1 /* 2 * SMBus driver for ACPI SMBus CMI 3 * 4 * Copyright (C) 2009 Crane Cai <crane.cai@amd.com> 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 version 2. 9 */ 10 11 #include <linux/module.h> 12 #include <linux/slab.h> 13 #include <linux/kernel.h> 14 #include <linux/stddef.h> 15 #include <linux/i2c.h> 16 #include <linux/acpi.h> 17 18 #define ACPI_SMBUS_HC_CLASS "smbus" 19 #define ACPI_SMBUS_HC_DEVICE_NAME "cmi" 20 21 /* SMBUS HID definition as supported by Microsoft Windows */ 22 #define ACPI_SMBUS_MS_HID "SMB0001" 23 24 ACPI_MODULE_NAME("smbus_cmi"); 25 26 struct smbus_methods_t { 27 char *mt_info; 28 char *mt_sbr; 29 char *mt_sbw; 30 }; 31 32 struct acpi_smbus_cmi { 33 acpi_handle handle; 34 struct i2c_adapter adapter; 35 u8 cap_info:1; 36 u8 cap_read:1; 37 u8 cap_write:1; 38 struct smbus_methods_t *methods; 39 }; 40 41 static const struct smbus_methods_t smbus_methods = { 42 .mt_info = "_SBI", 43 .mt_sbr = "_SBR", 44 .mt_sbw = "_SBW", 45 }; 46 47 /* Some IBM BIOSes omit the leading underscore */ 48 static const struct smbus_methods_t ibm_smbus_methods = { 49 .mt_info = "SBI_", 50 .mt_sbr = "SBR_", 51 .mt_sbw = "SBW_", 52 }; 53 54 static const struct acpi_device_id acpi_smbus_cmi_ids[] = { 55 {"SMBUS01", (kernel_ulong_t)&smbus_methods}, 56 {ACPI_SMBUS_IBM_HID, (kernel_ulong_t)&ibm_smbus_methods}, 57 {ACPI_SMBUS_MS_HID, (kernel_ulong_t)&smbus_methods}, 58 {"", 0} 59 }; 60 MODULE_DEVICE_TABLE(acpi, acpi_smbus_cmi_ids); 61 62 #define ACPI_SMBUS_STATUS_OK 0x00 63 #define ACPI_SMBUS_STATUS_FAIL 0x07 64 #define ACPI_SMBUS_STATUS_DNAK 0x10 65 #define ACPI_SMBUS_STATUS_DERR 0x11 66 #define ACPI_SMBUS_STATUS_CMD_DENY 0x12 67 #define ACPI_SMBUS_STATUS_UNKNOWN 0x13 68 #define ACPI_SMBUS_STATUS_ACC_DENY 0x17 69 #define ACPI_SMBUS_STATUS_TIMEOUT 0x18 70 #define ACPI_SMBUS_STATUS_NOTSUP 0x19 71 #define ACPI_SMBUS_STATUS_BUSY 0x1a 72 #define ACPI_SMBUS_STATUS_PEC 0x1f 73 74 #define ACPI_SMBUS_PRTCL_WRITE 0x00 75 #define ACPI_SMBUS_PRTCL_READ 0x01 76 #define ACPI_SMBUS_PRTCL_QUICK 0x02 77 #define ACPI_SMBUS_PRTCL_BYTE 0x04 78 #define ACPI_SMBUS_PRTCL_BYTE_DATA 0x06 79 #define ACPI_SMBUS_PRTCL_WORD_DATA 0x08 80 #define ACPI_SMBUS_PRTCL_BLOCK_DATA 0x0a 81 82 83 static int 84 acpi_smbus_cmi_access(struct i2c_adapter *adap, u16 addr, unsigned short flags, 85 char read_write, u8 command, int size, 86 union i2c_smbus_data *data) 87 { 88 int result = 0; 89 struct acpi_smbus_cmi *smbus_cmi = adap->algo_data; 90 unsigned char protocol; 91 acpi_status status = 0; 92 struct acpi_object_list input; 93 union acpi_object mt_params[5]; 94 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 95 union acpi_object *obj; 96 union acpi_object *pkg; 97 char *method; 98 int len = 0; 99 100 dev_dbg(&adap->dev, "access size: %d %s\n", size, 101 (read_write) ? "READ" : "WRITE"); 102 switch (size) { 103 case I2C_SMBUS_QUICK: 104 protocol = ACPI_SMBUS_PRTCL_QUICK; 105 command = 0; 106 if (read_write == I2C_SMBUS_WRITE) { 107 mt_params[3].type = ACPI_TYPE_INTEGER; 108 mt_params[3].integer.value = 0; 109 mt_params[4].type = ACPI_TYPE_INTEGER; 110 mt_params[4].integer.value = 0; 111 } 112 break; 113 114 case I2C_SMBUS_BYTE: 115 protocol = ACPI_SMBUS_PRTCL_BYTE; 116 if (read_write == I2C_SMBUS_WRITE) { 117 mt_params[3].type = ACPI_TYPE_INTEGER; 118 mt_params[3].integer.value = 0; 119 mt_params[4].type = ACPI_TYPE_INTEGER; 120 mt_params[4].integer.value = 0; 121 } else { 122 command = 0; 123 } 124 break; 125 126 case I2C_SMBUS_BYTE_DATA: 127 protocol = ACPI_SMBUS_PRTCL_BYTE_DATA; 128 if (read_write == I2C_SMBUS_WRITE) { 129 mt_params[3].type = ACPI_TYPE_INTEGER; 130 mt_params[3].integer.value = 1; 131 mt_params[4].type = ACPI_TYPE_INTEGER; 132 mt_params[4].integer.value = data->byte; 133 } 134 break; 135 136 case I2C_SMBUS_WORD_DATA: 137 protocol = ACPI_SMBUS_PRTCL_WORD_DATA; 138 if (read_write == I2C_SMBUS_WRITE) { 139 mt_params[3].type = ACPI_TYPE_INTEGER; 140 mt_params[3].integer.value = 2; 141 mt_params[4].type = ACPI_TYPE_INTEGER; 142 mt_params[4].integer.value = data->word; 143 } 144 break; 145 146 case I2C_SMBUS_BLOCK_DATA: 147 protocol = ACPI_SMBUS_PRTCL_BLOCK_DATA; 148 if (read_write == I2C_SMBUS_WRITE) { 149 len = data->block[0]; 150 if (len == 0 || len > I2C_SMBUS_BLOCK_MAX) 151 return -EINVAL; 152 mt_params[3].type = ACPI_TYPE_INTEGER; 153 mt_params[3].integer.value = len; 154 mt_params[4].type = ACPI_TYPE_BUFFER; 155 mt_params[4].buffer.pointer = data->block + 1; 156 } 157 break; 158 159 default: 160 dev_warn(&adap->dev, "Unsupported transaction %d\n", size); 161 return -EOPNOTSUPP; 162 } 163 164 if (read_write == I2C_SMBUS_READ) { 165 protocol |= ACPI_SMBUS_PRTCL_READ; 166 method = smbus_cmi->methods->mt_sbr; 167 input.count = 3; 168 } else { 169 protocol |= ACPI_SMBUS_PRTCL_WRITE; 170 method = smbus_cmi->methods->mt_sbw; 171 input.count = 5; 172 } 173 174 input.pointer = mt_params; 175 mt_params[0].type = ACPI_TYPE_INTEGER; 176 mt_params[0].integer.value = protocol; 177 mt_params[1].type = ACPI_TYPE_INTEGER; 178 mt_params[1].integer.value = addr; 179 mt_params[2].type = ACPI_TYPE_INTEGER; 180 mt_params[2].integer.value = command; 181 182 status = acpi_evaluate_object(smbus_cmi->handle, method, &input, 183 &buffer); 184 if (ACPI_FAILURE(status)) { 185 acpi_handle_err(smbus_cmi->handle, 186 "Failed to evaluate %s: %i\n", method, status); 187 return -EIO; 188 } 189 190 pkg = buffer.pointer; 191 if (pkg && pkg->type == ACPI_TYPE_PACKAGE) 192 obj = pkg->package.elements; 193 else { 194 acpi_handle_err(smbus_cmi->handle, "Invalid argument type\n"); 195 result = -EIO; 196 goto out; 197 } 198 if (obj == NULL || obj->type != ACPI_TYPE_INTEGER) { 199 acpi_handle_err(smbus_cmi->handle, "Invalid argument type\n"); 200 result = -EIO; 201 goto out; 202 } 203 204 result = obj->integer.value; 205 acpi_handle_debug(smbus_cmi->handle, "%s return status: %i\n", method, 206 result); 207 208 switch (result) { 209 case ACPI_SMBUS_STATUS_OK: 210 result = 0; 211 break; 212 case ACPI_SMBUS_STATUS_BUSY: 213 result = -EBUSY; 214 goto out; 215 case ACPI_SMBUS_STATUS_TIMEOUT: 216 result = -ETIMEDOUT; 217 goto out; 218 case ACPI_SMBUS_STATUS_DNAK: 219 result = -ENXIO; 220 goto out; 221 default: 222 result = -EIO; 223 goto out; 224 } 225 226 if (read_write == I2C_SMBUS_WRITE || size == I2C_SMBUS_QUICK) 227 goto out; 228 229 obj = pkg->package.elements + 1; 230 if (obj->type != ACPI_TYPE_INTEGER) { 231 acpi_handle_err(smbus_cmi->handle, "Invalid argument type\n"); 232 result = -EIO; 233 goto out; 234 } 235 236 len = obj->integer.value; 237 obj = pkg->package.elements + 2; 238 switch (size) { 239 case I2C_SMBUS_BYTE: 240 case I2C_SMBUS_BYTE_DATA: 241 case I2C_SMBUS_WORD_DATA: 242 if (obj->type != ACPI_TYPE_INTEGER) { 243 acpi_handle_err(smbus_cmi->handle, 244 "Invalid argument type\n"); 245 result = -EIO; 246 goto out; 247 } 248 if (len == 2) 249 data->word = obj->integer.value; 250 else 251 data->byte = obj->integer.value; 252 break; 253 case I2C_SMBUS_BLOCK_DATA: 254 if (obj->type != ACPI_TYPE_BUFFER) { 255 acpi_handle_err(smbus_cmi->handle, 256 "Invalid argument type\n"); 257 result = -EIO; 258 goto out; 259 } 260 if (len == 0 || len > I2C_SMBUS_BLOCK_MAX) 261 return -EPROTO; 262 data->block[0] = len; 263 memcpy(data->block + 1, obj->buffer.pointer, len); 264 break; 265 } 266 267 out: 268 kfree(buffer.pointer); 269 dev_dbg(&adap->dev, "Transaction status: %i\n", result); 270 return result; 271 } 272 273 static u32 acpi_smbus_cmi_func(struct i2c_adapter *adapter) 274 { 275 struct acpi_smbus_cmi *smbus_cmi = adapter->algo_data; 276 u32 ret; 277 278 ret = smbus_cmi->cap_read | smbus_cmi->cap_write ? 279 I2C_FUNC_SMBUS_QUICK : 0; 280 281 ret |= smbus_cmi->cap_read ? 282 (I2C_FUNC_SMBUS_READ_BYTE | 283 I2C_FUNC_SMBUS_READ_BYTE_DATA | 284 I2C_FUNC_SMBUS_READ_WORD_DATA | 285 I2C_FUNC_SMBUS_READ_BLOCK_DATA) : 0; 286 287 ret |= smbus_cmi->cap_write ? 288 (I2C_FUNC_SMBUS_WRITE_BYTE | 289 I2C_FUNC_SMBUS_WRITE_BYTE_DATA | 290 I2C_FUNC_SMBUS_WRITE_WORD_DATA | 291 I2C_FUNC_SMBUS_WRITE_BLOCK_DATA) : 0; 292 293 return ret; 294 } 295 296 static const struct i2c_algorithm acpi_smbus_cmi_algorithm = { 297 .smbus_xfer = acpi_smbus_cmi_access, 298 .functionality = acpi_smbus_cmi_func, 299 }; 300 301 302 static int acpi_smbus_cmi_add_cap(struct acpi_smbus_cmi *smbus_cmi, 303 const char *name) 304 { 305 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 306 struct acpi_handle *handle = smbus_cmi->handle; 307 union acpi_object *obj; 308 acpi_status status; 309 310 if (!strcmp(name, smbus_cmi->methods->mt_info)) { 311 status = acpi_evaluate_object(smbus_cmi->handle, 312 smbus_cmi->methods->mt_info, 313 NULL, &buffer); 314 if (ACPI_FAILURE(status)) { 315 acpi_handle_err(handle, "Failed to evaluate %s: %i\n", 316 smbus_cmi->methods->mt_info, status); 317 return -EIO; 318 } 319 320 obj = buffer.pointer; 321 if (obj && obj->type == ACPI_TYPE_PACKAGE) 322 obj = obj->package.elements; 323 else { 324 acpi_handle_err(handle, "Invalid argument type\n"); 325 kfree(buffer.pointer); 326 return -EIO; 327 } 328 329 if (obj->type != ACPI_TYPE_INTEGER) { 330 acpi_handle_err(handle, "Invalid argument type\n"); 331 kfree(buffer.pointer); 332 return -EIO; 333 } else 334 acpi_handle_debug(handle, "SMBus CMI Version %x\n", 335 (int)obj->integer.value); 336 337 kfree(buffer.pointer); 338 smbus_cmi->cap_info = 1; 339 } else if (!strcmp(name, smbus_cmi->methods->mt_sbr)) 340 smbus_cmi->cap_read = 1; 341 else if (!strcmp(name, smbus_cmi->methods->mt_sbw)) 342 smbus_cmi->cap_write = 1; 343 else 344 acpi_handle_debug(handle, "Unsupported CMI method: %s\n", name); 345 346 return 0; 347 } 348 349 static acpi_status acpi_smbus_cmi_query_methods(acpi_handle handle, u32 level, 350 void *context, void **return_value) 351 { 352 char node_name[5]; 353 struct acpi_buffer buffer = { sizeof(node_name), node_name }; 354 struct acpi_smbus_cmi *smbus_cmi = context; 355 acpi_status status; 356 357 status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer); 358 359 if (ACPI_SUCCESS(status)) 360 acpi_smbus_cmi_add_cap(smbus_cmi, node_name); 361 362 return AE_OK; 363 } 364 365 static int acpi_smbus_cmi_add(struct acpi_device *device) 366 { 367 struct acpi_smbus_cmi *smbus_cmi; 368 const struct acpi_device_id *id; 369 370 smbus_cmi = kzalloc(sizeof(struct acpi_smbus_cmi), GFP_KERNEL); 371 if (!smbus_cmi) 372 return -ENOMEM; 373 374 smbus_cmi->handle = device->handle; 375 strcpy(acpi_device_name(device), ACPI_SMBUS_HC_DEVICE_NAME); 376 strcpy(acpi_device_class(device), ACPI_SMBUS_HC_CLASS); 377 device->driver_data = smbus_cmi; 378 smbus_cmi->cap_info = 0; 379 smbus_cmi->cap_read = 0; 380 smbus_cmi->cap_write = 0; 381 382 for (id = acpi_smbus_cmi_ids; id->id[0]; id++) 383 if (!strcmp(id->id, acpi_device_hid(device))) 384 smbus_cmi->methods = 385 (struct smbus_methods_t *) id->driver_data; 386 387 acpi_walk_namespace(ACPI_TYPE_METHOD, smbus_cmi->handle, 1, 388 acpi_smbus_cmi_query_methods, NULL, smbus_cmi, NULL); 389 390 if (smbus_cmi->cap_info == 0) 391 goto err; 392 393 snprintf(smbus_cmi->adapter.name, sizeof(smbus_cmi->adapter.name), 394 "SMBus CMI adapter %s", 395 acpi_device_name(device)); 396 smbus_cmi->adapter.owner = THIS_MODULE; 397 smbus_cmi->adapter.algo = &acpi_smbus_cmi_algorithm; 398 smbus_cmi->adapter.algo_data = smbus_cmi; 399 smbus_cmi->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_SPD; 400 smbus_cmi->adapter.dev.parent = &device->dev; 401 402 if (i2c_add_adapter(&smbus_cmi->adapter)) { 403 dev_err(&device->dev, "Couldn't register adapter!\n"); 404 goto err; 405 } 406 407 return 0; 408 409 err: 410 kfree(smbus_cmi); 411 device->driver_data = NULL; 412 return -EIO; 413 } 414 415 static int acpi_smbus_cmi_remove(struct acpi_device *device) 416 { 417 struct acpi_smbus_cmi *smbus_cmi = acpi_driver_data(device); 418 419 i2c_del_adapter(&smbus_cmi->adapter); 420 kfree(smbus_cmi); 421 device->driver_data = NULL; 422 423 return 0; 424 } 425 426 static struct acpi_driver acpi_smbus_cmi_driver = { 427 .name = ACPI_SMBUS_HC_DEVICE_NAME, 428 .class = ACPI_SMBUS_HC_CLASS, 429 .ids = acpi_smbus_cmi_ids, 430 .ops = { 431 .add = acpi_smbus_cmi_add, 432 .remove = acpi_smbus_cmi_remove, 433 }, 434 }; 435 module_acpi_driver(acpi_smbus_cmi_driver); 436 437 MODULE_LICENSE("GPL"); 438 MODULE_AUTHOR("Crane Cai <crane.cai@amd.com>"); 439 MODULE_DESCRIPTION("ACPI SMBus CMI driver"); 440