drivers/iio/adc/axp288_adc.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * axp288_adc.c - X-Powers AXP288 PMIC ADC Driver
   4  *
   5  * Copyright (C) 2014 Intel Corporation
   6  *
   7  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   8  */
   9
  10 #include <linux/dmi.h>
  11 #include <linux/module.h>
  12 #include <linux/mutex.h>
  13 #include <linux/kernel.h>
  14 #include <linux/device.h>
  15 #include <linux/regmap.h>
  16 #include <linux/mfd/axp20x.h>
  17 #include <linux/platform_device.h>
  18
  19 #include <linux/iio/iio.h>
  20 #include <linux/iio/machine.h>
  21 #include <linux/iio/driver.h>
  22
  23 /*
  24  * This mask enables all ADCs except for the battery temp-sensor (TS), that is
  25  * left as-is to avoid breaking charging on devices without a temp-sensor.
  26  */
  27 #define AXP288_ADC_EN_MASK                              0xF0
  28 #define AXP288_ADC_TS_ENABLE                            0x01
  29
  30 #define AXP288_ADC_TS_BIAS_MASK                         GENMASK(5, 4)
  31 #define AXP288_ADC_TS_BIAS_20UA                         (0 << 4)
  32 #define AXP288_ADC_TS_BIAS_40UA                         (1 << 4)
  33 #define AXP288_ADC_TS_BIAS_60UA                         (2 << 4)
  34 #define AXP288_ADC_TS_BIAS_80UA                         (3 << 4)
  35 #define AXP288_ADC_TS_CURRENT_ON_OFF_MASK               GENMASK(1, 0)
  36 #define AXP288_ADC_TS_CURRENT_OFF                       (0 << 0)
  37 #define AXP288_ADC_TS_CURRENT_ON_WHEN_CHARGING          (1 << 0)
  38 #define AXP288_ADC_TS_CURRENT_ON_ONDEMAND               (2 << 0)
  39 #define AXP288_ADC_TS_CURRENT_ON                        (3 << 0)
  40
  41 enum axp288_adc_id {
  42         AXP288_ADC_TS,
  43         AXP288_ADC_PMIC,
  44         AXP288_ADC_GP,
  45         AXP288_ADC_BATT_CHRG_I,
  46         AXP288_ADC_BATT_DISCHRG_I,
  47         AXP288_ADC_BATT_V,
  48         AXP288_ADC_NR_CHAN,
  49 };
  50
  51 struct axp288_adc_info {
  52         int irq;
  53         struct regmap *regmap;
  54         /* lock to protect against multiple access to the device */
  55         struct mutex lock;
  56         bool ts_enabled;
  57 };
  58
  59 static const struct iio_chan_spec axp288_adc_channels[] = {
  60         {
  61                 .indexed = 1,
  62                 .type = IIO_TEMP,
  63                 .channel = 0,
  64                 .address = AXP288_TS_ADC_H,
  65                 .datasheet_name = "TS_PIN",
  66                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
  67         }, {
  68                 .indexed = 1,
  69                 .type = IIO_TEMP,
  70                 .channel = 1,
  71                 .address = AXP288_PMIC_ADC_H,
  72                 .datasheet_name = "PMIC_TEMP",
  73                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
  74         }, {
  75                 .indexed = 1,
  76                 .type = IIO_TEMP,
  77                 .channel = 2,
  78                 .address = AXP288_GP_ADC_H,
  79                 .datasheet_name = "GPADC",
  80                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
  81         }, {
  82                 .indexed = 1,
  83                 .type = IIO_CURRENT,
  84                 .channel = 3,
  85                 .address = AXP20X_BATT_CHRG_I_H,
  86                 .datasheet_name = "BATT_CHG_I",
  87                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
  88         }, {
  89                 .indexed = 1,
  90                 .type = IIO_CURRENT,
  91                 .channel = 4,
  92                 .address = AXP20X_BATT_DISCHRG_I_H,
  93                 .datasheet_name = "BATT_DISCHRG_I",
  94                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
  95         }, {
  96                 .indexed = 1,
  97                 .type = IIO_VOLTAGE,
  98                 .channel = 5,
  99                 .address = AXP20X_BATT_V_H,
 100                 .datasheet_name = "BATT_V",
 101                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
 102         },
 103 };
 104
 105 /* for consumer drivers */
 106 static const struct iio_map axp288_adc_default_maps[] = {
 107         IIO_MAP("TS_PIN", "axp288-batt", "axp288-batt-temp"),
 108         IIO_MAP("PMIC_TEMP", "axp288-pmic", "axp288-pmic-temp"),
 109         IIO_MAP("GPADC", "axp288-gpadc", "axp288-system-temp"),
 110         IIO_MAP("BATT_CHG_I", "axp288-chrg", "axp288-chrg-curr"),
 111         IIO_MAP("BATT_DISCHRG_I", "axp288-chrg", "axp288-chrg-d-curr"),
 112         IIO_MAP("BATT_V", "axp288-batt", "axp288-batt-volt"),
 113         {},
 114 };
 115
 116 static int axp288_adc_read_channel(int *val, unsigned long address,
 117                                 struct regmap *regmap)
 118 {
 119         u8 buf[2];
 120
 121         if (regmap_bulk_read(regmap, address, buf, 2))
 122                 return -EIO;
 123         *val = (buf[0] << 4) + ((buf[1] >> 4) & 0x0F);
 124
 125         return IIO_VAL_INT;
 126 }
 127
 128 /*
 129  * The current-source used for the battery temp-sensor (TS) is shared
 130  * with the GPADC. For proper fuel-gauge and charger operation the TS
 131  * current-source needs to be permanently on. But to read the GPADC we
 132  * need to temporary switch the TS current-source to ondemand, so that
 133  * the GPADC can use it, otherwise we will always read an all 0 value.
 134  */
 135 static int axp288_adc_set_ts(struct axp288_adc_info *info,
 136                              unsigned int mode, unsigned long address)
 137 {
 138         int ret;
 139
 140         /* No need to switch the current-source if the TS pin is disabled */
 141         if (!info->ts_enabled)
 142                 return 0;
 143
 144         /* Channels other than GPADC do not need the current source */
 145         if (address != AXP288_GP_ADC_H)
 146                 return 0;
 147
 148         ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
 149                                  AXP288_ADC_TS_CURRENT_ON_OFF_MASK, mode);
 150         if (ret)
 151                 return ret;
 152
 153         /* When switching to the GPADC pin give things some time to settle */
 154         if (mode == AXP288_ADC_TS_CURRENT_ON_ONDEMAND)
 155                 usleep_range(6000, 10000);
 156
 157         return 0;
 158 }
 159
 160 static int axp288_adc_read_raw(struct iio_dev *indio_dev,
 161                         struct iio_chan_spec const *chan,
 162                         int *val, int *val2, long mask)
 163 {
 164         int ret;
 165         struct axp288_adc_info *info = iio_priv(indio_dev);
 166
 167         mutex_lock(&info->lock);
 168         switch (mask) {
 169         case IIO_CHAN_INFO_RAW:
 170                 if (axp288_adc_set_ts(info, AXP288_ADC_TS_CURRENT_ON_ONDEMAND,
 171                                         chan->address)) {
 172                         dev_err(&indio_dev->dev, "GPADC mode\n");
 173                         ret = -EINVAL;
 174                         break;
 175                 }
 176                 ret = axp288_adc_read_channel(val, chan->address, info->regmap);
 177                 if (axp288_adc_set_ts(info, AXP288_ADC_TS_CURRENT_ON,
 178                                                 chan->address))
 179                         dev_err(&indio_dev->dev, "TS pin restore\n");
 180                 break;
 181         default:
 182                 ret = -EINVAL;
 183         }
 184         mutex_unlock(&info->lock);
 185
 186         return ret;
 187 }
 188
 189 /*
 190  * We rely on the machine's firmware to correctly setup the TS pin bias current
 191  * at boot. This lists systems with broken fw where we need to set it ourselves.
 192  */
 193 static const struct dmi_system_id axp288_adc_ts_bias_override[] = {
 194         {
 195                 /* Lenovo Ideapad 100S (11 inch) */
 196                 .matches = {
 197                   DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
 198                   DMI_MATCH(DMI_PRODUCT_VERSION, "Lenovo ideapad 100S-11IBY"),
 199                 },
 200                 .driver_data = (void *)(uintptr_t)AXP288_ADC_TS_BIAS_80UA,
 201         },
 202         {
 203                 /* Nuvision Solo 10 Draw */
 204                 .matches = {
 205                   DMI_MATCH(DMI_SYS_VENDOR, "TMAX"),
 206                   DMI_MATCH(DMI_PRODUCT_NAME, "TM101W610L"),
 207                 },
 208                 .driver_data = (void *)(uintptr_t)AXP288_ADC_TS_BIAS_80UA,
 209         },
 210         {}
 211 };
 212
 213 static int axp288_adc_initialize(struct axp288_adc_info *info)
 214 {
 215         const struct dmi_system_id *bias_override;
 216         int ret, adc_enable_val;
 217
 218         bias_override = dmi_first_match(axp288_adc_ts_bias_override);
 219         if (bias_override) {
 220                 ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
 221                                          AXP288_ADC_TS_BIAS_MASK,
 222                                          (uintptr_t)bias_override->driver_data);
 223                 if (ret)
 224                         return ret;
 225         }
 226
 227         /*
 228          * Determine if the TS pin is enabled and set the TS current-source
 229          * accordingly.
 230          */
 231         ret = regmap_read(info->regmap, AXP20X_ADC_EN1, &adc_enable_val);
 232         if (ret)
 233                 return ret;
 234
 235         if (adc_enable_val & AXP288_ADC_TS_ENABLE) {
 236                 info->ts_enabled = true;
 237                 ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
 238                                          AXP288_ADC_TS_CURRENT_ON_OFF_MASK,
 239                                          AXP288_ADC_TS_CURRENT_ON);
 240         } else {
 241                 info->ts_enabled = false;
 242                 ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
 243                                          AXP288_ADC_TS_CURRENT_ON_OFF_MASK,
 244                                          AXP288_ADC_TS_CURRENT_OFF);
 245         }
 246         if (ret)
 247                 return ret;
 248
 249         /* Turn on the ADC for all channels except TS, leave TS as is */
 250         return regmap_set_bits(info->regmap, AXP20X_ADC_EN1,
 251                                AXP288_ADC_EN_MASK);
 252 }
 253
 254 static const struct iio_info axp288_adc_iio_info = {
 255         .read_raw = &axp288_adc_read_raw,
 256 };
 257
 258 static int axp288_adc_probe(struct platform_device *pdev)
 259 {
 260         int ret;
 261         struct axp288_adc_info *info;
 262         struct iio_dev *indio_dev;
 263         struct axp20x_dev *axp20x = dev_get_drvdata(pdev->dev.parent);
 264
 265         indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*info));
 266         if (!indio_dev)
 267                 return -ENOMEM;
 268
 269         info = iio_priv(indio_dev);
 270         info->irq = platform_get_irq(pdev, 0);
 271         if (info->irq < 0)
 272                 return info->irq;
 273
 274         info->regmap = axp20x->regmap;
 275         /*
 276          * Set ADC to enabled state at all time, including system suspend.
 277          * otherwise internal fuel gauge functionality may be affected.
 278          */
 279         ret = axp288_adc_initialize(info);
 280         if (ret) {
 281                 dev_err(&pdev->dev, "unable to enable ADC device\n");
 282                 return ret;
 283         }
 284
 285         indio_dev->name = pdev->name;
 286         indio_dev->channels = axp288_adc_channels;
 287         indio_dev->num_channels = ARRAY_SIZE(axp288_adc_channels);
 288         indio_dev->info = &axp288_adc_iio_info;
 289         indio_dev->modes = INDIO_DIRECT_MODE;
 290
 291         ret = devm_iio_map_array_register(&pdev->dev, indio_dev, axp288_adc_default_maps);
 292         if (ret < 0)
 293                 return ret;
 294
 295         mutex_init(&info->lock);
 296
 297         return devm_iio_device_register(&pdev->dev, indio_dev);
 298 }
 299
 300 static const struct platform_device_id axp288_adc_id_table[] = {
 301         { .name = "axp288_adc" },
 302         { }
 303 };
 304
 305 static struct platform_driver axp288_adc_driver = {
 306         .probe = axp288_adc_probe,
 307         .id_table = axp288_adc_id_table,
 308         .driver = {
 309                 .name = "axp288_adc",
 310         },
 311 };
 312
 313 MODULE_DEVICE_TABLE(platform, axp288_adc_id_table);
 314
 315 module_platform_driver(axp288_adc_driver);
 316
 317 MODULE_AUTHOR("Jacob Pan <jacob.jun.pan@linux.intel.com>");
 318 MODULE_DESCRIPTION("X-Powers AXP288 ADC Driver");
 319 MODULE_LICENSE("GPL");