iio: adc: mp2629: Add support for mp2629 ADC driver

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>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 12bb8b7..a864ede 100644 (file)
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -692,6 +692,16 @@ 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 6378078..78a1963 100644 (file)
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -65,6 +65,7 @@ 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 (file)
index 0000000..331a9a7
--- /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 baaeeaf..89b7069 100644 (file)
--- 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