LXR linux/drivers/iio/adc/axp288

   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/kernel.h>
  13#include <linux/device.h>
  14#include <linux/regmap.h>
  15#include <linux/mfd/axp20x.h>
  16#include <linux/platform_device.h>
  17
  18#include <linux/iio/iio.h>
  19#include <linux/iio/machine.h>
  20#include <linux/iio/driver.h>
  21
  22/*
  23 * This mask enables all ADCs except for the battery temp-sensor (TS), that is
  24 * left as-is to avoid breaking charging on devices without a temp-sensor.
  25 */
  26#define AXP288_ADC_EN_MASK                              0xF0
  27#define AXP288_ADC_TS_ENABLE                            0x01
  28
  29#define AXP288_ADC_TS_BIAS_MASK                         GENMASK(5, 4)
  30#define AXP288_ADC_TS_BIAS_20UA                         (0 << 4)
  31#define AXP288_ADC_TS_BIAS_40UA                         (1 << 4)
  32#define AXP288_ADC_TS_BIAS_60UA                         (2 << 4)
  33#define AXP288_ADC_TS_BIAS_80UA                         (3 << 4)
  34#define AXP288_ADC_TS_CURRENT_ON_OFF_MASK               GENMASK(1, 0)
  35#define AXP288_ADC_TS_CURRENT_OFF                       (0 << 0)
  36#define AXP288_ADC_TS_CURRENT_ON_WHEN_CHARGING          (1 << 0)
  37#define AXP288_ADC_TS_CURRENT_ON_ONDEMAND               (2 << 0)
  38#define AXP288_ADC_TS_CURRENT_ON                        (3 << 0)
  39
  40enum axp288_adc_id {
  41        AXP288_ADC_TS,
  42        AXP288_ADC_PMIC,
  43        AXP288_ADC_GP,
  44        AXP288_ADC_BATT_CHRG_I,
  45        AXP288_ADC_BATT_DISCHRG_I,
  46        AXP288_ADC_BATT_V,
  47        AXP288_ADC_NR_CHAN,
  48};
  49
  50struct axp288_adc_info {
  51        int irq;
  52        struct regmap *regmap;
  53        bool ts_enabled;
  54};
  55
  56static const struct iio_chan_spec axp288_adc_channels[] = {
  57        {
  58                .indexed = 1,
  59                .type = IIO_TEMP,
  60                .channel = 0,
  61                .address = AXP288_TS_ADC_H,
  62                .datasheet_name = "TS_PIN",
  63                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
  64        }, {
  65                .indexed = 1,
  66                .type = IIO_TEMP,
  67                .channel = 1,
  68                .address = AXP288_PMIC_ADC_H,
  69                .datasheet_name = "PMIC_TEMP",
  70                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
  71        }, {
  72                .indexed = 1,
  73                .type = IIO_TEMP,
  74                .channel = 2,
  75                .address = AXP288_GP_ADC_H,
  76                .datasheet_name = "GPADC",
  77                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
  78        }, {
  79                .indexed = 1,
  80                .type = IIO_CURRENT,
  81                .channel = 3,
  82                .address = AXP20X_BATT_CHRG_I_H,
  83                .datasheet_name = "BATT_CHG_I",
  84                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
  85        }, {
  86                .indexed = 1,
  87                .type = IIO_CURRENT,
  88                .channel = 4,
  89                .address = AXP20X_BATT_DISCHRG_I_H,
  90                .datasheet_name = "BATT_DISCHRG_I",
  91                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
  92        }, {
  93                .indexed = 1,
  94                .type = IIO_VOLTAGE,
  95                .channel = 5,
  96                .address = AXP20X_BATT_V_H,
  97                .datasheet_name = "BATT_V",
  98                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
  99        },
 100};
 101
 102/* for consumer drivers */
 103static struct iio_map axp288_adc_default_maps[] = {
 104        IIO_MAP("TS_PIN", "axp288-batt", "axp288-batt-temp"),
 105        IIO_MAP("PMIC_TEMP", "axp288-pmic", "axp288-pmic-temp"),
 106        IIO_MAP("GPADC", "axp288-gpadc", "axp288-system-temp"),
 107        IIO_MAP("BATT_CHG_I", "axp288-chrg", "axp288-chrg-curr"),
 108        IIO_MAP("BATT_DISCHRG_I", "axp288-chrg", "axp288-chrg-d-curr"),
 109        IIO_MAP("BATT_V", "axp288-batt", "axp288-batt-volt"),
 110        {},
 111};
 112
 113static int axp288_adc_read_channel(int *val, unsigned long address,
 114                                struct regmap *regmap)
 115{
 116        u8 buf[2];
 117
 118        if (regmap_bulk_read(regmap, address, buf, 2))
 119                return -EIO;
 120        *val = (buf[0] << 4) + ((buf[1] >> 4) & 0x0F);
 121
 122        return IIO_VAL_INT;
 123}
 124
 125/*
 126 * The current-source used for the battery temp-sensor (TS) is shared
 127 * with the GPADC. For proper fuel-gauge and charger operation the TS
 128 * current-source needs to be permanently on. But to read the GPADC we
 129 * need to temporary switch the TS current-source to ondemand, so that
 130 * the GPADC can use it, otherwise we will always read an all 0 value.
 131 */
 132static int axp288_adc_set_ts(struct axp288_adc_info *info,
 133                             unsigned int mode, unsigned long address)
 134{
 135        int ret;
 136
 137        /* No need to switch the current-source if the TS pin is disabled */
 138        if (!info->ts_enabled)
 139                return 0;
 140
 141        /* Channels other than GPADC do not need the current source */
 142        if (address != AXP288_GP_ADC_H)
 143                return 0;
 144
 145        ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
 146                                 AXP288_ADC_TS_CURRENT_ON_OFF_MASK, mode);
 147        if (ret)
 148                return ret;
 149
 150        /* When switching to the GPADC pin give things some time to settle */
 151        if (mode == AXP288_ADC_TS_CURRENT_ON_ONDEMAND)
 152                usleep_range(6000, 10000);
 153
 154        return 0;
 155}
 156
 157static int axp288_adc_read_raw(struct iio_dev *indio_dev,
 158                        struct iio_chan_spec const *chan,
 159                        int *val, int *val2, long mask)
 160{
 161        int ret;
 162        struct axp288_adc_info *info = iio_priv(indio_dev);
 163
 164        mutex_lock(&indio_dev->mlock);
 165        switch (mask) {
 166        case IIO_CHAN_INFO_RAW:
 167                if (axp288_adc_set_ts(info, AXP288_ADC_TS_CURRENT_ON_ONDEMAND,
 168                                        chan->address)) {
 169                        dev_err(&indio_dev->dev, "GPADC mode\n");
 170                        ret = -EINVAL;
 171                        break;
 172                }
 173                ret = axp288_adc_read_channel(val, chan->address, info->regmap);
 174                if (axp288_adc_set_ts(info, AXP288_ADC_TS_CURRENT_ON,
 175                                                chan->address))
 176                        dev_err(&indio_dev->dev, "TS pin restore\n");
 177                break;
 178        default:
 179                ret = -EINVAL;
 180        }
 181        mutex_unlock(&indio_dev->mlock);
 182
 183        return ret;
 184}
 185
 186/*
 187 * We rely on the machine's firmware to correctly setup the TS pin bias current
 188 * at boot. This lists systems with broken fw where we need to set it ourselves.
 189 */
 190static const struct dmi_system_id axp288_adc_ts_bias_override[] = {
 191        {
 192                /* Lenovo Ideapad 100S (11 inch) */
 193                .matches = {
 194                  DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
 195                  DMI_MATCH(DMI_PRODUCT_VERSION, "Lenovo ideapad 100S-11IBY"),
 196                },
 197                .driver_data = (void *)(uintptr_t)AXP288_ADC_TS_BIAS_80UA,
 198        },
 199        {}
 200};
 201
 202static int axp288_adc_initialize(struct axp288_adc_info *info)
 203{
 204        const struct dmi_system_id *bias_override;
 205        int ret, adc_enable_val;
 206
 207        bias_override = dmi_first_match(axp288_adc_ts_bias_override);
 208        if (bias_override) {
 209                ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
 210                                         AXP288_ADC_TS_BIAS_MASK,
 211                                         (uintptr_t)bias_override->driver_data);
 212                if (ret)
 213                        return ret;
 214        }
 215
 216        /*
 217         * Determine if the TS pin is enabled and set the TS current-source
 218         * accordingly.
 219         */
 220        ret = regmap_read(info->regmap, AXP20X_ADC_EN1, &adc_enable_val);
 221        if (ret)
 222                return ret;
 223
 224        if (adc_enable_val & AXP288_ADC_TS_ENABLE) {
 225                info->ts_enabled = true;
 226                ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
 227                                         AXP288_ADC_TS_CURRENT_ON_OFF_MASK,
 228                                         AXP288_ADC_TS_CURRENT_ON);
 229        } else {
 230                info->ts_enabled = false;
 231                ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
 232                                         AXP288_ADC_TS_CURRENT_ON_OFF_MASK,
 233                                         AXP288_ADC_TS_CURRENT_OFF);
 234        }
 235        if (ret)
 236                return ret;
 237
 238        /* Turn on the ADC for all channels except TS, leave TS as is */
 239        return regmap_update_bits(info->regmap, AXP20X_ADC_EN1,
 240                                  AXP288_ADC_EN_MASK, AXP288_ADC_EN_MASK);
 241}
 242
 243static const struct iio_info axp288_adc_iio_info = {
 244        .read_raw = &axp288_adc_read_raw,
 245};
 246
 247static int axp288_adc_probe(struct platform_device *pdev)
 248{
 249        int ret;
 250        struct axp288_adc_info *info;
 251        struct iio_dev *indio_dev;
 252        struct axp20x_dev *axp20x = dev_get_drvdata(pdev->dev.parent);
 253
 254        indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*info));
 255        if (!indio_dev)
 256                return -ENOMEM;
 257
 258        info = iio_priv(indio_dev);
 259        info->irq = platform_get_irq(pdev, 0);
 260        if (info->irq < 0)
 261                return info->irq;
 262        platform_set_drvdata(pdev, indio_dev);
 263        info->regmap = axp20x->regmap;
 264        /*
 265         * Set ADC to enabled state at all time, including system suspend.
 266         * otherwise internal fuel gauge functionality may be affected.
 267         */
 268        ret = axp288_adc_initialize(info);
 269        if (ret) {
 270                dev_err(&pdev->dev, "unable to enable ADC device\n");
 271                return ret;
 272        }
 273
 274        indio_dev->name = pdev->name;
 275        indio_dev->channels = axp288_adc_channels;
 276        indio_dev->num_channels = ARRAY_SIZE(axp288_adc_channels);
 277        indio_dev->info = &axp288_adc_iio_info;
 278        indio_dev->modes = INDIO_DIRECT_MODE;
 279        ret = iio_map_array_register(indio_dev, axp288_adc_default_maps);
 280        if (ret < 0)
 281                return ret;
 282
 283        ret = iio_device_register(indio_dev);
 284        if (ret < 0) {
 285                dev_err(&pdev->dev, "unable to register iio device\n");
 286                goto err_array_unregister;
 287        }
 288        return 0;
 289
 290err_array_unregister:
 291        iio_map_array_unregister(indio_dev);
 292
 293        return ret;
 294}
 295
 296static int axp288_adc_remove(struct platform_device *pdev)
 297{
 298        struct iio_dev *indio_dev = platform_get_drvdata(pdev);
 299
 300        iio_device_unregister(indio_dev);
 301        iio_map_array_unregister(indio_dev);
 302
 303        return 0;
 304}
 305
 306static const struct platform_device_id axp288_adc_id_table[] = {
 307        { .name = "axp288_adc" },
 308        {},
 309};
 310
 311static struct platform_driver axp288_adc_driver = {
 312        .probe = axp288_adc_probe,
 313        .remove = axp288_adc_remove,
 314        .id_table = axp288_adc_id_table,
 315        .driver = {
 316                .name = "axp288_adc",
 317        },
 318};
 319
 320MODULE_DEVICE_TABLE(platform, axp288_adc_id_table);
 321
 322module_platform_driver(axp288_adc_driver);
 323
 324MODULE_AUTHOR("Jacob Pan <jacob.jun.pan@linux.intel.com>");
 325MODULE_DESCRIPTION("X-Powers AXP288 ADC Driver");
 326MODULE_LICENSE("GPL");
 327