1 /* 2 * Battery charger driver for TI BQ24735 3 * 4 * Copyright (c) 2013, NVIDIA CORPORATION. All rights reserved. 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; 9 * 10 * This program is distributed in the hope that it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 13 * more details. 14 * 15 * You should have received a copy of the GNU General Public License along 16 * with this program; if not, write to the Free Software Foundation, Inc., 17 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 18 */ 19 20 #include <linux/err.h> 21 #include <linux/gpio.h> 22 #include <linux/i2c.h> 23 #include <linux/init.h> 24 #include <linux/interrupt.h> 25 #include <linux/kernel.h> 26 #include <linux/module.h> 27 #include <linux/of.h> 28 #include <linux/gpio/consumer.h> 29 #include <linux/power_supply.h> 30 #include <linux/slab.h> 31 32 #include <linux/power/bq24735-charger.h> 33 34 #define BQ24735_CHG_OPT 0x12 35 #define BQ24735_CHG_OPT_CHARGE_DISABLE (1 << 0) 36 #define BQ24735_CHG_OPT_AC_PRESENT (1 << 4) 37 #define BQ24735_CHARGE_CURRENT 0x14 38 #define BQ24735_CHARGE_CURRENT_MASK 0x1fc0 39 #define BQ24735_CHARGE_VOLTAGE 0x15 40 #define BQ24735_CHARGE_VOLTAGE_MASK 0x7ff0 41 #define BQ24735_INPUT_CURRENT 0x3f 42 #define BQ24735_INPUT_CURRENT_MASK 0x1f80 43 #define BQ24735_MANUFACTURER_ID 0xfe 44 #define BQ24735_DEVICE_ID 0xff 45 46 struct bq24735 { 47 struct power_supply *charger; 48 struct power_supply_desc charger_desc; 49 struct i2c_client *client; 50 struct bq24735_platform *pdata; 51 struct mutex lock; 52 struct gpio_desc *status_gpio; 53 struct delayed_work poll; 54 u32 poll_interval; 55 bool charging; 56 }; 57 58 static inline struct bq24735 *to_bq24735(struct power_supply *psy) 59 { 60 return power_supply_get_drvdata(psy); 61 } 62 63 static enum power_supply_property bq24735_charger_properties[] = { 64 POWER_SUPPLY_PROP_STATUS, 65 POWER_SUPPLY_PROP_ONLINE, 66 }; 67 68 static int bq24735_charger_property_is_writeable(struct power_supply *psy, 69 enum power_supply_property psp) 70 { 71 switch (psp) { 72 case POWER_SUPPLY_PROP_STATUS: 73 return 1; 74 default: 75 break; 76 } 77 78 return 0; 79 } 80 81 static inline int bq24735_write_word(struct i2c_client *client, u8 reg, 82 u16 value) 83 { 84 return i2c_smbus_write_word_data(client, reg, le16_to_cpu(value)); 85 } 86 87 static inline int bq24735_read_word(struct i2c_client *client, u8 reg) 88 { 89 s32 ret = i2c_smbus_read_word_data(client, reg); 90 91 return ret < 0 ? ret : le16_to_cpu(ret); 92 } 93 94 static int bq24735_update_word(struct i2c_client *client, u8 reg, 95 u16 mask, u16 value) 96 { 97 unsigned int tmp; 98 int ret; 99 100 ret = bq24735_read_word(client, reg); 101 if (ret < 0) 102 return ret; 103 104 tmp = ret & ~mask; 105 tmp |= value & mask; 106 107 return bq24735_write_word(client, reg, tmp); 108 } 109 110 static int bq24735_config_charger(struct bq24735 *charger) 111 { 112 struct bq24735_platform *pdata = charger->pdata; 113 int ret; 114 u16 value; 115 116 if (pdata->ext_control) 117 return 0; 118 119 if (pdata->charge_current) { 120 value = pdata->charge_current & BQ24735_CHARGE_CURRENT_MASK; 121 122 ret = bq24735_write_word(charger->client, 123 BQ24735_CHARGE_CURRENT, value); 124 if (ret < 0) { 125 dev_err(&charger->client->dev, 126 "Failed to write charger current : %d\n", 127 ret); 128 return ret; 129 } 130 } 131 132 if (pdata->charge_voltage) { 133 value = pdata->charge_voltage & BQ24735_CHARGE_VOLTAGE_MASK; 134 135 ret = bq24735_write_word(charger->client, 136 BQ24735_CHARGE_VOLTAGE, value); 137 if (ret < 0) { 138 dev_err(&charger->client->dev, 139 "Failed to write charger voltage : %d\n", 140 ret); 141 return ret; 142 } 143 } 144 145 if (pdata->input_current) { 146 value = pdata->input_current & BQ24735_INPUT_CURRENT_MASK; 147 148 ret = bq24735_write_word(charger->client, 149 BQ24735_INPUT_CURRENT, value); 150 if (ret < 0) { 151 dev_err(&charger->client->dev, 152 "Failed to write input current : %d\n", 153 ret); 154 return ret; 155 } 156 } 157 158 return 0; 159 } 160 161 static inline int bq24735_enable_charging(struct bq24735 *charger) 162 { 163 int ret; 164 165 if (charger->pdata->ext_control) 166 return 0; 167 168 ret = bq24735_config_charger(charger); 169 if (ret) 170 return ret; 171 172 return bq24735_update_word(charger->client, BQ24735_CHG_OPT, 173 BQ24735_CHG_OPT_CHARGE_DISABLE, 0); 174 } 175 176 static inline int bq24735_disable_charging(struct bq24735 *charger) 177 { 178 if (charger->pdata->ext_control) 179 return 0; 180 181 return bq24735_update_word(charger->client, BQ24735_CHG_OPT, 182 BQ24735_CHG_OPT_CHARGE_DISABLE, 183 BQ24735_CHG_OPT_CHARGE_DISABLE); 184 } 185 186 static bool bq24735_charger_is_present(struct bq24735 *charger) 187 { 188 if (charger->status_gpio) { 189 return !gpiod_get_value_cansleep(charger->status_gpio); 190 } else { 191 int ac = 0; 192 193 ac = bq24735_read_word(charger->client, BQ24735_CHG_OPT); 194 if (ac < 0) { 195 dev_dbg(&charger->client->dev, 196 "Failed to read charger options : %d\n", 197 ac); 198 return false; 199 } 200 return (ac & BQ24735_CHG_OPT_AC_PRESENT) ? true : false; 201 } 202 203 return false; 204 } 205 206 static int bq24735_charger_is_charging(struct bq24735 *charger) 207 { 208 int ret; 209 210 if (!bq24735_charger_is_present(charger)) 211 return 0; 212 213 ret = bq24735_read_word(charger->client, BQ24735_CHG_OPT); 214 if (ret < 0) 215 return ret; 216 217 return !(ret & BQ24735_CHG_OPT_CHARGE_DISABLE); 218 } 219 220 static void bq24735_update(struct bq24735 *charger) 221 { 222 mutex_lock(&charger->lock); 223 224 if (charger->charging && bq24735_charger_is_present(charger)) 225 bq24735_enable_charging(charger); 226 else 227 bq24735_disable_charging(charger); 228 229 mutex_unlock(&charger->lock); 230 231 power_supply_changed(charger->charger); 232 } 233 234 static irqreturn_t bq24735_charger_isr(int irq, void *devid) 235 { 236 struct power_supply *psy = devid; 237 struct bq24735 *charger = to_bq24735(psy); 238 239 bq24735_update(charger); 240 241 return IRQ_HANDLED; 242 } 243 244 static void bq24735_poll(struct work_struct *work) 245 { 246 struct bq24735 *charger = container_of(work, struct bq24735, poll.work); 247 248 bq24735_update(charger); 249 250 schedule_delayed_work(&charger->poll, 251 msecs_to_jiffies(charger->poll_interval)); 252 } 253 254 static int bq24735_charger_get_property(struct power_supply *psy, 255 enum power_supply_property psp, 256 union power_supply_propval *val) 257 { 258 struct bq24735 *charger = to_bq24735(psy); 259 260 switch (psp) { 261 case POWER_SUPPLY_PROP_ONLINE: 262 val->intval = bq24735_charger_is_present(charger) ? 1 : 0; 263 break; 264 case POWER_SUPPLY_PROP_STATUS: 265 switch (bq24735_charger_is_charging(charger)) { 266 case 1: 267 val->intval = POWER_SUPPLY_STATUS_CHARGING; 268 break; 269 case 0: 270 val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING; 271 break; 272 default: 273 val->intval = POWER_SUPPLY_STATUS_UNKNOWN; 274 break; 275 } 276 break; 277 default: 278 return -EINVAL; 279 } 280 281 return 0; 282 } 283 284 static int bq24735_charger_set_property(struct power_supply *psy, 285 enum power_supply_property psp, 286 const union power_supply_propval *val) 287 { 288 struct bq24735 *charger = to_bq24735(psy); 289 int ret; 290 291 switch (psp) { 292 case POWER_SUPPLY_PROP_STATUS: 293 switch (val->intval) { 294 case POWER_SUPPLY_STATUS_CHARGING: 295 mutex_lock(&charger->lock); 296 charger->charging = true; 297 ret = bq24735_enable_charging(charger); 298 mutex_unlock(&charger->lock); 299 if (ret) 300 return ret; 301 break; 302 case POWER_SUPPLY_STATUS_DISCHARGING: 303 case POWER_SUPPLY_STATUS_NOT_CHARGING: 304 mutex_lock(&charger->lock); 305 charger->charging = false; 306 ret = bq24735_disable_charging(charger); 307 mutex_unlock(&charger->lock); 308 if (ret) 309 return ret; 310 break; 311 default: 312 return -EINVAL; 313 } 314 power_supply_changed(psy); 315 break; 316 default: 317 return -EPERM; 318 } 319 320 return 0; 321 } 322 323 static struct bq24735_platform *bq24735_parse_dt_data(struct i2c_client *client) 324 { 325 struct bq24735_platform *pdata; 326 struct device_node *np = client->dev.of_node; 327 u32 val; 328 int ret; 329 330 pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL); 331 if (!pdata) { 332 dev_err(&client->dev, 333 "Memory alloc for bq24735 pdata failed\n"); 334 return NULL; 335 } 336 337 ret = of_property_read_u32(np, "ti,charge-current", &val); 338 if (!ret) 339 pdata->charge_current = val; 340 341 ret = of_property_read_u32(np, "ti,charge-voltage", &val); 342 if (!ret) 343 pdata->charge_voltage = val; 344 345 ret = of_property_read_u32(np, "ti,input-current", &val); 346 if (!ret) 347 pdata->input_current = val; 348 349 pdata->ext_control = of_property_read_bool(np, "ti,external-control"); 350 351 return pdata; 352 } 353 354 static int bq24735_charger_probe(struct i2c_client *client, 355 const struct i2c_device_id *id) 356 { 357 int ret; 358 struct bq24735 *charger; 359 struct power_supply_desc *supply_desc; 360 struct power_supply_config psy_cfg = {}; 361 char *name; 362 363 charger = devm_kzalloc(&client->dev, sizeof(*charger), GFP_KERNEL); 364 if (!charger) 365 return -ENOMEM; 366 367 mutex_init(&charger->lock); 368 charger->charging = true; 369 charger->pdata = client->dev.platform_data; 370 371 if (IS_ENABLED(CONFIG_OF) && !charger->pdata && client->dev.of_node) 372 charger->pdata = bq24735_parse_dt_data(client); 373 374 if (!charger->pdata) { 375 dev_err(&client->dev, "no platform data provided\n"); 376 return -EINVAL; 377 } 378 379 name = (char *)charger->pdata->name; 380 if (!name) { 381 name = devm_kasprintf(&client->dev, GFP_KERNEL, 382 "bq24735@%s", 383 dev_name(&client->dev)); 384 if (!name) { 385 dev_err(&client->dev, "Failed to alloc device name\n"); 386 return -ENOMEM; 387 } 388 } 389 390 charger->client = client; 391 392 supply_desc = &charger->charger_desc; 393 394 supply_desc->name = name; 395 supply_desc->type = POWER_SUPPLY_TYPE_MAINS; 396 supply_desc->properties = bq24735_charger_properties; 397 supply_desc->num_properties = ARRAY_SIZE(bq24735_charger_properties); 398 supply_desc->get_property = bq24735_charger_get_property; 399 supply_desc->set_property = bq24735_charger_set_property; 400 supply_desc->property_is_writeable = 401 bq24735_charger_property_is_writeable; 402 403 psy_cfg.supplied_to = charger->pdata->supplied_to; 404 psy_cfg.num_supplicants = charger->pdata->num_supplicants; 405 psy_cfg.of_node = client->dev.of_node; 406 psy_cfg.drv_data = charger; 407 408 i2c_set_clientdata(client, charger); 409 410 charger->status_gpio = devm_gpiod_get_optional(&client->dev, 411 "ti,ac-detect", 412 GPIOD_IN); 413 if (IS_ERR(charger->status_gpio)) { 414 ret = PTR_ERR(charger->status_gpio); 415 dev_err(&client->dev, "Getting gpio failed: %d\n", ret); 416 return ret; 417 } 418 419 if (bq24735_charger_is_present(charger)) { 420 ret = bq24735_read_word(client, BQ24735_MANUFACTURER_ID); 421 if (ret < 0) { 422 dev_err(&client->dev, "Failed to read manufacturer id : %d\n", 423 ret); 424 return ret; 425 } else if (ret != 0x0040) { 426 dev_err(&client->dev, 427 "manufacturer id mismatch. 0x0040 != 0x%04x\n", ret); 428 return -ENODEV; 429 } 430 431 ret = bq24735_read_word(client, BQ24735_DEVICE_ID); 432 if (ret < 0) { 433 dev_err(&client->dev, "Failed to read device id : %d\n", ret); 434 return ret; 435 } else if (ret != 0x000B) { 436 dev_err(&client->dev, 437 "device id mismatch. 0x000b != 0x%04x\n", ret); 438 return -ENODEV; 439 } 440 441 ret = bq24735_enable_charging(charger); 442 if (ret < 0) { 443 dev_err(&client->dev, "Failed to enable charging\n"); 444 return ret; 445 } 446 } 447 448 charger->charger = devm_power_supply_register(&client->dev, supply_desc, 449 &psy_cfg); 450 if (IS_ERR(charger->charger)) { 451 ret = PTR_ERR(charger->charger); 452 dev_err(&client->dev, "Failed to register power supply: %d\n", 453 ret); 454 return ret; 455 } 456 457 if (client->irq) { 458 ret = devm_request_threaded_irq(&client->dev, client->irq, 459 NULL, bq24735_charger_isr, 460 IRQF_TRIGGER_RISING | 461 IRQF_TRIGGER_FALLING | 462 IRQF_ONESHOT, 463 supply_desc->name, 464 charger->charger); 465 if (ret) { 466 dev_err(&client->dev, 467 "Unable to register IRQ %d err %d\n", 468 client->irq, ret); 469 return ret; 470 } 471 } else { 472 ret = device_property_read_u32(&client->dev, "poll-interval", 473 &charger->poll_interval); 474 if (ret) 475 return 0; 476 if (!charger->poll_interval) 477 return 0; 478 479 INIT_DELAYED_WORK(&charger->poll, bq24735_poll); 480 schedule_delayed_work(&charger->poll, 481 msecs_to_jiffies(charger->poll_interval)); 482 } 483 484 return 0; 485 } 486 487 static int bq24735_charger_remove(struct i2c_client *client) 488 { 489 struct bq24735 *charger = i2c_get_clientdata(client); 490 491 if (charger->poll_interval) 492 cancel_delayed_work_sync(&charger->poll); 493 494 return 0; 495 } 496 497 static const struct i2c_device_id bq24735_charger_id[] = { 498 { "bq24735-charger", 0 }, 499 {} 500 }; 501 MODULE_DEVICE_TABLE(i2c, bq24735_charger_id); 502 503 static const struct of_device_id bq24735_match_ids[] = { 504 { .compatible = "ti,bq24735", }, 505 { /* end */ } 506 }; 507 MODULE_DEVICE_TABLE(of, bq24735_match_ids); 508 509 static struct i2c_driver bq24735_charger_driver = { 510 .driver = { 511 .name = "bq24735-charger", 512 .of_match_table = bq24735_match_ids, 513 }, 514 .probe = bq24735_charger_probe, 515 .remove = bq24735_charger_remove, 516 .id_table = bq24735_charger_id, 517 }; 518 519 module_i2c_driver(bq24735_charger_driver); 520 521 MODULE_DESCRIPTION("bq24735 battery charging driver"); 522 MODULE_AUTHOR("Darbha Sriharsha <dsriharsha@nvidia.com>"); 523 MODULE_LICENSE("GPL v2"); 524