1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Supports for the power IC on the Surface 3 tablet. 4 * 5 * (C) Copyright 2016-2018 Red Hat, Inc 6 * (C) Copyright 2016-2018 Benjamin Tissoires <benjamin.tissoires@gmail.com> 7 * (C) Copyright 2016 Stephen Just <stephenjust@gmail.com> 8 * 9 * This driver has been reverse-engineered by parsing the DSDT of the Surface 3 10 * and looking at the registers of the chips. 11 * 12 * The DSDT allowed to find out that: 13 * - the driver is required for the ACPI BAT0 device to communicate to the chip 14 * through an operation region. 15 * - the various defines for the operation region functions to communicate with 16 * this driver 17 * - the DSM 3f99e367-6220-4955-8b0f-06ef2ae79412 allows to trigger ACPI 18 * events to BAT0 (the code is all available in the DSDT). 19 * 20 * Further findings regarding the 2 chips declared in the MSHW0011 are: 21 * - there are 2 chips declared: 22 * . 0x22 seems to control the ADP1 line status (and probably the charger) 23 * . 0x55 controls the battery directly 24 * - the battery chip uses a SMBus protocol (using plain SMBus allows non 25 * destructive commands): 26 * . the commands/registers used are in the range 0x00..0x7F 27 * . if bit 8 (0x80) is set in the SMBus command, the returned value is the 28 * same as when it is not set. There is a high chance this bit is the 29 * read/write 30 * . the various registers semantic as been deduced by observing the register 31 * dumps. 32 */ 33 34 #include <linux/acpi.h> 35 #include <linux/bits.h> 36 #include <linux/freezer.h> 37 #include <linux/i2c.h> 38 #include <linux/kernel.h> 39 #include <linux/kthread.h> 40 #include <linux/slab.h> 41 #include <linux/types.h> 42 #include <linux/uuid.h> 43 #include <asm/unaligned.h> 44 45 #define SURFACE_3_POLL_INTERVAL (2 * HZ) 46 #define SURFACE_3_STRLEN 10 47 48 struct mshw0011_data { 49 struct i2c_client *adp1; 50 struct i2c_client *bat0; 51 unsigned short notify_mask; 52 struct task_struct *poll_task; 53 bool kthread_running; 54 55 bool charging; 56 bool bat_charging; 57 u8 trip_point; 58 s32 full_capacity; 59 }; 60 61 struct mshw0011_handler_data { 62 struct acpi_connection_info info; 63 struct i2c_client *client; 64 }; 65 66 struct bix { 67 u32 revision; 68 u32 power_unit; 69 u32 design_capacity; 70 u32 last_full_charg_capacity; 71 u32 battery_technology; 72 u32 design_voltage; 73 u32 design_capacity_of_warning; 74 u32 design_capacity_of_low; 75 u32 cycle_count; 76 u32 measurement_accuracy; 77 u32 max_sampling_time; 78 u32 min_sampling_time; 79 u32 max_average_interval; 80 u32 min_average_interval; 81 u32 battery_capacity_granularity_1; 82 u32 battery_capacity_granularity_2; 83 char model[SURFACE_3_STRLEN]; 84 char serial[SURFACE_3_STRLEN]; 85 char type[SURFACE_3_STRLEN]; 86 char OEM[SURFACE_3_STRLEN]; 87 } __packed; 88 89 struct bst { 90 u32 battery_state; 91 s32 battery_present_rate; 92 u32 battery_remaining_capacity; 93 u32 battery_present_voltage; 94 } __packed; 95 96 struct gsb_command { 97 u8 arg0; 98 u8 arg1; 99 u8 arg2; 100 } __packed; 101 102 struct gsb_buffer { 103 u8 status; 104 u8 len; 105 u8 ret; 106 union { 107 struct gsb_command cmd; 108 struct bst bst; 109 struct bix bix; 110 } __packed; 111 } __packed; 112 113 #define ACPI_BATTERY_STATE_DISCHARGING BIT(0) 114 #define ACPI_BATTERY_STATE_CHARGING BIT(1) 115 #define ACPI_BATTERY_STATE_CRITICAL BIT(2) 116 117 #define MSHW0011_CMD_DEST_BAT0 0x01 118 #define MSHW0011_CMD_DEST_ADP1 0x03 119 120 #define MSHW0011_CMD_BAT0_STA 0x01 121 #define MSHW0011_CMD_BAT0_BIX 0x02 122 #define MSHW0011_CMD_BAT0_BCT 0x03 123 #define MSHW0011_CMD_BAT0_BTM 0x04 124 #define MSHW0011_CMD_BAT0_BST 0x05 125 #define MSHW0011_CMD_BAT0_BTP 0x06 126 #define MSHW0011_CMD_ADP1_PSR 0x07 127 #define MSHW0011_CMD_BAT0_PSOC 0x09 128 #define MSHW0011_CMD_BAT0_PMAX 0x0a 129 #define MSHW0011_CMD_BAT0_PSRC 0x0b 130 #define MSHW0011_CMD_BAT0_CHGI 0x0c 131 #define MSHW0011_CMD_BAT0_ARTG 0x0d 132 133 #define MSHW0011_NOTIFY_GET_VERSION 0x00 134 #define MSHW0011_NOTIFY_ADP1 0x01 135 #define MSHW0011_NOTIFY_BAT0_BST 0x02 136 #define MSHW0011_NOTIFY_BAT0_BIX 0x05 137 138 #define MSHW0011_ADP1_REG_PSR 0x04 139 140 #define MSHW0011_BAT0_REG_CAPACITY 0x0c 141 #define MSHW0011_BAT0_REG_FULL_CHG_CAPACITY 0x0e 142 #define MSHW0011_BAT0_REG_DESIGN_CAPACITY 0x40 143 #define MSHW0011_BAT0_REG_VOLTAGE 0x08 144 #define MSHW0011_BAT0_REG_RATE 0x14 145 #define MSHW0011_BAT0_REG_OEM 0x45 146 #define MSHW0011_BAT0_REG_TYPE 0x4e 147 #define MSHW0011_BAT0_REG_SERIAL_NO 0x56 148 #define MSHW0011_BAT0_REG_CYCLE_CNT 0x6e 149 150 #define MSHW0011_EV_2_5_MASK GENMASK(8, 0) 151 152 /* 3f99e367-6220-4955-8b0f-06ef2ae79412 */ 153 static const guid_t mshw0011_guid = 154 GUID_INIT(0x3F99E367, 0x6220, 0x4955, 0x8B, 0x0F, 0x06, 0xEF, 155 0x2A, 0xE7, 0x94, 0x12); 156 157 static int 158 mshw0011_notify(struct mshw0011_data *cdata, u8 arg1, u8 arg2, 159 unsigned int *ret_value) 160 { 161 union acpi_object *obj; 162 acpi_handle handle; 163 unsigned int i; 164 165 handle = ACPI_HANDLE(&cdata->adp1->dev); 166 if (!handle) 167 return -ENODEV; 168 169 obj = acpi_evaluate_dsm_typed(handle, &mshw0011_guid, arg1, arg2, NULL, 170 ACPI_TYPE_BUFFER); 171 if (!obj) { 172 dev_err(&cdata->adp1->dev, "device _DSM execution failed\n"); 173 return -ENODEV; 174 } 175 176 *ret_value = 0; 177 for (i = 0; i < obj->buffer.length; i++) 178 *ret_value |= obj->buffer.pointer[i] << (i * 8); 179 180 ACPI_FREE(obj); 181 return 0; 182 } 183 184 static const struct bix default_bix = { 185 .revision = 0x00, 186 .power_unit = 0x01, 187 .design_capacity = 0x1dca, 188 .last_full_charg_capacity = 0x1dca, 189 .battery_technology = 0x01, 190 .design_voltage = 0x10df, 191 .design_capacity_of_warning = 0x8f, 192 .design_capacity_of_low = 0x47, 193 .cycle_count = 0xffffffff, 194 .measurement_accuracy = 0x00015f90, 195 .max_sampling_time = 0x03e8, 196 .min_sampling_time = 0x03e8, 197 .max_average_interval = 0x03e8, 198 .min_average_interval = 0x03e8, 199 .battery_capacity_granularity_1 = 0x45, 200 .battery_capacity_granularity_2 = 0x11, 201 .model = "P11G8M", 202 .serial = "", 203 .type = "LION", 204 .OEM = "", 205 }; 206 207 static int mshw0011_bix(struct mshw0011_data *cdata, struct bix *bix) 208 { 209 struct i2c_client *client = cdata->bat0; 210 char buf[SURFACE_3_STRLEN]; 211 int ret; 212 213 *bix = default_bix; 214 215 /* get design capacity */ 216 ret = i2c_smbus_read_word_data(client, 217 MSHW0011_BAT0_REG_DESIGN_CAPACITY); 218 if (ret < 0) { 219 dev_err(&client->dev, "Error reading design capacity: %d\n", 220 ret); 221 return ret; 222 } 223 bix->design_capacity = ret; 224 225 /* get last full charge capacity */ 226 ret = i2c_smbus_read_word_data(client, 227 MSHW0011_BAT0_REG_FULL_CHG_CAPACITY); 228 if (ret < 0) { 229 dev_err(&client->dev, 230 "Error reading last full charge capacity: %d\n", ret); 231 return ret; 232 } 233 bix->last_full_charg_capacity = ret; 234 235 /* 236 * Get serial number, on some devices (with unofficial replacement 237 * battery?) reading any of the serial number range addresses gets 238 * nacked in this case just leave the serial number empty. 239 */ 240 ret = i2c_smbus_read_i2c_block_data(client, MSHW0011_BAT0_REG_SERIAL_NO, 241 sizeof(buf), buf); 242 if (ret == -EREMOTEIO) { 243 /* no serial number available */ 244 } else if (ret != sizeof(buf)) { 245 dev_err(&client->dev, "Error reading serial no: %d\n", ret); 246 return ret; 247 } else { 248 snprintf(bix->serial, ARRAY_SIZE(bix->serial), "%3pE%6pE", buf + 7, buf); 249 } 250 251 /* get cycle count */ 252 ret = i2c_smbus_read_word_data(client, MSHW0011_BAT0_REG_CYCLE_CNT); 253 if (ret < 0) { 254 dev_err(&client->dev, "Error reading cycle count: %d\n", ret); 255 return ret; 256 } 257 bix->cycle_count = ret; 258 259 /* get OEM name */ 260 ret = i2c_smbus_read_i2c_block_data(client, MSHW0011_BAT0_REG_OEM, 261 4, buf); 262 if (ret != 4) { 263 dev_err(&client->dev, "Error reading cycle count: %d\n", ret); 264 return ret; 265 } 266 snprintf(bix->OEM, ARRAY_SIZE(bix->OEM), "%3pE", buf); 267 268 return 0; 269 } 270 271 static int mshw0011_bst(struct mshw0011_data *cdata, struct bst *bst) 272 { 273 struct i2c_client *client = cdata->bat0; 274 int rate, capacity, voltage, state; 275 s16 tmp; 276 277 rate = i2c_smbus_read_word_data(client, MSHW0011_BAT0_REG_RATE); 278 if (rate < 0) 279 return rate; 280 281 capacity = i2c_smbus_read_word_data(client, MSHW0011_BAT0_REG_CAPACITY); 282 if (capacity < 0) 283 return capacity; 284 285 voltage = i2c_smbus_read_word_data(client, MSHW0011_BAT0_REG_VOLTAGE); 286 if (voltage < 0) 287 return voltage; 288 289 tmp = rate; 290 bst->battery_present_rate = abs((s32)tmp); 291 292 state = 0; 293 if ((s32) tmp > 0) 294 state |= ACPI_BATTERY_STATE_CHARGING; 295 else if ((s32) tmp < 0) 296 state |= ACPI_BATTERY_STATE_DISCHARGING; 297 bst->battery_state = state; 298 299 bst->battery_remaining_capacity = capacity; 300 bst->battery_present_voltage = voltage; 301 302 return 0; 303 } 304 305 static int mshw0011_adp_psr(struct mshw0011_data *cdata) 306 { 307 return i2c_smbus_read_byte_data(cdata->adp1, MSHW0011_ADP1_REG_PSR); 308 } 309 310 static int mshw0011_isr(struct mshw0011_data *cdata) 311 { 312 struct bst bst; 313 struct bix bix; 314 int ret; 315 bool status, bat_status; 316 317 ret = mshw0011_adp_psr(cdata); 318 if (ret < 0) 319 return ret; 320 321 status = ret; 322 if (status != cdata->charging) 323 mshw0011_notify(cdata, cdata->notify_mask, 324 MSHW0011_NOTIFY_ADP1, &ret); 325 326 cdata->charging = status; 327 328 ret = mshw0011_bst(cdata, &bst); 329 if (ret < 0) 330 return ret; 331 332 bat_status = bst.battery_state; 333 if (bat_status != cdata->bat_charging) 334 mshw0011_notify(cdata, cdata->notify_mask, 335 MSHW0011_NOTIFY_BAT0_BST, &ret); 336 337 cdata->bat_charging = bat_status; 338 339 ret = mshw0011_bix(cdata, &bix); 340 if (ret < 0) 341 return ret; 342 343 if (bix.last_full_charg_capacity != cdata->full_capacity) 344 mshw0011_notify(cdata, cdata->notify_mask, 345 MSHW0011_NOTIFY_BAT0_BIX, &ret); 346 347 cdata->full_capacity = bix.last_full_charg_capacity; 348 349 return 0; 350 } 351 352 static int mshw0011_poll_task(void *data) 353 { 354 struct mshw0011_data *cdata = data; 355 int ret = 0; 356 357 cdata->kthread_running = true; 358 359 set_freezable(); 360 361 while (!kthread_should_stop()) { 362 schedule_timeout_interruptible(SURFACE_3_POLL_INTERVAL); 363 try_to_freeze(); 364 ret = mshw0011_isr(data); 365 if (ret) 366 break; 367 } 368 369 cdata->kthread_running = false; 370 return ret; 371 } 372 373 static acpi_status 374 mshw0011_space_handler(u32 function, acpi_physical_address command, 375 u32 bits, u64 *value64, 376 void *handler_context, void *region_context) 377 { 378 struct gsb_buffer *gsb = (struct gsb_buffer *)value64; 379 struct mshw0011_handler_data *data = handler_context; 380 struct acpi_connection_info *info = &data->info; 381 struct acpi_resource_i2c_serialbus *sb; 382 struct i2c_client *client = data->client; 383 struct mshw0011_data *cdata = i2c_get_clientdata(client); 384 struct acpi_resource *ares; 385 u32 accessor_type = function >> 16; 386 acpi_status ret; 387 int status = 1; 388 389 ret = acpi_buffer_to_resource(info->connection, info->length, &ares); 390 if (ACPI_FAILURE(ret)) 391 return ret; 392 393 if (!value64 || !i2c_acpi_get_i2c_resource(ares, &sb)) { 394 ret = AE_BAD_PARAMETER; 395 goto err; 396 } 397 398 if (accessor_type != ACPI_GSB_ACCESS_ATTRIB_RAW_PROCESS) { 399 ret = AE_BAD_PARAMETER; 400 goto err; 401 } 402 403 if (gsb->cmd.arg0 == MSHW0011_CMD_DEST_ADP1 && 404 gsb->cmd.arg1 == MSHW0011_CMD_ADP1_PSR) { 405 status = mshw0011_adp_psr(cdata); 406 if (status >= 0) { 407 ret = AE_OK; 408 goto out; 409 } else { 410 ret = AE_ERROR; 411 goto err; 412 } 413 } 414 415 if (gsb->cmd.arg0 != MSHW0011_CMD_DEST_BAT0) { 416 ret = AE_BAD_PARAMETER; 417 goto err; 418 } 419 420 switch (gsb->cmd.arg1) { 421 case MSHW0011_CMD_BAT0_STA: 422 break; 423 case MSHW0011_CMD_BAT0_BIX: 424 ret = mshw0011_bix(cdata, &gsb->bix); 425 break; 426 case MSHW0011_CMD_BAT0_BTP: 427 cdata->trip_point = gsb->cmd.arg2; 428 break; 429 case MSHW0011_CMD_BAT0_BST: 430 ret = mshw0011_bst(cdata, &gsb->bst); 431 break; 432 default: 433 dev_info(&cdata->bat0->dev, "command(0x%02x) is not supported.\n", gsb->cmd.arg1); 434 ret = AE_BAD_PARAMETER; 435 goto err; 436 } 437 438 out: 439 gsb->ret = status; 440 gsb->status = 0; 441 442 err: 443 ACPI_FREE(ares); 444 return ret; 445 } 446 447 static int mshw0011_install_space_handler(struct i2c_client *client) 448 { 449 struct acpi_device *adev; 450 struct mshw0011_handler_data *data; 451 acpi_status status; 452 453 adev = ACPI_COMPANION(&client->dev); 454 if (!adev) 455 return -ENODEV; 456 457 data = kzalloc(sizeof(struct mshw0011_handler_data), 458 GFP_KERNEL); 459 if (!data) 460 return -ENOMEM; 461 462 data->client = client; 463 status = acpi_bus_attach_private_data(adev->handle, (void *)data); 464 if (ACPI_FAILURE(status)) { 465 kfree(data); 466 return -ENOMEM; 467 } 468 469 status = acpi_install_address_space_handler(adev->handle, 470 ACPI_ADR_SPACE_GSBUS, 471 &mshw0011_space_handler, 472 NULL, 473 data); 474 if (ACPI_FAILURE(status)) { 475 dev_err(&client->dev, "Error installing i2c space handler\n"); 476 acpi_bus_detach_private_data(adev->handle); 477 kfree(data); 478 return -ENOMEM; 479 } 480 481 acpi_dev_clear_dependencies(adev); 482 return 0; 483 } 484 485 static void mshw0011_remove_space_handler(struct i2c_client *client) 486 { 487 struct mshw0011_handler_data *data; 488 acpi_handle handle; 489 acpi_status status; 490 491 handle = ACPI_HANDLE(&client->dev); 492 if (!handle) 493 return; 494 495 acpi_remove_address_space_handler(handle, 496 ACPI_ADR_SPACE_GSBUS, 497 &mshw0011_space_handler); 498 499 status = acpi_bus_get_private_data(handle, (void **)&data); 500 if (ACPI_SUCCESS(status)) 501 kfree(data); 502 503 acpi_bus_detach_private_data(handle); 504 } 505 506 static int mshw0011_probe(struct i2c_client *client) 507 { 508 struct i2c_board_info board_info; 509 struct device *dev = &client->dev; 510 struct i2c_client *bat0; 511 struct mshw0011_data *data; 512 int error, mask; 513 514 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); 515 if (!data) 516 return -ENOMEM; 517 518 data->adp1 = client; 519 i2c_set_clientdata(client, data); 520 521 memset(&board_info, 0, sizeof(board_info)); 522 strscpy(board_info.type, "MSHW0011-bat0", I2C_NAME_SIZE); 523 524 bat0 = i2c_acpi_new_device(dev, 1, &board_info); 525 if (IS_ERR(bat0)) 526 return PTR_ERR(bat0); 527 528 data->bat0 = bat0; 529 i2c_set_clientdata(bat0, data); 530 531 error = mshw0011_notify(data, 1, MSHW0011_NOTIFY_GET_VERSION, &mask); 532 if (error) 533 goto out_err; 534 535 data->notify_mask = mask == MSHW0011_EV_2_5_MASK; 536 537 data->poll_task = kthread_run(mshw0011_poll_task, data, "mshw0011_adp"); 538 if (IS_ERR(data->poll_task)) { 539 error = PTR_ERR(data->poll_task); 540 dev_err(&client->dev, "Unable to run kthread err %d\n", error); 541 goto out_err; 542 } 543 544 error = mshw0011_install_space_handler(client); 545 if (error) 546 goto out_err; 547 548 return 0; 549 550 out_err: 551 if (data->kthread_running) 552 kthread_stop(data->poll_task); 553 i2c_unregister_device(data->bat0); 554 return error; 555 } 556 557 static void mshw0011_remove(struct i2c_client *client) 558 { 559 struct mshw0011_data *cdata = i2c_get_clientdata(client); 560 561 mshw0011_remove_space_handler(client); 562 563 if (cdata->kthread_running) 564 kthread_stop(cdata->poll_task); 565 566 i2c_unregister_device(cdata->bat0); 567 } 568 569 static const struct acpi_device_id mshw0011_acpi_match[] = { 570 { "MSHW0011", 0 }, 571 { } 572 }; 573 MODULE_DEVICE_TABLE(acpi, mshw0011_acpi_match); 574 575 static struct i2c_driver mshw0011_driver = { 576 .probe = mshw0011_probe, 577 .remove = mshw0011_remove, 578 .driver = { 579 .name = "mshw0011", 580 .acpi_match_table = mshw0011_acpi_match, 581 }, 582 }; 583 module_i2c_driver(mshw0011_driver); 584 585 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>"); 586 MODULE_DESCRIPTION("mshw0011 driver"); 587 MODULE_LICENSE("GPL v2"); 588