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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * SMBus driver for ACPI SMBus CMI4 *5 * Copyright (C) 2009 Crane Cai <crane.cai@amd.com>6 */7 8#include <linux/module.h>9#include <linux/platform_device.h>10#include <linux/slab.h>11#include <linux/kernel.h>12#include <linux/stddef.h>13#include <linux/i2c.h>14#include <linux/acpi.h>15 16struct smbus_methods_t {17 char *mt_info;18 char *mt_sbr;19 char *mt_sbw;20};21 22struct acpi_smbus_cmi {23 acpi_handle handle;24 struct i2c_adapter adapter;25 u8 cap_info:1;26 u8 cap_read:1;27 u8 cap_write:1;28 const struct smbus_methods_t *methods;29};30 31static const struct smbus_methods_t smbus_methods = {32 .mt_info = "_SBI",33 .mt_sbr = "_SBR",34 .mt_sbw = "_SBW",35};36 37/* Some IBM BIOSes omit the leading underscore */38static const struct smbus_methods_t ibm_smbus_methods = {39 .mt_info = "SBI_",40 .mt_sbr = "SBR_",41 .mt_sbw = "SBW_",42};43 44static const struct acpi_device_id acpi_smbus_cmi_ids[] = {45 {"SMBUS01", (kernel_ulong_t)&smbus_methods},46 {ACPI_SMBUS_IBM_HID, (kernel_ulong_t)&ibm_smbus_methods},47 {ACPI_SMBUS_MS_HID, (kernel_ulong_t)&smbus_methods},48 {"", 0}49};50MODULE_DEVICE_TABLE(acpi, acpi_smbus_cmi_ids);51 52#define ACPI_SMBUS_STATUS_OK 0x0053#define ACPI_SMBUS_STATUS_FAIL 0x0754#define ACPI_SMBUS_STATUS_DNAK 0x1055#define ACPI_SMBUS_STATUS_DERR 0x1156#define ACPI_SMBUS_STATUS_CMD_DENY 0x1257#define ACPI_SMBUS_STATUS_UNKNOWN 0x1358#define ACPI_SMBUS_STATUS_ACC_DENY 0x1759#define ACPI_SMBUS_STATUS_TIMEOUT 0x1860#define ACPI_SMBUS_STATUS_NOTSUP 0x1961#define ACPI_SMBUS_STATUS_BUSY 0x1a62#define ACPI_SMBUS_STATUS_PEC 0x1f63 64#define ACPI_SMBUS_PRTCL_WRITE 0x0065#define ACPI_SMBUS_PRTCL_READ 0x0166#define ACPI_SMBUS_PRTCL_QUICK 0x0267#define ACPI_SMBUS_PRTCL_BYTE 0x0468#define ACPI_SMBUS_PRTCL_BYTE_DATA 0x0669#define ACPI_SMBUS_PRTCL_WORD_DATA 0x0870#define ACPI_SMBUS_PRTCL_BLOCK_DATA 0x0a71 72 73static int74acpi_smbus_cmi_access(struct i2c_adapter *adap, u16 addr, unsigned short flags,75 char read_write, u8 command, int size,76 union i2c_smbus_data *data)77{78 int result = 0;79 struct acpi_smbus_cmi *smbus_cmi = adap->algo_data;80 unsigned char protocol;81 acpi_status status = 0;82 struct acpi_object_list input;83 union acpi_object mt_params[5];84 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };85 union acpi_object *obj;86 union acpi_object *pkg;87 char *method;88 int len = 0;89 90 dev_dbg(&adap->dev, "access size: %d %s\n", size,91 (read_write) ? "READ" : "WRITE");92 switch (size) {93 case I2C_SMBUS_QUICK:94 protocol = ACPI_SMBUS_PRTCL_QUICK;95 command = 0;96 if (read_write == I2C_SMBUS_WRITE) {97 mt_params[3].type = ACPI_TYPE_INTEGER;98 mt_params[3].integer.value = 0;99 mt_params[4].type = ACPI_TYPE_INTEGER;100 mt_params[4].integer.value = 0;101 }102 break;103 104 case I2C_SMBUS_BYTE:105 protocol = ACPI_SMBUS_PRTCL_BYTE;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 } else {112 command = 0;113 }114 break;115 116 case I2C_SMBUS_BYTE_DATA:117 protocol = ACPI_SMBUS_PRTCL_BYTE_DATA;118 if (read_write == I2C_SMBUS_WRITE) {119 mt_params[3].type = ACPI_TYPE_INTEGER;120 mt_params[3].integer.value = 1;121 mt_params[4].type = ACPI_TYPE_INTEGER;122 mt_params[4].integer.value = data->byte;123 }124 break;125 126 case I2C_SMBUS_WORD_DATA:127 protocol = ACPI_SMBUS_PRTCL_WORD_DATA;128 if (read_write == I2C_SMBUS_WRITE) {129 mt_params[3].type = ACPI_TYPE_INTEGER;130 mt_params[3].integer.value = 2;131 mt_params[4].type = ACPI_TYPE_INTEGER;132 mt_params[4].integer.value = data->word;133 }134 break;135 136 case I2C_SMBUS_BLOCK_DATA:137 protocol = ACPI_SMBUS_PRTCL_BLOCK_DATA;138 if (read_write == I2C_SMBUS_WRITE) {139 len = data->block[0];140 if (len == 0 || len > I2C_SMBUS_BLOCK_MAX)141 return -EINVAL;142 mt_params[3].type = ACPI_TYPE_INTEGER;143 mt_params[3].integer.value = len;144 mt_params[4].type = ACPI_TYPE_BUFFER;145 mt_params[4].buffer.length = len;146 mt_params[4].buffer.pointer = data->block + 1;147 }148 break;149 150 default:151 dev_warn(&adap->dev, "Unsupported transaction %d\n", size);152 return -EOPNOTSUPP;153 }154 155 if (read_write == I2C_SMBUS_READ) {156 protocol |= ACPI_SMBUS_PRTCL_READ;157 method = smbus_cmi->methods->mt_sbr;158 input.count = 3;159 } else {160 protocol |= ACPI_SMBUS_PRTCL_WRITE;161 method = smbus_cmi->methods->mt_sbw;162 input.count = 5;163 }164 165 input.pointer = mt_params;166 mt_params[0].type = ACPI_TYPE_INTEGER;167 mt_params[0].integer.value = protocol;168 mt_params[1].type = ACPI_TYPE_INTEGER;169 mt_params[1].integer.value = addr;170 mt_params[2].type = ACPI_TYPE_INTEGER;171 mt_params[2].integer.value = command;172 173 status = acpi_evaluate_object(smbus_cmi->handle, method, &input,174 &buffer);175 if (ACPI_FAILURE(status)) {176 acpi_handle_err(smbus_cmi->handle,177 "Failed to evaluate %s: %i\n", method, status);178 return -EIO;179 }180 181 pkg = buffer.pointer;182 if (pkg && pkg->type == ACPI_TYPE_PACKAGE)183 obj = pkg->package.elements;184 else {185 acpi_handle_err(smbus_cmi->handle, "Invalid argument type\n");186 result = -EIO;187 goto out;188 }189 if (obj == NULL || obj->type != ACPI_TYPE_INTEGER) {190 acpi_handle_err(smbus_cmi->handle, "Invalid argument type\n");191 result = -EIO;192 goto out;193 }194 195 result = obj->integer.value;196 acpi_handle_debug(smbus_cmi->handle, "%s return status: %i\n", method,197 result);198 199 switch (result) {200 case ACPI_SMBUS_STATUS_OK:201 result = 0;202 break;203 case ACPI_SMBUS_STATUS_BUSY:204 result = -EBUSY;205 goto out;206 case ACPI_SMBUS_STATUS_TIMEOUT:207 result = -ETIMEDOUT;208 goto out;209 case ACPI_SMBUS_STATUS_DNAK:210 result = -ENXIO;211 goto out;212 default:213 result = -EIO;214 goto out;215 }216 217 if (read_write == I2C_SMBUS_WRITE || size == I2C_SMBUS_QUICK)218 goto out;219 220 obj = pkg->package.elements + 1;221 if (obj->type != ACPI_TYPE_INTEGER) {222 acpi_handle_err(smbus_cmi->handle, "Invalid argument type\n");223 result = -EIO;224 goto out;225 }226 227 len = obj->integer.value;228 obj = pkg->package.elements + 2;229 switch (size) {230 case I2C_SMBUS_BYTE:231 case I2C_SMBUS_BYTE_DATA:232 case I2C_SMBUS_WORD_DATA:233 if (obj->type != ACPI_TYPE_INTEGER) {234 acpi_handle_err(smbus_cmi->handle,235 "Invalid argument type\n");236 result = -EIO;237 goto out;238 }239 if (len == 2)240 data->word = obj->integer.value;241 else242 data->byte = obj->integer.value;243 break;244 case I2C_SMBUS_BLOCK_DATA:245 if (obj->type != ACPI_TYPE_BUFFER) {246 acpi_handle_err(smbus_cmi->handle,247 "Invalid argument type\n");248 result = -EIO;249 goto out;250 }251 if (len == 0 || len > I2C_SMBUS_BLOCK_MAX)252 return -EPROTO;253 data->block[0] = len;254 memcpy(data->block + 1, obj->buffer.pointer, len);255 break;256 }257 258out:259 kfree(buffer.pointer);260 dev_dbg(&adap->dev, "Transaction status: %i\n", result);261 return result;262}263 264static u32 acpi_smbus_cmi_func(struct i2c_adapter *adapter)265{266 struct acpi_smbus_cmi *smbus_cmi = adapter->algo_data;267 u32 ret;268 269 ret = smbus_cmi->cap_read | smbus_cmi->cap_write ?270 I2C_FUNC_SMBUS_QUICK : 0;271 272 ret |= smbus_cmi->cap_read ?273 (I2C_FUNC_SMBUS_READ_BYTE |274 I2C_FUNC_SMBUS_READ_BYTE_DATA |275 I2C_FUNC_SMBUS_READ_WORD_DATA |276 I2C_FUNC_SMBUS_READ_BLOCK_DATA) : 0;277 278 ret |= smbus_cmi->cap_write ?279 (I2C_FUNC_SMBUS_WRITE_BYTE |280 I2C_FUNC_SMBUS_WRITE_BYTE_DATA |281 I2C_FUNC_SMBUS_WRITE_WORD_DATA |282 I2C_FUNC_SMBUS_WRITE_BLOCK_DATA) : 0;283 284 return ret;285}286 287static const struct i2c_algorithm acpi_smbus_cmi_algorithm = {288 .smbus_xfer = acpi_smbus_cmi_access,289 .functionality = acpi_smbus_cmi_func,290};291 292 293static int acpi_smbus_cmi_add_cap(struct acpi_smbus_cmi *smbus_cmi,294 const char *name)295{296 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };297 struct acpi_handle *handle = smbus_cmi->handle;298 union acpi_object *obj;299 acpi_status status;300 301 if (!strcmp(name, smbus_cmi->methods->mt_info)) {302 status = acpi_evaluate_object(smbus_cmi->handle,303 smbus_cmi->methods->mt_info,304 NULL, &buffer);305 if (ACPI_FAILURE(status)) {306 acpi_handle_err(handle, "Failed to evaluate %s: %i\n",307 smbus_cmi->methods->mt_info, status);308 return -EIO;309 }310 311 obj = buffer.pointer;312 if (obj && obj->type == ACPI_TYPE_PACKAGE)313 obj = obj->package.elements;314 else {315 acpi_handle_err(handle, "Invalid argument type\n");316 kfree(buffer.pointer);317 return -EIO;318 }319 320 if (obj->type != ACPI_TYPE_INTEGER) {321 acpi_handle_err(handle, "Invalid argument type\n");322 kfree(buffer.pointer);323 return -EIO;324 } else325 acpi_handle_debug(handle, "SMBus CMI Version %x\n",326 (int)obj->integer.value);327 328 kfree(buffer.pointer);329 smbus_cmi->cap_info = 1;330 } else if (!strcmp(name, smbus_cmi->methods->mt_sbr))331 smbus_cmi->cap_read = 1;332 else if (!strcmp(name, smbus_cmi->methods->mt_sbw))333 smbus_cmi->cap_write = 1;334 else335 acpi_handle_debug(handle, "Unsupported CMI method: %s\n", name);336 337 return 0;338}339 340static acpi_status acpi_smbus_cmi_query_methods(acpi_handle handle, u32 level,341 void *context, void **return_value)342{343 char node_name[5];344 struct acpi_buffer buffer = { sizeof(node_name), node_name };345 struct acpi_smbus_cmi *smbus_cmi = context;346 acpi_status status;347 348 status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);349 350 if (ACPI_SUCCESS(status))351 acpi_smbus_cmi_add_cap(smbus_cmi, node_name);352 353 return AE_OK;354}355 356static int smbus_cmi_probe(struct platform_device *device)357{358 struct device *dev = &device->dev;359 struct acpi_smbus_cmi *smbus_cmi;360 int ret;361 362 smbus_cmi = kzalloc(sizeof(struct acpi_smbus_cmi), GFP_KERNEL);363 if (!smbus_cmi)364 return -ENOMEM;365 366 smbus_cmi->handle = ACPI_HANDLE(dev);367 smbus_cmi->methods = device_get_match_data(dev);368 369 platform_set_drvdata(device, smbus_cmi);370 371 smbus_cmi->cap_info = 0;372 smbus_cmi->cap_read = 0;373 smbus_cmi->cap_write = 0;374 375 acpi_walk_namespace(ACPI_TYPE_METHOD, smbus_cmi->handle, 1,376 acpi_smbus_cmi_query_methods, NULL, smbus_cmi, NULL);377 378 if (smbus_cmi->cap_info == 0) {379 ret = -ENODEV;380 goto err;381 }382 383 snprintf(smbus_cmi->adapter.name, sizeof(smbus_cmi->adapter.name),384 "SMBus CMI adapter %s", dev_name(dev));385 smbus_cmi->adapter.owner = THIS_MODULE;386 smbus_cmi->adapter.algo = &acpi_smbus_cmi_algorithm;387 smbus_cmi->adapter.algo_data = smbus_cmi;388 smbus_cmi->adapter.class = I2C_CLASS_HWMON;389 smbus_cmi->adapter.dev.parent = &device->dev;390 391 ret = i2c_add_adapter(&smbus_cmi->adapter);392 if (ret) {393 dev_err(&device->dev, "Couldn't register adapter!\n");394 goto err;395 }396 397 return 0;398 399err:400 kfree(smbus_cmi);401 return ret;402}403 404static void smbus_cmi_remove(struct platform_device *device)405{406 struct acpi_smbus_cmi *smbus_cmi = platform_get_drvdata(device);407 408 i2c_del_adapter(&smbus_cmi->adapter);409 kfree(smbus_cmi);410}411 412static struct platform_driver smbus_cmi_driver = {413 .probe = smbus_cmi_probe,414 .remove_new = smbus_cmi_remove,415 .driver = {416 .name = "smbus_cmi",417 .acpi_match_table = acpi_smbus_cmi_ids,418 },419};420module_platform_driver(smbus_cmi_driver);421 422MODULE_LICENSE("GPL");423MODULE_AUTHOR("Crane Cai <crane.cai@amd.com>");424MODULE_DESCRIPTION("ACPI SMBus CMI driver");425