[PATCH v11 3/6] iio: adc: mp2629: Add support for mp2629 ADC driver

Saravanan Sekar
2020-04-30T15:58:45Z

Add support for 8-bit resolution ADC readings for input power
supply and battery charging measurement. Provides voltage, current
readings to mp2629 power supply driver.

Signed-off-by: Saravanan Sekar <sravanhome@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---
drivers/iio/adc/Kconfig | 10 ++
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/mp2629_adc.c | 208 +++++++++++++++++++++++++++++++++++
include/linux/mfd/mp2629.h | 9 ++
4 files changed, 228 insertions(+)
create mode 100644 drivers/iio/adc/mp2629_adc.c

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 82e33082958c..ef0c0cd31855 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -680,6 +680,16 @@ config MESON_SARADC
To compile this driver as a module, choose M here: the
module will be called meson_saradc.

+config MP2629_ADC
+ tristate "Monolithic MP2629 ADC driver"
+ depends on MFD_MP2629
+ help
+ Say yes to have support for battery charger IC MP2629 ADC device
+ accessed over I2C.
+
+ This driver provides ADC conversion of system, input power supply
+ and battery voltage & current information.
+
config NAU7802
tristate "Nuvoton NAU7802 ADC driver"
depends on I2C
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 919228900df9..f14416c245a6 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -64,6 +64,7 @@ obj-$(CONFIG_MCP3911) += mcp3911.o
obj-$(CONFIG_MEDIATEK_MT6577_AUXADC) += mt6577_auxadc.o
obj-$(CONFIG_MEN_Z188_ADC) += men_z188_adc.o
obj-$(CONFIG_MESON_SARADC) += meson_saradc.o
+obj-$(CONFIG_MP2629_ADC) += mp2629_adc.o
obj-$(CONFIG_MXS_LRADC_ADC) += mxs-lradc-adc.o
obj-$(CONFIG_NAU7802) += nau7802.o
obj-$(CONFIG_NPCM_ADC) += npcm_adc.o
diff --git a/drivers/iio/adc/mp2629_adc.c b/drivers/iio/adc/mp2629_adc.c
new file mode 100644
index 000000000000..331a9a728217
--- /dev/null
+++ b/drivers/iio/adc/mp2629_adc.c
@@ -0,0 +1,208 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * MP2629 Driver for ADC
+ *
+ * Copyright 2020 Monolithic Power Systems, Inc
+ *
+ * Author: Saravanan Sekar <sravanhome@gmail.com>
+ */
+
+#include <linux/iio/driver.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/machine.h>
+#include <linux/mfd/mp2629.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#define MP2629_REG_ADC_CTRL 0x03
+#define MP2629_REG_BATT_VOLT 0x0e
+#define MP2629_REG_SYSTEM_VOLT 0x0f
+#define MP2629_REG_INPUT_VOLT 0x11
+#define MP2629_REG_BATT_CURRENT 0x12
+#define MP2629_REG_INPUT_CURRENT 0x13
+
+#define MP2629_ADC_START BIT(7)
+#define MP2629_ADC_CONTINUOUS BIT(6)
+
+#define MP2629_MAP(_mp, _mpc) IIO_MAP(#_mp, "mp2629_charger", "mp2629-"_mpc)
+
+#define MP2629_ADC_CHAN(_ch, _type) { \
+ .type = _type, \
+ .indexed = 1, \
+ .datasheet_name = #_ch, \
+ .channel = MP2629_ ## _ch, \
+ .address = MP2629_REG_ ## _ch, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
+}
+
+struct mp2629_adc {
+ struct regmap *regmap;
+ struct device *dev;
+};
+
+static struct iio_chan_spec mp2629_channels[] = {
+ MP2629_ADC_CHAN(BATT_VOLT, IIO_VOLTAGE),
+ MP2629_ADC_CHAN(SYSTEM_VOLT, IIO_VOLTAGE),
+ MP2629_ADC_CHAN(INPUT_VOLT, IIO_VOLTAGE),
+ MP2629_ADC_CHAN(BATT_CURRENT, IIO_CURRENT),
+ MP2629_ADC_CHAN(INPUT_CURRENT, IIO_CURRENT)
+};
+
+static struct iio_map mp2629_adc_maps[] = {
+ MP2629_MAP(BATT_VOLT, "batt-volt"),
+ MP2629_MAP(SYSTEM_VOLT, "system-volt"),
+ MP2629_MAP(INPUT_VOLT, "input-volt"),
+ MP2629_MAP(BATT_CURRENT, "batt-current"),
+ MP2629_MAP(INPUT_CURRENT, "input-current")
+};
+
+static int mp2629_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct mp2629_adc *info = iio_priv(indio_dev);
+ unsigned int rval;
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ ret = regmap_read(info->regmap, chan->address, &rval);
+ if (ret)
+ return ret;
+
+ if (chan->address == MP2629_INPUT_VOLT)
+ rval &= GENMASK(6, 0);
+ *val = rval;
+ return IIO_VAL_INT;
+
+ case IIO_CHAN_INFO_SCALE:
+ switch (chan->channel) {
+ case MP2629_BATT_VOLT:
+ case MP2629_SYSTEM_VOLT:
+ *val = 20;
+ return IIO_VAL_INT;
+
+ case MP2629_INPUT_VOLT:
+ *val = 60;
+ return IIO_VAL_INT;
+
+ case MP2629_BATT_CURRENT:
+ *val = 175;
+ *val2 = 10;
+ return IIO_VAL_FRACTIONAL;
+
+ case MP2629_INPUT_CURRENT:
+ *val = 133;
+ *val2 = 10;
+ return IIO_VAL_FRACTIONAL;
+
+ default:
+ return -EINVAL;
+ }
+
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct iio_info mp2629_adc_info = {
+ .read_raw = &mp2629_read_raw,
+};
+
+static int mp2629_adc_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct mp2629_data *ddata = dev_get_drvdata(dev->parent);
+ struct mp2629_adc *info;
+ struct iio_dev *indio_dev;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(dev, sizeof(*info));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ info = iio_priv(indio_dev);
+ info->regmap = ddata->regmap;
+ info->dev = dev;
+ platform_set_drvdata(pdev, indio_dev);
+
+ ret = regmap_update_bits(info->regmap, MP2629_REG_ADC_CTRL,
+ MP2629_ADC_START | MP2629_ADC_CONTINUOUS,
+ MP2629_ADC_START | MP2629_ADC_CONTINUOUS);
+ if (ret) {
+ dev_err(dev, "adc enable fail: %d\n", ret);
+ return ret;
+ }
+
+ ret = iio_map_array_register(indio_dev, mp2629_adc_maps);
+ if (ret) {
+ dev_err(dev, "IIO maps register fail: %d\n", ret);
+ goto fail_disable;
+ }
+
+ indio_dev->name = "mp2629-adc";
+ indio_dev->dev.parent = dev;
+ indio_dev->channels = mp2629_channels;
+ indio_dev->num_channels = ARRAY_SIZE(mp2629_channels);
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->info = &mp2629_adc_info;
+
+ ret = iio_device_register(indio_dev);
+ if (ret) {
+ dev_err(dev, "IIO device register fail: %d\n", ret);
+ goto fail_map_unregister;
+ }
+
+ return 0;
+
+fail_map_unregister:
+ iio_map_array_unregister(indio_dev);
+
+fail_disable:
+ regmap_update_bits(info->regmap, MP2629_REG_ADC_CTRL,
+ MP2629_ADC_CONTINUOUS, 0);
+ regmap_update_bits(info->regmap, MP2629_REG_ADC_CTRL,
+ MP2629_ADC_START, 0);
+
+ return ret;
+}
+
+static int mp2629_adc_remove(struct platform_device *pdev)
+{
+ struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+ struct mp2629_adc *info = iio_priv(indio_dev);
+
+ iio_device_unregister(indio_dev);
+
+ iio_map_array_unregister(indio_dev);
+
+ regmap_update_bits(info->regmap, MP2629_REG_ADC_CTRL,
+ MP2629_ADC_CONTINUOUS, 0);
+ regmap_update_bits(info->regmap, MP2629_REG_ADC_CTRL,
+ MP2629_ADC_START, 0);
+
+ return 0;
+}
+
+static const struct of_device_id mp2629_adc_of_match[] = {
+ { .compatible = "mps,mp2629_adc"},
+ {}
+};
+MODULE_DEVICE_TABLE(of, mp2629_adc_of_match);
+
+static struct platform_driver mp2629_adc_driver = {
+ .driver = {
+ .name = "mp2629_adc",
+ .of_match_table = mp2629_adc_of_match,
+ },
+ .probe = mp2629_adc_probe,
+ .remove = mp2629_adc_remove,
+};
+module_platform_driver(mp2629_adc_driver);
+
+MODULE_AUTHOR("Saravanan Sekar <sravanhome@gmail.com>");
+MODULE_DESCRIPTION("MP2629 ADC driver");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/mfd/mp2629.h b/include/linux/mfd/mp2629.h
index baaeeaf82949..89b706900b57 100644
--- a/include/linux/mfd/mp2629.h
+++ b/include/linux/mfd/mp2629.h
@@ -14,4 +14,13 @@ struct mp2629_data {
struct regmap *regmap;
};

+enum mp2629_adc_chan {
+ MP2629_BATT_VOLT,
+ MP2629_SYSTEM_VOLT,
+ MP2629_INPUT_VOLT,
+ MP2629_BATT_CURRENT,
+ MP2629_INPUT_CURRENT,
+ MP2629_ADC_CHAN_END
+};
+
#endif
--
2.17.1