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 /* for consumer drivers */
  96 static struct iio_map axp288_adc_default_maps[] = {
  97         IIO_MAP("TS_PIN", "axp288-batt", "axp288-batt-temp"),
  98         IIO_MAP("PMIC_TEMP", "axp288-pmic", "axp288-pmic-temp"),
  99         IIO_MAP("GPADC", "axp288-gpadc", "axp288-system-temp"),
 100         IIO_MAP("BATT_CHG_I", "axp288-chrg", "axp288-chrg-curr"),
 101         IIO_MAP("BATT_DISCHRG_I", "axp288-chrg", "axp288-chrg-d-curr"),
 102         IIO_MAP("BATT_V", "axp288-batt", "axp288-batt-volt"),
 103         {},
 104 };
 105
 106 static int axp288_adc_read_channel(int *val, unsigned long address,
 107                                 struct regmap *regmap)
 108 {
 109         u8 buf[2];
 110
 111         if (regmap_bulk_read(regmap, address, buf, 2))
 112                 return -EIO;
 113         *val = (buf[0] << 4) + ((buf[1] >> 4) & 0x0F);
 114
 115         return IIO_VAL_INT;
 116 }
 117
 118 static int axp288_adc_set_ts(struct regmap *regmap, unsigned int mode,
 119                                 unsigned long address)
 120 {
 121         int ret;
 122
 123         /* channels other than GPADC do not need to switch TS pin */
 124         if (address != AXP288_GP_ADC_H)
 125                 return 0;
 126
 127         ret = regmap_write(regmap, AXP288_ADC_TS_PIN_CTRL, mode);
 128         if (ret)
 129                 return ret;
 130
 131         /* When switching to the GPADC pin give things some time to settle */
 132         if (mode == AXP288_ADC_TS_PIN_GPADC)
 133                 usleep_range(6000, 10000);
 134
 135         return 0;
 136 }
 137
 138 static int axp288_adc_read_raw(struct iio_dev *indio_dev,
 139                         struct iio_chan_spec const *chan,
 140                         int *val, int *val2, long mask)
 141 {
 142         int ret;
 143         struct axp288_adc_info *info = iio_priv(indio_dev);
 144
 145         mutex_lock(&indio_dev->mlock);
 146         switch (mask) {
 147         case IIO_CHAN_INFO_RAW:
 148                 if (axp288_adc_set_ts(info->regmap, AXP288_ADC_TS_PIN_GPADC,
 149                                         chan->address)) {
 150                         dev_err(&indio_dev->dev, "GPADC mode\n");
 151                         ret = -EINVAL;
 152                         break;
 153                 }
 154                 ret = axp288_adc_read_channel(val, chan->address, info->regmap);
 155                 if (axp288_adc_set_ts(info->regmap, AXP288_ADC_TS_PIN_ON,
 156                                                 chan->address))
 157                         dev_err(&indio_dev->dev, "TS pin restore\n");
 158                 break;
 159         default:
 160                 ret = -EINVAL;
 161         }
 162         mutex_unlock(&indio_dev->mlock);
 163
 164         return ret;
 165 }
 166
 167 static int axp288_adc_set_state(struct regmap *regmap)
 168 {
 169         /* ADC should be always enabled for internal FG to function */
 170         if (regmap_write(regmap, AXP288_ADC_TS_PIN_CTRL, AXP288_ADC_TS_PIN_ON))
 171                 return -EIO;
 172
 173         return regmap_write(regmap, AXP20X_ADC_EN1, AXP288_ADC_EN_MASK);
 174 }
 175
 176 static const struct iio_info axp288_adc_iio_info = {
 177         .read_raw = &axp288_adc_read_raw,
 178 };
 179
 180 static int axp288_adc_probe(struct platform_device *pdev)
 181 {
 182         int ret;
 183         struct axp288_adc_info *info;
 184         struct iio_dev *indio_dev;
 185         struct axp20x_dev *axp20x = dev_get_drvdata(pdev->dev.parent);
 186
 187         indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*info));
 188         if (!indio_dev)
 189                 return -ENOMEM;
 190
 191         info = iio_priv(indio_dev);
 192         info->irq = platform_get_irq(pdev, 0);
 193         if (info->irq < 0) {
 194                 dev_err(&pdev->dev, "no irq resource?\n");
 195                 return info->irq;
 196         }
 197         platform_set_drvdata(pdev, indio_dev);
 198         info->regmap = axp20x->regmap;
 199         /*
 200          * Set ADC to enabled state at all time, including system suspend.
 201          * otherwise internal fuel gauge functionality may be affected.
 202          */
 203         ret = axp288_adc_set_state(axp20x->regmap);
 204         if (ret) {
 205                 dev_err(&pdev->dev, "unable to enable ADC device\n");
 206                 return ret;
 207         }
 208
 209         indio_dev->dev.parent = &pdev->dev;
 210         indio_dev->name = pdev->name;
 211         indio_dev->channels = axp288_adc_channels;
 212         indio_dev->num_channels = ARRAY_SIZE(axp288_adc_channels);
 213         indio_dev->info = &axp288_adc_iio_info;
 214         indio_dev->modes = INDIO_DIRECT_MODE;
 215         ret = iio_map_array_register(indio_dev, axp288_adc_default_maps);
 216         if (ret < 0)
 217                 return ret;
 218
 219         ret = iio_device_register(indio_dev);
 220         if (ret < 0) {
 221                 dev_err(&pdev->dev, "unable to register iio device\n");
 222                 goto err_array_unregister;
 223         }
 224         return 0;
 225
 226 err_array_unregister:
 227         iio_map_array_unregister(indio_dev);
 228
 229         return ret;
 230 }
 231
 232 static int axp288_adc_remove(struct platform_device *pdev)
 233 {
 234         struct iio_dev *indio_dev = platform_get_drvdata(pdev);
 235
 236         iio_device_unregister(indio_dev);
 237         iio_map_array_unregister(indio_dev);
 238
 239         return 0;
 240 }
 241
 242 static const struct platform_device_id axp288_adc_id_table[] = {
 243         { .name = "axp288_adc" },
 244         {},
 245 };
 246
 247 static struct platform_driver axp288_adc_driver = {
 248         .probe = axp288_adc_probe,
 249         .remove = axp288_adc_remove,
 250         .id_table = axp288_adc_id_table,
 251         .driver = {
 252                 .name = "axp288_adc",
 253         },
 254 };
 255
 256 MODULE_DEVICE_TABLE(platform, axp288_adc_id_table);
 257
 258 module_platform_driver(axp288_adc_driver);
 259
 260 MODULE_AUTHOR("Jacob Pan <jacob.jun.pan@linux.intel.com>");
 261 MODULE_DESCRIPTION("X-Powers AXP288 ADC Driver");
 262 MODULE_LICENSE("GPL");