LXR linux/drivers/power/supply/rx51

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Nokia RX-51 battery driver
   4 *
   5 * Copyright (C) 2012  Pali Rohár <pali@kernel.org>
   6 */
   7
   8#include <linux/module.h>
   9#include <linux/param.h>
  10#include <linux/platform_device.h>
  11#include <linux/power_supply.h>
  12#include <linux/slab.h>
  13#include <linux/iio/consumer.h>
  14#include <linux/of.h>
  15
  16struct rx51_device_info {
  17        struct device *dev;
  18        struct power_supply *bat;
  19        struct power_supply_desc bat_desc;
  20        struct iio_channel *channel_temp;
  21        struct iio_channel *channel_bsi;
  22        struct iio_channel *channel_vbat;
  23};
  24
  25/*
  26 * Read ADCIN channel value, code copied from maemo kernel
  27 */
  28static int rx51_battery_read_adc(struct iio_channel *channel)
  29{
  30        int val, err;
  31        err = iio_read_channel_average_raw(channel, &val);
  32        if (err < 0)
  33                return err;
  34        return val;
  35}
  36
  37/*
  38 * Read ADCIN channel 12 (voltage) and convert RAW value to micro voltage
  39 * This conversion formula was extracted from maemo program bsi-read
  40 */
  41static int rx51_battery_read_voltage(struct rx51_device_info *di)
  42{
  43        int voltage = rx51_battery_read_adc(di->channel_vbat);
  44
  45        if (voltage < 0) {
  46                dev_err(di->dev, "Could not read ADC: %d\n", voltage);
  47                return voltage;
  48        }
  49
  50        return 1000 * (10000 * voltage / 1705);
  51}
  52
  53/*
  54 * Temperature look-up tables
  55 * TEMP = (1/(t1 + 1/298) - 273.15)
  56 * Where t1 = (1/B) * ln((RAW_ADC_U * 2.5)/(R * I * 255))
  57 * Formula is based on experimental data, RX-51 CAL data, maemo program bme
  58 * and formula from da9052 driver with values R = 100, B = 3380, I = 0.00671
  59 */
  60
  61/*
  62 * Table1 (temperature for first 25 RAW values)
  63 * Usage: TEMP = rx51_temp_table1[RAW]
  64 *   RAW is between 1 and 24
  65 *   TEMP is between 201 C and 55 C
  66 */
  67static u8 rx51_temp_table1[] = {
  68        255, 201, 159, 138, 124, 114, 106,  99,  94,  89,  85,  82,  78,  75,
  69         73,  70,  68,  66,  64,  62,  61,  59,  57,  56,  55
  70};
  71
  72/*
  73 * Table2 (lowest RAW value for temperature)
  74 * Usage: RAW = rx51_temp_table2[TEMP-rx51_temp_table2_first]
  75 *   TEMP is between 53 C and -32 C
  76 *   RAW is between 25 and 993
  77 */
  78#define rx51_temp_table2_first 53
  79static u16 rx51_temp_table2[] = {
  80         25,  26,  27,  28,  29,  30,  31,  32,  33,  34,  35,  36,  37,  39,
  81         40,  41,  43,  44,  46,  48,  49,  51,  53,  55,  57,  59,  61,  64,
  82         66,  69,  71,  74,  77,  80,  83,  86,  90,  94,  97, 101, 106, 110,
  83        115, 119, 125, 130, 136, 141, 148, 154, 161, 168, 176, 184, 202, 211,
  84        221, 231, 242, 254, 266, 279, 293, 308, 323, 340, 357, 375, 395, 415,
  85        437, 460, 485, 511, 539, 568, 600, 633, 669, 706, 747, 790, 836, 885,
  86        937, 993, 1024
  87};
  88
  89/*
  90 * Read ADCIN channel 0 (battery temp) and convert value to tenths of Celsius
  91 * Use Temperature look-up tables for conversation
  92 */
  93static int rx51_battery_read_temperature(struct rx51_device_info *di)
  94{
  95        int min = 0;
  96        int max = ARRAY_SIZE(rx51_temp_table2) - 1;
  97        int raw = rx51_battery_read_adc(di->channel_temp);
  98
  99        if (raw < 0)
 100                dev_err(di->dev, "Could not read ADC: %d\n", raw);
 101
 102        /* Zero and negative values are undefined */
 103        if (raw <= 0)
 104                return INT_MAX;
 105
 106        /* ADC channels are 10 bit, higher value are undefined */
 107        if (raw >= (1 << 10))
 108                return INT_MIN;
 109
 110        /* First check for temperature in first direct table */
 111        if (raw < ARRAY_SIZE(rx51_temp_table1))
 112                return rx51_temp_table1[raw] * 10;
 113
 114        /* Binary search RAW value in second inverse table */
 115        while (max - min > 1) {
 116                int mid = (max + min) / 2;
 117                if (rx51_temp_table2[mid] <= raw)
 118                        min = mid;
 119                else if (rx51_temp_table2[mid] > raw)
 120                        max = mid;
 121                if (rx51_temp_table2[mid] == raw)
 122                        break;
 123        }
 124
 125        return (rx51_temp_table2_first - min) * 10;
 126}
 127
 128/*
 129 * Read ADCIN channel 4 (BSI) and convert RAW value to micro Ah
 130 * This conversion formula was extracted from maemo program bsi-read
 131 */
 132static int rx51_battery_read_capacity(struct rx51_device_info *di)
 133{
 134        int capacity = rx51_battery_read_adc(di->channel_bsi);
 135
 136        if (capacity < 0) {
 137                dev_err(di->dev, "Could not read ADC: %d\n", capacity);
 138                return capacity;
 139        }
 140
 141        return 1280 * (1200 * capacity)/(1024 - capacity);
 142}
 143
 144/*
 145 * Return power_supply property
 146 */
 147static int rx51_battery_get_property(struct power_supply *psy,
 148                                        enum power_supply_property psp,
 149                                        union power_supply_propval *val)
 150{
 151        struct rx51_device_info *di = power_supply_get_drvdata(psy);
 152
 153        switch (psp) {
 154        case POWER_SUPPLY_PROP_TECHNOLOGY:
 155                val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
 156                break;
 157        case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
 158                val->intval = 4200000;
 159                break;
 160        case POWER_SUPPLY_PROP_PRESENT:
 161                val->intval = rx51_battery_read_voltage(di) ? 1 : 0;
 162                break;
 163        case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 164                val->intval = rx51_battery_read_voltage(di);
 165                break;
 166        case POWER_SUPPLY_PROP_TEMP:
 167                val->intval = rx51_battery_read_temperature(di);
 168                break;
 169        case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
 170                val->intval = rx51_battery_read_capacity(di);
 171                break;
 172        default:
 173                return -EINVAL;
 174        }
 175
 176        if (val->intval == INT_MAX || val->intval == INT_MIN)
 177                return -EINVAL;
 178
 179        return 0;
 180}
 181
 182static enum power_supply_property rx51_battery_props[] = {
 183        POWER_SUPPLY_PROP_TECHNOLOGY,
 184        POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
 185        POWER_SUPPLY_PROP_PRESENT,
 186        POWER_SUPPLY_PROP_VOLTAGE_NOW,
 187        POWER_SUPPLY_PROP_TEMP,
 188        POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
 189};
 190
 191static int rx51_battery_probe(struct platform_device *pdev)
 192{
 193        struct power_supply_config psy_cfg = {};
 194        struct rx51_device_info *di;
 195        int ret;
 196
 197        di = devm_kzalloc(&pdev->dev, sizeof(*di), GFP_KERNEL);
 198        if (!di)
 199                return -ENOMEM;
 200
 201        platform_set_drvdata(pdev, di);
 202
 203        di->dev = &pdev->dev;
 204        di->bat_desc.name = "rx51-battery";
 205        di->bat_desc.type = POWER_SUPPLY_TYPE_BATTERY;
 206        di->bat_desc.properties = rx51_battery_props;
 207        di->bat_desc.num_properties = ARRAY_SIZE(rx51_battery_props);
 208        di->bat_desc.get_property = rx51_battery_get_property;
 209
 210        psy_cfg.drv_data = di;
 211
 212        di->channel_temp = iio_channel_get(di->dev, "temp");
 213        if (IS_ERR(di->channel_temp)) {
 214                ret = PTR_ERR(di->channel_temp);
 215                goto error;
 216        }
 217
 218        di->channel_bsi  = iio_channel_get(di->dev, "bsi");
 219        if (IS_ERR(di->channel_bsi)) {
 220                ret = PTR_ERR(di->channel_bsi);
 221                goto error_channel_temp;
 222        }
 223
 224        di->channel_vbat = iio_channel_get(di->dev, "vbat");
 225        if (IS_ERR(di->channel_vbat)) {
 226                ret = PTR_ERR(di->channel_vbat);
 227                goto error_channel_bsi;
 228        }
 229
 230        di->bat = power_supply_register(di->dev, &di->bat_desc, &psy_cfg);
 231        if (IS_ERR(di->bat)) {
 232                ret = PTR_ERR(di->bat);
 233                goto error_channel_vbat;
 234        }
 235
 236        return 0;
 237
 238error_channel_vbat:
 239        iio_channel_release(di->channel_vbat);
 240error_channel_bsi:
 241        iio_channel_release(di->channel_bsi);
 242error_channel_temp:
 243        iio_channel_release(di->channel_temp);
 244error:
 245
 246        return ret;
 247}
 248
 249static int rx51_battery_remove(struct platform_device *pdev)
 250{
 251        struct rx51_device_info *di = platform_get_drvdata(pdev);
 252
 253        power_supply_unregister(di->bat);
 254
 255        iio_channel_release(di->channel_vbat);
 256        iio_channel_release(di->channel_bsi);
 257        iio_channel_release(di->channel_temp);
 258
 259        return 0;
 260}
 261
 262#ifdef CONFIG_OF
 263static const struct of_device_id n900_battery_of_match[] = {
 264        {.compatible = "nokia,n900-battery", },
 265        { },
 266};
 267MODULE_DEVICE_TABLE(of, n900_battery_of_match);
 268#endif
 269
 270static struct platform_driver rx51_battery_driver = {
 271        .probe = rx51_battery_probe,
 272        .remove = rx51_battery_remove,
 273        .driver = {
 274                .name = "rx51-battery",
 275                .of_match_table = of_match_ptr(n900_battery_of_match),
 276        },
 277};
 278module_platform_driver(rx51_battery_driver);
 279
 280MODULE_ALIAS("platform:rx51-battery");
 281MODULE_AUTHOR("Pali Rohár <pali@kernel.org>");
 282MODULE_DESCRIPTION("Nokia RX-51 battery driver");
 283MODULE_LICENSE("GPL");
 284