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/init.h> 16#include <linux/i2c.h> 17#include <linux/acpi.h> 18 19#define ACPI_SMBUS_HC_CLASS "smbus" 20#define ACPI_SMBUS_HC_DEVICE_NAME "cmi" 21 22ACPI_MODULE_NAME("smbus_cmi"); 23 24struct smbus_methods_t { 25 char *mt_info; 26 char *mt_sbr; 27 char *mt_sbw; 28}; 29 30struct acpi_smbus_cmi { 31 acpi_handle handle; 32 struct i2c_adapter adapter; 33 u8 cap_info:1; 34 u8 cap_read:1; 35 u8 cap_write:1; 36 struct smbus_methods_t *methods; 37}; 38 39static const struct smbus_methods_t smbus_methods = { 40 .mt_info = "_SBI", 41 .mt_sbr = "_SBR", 42 .mt_sbw = "_SBW", 43}; 44 45/* Some IBM BIOSes omit the leading underscore */ 46static const struct smbus_methods_t ibm_smbus_methods = { 47 .mt_info = "SBI_", 48 .mt_sbr = "SBR_", 49 .mt_sbw = "SBW_", 50}; 51 52static const struct acpi_device_id acpi_smbus_cmi_ids[] = { 53 {"SMBUS01", (kernel_ulong_t)&smbus_methods}, 54 {ACPI_SMBUS_IBM_HID, (kernel_ulong_t)&ibm_smbus_methods}, 55 {"", 0} 56}; 57MODULE_DEVICE_TABLE(acpi, acpi_smbus_cmi_ids); 58 59#define ACPI_SMBUS_STATUS_OK 0x00 60#define ACPI_SMBUS_STATUS_FAIL 0x07 61#define ACPI_SMBUS_STATUS_DNAK 0x10 62#define ACPI_SMBUS_STATUS_DERR 0x11 63#define ACPI_SMBUS_STATUS_CMD_DENY 0x12 64#define ACPI_SMBUS_STATUS_UNKNOWN 0x13 65#define ACPI_SMBUS_STATUS_ACC_DENY 0x17 66#define ACPI_SMBUS_STATUS_TIMEOUT 0x18 67#define ACPI_SMBUS_STATUS_NOTSUP 0x19 68#define ACPI_SMBUS_STATUS_BUSY 0x1a 69#define ACPI_SMBUS_STATUS_PEC 0x1f 70 71#define ACPI_SMBUS_PRTCL_WRITE 0x00 72#define ACPI_SMBUS_PRTCL_READ 0x01 73#define ACPI_SMBUS_PRTCL_QUICK 0x02 74#define ACPI_SMBUS_PRTCL_BYTE 0x04 75#define ACPI_SMBUS_PRTCL_BYTE_DATA 0x06 76#define ACPI_SMBUS_PRTCL_WORD_DATA 0x08 77#define ACPI_SMBUS_PRTCL_BLOCK_DATA 0x0a 78 79 80static int 81acpi_smbus_cmi_access(struct i2c_adapter *adap, u16 addr, unsigned short flags, 82 char read_write, u8 command, int size, 83 union i2c_smbus_data *data) 84{ 85 int result = 0; 86 struct acpi_smbus_cmi *smbus_cmi = adap->algo_data; 87 unsigned char protocol; 88 acpi_status status = 0; 89 struct acpi_object_list input; 90 union acpi_object mt_params[5]; 91 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 92 union acpi_object *obj; 93 union acpi_object *pkg; 94 char *method; 95 int len = 0; 96 97 dev_dbg(&adap->dev, "access size: %d %s\n", size, 98 (read_write) ? "READ" : "WRITE"); 99 switch (size) { 100 case I2C_SMBUS_QUICK: 101 protocol = ACPI_SMBUS_PRTCL_QUICK; 102 command = 0; 103 if (read_write == I2C_SMBUS_WRITE) { 104 mt_params[3].type = ACPI_TYPE_INTEGER; 105 mt_params[3].integer.value = 0; 106 mt_params[4].type = ACPI_TYPE_INTEGER; 107 mt_params[4].integer.value = 0; 108 } 109 break; 110 111 case I2C_SMBUS_BYTE: 112 protocol = ACPI_SMBUS_PRTCL_BYTE; 113 if (read_write == I2C_SMBUS_WRITE) { 114 mt_params[3].type = ACPI_TYPE_INTEGER; 115 mt_params[3].integer.value = 0; 116 mt_params[4].type = ACPI_TYPE_INTEGER; 117 mt_params[4].integer.value = 0; 118 } else { 119 command = 0; 120 } 121 break; 122 123 case I2C_SMBUS_BYTE_DATA: 124 protocol = ACPI_SMBUS_PRTCL_BYTE_DATA; 125 if (read_write == I2C_SMBUS_WRITE) { 126 mt_params[3].type = ACPI_TYPE_INTEGER; 127 mt_params[3].integer.value = 1; 128 mt_params[4].type = ACPI_TYPE_INTEGER; 129 mt_params[4].integer.value = data->byte; 130 } 131 break; 132 133 case I2C_SMBUS_WORD_DATA: 134 protocol = ACPI_SMBUS_PRTCL_WORD_DATA; 135 if (read_write == I2C_SMBUS_WRITE) { 136 mt_params[3].type = ACPI_TYPE_INTEGER; 137 mt_params[3].integer.value = 2; 138 mt_params[4].type = ACPI_TYPE_INTEGER; 139 mt_params[4].integer.value = data->word; 140 } 141 break; 142 143 case I2C_SMBUS_BLOCK_DATA: 144 protocol = ACPI_SMBUS_PRTCL_BLOCK_DATA; 145 if (read_write == I2C_SMBUS_WRITE) { 146 len = data->block[0]; 147 if (len == 0 || len > I2C_SMBUS_BLOCK_MAX) 148 return -EINVAL; 149 mt_params[3].type = ACPI_TYPE_INTEGER; 150 mt_params[3].integer.value = len; 151 mt_params[4].type = ACPI_TYPE_BUFFER; 152 mt_params[4].buffer.pointer = data->block + 1; 153 } 154 break; 155 156 default: 157 dev_warn(&adap->dev, "Unsupported transaction %d\n", size); 158 return -EOPNOTSUPP; 159 } 160 161 if (read_write == I2C_SMBUS_READ) { 162 protocol |= ACPI_SMBUS_PRTCL_READ; 163 method = smbus_cmi->methods->mt_sbr; 164 input.count = 3; 165 } else { 166 protocol |= ACPI_SMBUS_PRTCL_WRITE; 167 method = smbus_cmi->methods->mt_sbw; 168 input.count = 5; 169 } 170 171 input.pointer = mt_params; 172 mt_params[0].type = ACPI_TYPE_INTEGER; 173 mt_params[0].integer.value = protocol; 174 mt_params[1].type = ACPI_TYPE_INTEGER; 175 mt_params[1].integer.value = addr; 176 mt_params[2].type = ACPI_TYPE_INTEGER; 177 mt_params[2].integer.value = command; 178 179 status = acpi_evaluate_object(smbus_cmi->handle, method, &input, 180 &buffer); 181 if (ACPI_FAILURE(status)) { 182 ACPI_ERROR((AE_INFO, "Evaluating %s: %i", method, status)); 183 return -EIO; 184 } 185 186 pkg = buffer.pointer; 187 if (pkg && pkg->type == ACPI_TYPE_PACKAGE) 188 obj = pkg->package.elements; 189 else { 190 ACPI_ERROR((AE_INFO, "Invalid argument type")); 191 result = -EIO; 192 goto out; 193 } 194 if (obj == NULL || obj->type != ACPI_TYPE_INTEGER) { 195 ACPI_ERROR((AE_INFO, "Invalid argument type")); 196 result = -EIO; 197 goto out; 198 } 199 200 result = obj->integer.value; 201 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "%s return status: %i\n", 202 method, result)); 203 204 switch (result) { 205 case ACPI_SMBUS_STATUS_OK: 206 result = 0; 207 break; 208 case ACPI_SMBUS_STATUS_BUSY: 209 result = -EBUSY; 210 goto out; 211 case ACPI_SMBUS_STATUS_TIMEOUT: 212 result = -ETIMEDOUT; 213 goto out; 214 case ACPI_SMBUS_STATUS_DNAK: 215 result = -ENXIO; 216 goto out; 217 default: 218 result = -EIO; 219 goto out; 220 } 221 222 if (read_write == I2C_SMBUS_WRITE || size == I2C_SMBUS_QUICK) 223 goto out; 224 225 obj = pkg->package.elements + 1; 226 if (obj == NULL || obj->type != ACPI_TYPE_INTEGER) { 227 ACPI_ERROR((AE_INFO, "Invalid argument type")); 228 result = -EIO; 229 goto out; 230 } 231 232 len = obj->integer.value; 233 obj = pkg->package.elements + 2; 234 switch (size) { 235 case I2C_SMBUS_BYTE: 236 case I2C_SMBUS_BYTE_DATA: 237 case I2C_SMBUS_WORD_DATA: 238 if (obj == NULL || obj->type != ACPI_TYPE_INTEGER) { 239 ACPI_ERROR((AE_INFO, "Invalid argument type")); 240 result = -EIO; 241 goto out; 242 } 243 if (len == 2) 244 data->word = obj->integer.value; 245 else 246 data->byte = obj->integer.value; 247 break; 248 case I2C_SMBUS_BLOCK_DATA: 249 if (obj == NULL || obj->type != ACPI_TYPE_BUFFER) { 250 ACPI_ERROR((AE_INFO, "Invalid argument type")); 251 result = -EIO; 252 goto out; 253 } 254 if (len == 0 || len > I2C_SMBUS_BLOCK_MAX) 255 return -EPROTO; 256 data->block[0] = len; 257 memcpy(data->block + 1, obj->buffer.pointer, len); 258 break; 259 } 260 261out: 262 kfree(buffer.pointer); 263 dev_dbg(&adap->dev, "Transaction status: %i\n", result); 264 return result; 265} 266 267static u32 acpi_smbus_cmi_func(struct i2c_adapter *adapter) 268{ 269 struct acpi_smbus_cmi *smbus_cmi = adapter->algo_data; 270 u32 ret; 271 272 ret = smbus_cmi->cap_read | smbus_cmi->cap_write ? 273 I2C_FUNC_SMBUS_QUICK : 0; 274 275 ret |= smbus_cmi->cap_read ? 276 (I2C_FUNC_SMBUS_READ_BYTE | 277 I2C_FUNC_SMBUS_READ_BYTE_DATA | 278 I2C_FUNC_SMBUS_READ_WORD_DATA | 279 I2C_FUNC_SMBUS_READ_BLOCK_DATA) : 0; 280 281 ret |= smbus_cmi->cap_write ? 282 (I2C_FUNC_SMBUS_WRITE_BYTE | 283 I2C_FUNC_SMBUS_WRITE_BYTE_DATA | 284 I2C_FUNC_SMBUS_WRITE_WORD_DATA | 285 I2C_FUNC_SMBUS_WRITE_BLOCK_DATA) : 0; 286 287 return ret; 288} 289 290static const struct i2c_algorithm acpi_smbus_cmi_algorithm = { 291 .smbus_xfer = acpi_smbus_cmi_access, 292 .functionality = acpi_smbus_cmi_func, 293}; 294 295 296static int acpi_smbus_cmi_add_cap(struct acpi_smbus_cmi *smbus_cmi, 297 const char *name) 298{ 299 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 300 union acpi_object *obj; 301 acpi_status status; 302 303 if (!strcmp(name, smbus_cmi->methods->mt_info)) { 304 status = acpi_evaluate_object(smbus_cmi->handle, 305 smbus_cmi->methods->mt_info, 306 NULL, &buffer); 307 if (ACPI_FAILURE(status)) { 308 ACPI_ERROR((AE_INFO, "Evaluating %s: %i", 309 smbus_cmi->methods->mt_info, status)); 310 return -EIO; 311 } 312 313 obj = buffer.pointer; 314 if (obj && obj->type == ACPI_TYPE_PACKAGE) 315 obj = obj->package.elements; 316 else { 317 ACPI_ERROR((AE_INFO, "Invalid argument type")); 318 kfree(buffer.pointer); 319 return -EIO; 320 } 321 322 if (obj->type != ACPI_TYPE_INTEGER) { 323 ACPI_ERROR((AE_INFO, "Invalid argument type")); 324 kfree(buffer.pointer); 325 return -EIO; 326 } else 327 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "SMBus CMI Version %x" 328 "\n", (int)obj->integer.value)); 329 330 kfree(buffer.pointer); 331 smbus_cmi->cap_info = 1; 332 } else if (!strcmp(name, smbus_cmi->methods->mt_sbr)) 333 smbus_cmi->cap_read = 1; 334 else if (!strcmp(name, smbus_cmi->methods->mt_sbw)) 335 smbus_cmi->cap_write = 1; 336 else 337 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Unsupported CMI method: %s\n", 338 name)); 339 340 return 0; 341} 342 343static acpi_status acpi_smbus_cmi_query_methods(acpi_handle handle, u32 level, 344 void *context, void **return_value) 345{ 346 char node_name[5]; 347 struct acpi_buffer buffer = { sizeof(node_name), node_name }; 348 struct acpi_smbus_cmi *smbus_cmi = context; 349 acpi_status status; 350 351 status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer); 352 353 if (ACPI_SUCCESS(status)) 354 acpi_smbus_cmi_add_cap(smbus_cmi, node_name); 355 356 return AE_OK; 357} 358 359static int acpi_smbus_cmi_add(struct acpi_device *device) 360{ 361 struct acpi_smbus_cmi *smbus_cmi; 362 const struct acpi_device_id *id; 363 364 smbus_cmi = kzalloc(sizeof(struct acpi_smbus_cmi), GFP_KERNEL); 365 if (!smbus_cmi) 366 return -ENOMEM; 367 368 smbus_cmi->handle = device->handle; 369 strcpy(acpi_device_name(device), ACPI_SMBUS_HC_DEVICE_NAME); 370 strcpy(acpi_device_class(device), ACPI_SMBUS_HC_CLASS); 371 device->driver_data = smbus_cmi; 372 smbus_cmi->cap_info = 0; 373 smbus_cmi->cap_read = 0; 374 smbus_cmi->cap_write = 0; 375 376 for (id = acpi_smbus_cmi_ids; id->id[0]; id++) 377 if (!strcmp(id->id, acpi_device_hid(device))) 378 smbus_cmi->methods = 379 (struct smbus_methods_t *) id->driver_data; 380 381 acpi_walk_namespace(ACPI_TYPE_METHOD, smbus_cmi->handle, 1, 382 acpi_smbus_cmi_query_methods, NULL, smbus_cmi, NULL); 383 384 if (smbus_cmi->cap_info == 0) 385 goto err; 386 387 snprintf(smbus_cmi->adapter.name, sizeof(smbus_cmi->adapter.name), 388 "SMBus CMI adapter %s", 389 acpi_device_name(device)); 390 smbus_cmi->adapter.owner = THIS_MODULE; 391 smbus_cmi->adapter.algo = &acpi_smbus_cmi_algorithm; 392 smbus_cmi->adapter.algo_data = smbus_cmi; 393 smbus_cmi->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_SPD; 394 smbus_cmi->adapter.dev.parent = &device->dev; 395 396 if (i2c_add_adapter(&smbus_cmi->adapter)) { 397 dev_err(&device->dev, "Couldn't register adapter!\n"); 398 goto err; 399 } 400 401 return 0; 402 403err: 404 kfree(smbus_cmi); 405 device->driver_data = NULL; 406 return -EIO; 407} 408 409static int acpi_smbus_cmi_remove(struct acpi_device *device, int type) 410{ 411 struct acpi_smbus_cmi *smbus_cmi = acpi_driver_data(device); 412 413 i2c_del_adapter(&smbus_cmi->adapter); 414 kfree(smbus_cmi); 415 device->driver_data = NULL; 416 417 return 0; 418} 419 420static struct acpi_driver acpi_smbus_cmi_driver = { 421 .name = ACPI_SMBUS_HC_DEVICE_NAME, 422 .class = ACPI_SMBUS_HC_CLASS, 423 .ids = acpi_smbus_cmi_ids, 424 .ops = { 425 .add = acpi_smbus_cmi_add, 426 .remove = acpi_smbus_cmi_remove, 427 }, 428}; 429 430static int __init acpi_smbus_cmi_init(void) 431{ 432 return acpi_bus_register_driver(&acpi_smbus_cmi_driver); 433} 434 435static void __exit acpi_smbus_cmi_exit(void) 436{ 437 acpi_bus_unregister_driver(&acpi_smbus_cmi_driver); 438} 439 440module_init(acpi_smbus_cmi_init); 441module_exit(acpi_smbus_cmi_exit); 442 443MODULE_LICENSE("GPL"); 444MODULE_AUTHOR("Crane Cai <crane.cai@amd.com>"); 445MODULE_DESCRIPTION("ACPI SMBus CMI driver"); 446