iio/adc/mp2629_adc.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  * MP2629 Driver for ADC
0004  *
0005  * Copyright 2020 Monolithic Power Systems, Inc
0006  *
0007  * Author: Saravanan Sekar <sravanhome@gmail.com>
0008  */
0009
0010 #include <linux/iio/driver.h>
0011 #include <linux/iio/iio.h>
0012 #include <linux/iio/machine.h>
0013 #include <linux/mfd/mp2629.h>
0014 #include <linux/mod_devicetable.h>
0015 #include <linux/module.h>
0016 #include <linux/mutex.h>
0017 #include <linux/platform_device.h>
0018 #include <linux/regmap.h>
0019
0020 #define MP2629_REG_ADC_CTRL     0x03
0021 #define MP2629_REG_BATT_VOLT        0x0e
0022 #define MP2629_REG_SYSTEM_VOLT      0x0f
0023 #define MP2629_REG_INPUT_VOLT       0x11
0024 #define MP2629_REG_BATT_CURRENT     0x12
0025 #define MP2629_REG_INPUT_CURRENT    0x13
0026
0027 #define MP2629_ADC_START        BIT(7)
0028 #define MP2629_ADC_CONTINUOUS       BIT(6)
0029
0030 #define MP2629_MAP(_mp, _mpc) IIO_MAP(#_mp, "mp2629_charger", "mp2629-"_mpc)
0031
0032 #define MP2629_ADC_CHAN(_ch, _type) {               \
0033     .type = _type,                      \
0034     .indexed = 1,                       \
0035     .datasheet_name = #_ch,                 \
0036     .channel = MP2629_ ## _ch,              \
0037     .address = MP2629_REG_ ## _ch,              \
0038     .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),       \
0039     .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),   \
0040 }
0041
0042 struct mp2629_adc {
0043     struct regmap *regmap;
0044     struct device *dev;
0045 };
0046
0047 static struct iio_chan_spec mp2629_channels[] = {
0048     MP2629_ADC_CHAN(BATT_VOLT, IIO_VOLTAGE),
0049     MP2629_ADC_CHAN(SYSTEM_VOLT, IIO_VOLTAGE),
0050     MP2629_ADC_CHAN(INPUT_VOLT, IIO_VOLTAGE),
0051     MP2629_ADC_CHAN(BATT_CURRENT, IIO_CURRENT),
0052     MP2629_ADC_CHAN(INPUT_CURRENT, IIO_CURRENT)
0053 };
0054
0055 static struct iio_map mp2629_adc_maps[] = {
0056     MP2629_MAP(BATT_VOLT, "batt-volt"),
0057     MP2629_MAP(SYSTEM_VOLT, "system-volt"),
0058     MP2629_MAP(INPUT_VOLT, "input-volt"),
0059     MP2629_MAP(BATT_CURRENT, "batt-current"),
0060     MP2629_MAP(INPUT_CURRENT, "input-current")
0061 };
0062
0063 static int mp2629_read_raw(struct iio_dev *indio_dev,
0064             struct iio_chan_spec const *chan,
0065             int *val, int *val2, long mask)
0066 {
0067     struct mp2629_adc *info = iio_priv(indio_dev);
0068     unsigned int rval;
0069     int ret;
0070
0071     switch (mask) {
0072     case IIO_CHAN_INFO_RAW:
0073         ret = regmap_read(info->regmap, chan->address, &rval);
0074         if (ret)
0075             return ret;
0076
0077         if (chan->address == MP2629_INPUT_VOLT)
0078             rval &= GENMASK(6, 0);
0079         *val = rval;
0080         return IIO_VAL_INT;
0081
0082     case IIO_CHAN_INFO_SCALE:
0083         switch (chan->channel) {
0084         case MP2629_BATT_VOLT:
0085         case MP2629_SYSTEM_VOLT:
0086             *val = 20;
0087             return IIO_VAL_INT;
0088
0089         case MP2629_INPUT_VOLT:
0090             *val = 60;
0091             return IIO_VAL_INT;
0092
0093         case MP2629_BATT_CURRENT:
0094             *val = 175;
0095             *val2 = 10;
0096             return IIO_VAL_FRACTIONAL;
0097
0098         case MP2629_INPUT_CURRENT:
0099             *val = 133;
0100             *val2 = 10;
0101             return IIO_VAL_FRACTIONAL;
0102
0103         default:
0104             return -EINVAL;
0105         }
0106
0107     default:
0108         return -EINVAL;
0109     }
0110 }
0111
0112 static const struct iio_info mp2629_adc_info = {
0113     .read_raw = &mp2629_read_raw,
0114 };
0115
0116 static int mp2629_adc_probe(struct platform_device *pdev)
0117 {
0118     struct device *dev = &pdev->dev;
0119     struct mp2629_data *ddata = dev_get_drvdata(dev->parent);
0120     struct mp2629_adc *info;
0121     struct iio_dev *indio_dev;
0122     int ret;
0123
0124     indio_dev = devm_iio_device_alloc(dev, sizeof(*info));
0125     if (!indio_dev)
0126         return -ENOMEM;
0127
0128     info = iio_priv(indio_dev);
0129     info->regmap = ddata->regmap;
0130     info->dev = dev;
0131     platform_set_drvdata(pdev, indio_dev);
0132
0133     ret = regmap_update_bits(info->regmap, MP2629_REG_ADC_CTRL,
0134                 MP2629_ADC_START | MP2629_ADC_CONTINUOUS,
0135                 MP2629_ADC_START | MP2629_ADC_CONTINUOUS);
0136     if (ret) {
0137         dev_err(dev, "adc enable fail: %d\n", ret);
0138         return ret;
0139     }
0140
0141     ret = iio_map_array_register(indio_dev, mp2629_adc_maps);
0142     if (ret) {
0143         dev_err(dev, "IIO maps register fail: %d\n", ret);
0144         goto fail_disable;
0145     }
0146
0147     indio_dev->name = "mp2629-adc";
0148     indio_dev->channels = mp2629_channels;
0149     indio_dev->num_channels = ARRAY_SIZE(mp2629_channels);
0150     indio_dev->modes = INDIO_DIRECT_MODE;
0151     indio_dev->info = &mp2629_adc_info;
0152
0153     ret = iio_device_register(indio_dev);
0154     if (ret) {
0155         dev_err(dev, "IIO device register fail: %d\n", ret);
0156         goto fail_map_unregister;
0157     }
0158
0159     return 0;
0160
0161 fail_map_unregister:
0162     iio_map_array_unregister(indio_dev);
0163
0164 fail_disable:
0165     regmap_update_bits(info->regmap, MP2629_REG_ADC_CTRL,
0166                      MP2629_ADC_CONTINUOUS, 0);
0167     regmap_update_bits(info->regmap, MP2629_REG_ADC_CTRL,
0168                      MP2629_ADC_START, 0);
0169
0170     return ret;
0171 }
0172
0173 static int mp2629_adc_remove(struct platform_device *pdev)
0174 {
0175     struct iio_dev *indio_dev = platform_get_drvdata(pdev);
0176     struct mp2629_adc *info = iio_priv(indio_dev);
0177
0178     iio_device_unregister(indio_dev);
0179
0180     iio_map_array_unregister(indio_dev);
0181
0182     regmap_update_bits(info->regmap, MP2629_REG_ADC_CTRL,
0183                      MP2629_ADC_CONTINUOUS, 0);
0184     regmap_update_bits(info->regmap, MP2629_REG_ADC_CTRL,
0185                      MP2629_ADC_START, 0);
0186
0187     return 0;
0188 }
0189
0190 static const struct of_device_id mp2629_adc_of_match[] = {
0191     { .compatible = "mps,mp2629_adc"},
0192     {}
0193 };
0194 MODULE_DEVICE_TABLE(of, mp2629_adc_of_match);
0195
0196 static struct platform_driver mp2629_adc_driver = {
0197     .driver = {
0198         .name = "mp2629_adc",
0199         .of_match_table = mp2629_adc_of_match,
0200     },
0201     .probe      = mp2629_adc_probe,
0202     .remove     = mp2629_adc_remove,
0203 };
0204 module_platform_driver(mp2629_adc_driver);
0205
0206 MODULE_AUTHOR("Saravanan Sekar <sravanhome@gmail.com>");
0207 MODULE_DESCRIPTION("MP2629 ADC driver");
0208 MODULE_LICENSE("GPL");