drivers/iio/adc/axp288_adc.c

   1 /*
   2  * axp288_adc.c - X-Powers AXP288 PMIC ADC Driver
   3  *
   4  * Copyright (C) 2014 Intel Corporation
   5  *
   6  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; version 2 of the License.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  15  * General Public License for more details.
  16  *
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/kernel.h>
  21 #include <linux/device.h>
  22 #include <linux/regmap.h>
  23 #include <linux/mfd/axp20x.h>
  24 #include <linux/platform_device.h>
  25
  26 #include <linux/iio/iio.h>
  27 #include <linux/iio/machine.h>
  28 #include <linux/iio/driver.h>
  29
  30 #define AXP288_ADC_EN_MASK              0xF1
  31 #define AXP288_ADC_TS_PIN_GPADC         0xF2
  32 #define AXP288_ADC_TS_PIN_ON            0xF3
  33
  34 enum axp288_adc_id {
  35         AXP288_ADC_TS,
  36         AXP288_ADC_PMIC,
  37         AXP288_ADC_GP,
  38         AXP288_ADC_BATT_CHRG_I,
  39         AXP288_ADC_BATT_DISCHRG_I,
  40         AXP288_ADC_BATT_V,
  41         AXP288_ADC_NR_CHAN,
  42 };
  43
  44 struct axp288_adc_info {
  45         int irq;
  46         struct regmap *regmap;
  47 };
  48
  49 static const struct iio_chan_spec axp288_adc_channels[] = {
  50         {
  51                 .indexed = 1,
  52                 .type = IIO_TEMP,
  53                 .channel = 0,
  54                 .address = AXP288_TS_ADC_H,
  55                 .datasheet_name = "TS_PIN",
  56                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
  57         }, {
  58                 .indexed = 1,
  59                 .type = IIO_TEMP,
  60                 .channel = 1,
  61                 .address = AXP288_PMIC_ADC_H,
  62                 .datasheet_name = "PMIC_TEMP",
  63                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
  64         }, {
  65                 .indexed = 1,
  66                 .type = IIO_TEMP,
  67                 .channel = 2,
  68                 .address = AXP288_GP_ADC_H,
  69                 .datasheet_name = "GPADC",
  70                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
  71         }, {
  72                 .indexed = 1,
  73                 .type = IIO_CURRENT,
  74                 .channel = 3,
  75                 .address = AXP20X_BATT_CHRG_I_H,
  76                 .datasheet_name = "BATT_CHG_I",
  77                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
  78         }, {
  79                 .indexed = 1,
  80                 .type = IIO_CURRENT,
  81                 .channel = 4,
  82                 .address = AXP20X_BATT_DISCHRG_I_H,
  83                 .datasheet_name = "BATT_DISCHRG_I",
  84                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
  85         }, {
  86                 .indexed = 1,
  87                 .type = IIO_VOLTAGE,
  88                 .channel = 5,
  89                 .address = AXP20X_BATT_V_H,
  90                 .datasheet_name = "BATT_V",
  91                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
  92         },
  93 };
  94
  95 #define AXP288_ADC_MAP(_adc_channel_label, _consumer_dev_name,  \
  96                 _consumer_channel)                              \
  97         {                                                       \
  98                 .adc_channel_label = _adc_channel_label,        \
  99                 .consumer_dev_name = _consumer_dev_name,        \
 100                 .consumer_channel = _consumer_channel,          \
 101         }
 102
 103 /* for consumer drivers */
 104 static struct iio_map axp288_adc_default_maps[] = {
 105         AXP288_ADC_MAP("TS_PIN", "axp288-batt", "axp288-batt-temp"),
 106         AXP288_ADC_MAP("PMIC_TEMP", "axp288-pmic", "axp288-pmic-temp"),
 107         AXP288_ADC_MAP("GPADC", "axp288-gpadc", "axp288-system-temp"),
 108         AXP288_ADC_MAP("BATT_CHG_I", "axp288-chrg", "axp288-chrg-curr"),
 109         AXP288_ADC_MAP("BATT_DISCHRG_I", "axp288-chrg", "axp288-chrg-d-curr"),
 110         AXP288_ADC_MAP("BATT_V", "axp288-batt", "axp288-batt-volt"),
 111         {},
 112 };
 113
 114 static int axp288_adc_read_channel(int *val, unsigned long address,
 115                                 struct regmap *regmap)
 116 {
 117         u8 buf[2];
 118
 119         if (regmap_bulk_read(regmap, address, buf, 2))
 120                 return -EIO;
 121         *val = (buf[0] << 4) + ((buf[1] >> 4) & 0x0F);
 122
 123         return IIO_VAL_INT;
 124 }
 125
 126 static int axp288_adc_set_ts(struct regmap *regmap, unsigned int mode,
 127                                 unsigned long address)
 128 {
 129         int ret;
 130
 131         /* channels other than GPADC do not need to switch TS pin */
 132         if (address != AXP288_GP_ADC_H)
 133                 return 0;
 134
 135         ret = regmap_write(regmap, AXP288_ADC_TS_PIN_CTRL, mode);
 136         if (ret)
 137                 return ret;
 138
 139         /* When switching to the GPADC pin give things some time to settle */
 140         if (mode == AXP288_ADC_TS_PIN_GPADC)
 141                 usleep_range(6000, 10000);
 142
 143         return 0;
 144 }
 145
 146 static int axp288_adc_read_raw(struct iio_dev *indio_dev,
 147                         struct iio_chan_spec const *chan,
 148                         int *val, int *val2, long mask)
 149 {
 150         int ret;
 151         struct axp288_adc_info *info = iio_priv(indio_dev);
 152
 153         mutex_lock(&indio_dev->mlock);
 154         switch (mask) {
 155         case IIO_CHAN_INFO_RAW:
 156                 if (axp288_adc_set_ts(info->regmap, AXP288_ADC_TS_PIN_GPADC,
 157                                         chan->address)) {
 158                         dev_err(&indio_dev->dev, "GPADC mode\n");
 159                         ret = -EINVAL;
 160                         break;
 161                 }
 162                 ret = axp288_adc_read_channel(val, chan->address, info->regmap);
 163                 if (axp288_adc_set_ts(info->regmap, AXP288_ADC_TS_PIN_ON,
 164                                                 chan->address))
 165                         dev_err(&indio_dev->dev, "TS pin restore\n");
 166                 break;
 167         default:
 168                 ret = -EINVAL;
 169         }
 170         mutex_unlock(&indio_dev->mlock);
 171
 172         return ret;
 173 }
 174
 175 static int axp288_adc_set_state(struct regmap *regmap)
 176 {
 177         /* ADC should be always enabled for internal FG to function */
 178         if (regmap_write(regmap, AXP288_ADC_TS_PIN_CTRL, AXP288_ADC_TS_PIN_ON))
 179                 return -EIO;
 180
 181         return regmap_write(regmap, AXP20X_ADC_EN1, AXP288_ADC_EN_MASK);
 182 }
 183
 184 static const struct iio_info axp288_adc_iio_info = {
 185         .read_raw = &axp288_adc_read_raw,
 186         .driver_module = THIS_MODULE,
 187 };
 188
 189 static int axp288_adc_probe(struct platform_device *pdev)
 190 {
 191         int ret;
 192         struct axp288_adc_info *info;
 193         struct iio_dev *indio_dev;
 194         struct axp20x_dev *axp20x = dev_get_drvdata(pdev->dev.parent);
 195
 196         indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*info));
 197         if (!indio_dev)
 198                 return -ENOMEM;
 199
 200         info = iio_priv(indio_dev);
 201         info->irq = platform_get_irq(pdev, 0);
 202         if (info->irq < 0) {
 203                 dev_err(&pdev->dev, "no irq resource?\n");
 204                 return info->irq;
 205         }
 206         platform_set_drvdata(pdev, indio_dev);
 207         info->regmap = axp20x->regmap;
 208         /*
 209          * Set ADC to enabled state at all time, including system suspend.
 210          * otherwise internal fuel gauge functionality may be affected.
 211          */
 212         ret = axp288_adc_set_state(axp20x->regmap);
 213         if (ret) {
 214                 dev_err(&pdev->dev, "unable to enable ADC device\n");
 215                 return ret;
 216         }
 217
 218         indio_dev->dev.parent = &pdev->dev;
 219         indio_dev->name = pdev->name;
 220         indio_dev->channels = axp288_adc_channels;
 221         indio_dev->num_channels = ARRAY_SIZE(axp288_adc_channels);
 222         indio_dev->info = &axp288_adc_iio_info;
 223         indio_dev->modes = INDIO_DIRECT_MODE;
 224         ret = iio_map_array_register(indio_dev, axp288_adc_default_maps);
 225         if (ret < 0)
 226                 return ret;
 227
 228         ret = iio_device_register(indio_dev);
 229         if (ret < 0) {
 230                 dev_err(&pdev->dev, "unable to register iio device\n");
 231                 goto err_array_unregister;
 232         }
 233         return 0;
 234
 235 err_array_unregister:
 236         iio_map_array_unregister(indio_dev);
 237
 238         return ret;
 239 }
 240
 241 static int axp288_adc_remove(struct platform_device *pdev)
 242 {
 243         struct iio_dev *indio_dev = platform_get_drvdata(pdev);
 244
 245         iio_device_unregister(indio_dev);
 246         iio_map_array_unregister(indio_dev);
 247
 248         return 0;
 249 }
 250
 251 static const struct platform_device_id axp288_adc_id_table[] = {
 252         { .name = "axp288_adc" },
 253         {},
 254 };
 255
 256 static struct platform_driver axp288_adc_driver = {
 257         .probe = axp288_adc_probe,
 258         .remove = axp288_adc_remove,
 259         .id_table = axp288_adc_id_table,
 260         .driver = {
 261                 .name = "axp288_adc",
 262         },
 263 };
 264
 265 MODULE_DEVICE_TABLE(platform, axp288_adc_id_table);
 266
 267 module_platform_driver(axp288_adc_driver);
 268
 269 MODULE_AUTHOR("Jacob Pan <jacob.jun.pan@linux.intel.com>");
 270 MODULE_DESCRIPTION("X-Powers AXP288 ADC Driver");
 271 MODULE_LICENSE("GPL");