create mode 100644 drivers/iio/adc/mt6370-adc.c
> 
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index 791612c..f4fdca8 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -752,6 +752,18 @@ config MEDIATEK_MT6360_ADC
>  	  is used in smartphones and tablets and supports a 11 channel
>  	  general purpose ADC.
>  
> +config MEDIATEK_MT6370_ADC
> +	tristate "MediaTek MT6370 ADC driver"
> +	depends on MFD_MT6370
> +	help
> +	  Say yes here to enable MediaTek MT6370 ADC support.
> +
> +	  This ADC driver provides 9 channels for system monitoring (charger
> +	  current, voltage, and temperature).
> +
> +	  This driver can also be built as a module. If so, the module
> +	  will be called "mt6370-adc".
> +
>  config MEDIATEK_MT6577_AUXADC
>  	tristate "MediaTek AUXADC driver"
>  	depends on ARCH_MEDIATEK || COMPILE_TEST
> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> index 46caba7..953fada 100644
> --- a/drivers/iio/adc/Makefile
> +++ b/drivers/iio/adc/Makefile
> @@ -69,6 +69,7 @@ obj-$(CONFIG_MCP320X) += mcp320x.o
>  obj-$(CONFIG_MCP3422) += mcp3422.o
>  obj-$(CONFIG_MCP3911) += mcp3911.o
>  obj-$(CONFIG_MEDIATEK_MT6360_ADC) += mt6360-adc.o
> +obj-$(CONFIG_MEDIATEK_MT6370_ADC) += mt6370-adc.o
>  obj-$(CONFIG_MEDIATEK_MT6577_AUXADC) += mt6577_auxadc.o
>  obj-$(CONFIG_MEN_Z188_ADC) += men_z188_adc.o
>  obj-$(CONFIG_MESON_SARADC) += meson_saradc.o
> diff --git a/drivers/iio/adc/mt6370-adc.c b/drivers/iio/adc/mt6370-adc.c
> new file mode 100644
> index 0000000..bc62e5a
> --- /dev/null
> +++ b/drivers/iio/adc/mt6370-adc.c
> @@ -0,0 +1,305 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (C) 2022 Richtek Technology Corp.
> + *
> + * Author: ChiaEn Wu <chiaen_wu@richtek.com>
> + */
> +
> +#include <linux/bits.h>
> +#include <linux/bitfield.h>
> +#include <linux/iio/iio.h>
> +#include <linux/kernel.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/sysfs.h>
> +#include <linux/units.h>
> +
> +#include <dt-bindings/iio/adc/mediatek,mt6370_adc.h>
> +
> +#define MT6370_REG_CHG_CTRL3		0x113
> +#define MT6370_REG_CHG_CTRL7		0x117
> +#define MT6370_REG_CHG_ADC		0x121
> +#define MT6370_REG_ADC_DATA_H		0x14C
> +
> +#define MT6370_ADC_START_MASK		BIT(0)
> +#define MT6370_ADC_IN_SEL_MASK		GENMASK(7, 4)
> +#define MT6370_AICR_ICHG_MASK		GENMASK(7, 2)
> +
> +#define MT6370_AICR_100_mA		0x0
> +#define MT6370_AICR_150_mA		0x1
> +#define MT6370_AICR_200_mA		0x2
> +#define MT6370_AICR_250_mA		0x3
> +#define MT6370_AICR_300_mA		0x4
> +#define MT6370_AICR_350_mA		0x5
> +
> +#define MT6370_ICHG_100_mA		0x0
> +#define MT6370_ICHG_200_mA		0x1
> +#define MT6370_ICHG_300_mA		0x2
> +#define MT6370_ICHG_400_mA		0x3
> +#define MT6370_ICHG_500_mA		0x4
> +#define MT6370_ICHG_600_mA		0x5
> +#define MT6370_ICHG_700_mA		0x6
> +#define MT6370_ICHG_800_mA		0x7
> +
> +#define ADC_CONV_TIME_MS		35
> +#define ADC_CONV_POLLING_TIME_US	1000
> +
> +struct mt6370_adc_data {
> +	struct device *dev;
> +	struct regmap *regmap;
> +	/*
> +	 * This mutex lock is for preventing the different ADC channels
> +	 * from being read at the same time.
> +	 */
> +	struct mutex adc_lock;
> +};
> +
> +static int mt6370_adc_read_channel(struct mt6370_adc_data *priv, int chan,
> +				   unsigned long addr, int *val)
> +{
> +	unsigned int reg_val;
> +	__be16 be_val;
> +	int ret;
> +
> +	mutex_lock(&priv->adc_lock);
> +
> +	reg_val = MT6370_ADC_START_MASK |
> +		  FIELD_PREP(MT6370_ADC_IN_SEL_MASK, addr);
> +	ret = regmap_write(priv->regmap, MT6370_REG_CHG_ADC, reg_val);
> +	if (ret)
> +		goto adc_unlock;
> +
> +	msleep(ADC_CONV_TIME_MS);
> +
> +	ret = regmap_read_poll_timeout(priv->regmap,
> +				       MT6370_REG_CHG_ADC, reg_val,
> +				       !(reg_val & MT6370_ADC_START_MASK),
> +				       ADC_CONV_POLLING_TIME_US,
> +				       ADC_CONV_TIME_MS * MILLI * 3);
> +	if (ret) {
> +		dev_err(priv->dev, "Failed to read ADC register (%d)\n", ret);
> +		goto adc_unlock;
> +	}
> +
> +	ret = regmap_raw_read(priv->regmap, MT6370_REG_ADC_DATA_H,
> +			      &be_val, sizeof(be_val));
> +	if (ret)
> +		goto adc_unlock;
> +
> +	*val = be16_to_cpu(be_val);
> +	ret = IIO_VAL_INT;
> +
> +adc_unlock:
> +	mutex_unlock(&priv->adc_lock);
> +
> +	return ret;
> +}
> +
> +static int mt6370_adc_read_scale(struct mt6370_adc_data *priv,
> +				 int chan, int *val1, int *val2)
> +{
> +	unsigned int reg_val;
> +	int ret;
> +
> +	switch (chan) {
> +	case MT6370_CHAN_VBAT:
> +	case MT6370_CHAN_VSYS:
> +	case MT6370_CHAN_CHG_VDDP:
> +		*val1 = 5;
> +		return IIO_VAL_INT;
> +	case MT6370_CHAN_IBUS:
> +		ret = regmap_read(priv->regmap, MT6370_REG_CHG_CTRL3, &reg_val);
> +		if (ret)
> +			return ret;
> +
> +		reg_val = FIELD_GET(MT6370_AICR_ICHG_MASK, reg_val);
> +		switch (reg_val) {
> +		case MT6370_AICR_100_mA:
> +		case MT6370_AICR_150_mA:
> +		case MT6370_AICR_200_mA:
> +		case MT6370_AICR_250_mA:
> +		case MT6370_AICR_300_mA:
> +		case MT6370_AICR_350_mA:
> +			*val1 = 3350;
> +			break;
> +		default:
> +			*val1 = 5000;
> +			break;
> +		}
> +
> +		*val2 = 100;
> +
> +		return IIO_VAL_FRACTIONAL;
> +	case MT6370_CHAN_IBAT:
> +		ret = regmap_read(priv->regmap, MT6370_REG_CHG_CTRL7, &reg_val);
> +		if (ret)
> +			return ret;
> +
> +		reg_val = FIELD_GET(MT6370_AICR_ICHG_MASK, reg_val);
> +		switch (reg_val) {
> +		case MT6370_ICHG_100_mA:
> +		case MT6370_ICHG_200_mA:
> +		case MT6370_ICHG_300_mA:
> +		case MT6370_ICHG_400_mA:
> +			*val1 = 2375;
> +			break;
> +		case MT6370_ICHG_500_mA:
> +		case MT6370_ICHG_600_mA:
> +		case MT6370_ICHG_700_mA:
> +		case MT6370_ICHG_800_mA:
> +			*val1 = 2680;
> +			break;
> +		default:
> +			*val1 = 5000;
> +			break;
> +		}
> +
> +		*val2 = 100;
> +
> +		return IIO_VAL_FRACTIONAL;
> +	case MT6370_CHAN_VBUSDIV5:
> +		*val1 = 25;
> +		return IIO_VAL_INT;
> +	case MT6370_CHAN_VBUSDIV2:
> +		*val1 = 10;
> +		return IIO_VAL_INT;
> +	case MT6370_CHAN_TS_BAT:
> +		*val1 = 25;
> +		*val2 = 10000;
> +		return IIO_VAL_FRACTIONAL;
> +	case MT6370_CHAN_TEMP_JC:
> +		*val1 = 2000;
> +		return IIO_VAL_INT;
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static int mt6370_adc_read_offset(struct mt6370_adc_data *priv,
> +				  int chan, int *val)
> +{
> +	*val = -20;
> +
> +	return IIO_VAL_INT;
> +}
> +
> +static int mt6370_adc_read_raw(struct iio_dev *iio_dev,
> +			       const struct iio_chan_spec *chan,
> +			       int *val, int *val2, long mask)
> +{
> +	struct mt6370_adc_data *priv = iio_priv(iio_dev);
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_RAW:
> +		return mt6370_adc_read_channel(priv, chan->channel,
> +					       chan->address, val);
> +	case IIO_CHAN_INFO_SCALE:
> +		return mt6370_adc_read_scale(priv, chan->channel, val, val2);
> +	case IIO_CHAN_INFO_OFFSET:
> +		return mt6370_adc_read_offset(priv, chan->channel, val);
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static const char * const mt6370_channel_labels[MT6370_CHAN_MAX] = {
> +	[MT6370_CHAN_VBUSDIV5] = "vbusdiv5",
> +	[MT6370_CHAN_VBUSDIV2] = "vbusdiv2",
> +	[MT6370_CHAN_VSYS] = "vsys",
> +	[MT6370_CHAN_VBAT] = "vbat",
> +	[MT6370_CHAN_TS_BAT] = "ts_bat",
> +	[MT6370_CHAN_IBUS] = "ibus",
> +	[MT6370_CHAN_IBAT] = "ibat",
> +	[MT6370_CHAN_CHG_VDDP] = "chg_vddp",
> +	[MT6370_CHAN_TEMP_JC] = "temp_jc",
> +};
> +
> +static int mt6370_adc_read_label(struct iio_dev *iio_dev,
> +				 struct iio_chan_spec const *chan, char *label)
> +{
> +	return sysfs_emit(label, "%s\n", mt6370_channel_labels[chan->channel]);
> +}
> +
> +static const struct iio_info mt6370_adc_iio_info = {
> +	.read_raw = mt6370_adc_read_raw,
> +	.read_label = mt6370_adc_read_label,
> +};
> +
> +#define MT6370_ADC_CHAN(_idx, _type, _addr, _extra_info) {	\
> +	.type = _type,						\
> +	.channel = MT6370_CHAN_##_idx,				\
> +	.address = _addr,					\
> +	.scan_index = MT6370_CHAN_##_idx,			\
> +	.indexed = 1,						\
> +	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\
> +			      BIT(IIO_CHAN_INFO_SCALE) |	\
> +			      _extra_info,			\
> +}
> +
> +static const struct iio_chan_spec mt6370_adc_channels[] = {
> +	MT6370_ADC_CHAN(VBUSDIV5, IIO_VOLTAGE, 1, 0),
> +	MT6370_ADC_CHAN(VBUSDIV2, IIO_VOLTAGE, 2, 0),
> +	MT6370_ADC_CHAN(VSYS, IIO_VOLTAGE, 3, 0),
> +	MT6370_ADC_CHAN(VBAT, IIO_VOLTAGE, 4, 0),
> +	MT6370_ADC_CHAN(TS_BAT, IIO_VOLTAGE, 6, 0),
> +	MT6370_ADC_CHAN(IBUS, IIO_CURRENT, 8, 0),
> +	MT6370_ADC_CHAN(IBAT, IIO_CURRENT, 9, 0),
> +	MT6370_ADC_CHAN(CHG_VDDP, IIO_VOLTAGE, 11, 0),
> +	MT6370_ADC_CHAN(TEMP_JC, IIO_TEMP, 12, BIT(IIO_CHAN_INFO_OFFSET)),
> +};
> +
> +static int mt6370_adc_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct mt6370_adc_data *priv;
> +	struct iio_dev *indio_dev;
> +	struct regmap *regmap;
> +	int ret;
> +
> +	regmap = dev_get_regmap(pdev->dev.parent, NULL);
> +	if (!regmap)
> +		return dev_err_probe(dev, -ENODEV, "Failed to get regmap\n");
> +
> +	indio_dev = devm_iio_device_alloc(dev, sizeof(*priv));
> +	if (!indio_dev)
> +		return -ENOMEM;
> +
> +	priv = iio_priv(indio_dev);
> +	priv->dev = dev;
> +	priv->regmap = regmap;
> +	mutex_init(&priv->adc_lock);
> +
> +	ret = regmap_write(priv->regmap, MT6370_REG_CHG_ADC, 0);
> +	if (ret)
> +		return dev_err_probe(dev, ret, "Failed to reset ADC\n");
> +
> +	indio_dev->name = "mt6370-adc";
> +	indio_dev->info = &mt6370_adc_iio_info;
> +	indio_dev->modes = INDIO_DIRECT_MODE;
> +	indio_dev->channels = mt6370_adc_channels;
> +	indio_dev->num_channels = ARRAY_SIZE(mt6370_adc_channels);
> +
> +	return devm_iio_device_register(dev, indio_dev);
> +}
> +
> +static const struct of_device_id mt6370_adc_of_id[] = {
> +	{ .compatible = "mediatek,mt6370-adc", },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, mt6370_adc_of_id);
> +
> +static struct platform_driver mt6370_adc_driver = {
> +	.driver = {
> +		.name = "mt6370-adc",
> +		.of_match_table = mt6370_adc_of_id,
> +	},
> +	.probe = mt6370_adc_probe,
> +};
> +module_platform_driver(mt6370_adc_driver);
> +
> +MODULE_AUTHOR("ChiaEn Wu <chiaen_wu@richtek.com>");
> +MODULE_DESCRIPTION("MT6370 ADC Driver");
> +MODULE_LICENSE("GPL v2");