[PATCH v3 10/14] iio: adc: mt6370: Add Mediatek MT6370 support

From: ChiaEn Wu
Date: Thu Jun 23 2022 - 07:59:18 EST

From: ChiaEn Wu <chiaen_wu@xxxxxxxxxxx>

Add Mediatek MT6370 ADC support.

Signed-off-by: ChiaEn Wu <chiaen_wu@xxxxxxxxxxx>
---

v3
- Refine Kconfig help text
- Refine all channel value in read_scale()
a. current: uA --> mA
b. voltage: uV --> mV
c. temperature: degrees Celsius --> milli degrees Celsius
- Add "default:" condition of switch statement in read_scale() and read_raw()
- Add error message for reading ADC register failed
- Add the comment for adc_lock
- Add <linux/mod_devicetable.h> header file for struct of_device_id
- Replace "adc" text with "ADC" in all of the error messages
---
drivers/iio/adc/Kconfig | 9 ++
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/mt6370-adc.c | 275 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 285 insertions(+)
create mode 100644 drivers/iio/adc/mt6370-adc.c

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 48ace74..c36b640 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 yes here to enable Mediatek MT6370 ADC support.
+
+ This ADC driver provides 9 channels for system monitoring (charger
+ current, voltage, and temperature).
+
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 39d806f..0ce285c 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 0000000..ed7f1b3
--- /dev/null
+++ b/drivers/iio/adc/mt6370-adc.c
@@ -0,0 +1,275 @@
+// 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/kernel.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.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_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;
+ /*
+ * 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)
+{
+ __be16 be_val;
+ unsigned int reg_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_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");
+ else
+ 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);
+ if (reg_val < MT6370_AICR_400MA)
+ *val1 = 3350;
+ else
+ *val1 = 5000;
+
+ *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);
+ if (reg_val < MT6370_ICHG_500MA)
+ *val1 = 2375;
+ else if (reg_val >= MT6370_ICHG_500MA &&
+ reg_val < MT6370_ICHG_900MA)
+ *val1 = 2680;
+ else
+ *val1 = 5000;
+
+ *val2 = 100;
+
+ return IIO_VAL_FRACTIONAL;
+ case MT6370_CHAN_VBUSDIV5:
+ *val1 = 25;
+ return IIO_VAL_INT;
+ case MT6370_CHAN_VBUSDIV2:
+ *val1 = 50;
+ 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_FRACTIONAL;
+ 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 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, _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)
+{
+ 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->adc_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 = "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(&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@xxxxxxxxxxx>");
+MODULE_DESCRIPTION("MT6370 ADC Drvier");
+MODULE_LICENSE("GPL v2");
--
2.7.4