Rhyland Klein | a7640bf | 2010-09-05 15:31:23 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Gas Gauge driver for TI's BQ20Z75 |
| 3 | * |
| 4 | * Copyright (c) 2010, NVIDIA Corporation. |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License as published by |
| 8 | * the Free Software Foundation; either version 2 of the License, or |
| 9 | * (at your option) any later version. |
| 10 | * |
| 11 | * This program is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for |
| 14 | * more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU General Public License along |
| 17 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 18 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. |
| 19 | */ |
| 20 | |
| 21 | #include <linux/init.h> |
| 22 | #include <linux/module.h> |
| 23 | #include <linux/kernel.h> |
| 24 | #include <linux/err.h> |
| 25 | #include <linux/power_supply.h> |
| 26 | #include <linux/i2c.h> |
| 27 | #include <linux/slab.h> |
| 28 | |
| 29 | enum { |
| 30 | REG_MANUFACTURER_DATA, |
| 31 | REG_TEMPERATURE, |
| 32 | REG_VOLTAGE, |
| 33 | REG_CURRENT, |
| 34 | REG_CAPACITY, |
| 35 | REG_TIME_TO_EMPTY, |
| 36 | REG_TIME_TO_FULL, |
| 37 | REG_STATUS, |
| 38 | REG_CYCLE_COUNT, |
| 39 | REG_SERIAL_NUMBER |
| 40 | }; |
| 41 | |
| 42 | /* manufacturer access defines */ |
| 43 | #define MANUFACTURER_ACCESS_STATUS 0x0006 |
| 44 | #define MANUFACTURER_ACCESS_SLEEP 0x0011 |
| 45 | |
| 46 | /* battery status value bits */ |
| 47 | #define BATTERY_CHARGING 0x40 |
| 48 | #define BATTERY_FULL_CHARGED 0x20 |
| 49 | #define BATTERY_FULL_DISCHARGED 0x10 |
| 50 | |
| 51 | #define BQ20Z75_DATA(_psp, _addr, _min_value, _max_value) { \ |
| 52 | .psp = _psp, \ |
| 53 | .addr = _addr, \ |
| 54 | .min_value = _min_value, \ |
| 55 | .max_value = _max_value, \ |
| 56 | } |
| 57 | |
| 58 | static const struct bq20z75_device_data { |
| 59 | enum power_supply_property psp; |
| 60 | u8 addr; |
| 61 | int min_value; |
| 62 | int max_value; |
| 63 | } bq20z75_data[] = { |
| 64 | [REG_MANUFACTURER_DATA] = |
| 65 | BQ20Z75_DATA(POWER_SUPPLY_PROP_PRESENT, 0x00, 0, 65535), |
| 66 | [REG_TEMPERATURE] = |
| 67 | BQ20Z75_DATA(POWER_SUPPLY_PROP_TEMP, 0x08, 0, 65535), |
| 68 | [REG_VOLTAGE] = |
| 69 | BQ20Z75_DATA(POWER_SUPPLY_PROP_VOLTAGE_NOW, 0x09, 0, 20000), |
| 70 | [REG_CURRENT] = |
| 71 | BQ20Z75_DATA(POWER_SUPPLY_PROP_CURRENT_NOW, 0x0A, -32768, |
| 72 | 32767), |
| 73 | [REG_CAPACITY] = |
| 74 | BQ20Z75_DATA(POWER_SUPPLY_PROP_CAPACITY, 0x0E, 0, 100), |
| 75 | [REG_TIME_TO_EMPTY] = |
| 76 | BQ20Z75_DATA(POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG, 0x12, 0, |
| 77 | 65535), |
| 78 | [REG_TIME_TO_FULL] = |
| 79 | BQ20Z75_DATA(POWER_SUPPLY_PROP_TIME_TO_FULL_AVG, 0x13, 0, |
| 80 | 65535), |
| 81 | [REG_STATUS] = |
| 82 | BQ20Z75_DATA(POWER_SUPPLY_PROP_STATUS, 0x16, 0, 65535), |
| 83 | [REG_CYCLE_COUNT] = |
| 84 | BQ20Z75_DATA(POWER_SUPPLY_PROP_CYCLE_COUNT, 0x17, 0, 65535), |
| 85 | [REG_SERIAL_NUMBER] = |
| 86 | BQ20Z75_DATA(POWER_SUPPLY_PROP_SERIAL_NUMBER, 0x1C, 0, 65535), |
| 87 | }; |
| 88 | |
| 89 | static enum power_supply_property bq20z75_properties[] = { |
| 90 | POWER_SUPPLY_PROP_STATUS, |
| 91 | POWER_SUPPLY_PROP_HEALTH, |
| 92 | POWER_SUPPLY_PROP_PRESENT, |
| 93 | POWER_SUPPLY_PROP_TECHNOLOGY, |
| 94 | POWER_SUPPLY_PROP_CYCLE_COUNT, |
| 95 | POWER_SUPPLY_PROP_VOLTAGE_NOW, |
| 96 | POWER_SUPPLY_PROP_CURRENT_NOW, |
| 97 | POWER_SUPPLY_PROP_CAPACITY, |
| 98 | POWER_SUPPLY_PROP_TEMP, |
| 99 | POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG, |
| 100 | POWER_SUPPLY_PROP_TIME_TO_FULL_AVG, |
| 101 | POWER_SUPPLY_PROP_SERIAL_NUMBER, |
| 102 | }; |
| 103 | |
| 104 | struct bq20z75_info { |
| 105 | struct i2c_client *client; |
| 106 | struct power_supply power_supply; |
| 107 | }; |
| 108 | |
| 109 | static int bq20z75_get_battery_presence_and_health( |
| 110 | struct i2c_client *client, enum power_supply_property psp, |
| 111 | union power_supply_propval *val) |
| 112 | { |
| 113 | s32 ret; |
| 114 | |
| 115 | /* Write to ManufacturerAccess with |
| 116 | * ManufacturerAccess command and then |
| 117 | * read the status */ |
| 118 | ret = i2c_smbus_write_word_data(client, |
| 119 | bq20z75_data[REG_MANUFACTURER_DATA].addr, |
| 120 | MANUFACTURER_ACCESS_STATUS); |
| 121 | if (ret < 0) { |
| 122 | dev_err(&client->dev, |
| 123 | "%s: i2c write for battery presence failed\n", |
| 124 | __func__); |
| 125 | return -ENODEV; |
| 126 | } |
| 127 | |
| 128 | ret = i2c_smbus_read_word_data(client, |
| 129 | bq20z75_data[REG_MANUFACTURER_DATA].addr); |
| 130 | if (ret < 0) { |
| 131 | dev_err(&client->dev, |
| 132 | "%s: i2c read for battery presence failed\n", |
| 133 | __func__); |
| 134 | return -EIO; |
| 135 | } |
| 136 | |
| 137 | if (ret < bq20z75_data[REG_MANUFACTURER_DATA].min_value || |
| 138 | ret > bq20z75_data[REG_MANUFACTURER_DATA].max_value) { |
| 139 | val->intval = 0; |
| 140 | return 0; |
| 141 | } |
| 142 | |
| 143 | /* Mask the upper nibble of 2nd byte and |
| 144 | * lower byte of response then |
| 145 | * shift the result by 8 to get status*/ |
| 146 | ret &= 0x0F00; |
| 147 | ret >>= 8; |
| 148 | if (psp == POWER_SUPPLY_PROP_PRESENT) { |
| 149 | if (ret == 0x0F) |
| 150 | /* battery removed */ |
| 151 | val->intval = 0; |
| 152 | else |
| 153 | val->intval = 1; |
| 154 | } else if (psp == POWER_SUPPLY_PROP_HEALTH) { |
| 155 | if (ret == 0x09) |
| 156 | val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE; |
| 157 | else if (ret == 0x0B) |
| 158 | val->intval = POWER_SUPPLY_HEALTH_OVERHEAT; |
| 159 | else if (ret == 0x0C) |
| 160 | val->intval = POWER_SUPPLY_HEALTH_DEAD; |
| 161 | else |
| 162 | val->intval = POWER_SUPPLY_HEALTH_GOOD; |
| 163 | } |
| 164 | |
| 165 | return 0; |
| 166 | } |
| 167 | |
| 168 | static int bq20z75_get_battery_property(struct i2c_client *client, |
| 169 | int reg_offset, enum power_supply_property psp, |
| 170 | union power_supply_propval *val) |
| 171 | { |
| 172 | s32 ret; |
| 173 | |
| 174 | ret = i2c_smbus_read_word_data(client, |
| 175 | bq20z75_data[reg_offset].addr); |
| 176 | if (ret < 0) { |
| 177 | dev_err(&client->dev, |
| 178 | "%s: i2c read for %d failed\n", __func__, reg_offset); |
| 179 | return -EIO; |
| 180 | } |
| 181 | |
| 182 | if (ret >= bq20z75_data[reg_offset].min_value && |
| 183 | ret <= bq20z75_data[reg_offset].max_value) { |
| 184 | val->intval = ret; |
| 185 | if (psp == POWER_SUPPLY_PROP_STATUS) { |
| 186 | if (ret & BATTERY_CHARGING) |
| 187 | val->intval = POWER_SUPPLY_STATUS_CHARGING; |
| 188 | else if (ret & BATTERY_FULL_CHARGED) |
| 189 | val->intval = POWER_SUPPLY_STATUS_FULL; |
| 190 | else if (ret & BATTERY_FULL_DISCHARGED) |
| 191 | val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING; |
| 192 | else |
| 193 | val->intval = POWER_SUPPLY_STATUS_DISCHARGING; |
| 194 | } |
| 195 | /* bq20z75 provides battery tempreture in 0.1°K |
| 196 | * so convert it to °C */ |
| 197 | else if (psp == POWER_SUPPLY_PROP_TEMP) |
| 198 | val->intval = ret - 2731; |
| 199 | } else { |
| 200 | if (psp == POWER_SUPPLY_PROP_STATUS) |
| 201 | val->intval = POWER_SUPPLY_STATUS_UNKNOWN; |
| 202 | else |
| 203 | val->intval = 0; |
| 204 | } |
| 205 | |
| 206 | return 0; |
| 207 | } |
| 208 | |
| 209 | static int bq20z75_get_battery_capacity(struct i2c_client *client, |
| 210 | union power_supply_propval *val) |
| 211 | { |
| 212 | s32 ret; |
| 213 | |
| 214 | ret = i2c_smbus_read_byte_data(client, bq20z75_data[REG_CAPACITY].addr); |
| 215 | if (ret < 0) { |
| 216 | dev_err(&client->dev, |
| 217 | "%s: i2c read for %d failed\n", __func__, REG_CAPACITY); |
| 218 | return -EIO; |
| 219 | } |
| 220 | |
| 221 | /* bq20z75 spec says that this can be >100 % |
| 222 | * even if max value is 100 % */ |
| 223 | val->intval = min(ret, 100); |
| 224 | |
| 225 | return 0; |
| 226 | } |
| 227 | |
| 228 | static int bq20z75_get_property(struct power_supply *psy, |
| 229 | enum power_supply_property psp, |
| 230 | union power_supply_propval *val) |
| 231 | { |
| 232 | int count; |
| 233 | int ret; |
| 234 | struct bq20z75_info *bq20z75_device = container_of(psy, |
| 235 | struct bq20z75_info, power_supply); |
| 236 | struct i2c_client *client = bq20z75_device->client; |
| 237 | |
| 238 | switch (psp) { |
| 239 | case POWER_SUPPLY_PROP_PRESENT: |
| 240 | case POWER_SUPPLY_PROP_HEALTH: |
| 241 | ret = bq20z75_get_battery_presence_and_health(client, psp, val); |
| 242 | if (ret) |
| 243 | return ret; |
| 244 | break; |
| 245 | |
| 246 | case POWER_SUPPLY_PROP_TECHNOLOGY: |
| 247 | val->intval = POWER_SUPPLY_TECHNOLOGY_LION; |
| 248 | break; |
| 249 | |
| 250 | case POWER_SUPPLY_PROP_CAPACITY: |
| 251 | ret = bq20z75_get_battery_capacity(client, val); |
| 252 | if (ret) |
| 253 | return ret; |
| 254 | break; |
| 255 | |
| 256 | case POWER_SUPPLY_PROP_STATUS: |
| 257 | case POWER_SUPPLY_PROP_CYCLE_COUNT: |
| 258 | case POWER_SUPPLY_PROP_VOLTAGE_NOW: |
| 259 | case POWER_SUPPLY_PROP_CURRENT_NOW: |
| 260 | case POWER_SUPPLY_PROP_TEMP: |
| 261 | case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG: |
| 262 | case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG: |
| 263 | case POWER_SUPPLY_PROP_SERIAL_NUMBER: |
| 264 | for (count = 0; count < ARRAY_SIZE(bq20z75_data); count++) { |
| 265 | if (psp == bq20z75_data[count].psp) |
| 266 | break; |
| 267 | } |
| 268 | |
| 269 | ret = bq20z75_get_battery_property(client, count, psp, val); |
| 270 | if (ret) |
| 271 | return ret; |
| 272 | break; |
| 273 | |
| 274 | default: |
| 275 | dev_err(&client->dev, |
| 276 | "%s: INVALID property\n", __func__); |
| 277 | return -EINVAL; |
| 278 | } |
| 279 | |
| 280 | dev_dbg(&client->dev, |
| 281 | "%s: property = %d, value = %d\n", __func__, psp, val->intval); |
| 282 | |
| 283 | return 0; |
| 284 | } |
| 285 | |
| 286 | static int bq20z75_probe(struct i2c_client *client, |
| 287 | const struct i2c_device_id *id) |
| 288 | { |
| 289 | struct bq20z75_info *bq20z75_device; |
| 290 | int rc; |
| 291 | |
| 292 | bq20z75_device = kzalloc(sizeof(struct bq20z75_info), GFP_KERNEL); |
| 293 | if (!bq20z75_device) |
| 294 | return -ENOMEM; |
| 295 | |
| 296 | bq20z75_device->client = client; |
| 297 | bq20z75_device->power_supply.name = "battery"; |
| 298 | bq20z75_device->power_supply.type = POWER_SUPPLY_TYPE_BATTERY; |
| 299 | bq20z75_device->power_supply.properties = bq20z75_properties; |
| 300 | bq20z75_device->power_supply.num_properties = |
| 301 | ARRAY_SIZE(bq20z75_properties); |
| 302 | bq20z75_device->power_supply.get_property = bq20z75_get_property; |
| 303 | |
| 304 | i2c_set_clientdata(client, bq20z75_device); |
| 305 | |
| 306 | rc = power_supply_register(&client->dev, &bq20z75_device->power_supply); |
| 307 | if (rc) { |
| 308 | dev_err(&client->dev, |
| 309 | "%s: Failed to register power supply\n", __func__); |
| 310 | kfree(bq20z75_device); |
| 311 | return rc; |
| 312 | } |
| 313 | |
| 314 | dev_info(&client->dev, |
| 315 | "%s: battery gas gauge device registered\n", client->name); |
| 316 | |
| 317 | return 0; |
| 318 | } |
| 319 | |
| 320 | static int bq20z75_remove(struct i2c_client *client) |
| 321 | { |
| 322 | struct bq20z75_info *bq20z75_device = i2c_get_clientdata(client); |
| 323 | |
| 324 | power_supply_unregister(&bq20z75_device->power_supply); |
| 325 | kfree(bq20z75_device); |
| 326 | bq20z75_device = NULL; |
| 327 | |
| 328 | return 0; |
| 329 | } |
| 330 | |
| 331 | #if defined CONFIG_PM |
| 332 | static int bq20z75_suspend(struct i2c_client *client, |
| 333 | pm_message_t state) |
| 334 | { |
| 335 | s32 ret; |
| 336 | |
| 337 | /* write to manufacturer access with sleep command */ |
| 338 | ret = i2c_smbus_write_word_data(client, |
| 339 | bq20z75_data[REG_MANUFACTURER_DATA].addr, |
| 340 | MANUFACTURER_ACCESS_SLEEP); |
| 341 | if (ret < 0) { |
| 342 | dev_err(&client->dev, |
| 343 | "%s: i2c write for %d failed\n", |
| 344 | __func__, MANUFACTURER_ACCESS_SLEEP); |
| 345 | return -EIO; |
| 346 | } |
| 347 | |
| 348 | return 0; |
| 349 | } |
| 350 | #else |
| 351 | #define bq20z75_suspend NULL |
| 352 | #endif |
| 353 | /* any smbus transaction will wake up bq20z75 */ |
| 354 | #define bq20z75_resume NULL |
| 355 | |
| 356 | static const struct i2c_device_id bq20z75_id[] = { |
| 357 | { "bq20z75", 0 }, |
| 358 | {} |
| 359 | }; |
| 360 | |
| 361 | static struct i2c_driver bq20z75_battery_driver = { |
| 362 | .probe = bq20z75_probe, |
| 363 | .remove = bq20z75_remove, |
| 364 | .suspend = bq20z75_suspend, |
| 365 | .resume = bq20z75_resume, |
| 366 | .id_table = bq20z75_id, |
| 367 | .driver = { |
| 368 | .name = "bq20z75-battery", |
| 369 | }, |
| 370 | }; |
| 371 | |
| 372 | static int __init bq20z75_battery_init(void) |
| 373 | { |
| 374 | return i2c_add_driver(&bq20z75_battery_driver); |
| 375 | } |
| 376 | module_init(bq20z75_battery_init); |
| 377 | |
| 378 | static void __exit bq20z75_battery_exit(void) |
| 379 | { |
| 380 | i2c_del_driver(&bq20z75_battery_driver); |
| 381 | } |
| 382 | module_exit(bq20z75_battery_exit); |
| 383 | |
| 384 | MODULE_DESCRIPTION("BQ20z75 battery monitor driver"); |
| 385 | MODULE_LICENSE("GPL"); |