Re: [RESEND 10/14] iio: adc: mt6370: Add Mediatek MT6370 support

On Tue, 31 May 2022 19:18:56 +0800 ChiaEn Wu peterwu.pub@gmail.com wrote:

From: ChiaEn Wu chiaen_wu@richtek.com

Add Mediatek MT6370 ADC support.

Signed-off-by: ChiaEn Wu chiaen_wu@richtek.com

Hi ChiaEn,

A few comments inline.

Thanks,

Jonathan

---

drivers/iio/adc/Kconfig | 9 ++ drivers/iio/adc/Makefile | 1 + drivers/iio/adc/mt6370-adc.c | 257 +++++++++++++++++++++++++++++++++++ 3 files changed, 267 insertions(+) create mode 100644 drivers/iio/adc/mt6370-adc.c

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index 71ab0a06aa82..d7932dd9b773 100644 --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig @@ -737,6 +737,15 @@ 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 Y here to enable MT6370 ADC support.
  

•  Integrated for System Monitoring includes
  

The wrapping of this text needs cleaning up.

•  is used in smartphones and tablets and supports a 9 channel
  

•  general purpose 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 39d806f6d457..0ce285c7e2d0 100644 --- a/drivers/iio/adc/Makefile +++ b/drivers/iio/adc/Makefile @@ -68,6 +68,7 @@ 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 000000000000..3320ebca17ad --- /dev/null +++ b/drivers/iio/adc/mt6370-adc.c @@ -0,0 +1,257 @@ +// SPDX-License-Identifier: GPL-2.0

+#include <dt-bindings/iio/adc/mediatek,mt6370_adc.h> +#include <linux/bits.h> +#include <linux/bitfield.h> +#include <linux/iio/iio.h> +#include <linux/irq.h>

Not seeing any interrupt support in here.

+#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/platform_device.h> +#include <linux/regmap.h>

+#define MT6370_REG_CHG_CTRL3 0x113 /* AICR */ +#define MT6370_REG_CHG_CTRL7 0x117 /* ICHG */ +#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_ADC_CHAN_SHIFT 4

Prefer using a mask and then FIELD_PREP

+#define MT6370_AICR_400MA 0x6 +#define MT6370_ICHG_500MA 0x4 +#define MT6370_ICHG_900MA 0x8

+#define ADC_CONV_TIME_US 35000 +#define ADC_CONV_POLLING_TIME 1000

+struct mt6370_adc_data {

• struct device *dev;
• struct regmap *regmap;
• struct mutex lock;

All locks need documentation. What is the scope of the lock? Looks like it protects device state when doing setup, wait for read, read cycles.

+};

+static int mt6370_adc_read_channel(struct mt6370_adc_data *priv, int chan,

• 		   unsigned long addr, int *val)
  

+{

• __be16 be_val;
• unsigned int reg_val;
• int ret;
• mutex_lock(&priv->lock);
• reg_val = MT6370_ADC_START_MASK | (addr << MT6370_ADC_CHAN_SHIFT);

FIELD_PREP for that shift?

• ret = regmap_write(priv->regmap, MT6370_REG_CHG_ADC, reg_val);
• if (ret)

• goto adc_unlock;
  

• msleep(ADC_CONV_TIME_US / 1000);
• ret = regmap_read_poll_timeout(priv->regmap,

• 		       MT6370_REG_CHG_ADC, reg_val,
  

• 		       !(reg_val & MT6370_ADC_START_MASK),
  

• 		       ADC_CONV_POLLING_TIME,
  

• 		       ADC_CONV_TIME_US * 3);
  

• if (ret) {

• if (ret == -ETIMEDOUT)
  

• 	dev_err(priv->dev, "Failed to wait adc conversion\n");
  

• 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->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 = 5000;
  

This seems very large. Voltages are in millivolts as per Documentation/ABI/testing/sysfs-bus-iio and this means each step is 5 volts.

So value in mv is currently 5 * _raw

• 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);
  

• if (reg_val < MT6370_AICR_400MA)
  

• 	*val1 = 33500;
  

• else
  

• 	*val1 = 50000;
  

• return IIO_VAL_INT;
  

• 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);
  

• if (reg_val < MT6370_ICHG_500MA)
  

• 	*val1 = 23750;
  

• else if (reg_val >= MT6370_ICHG_500MA &&
  

• 	 reg_val < MT6370_ICHG_900MA)
  

• 	*val1 = 26800;
  

• else
  

• 	*val1 = 50000;
  

• return IIO_VAL_INT;
  

• case MT6370_CHAN_VBUSDIV5:

• *val1 = 25000;
  

• return IIO_VAL_INT;
  

• case MT6370_CHAN_VBUSDIV2:

• *val1 = 50000;
  

• return IIO_VAL_INT;
  

• case MT6370_CHAN_TS_BAT:

• *val1 = 25;
  

• *val2 = 10000;
  

• return IIO_VAL_FRACTIONAL;
  

• case MT6370_CHAN_TEMP_JC:

• *val1 = 2;
  

• return IIO_VAL_INT;
  

• }
• return -EINVAL;

+}

+static int mt6370_adc_read_offset(struct mt6370_adc_data *priv,

• 		  int chan, int *val)
  

+{

• *val = (chan == MT6370_CHAN_TEMP_JC) ? -20 : 0;

Offset default is 0, so for channels where it doesn't apply don't provide the offset attribute at all.

• 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);
  

• }
• return -EINVAL;

+}

+static const char * const mt6370_channel_labels[MT6370_CHAN_MAX] = {

Perhaps define an enum with which to index this and the chan spec and hence ensure they end up matching. [vbusdiv5] = "vbusdiv5", etc

• "vbusdiv5", "vbusdiv2", "vsys", "vbat",
• "ts_bat", "ibus", "ibat", "chg_vddp",
• "temp_jc",

+};

+static int mt6370_adc_read_label(struct iio_dev *iio_dev,

• 		 struct iio_chan_spec const *chan, char *label)
  

+{

• return snprintf(label, PAGE_SIZE, "%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) { \

• .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) |	\
  

• 	      BIT(IIO_CHAN_INFO_OFFSET),	\
  

See above. Only temp_jc channel should hav an offset.

+}

+static const struct iio_chan_spec mt6370_adc_channels[] = {

• MT6370_ADC_CHAN(VBUSDIV5, IIO_VOLTAGE, 1),
• MT6370_ADC_CHAN(VBUSDIV2, IIO_VOLTAGE, 2),
• MT6370_ADC_CHAN(VSYS, IIO_VOLTAGE, 3),
• MT6370_ADC_CHAN(VBAT, IIO_VOLTAGE, 4),
• MT6370_ADC_CHAN(TS_BAT, IIO_VOLTAGE, 6),
• MT6370_ADC_CHAN(IBUS, IIO_CURRENT, 8),
• MT6370_ADC_CHAN(IBAT, IIO_CURRENT, 9),
• MT6370_ADC_CHAN(CHG_VDDP, IIO_VOLTAGE, 11),
• MT6370_ADC_CHAN(TEMP_JC, IIO_TEMP, 12),

+};

+static int mt6370_adc_probe(struct platform_device *pdev) +{

• int ret;
• struct mt6370_adc_data *priv;
• struct regmap *regmap;
• struct iio_dev *indio_dev;
• regmap = dev_get_regmap(pdev->dev.parent, NULL);
• if (!regmap) {

• dev_err(&pdev->dev, "Failed to get regmap\n");
  

• return -ENODEV;
  

• }
• indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*priv));
• if (!indio_dev)

• return -ENOMEM;
  

• priv = iio_priv(indio_dev);
• priv->dev = &pdev->dev;
• priv->regmap = regmap;
• mutex_init(&priv->lock);
• ret = regmap_write(priv->regmap, MT6370_REG_CHG_ADC, 0);
• if (ret) {

• dev_err(&pdev->dev, "Failed to reset adc\n");
  

• return ret;
  

• }
• indio_dev->name = dev_name(&pdev->dev);

What does this end up as? It's used for userspace ABI and should correspond to the part number, "mt6370-adc" probably appropriate in this case (I think it'll end up as simply "adc.x" currently?) Normally we just hard code this in the driver for whatever devices the driver supports.

• 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(&pdev->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 Drvier"); +MODULE_LICENSE("GPL v2");