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
  32 enum axp288_adc_id {
  33         AXP288_ADC_TS,
  34         AXP288_ADC_PMIC,
  35         AXP288_ADC_GP,
  36         AXP288_ADC_BATT_CHRG_I,
  37         AXP288_ADC_BATT_DISCHRG_I,
  38         AXP288_ADC_BATT_V,
  39         AXP288_ADC_NR_CHAN,
  40 };
  41
  42 struct axp288_adc_info {
  43         int irq;
  44         struct regmap *regmap;
  45 };
  46
  47 static const struct iio_chan_spec axp288_adc_channels[] = {
  48         {
  49                 .indexed = 1,
  50                 .type = IIO_TEMP,
  51                 .channel = 0,
  52                 .address = AXP288_TS_ADC_H,
  53                 .datasheet_name = "TS_PIN",
  54                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
  55         }, {
  56                 .indexed = 1,
  57                 .type = IIO_TEMP,
  58                 .channel = 1,
  59                 .address = AXP288_PMIC_ADC_H,
  60                 .datasheet_name = "PMIC_TEMP",
  61                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
  62         }, {
  63                 .indexed = 1,
  64                 .type = IIO_TEMP,
  65                 .channel = 2,
  66                 .address = AXP288_GP_ADC_H,
  67                 .datasheet_name = "GPADC",
  68                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
  69         }, {
  70                 .indexed = 1,
  71                 .type = IIO_CURRENT,
  72                 .channel = 3,
  73                 .address = AXP20X_BATT_CHRG_I_H,
  74                 .datasheet_name = "BATT_CHG_I",
  75                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
  76         }, {
  77                 .indexed = 1,
  78                 .type = IIO_CURRENT,
  79                 .channel = 4,
  80                 .address = AXP20X_BATT_DISCHRG_I_H,
  81                 .datasheet_name = "BATT_DISCHRG_I",
  82                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
  83         }, {
  84                 .indexed = 1,
  85                 .type = IIO_VOLTAGE,
  86                 .channel = 5,
  87                 .address = AXP20X_BATT_V_H,
  88                 .datasheet_name = "BATT_V",
  89                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
  90         },
  91 };
  92
  93 #define AXP288_ADC_MAP(_adc_channel_label, _consumer_dev_name,  \
  94                 _consumer_channel)                              \
  95         {                                                       \
  96                 .adc_channel_label = _adc_channel_label,        \
  97                 .consumer_dev_name = _consumer_dev_name,        \
  98                 .consumer_channel = _consumer_channel,          \
  99         }
 100
 101 /* for consumer drivers */
 102 static struct iio_map axp288_adc_default_maps[] = {
 103         AXP288_ADC_MAP("TS_PIN", "axp288-batt", "axp288-batt-temp"),
 104         AXP288_ADC_MAP("PMIC_TEMP", "axp288-pmic", "axp288-pmic-temp"),
 105         AXP288_ADC_MAP("GPADC", "axp288-gpadc", "axp288-system-temp"),
 106         AXP288_ADC_MAP("BATT_CHG_I", "axp288-chrg", "axp288-chrg-curr"),
 107         AXP288_ADC_MAP("BATT_DISCHRG_I", "axp288-chrg", "axp288-chrg-d-curr"),
 108         AXP288_ADC_MAP("BATT_V", "axp288-batt", "axp288-batt-volt"),
 109         {},
 110 };
 111
 112 static int axp288_adc_read_channel(int *val, unsigned long address,
 113                                 struct regmap *regmap)
 114 {
 115         u8 buf[2];
 116
 117         if (regmap_bulk_read(regmap, address, buf, 2))
 118                 return -EIO;
 119         *val = (buf[0] << 4) + ((buf[1] >> 4) & 0x0F);
 120
 121         return IIO_VAL_INT;
 122 }
 123
 124 static int axp288_adc_read_raw(struct iio_dev *indio_dev,
 125                         struct iio_chan_spec const *chan,
 126                         int *val, int *val2, long mask)
 127 {
 128         int ret;
 129         struct axp288_adc_info *info = iio_priv(indio_dev);
 130
 131         mutex_lock(&indio_dev->mlock);
 132         switch (mask) {
 133         case IIO_CHAN_INFO_RAW:
 134                 ret = axp288_adc_read_channel(val, chan->address, info->regmap);
 135                 break;
 136         default:
 137                 ret = -EINVAL;
 138         }
 139         mutex_unlock(&indio_dev->mlock);
 140
 141         return ret;
 142 }
 143
 144 static const struct iio_info axp288_adc_iio_info = {
 145         .read_raw = &axp288_adc_read_raw,
 146         .driver_module = THIS_MODULE,
 147 };
 148
 149 static int axp288_adc_probe(struct platform_device *pdev)
 150 {
 151         int ret;
 152         struct axp288_adc_info *info;
 153         struct iio_dev *indio_dev;
 154         struct axp20x_dev *axp20x = dev_get_drvdata(pdev->dev.parent);
 155
 156         indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*info));
 157         if (!indio_dev)
 158                 return -ENOMEM;
 159
 160         info = iio_priv(indio_dev);
 161         info->irq = platform_get_irq(pdev, 0);
 162         if (info->irq < 0) {
 163                 dev_err(&pdev->dev, "no irq resource?\n");
 164                 return info->irq;
 165         }
 166         platform_set_drvdata(pdev, indio_dev);
 167         info->regmap = axp20x->regmap;
 168         /*
 169          * Set ADC to enabled state at all time, including system suspend.
 170          * otherwise internal fuel gauge functionality may be affected.
 171          */
 172         ret = regmap_write(info->regmap, AXP20X_ADC_EN1, AXP288_ADC_EN_MASK);
 173         if (ret) {
 174                 dev_err(&pdev->dev, "unable to enable ADC device\n");
 175                 return ret;
 176         }
 177
 178         indio_dev->dev.parent = &pdev->dev;
 179         indio_dev->name = pdev->name;
 180         indio_dev->channels = axp288_adc_channels;
 181         indio_dev->num_channels = ARRAY_SIZE(axp288_adc_channels);
 182         indio_dev->info = &axp288_adc_iio_info;
 183         indio_dev->modes = INDIO_DIRECT_MODE;
 184         ret = iio_map_array_register(indio_dev, axp288_adc_default_maps);
 185         if (ret < 0)
 186                 return ret;
 187
 188         ret = iio_device_register(indio_dev);
 189         if (ret < 0) {
 190                 dev_err(&pdev->dev, "unable to register iio device\n");
 191                 goto err_array_unregister;
 192         }
 193         return 0;
 194
 195 err_array_unregister:
 196         iio_map_array_unregister(indio_dev);
 197
 198         return ret;
 199 }
 200
 201 static int axp288_adc_remove(struct platform_device *pdev)
 202 {
 203         struct iio_dev *indio_dev = platform_get_drvdata(pdev);
 204
 205         iio_device_unregister(indio_dev);
 206         iio_map_array_unregister(indio_dev);
 207
 208         return 0;
 209 }
 210
 211 static const struct platform_device_id axp288_adc_id_table[] = {
 212         { .name = "axp288_adc" },
 213         {},
 214 };
 215
 216 static struct platform_driver axp288_adc_driver = {
 217         .probe = axp288_adc_probe,
 218         .remove = axp288_adc_remove,
 219         .id_table = axp288_adc_id_table,
 220         .driver = {
 221                 .name = "axp288_adc",
 222         },
 223 };
 224
 225 MODULE_DEVICE_TABLE(platform, axp288_adc_id_table);
 226
 227 module_platform_driver(axp288_adc_driver);
 228
 229 MODULE_AUTHOR("Jacob Pan <jacob.jun.pan@linux.intel.com>");
 230 MODULE_DESCRIPTION("X-Powers AXP288 ADC Driver");
 231 MODULE_LICENSE("GPL");