1 // SPDX-License-Identifier: GPL-2.0-only
3 * SMBus driver for ACPI SMBus CMI
5 * Copyright (C) 2009 Crane Cai <crane.cai@amd.com>
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>
16 /* SMBUS HID definition as supported by Microsoft Windows */
17 #define ACPI_SMBUS_MS_HID "SMB0001"
19 struct smbus_methods_t {
25 struct acpi_smbus_cmi {
27 struct i2c_adapter adapter;
31 const struct smbus_methods_t *methods;
34 static const struct smbus_methods_t smbus_methods = {
40 /* Some IBM BIOSes omit the leading underscore */
41 static const struct smbus_methods_t ibm_smbus_methods = {
47 static const struct acpi_device_id acpi_smbus_cmi_ids[] = {
48 {"SMBUS01", (kernel_ulong_t)&smbus_methods},
49 {ACPI_SMBUS_IBM_HID, (kernel_ulong_t)&ibm_smbus_methods},
50 {ACPI_SMBUS_MS_HID, (kernel_ulong_t)&smbus_methods},
53 MODULE_DEVICE_TABLE(acpi, acpi_smbus_cmi_ids);
55 #define ACPI_SMBUS_STATUS_OK 0x00
56 #define ACPI_SMBUS_STATUS_FAIL 0x07
57 #define ACPI_SMBUS_STATUS_DNAK 0x10
58 #define ACPI_SMBUS_STATUS_DERR 0x11
59 #define ACPI_SMBUS_STATUS_CMD_DENY 0x12
60 #define ACPI_SMBUS_STATUS_UNKNOWN 0x13
61 #define ACPI_SMBUS_STATUS_ACC_DENY 0x17
62 #define ACPI_SMBUS_STATUS_TIMEOUT 0x18
63 #define ACPI_SMBUS_STATUS_NOTSUP 0x19
64 #define ACPI_SMBUS_STATUS_BUSY 0x1a
65 #define ACPI_SMBUS_STATUS_PEC 0x1f
67 #define ACPI_SMBUS_PRTCL_WRITE 0x00
68 #define ACPI_SMBUS_PRTCL_READ 0x01
69 #define ACPI_SMBUS_PRTCL_QUICK 0x02
70 #define ACPI_SMBUS_PRTCL_BYTE 0x04
71 #define ACPI_SMBUS_PRTCL_BYTE_DATA 0x06
72 #define ACPI_SMBUS_PRTCL_WORD_DATA 0x08
73 #define ACPI_SMBUS_PRTCL_BLOCK_DATA 0x0a
77 acpi_smbus_cmi_access(struct i2c_adapter *adap, u16 addr, unsigned short flags,
78 char read_write, u8 command, int size,
79 union i2c_smbus_data *data)
82 struct acpi_smbus_cmi *smbus_cmi = adap->algo_data;
83 unsigned char protocol;
84 acpi_status status = 0;
85 struct acpi_object_list input;
86 union acpi_object mt_params[5];
87 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
88 union acpi_object *obj;
89 union acpi_object *pkg;
93 dev_dbg(&adap->dev, "access size: %d %s\n", size,
94 (read_write) ? "READ" : "WRITE");
97 protocol = ACPI_SMBUS_PRTCL_QUICK;
99 if (read_write == I2C_SMBUS_WRITE) {
100 mt_params[3].type = ACPI_TYPE_INTEGER;
101 mt_params[3].integer.value = 0;
102 mt_params[4].type = ACPI_TYPE_INTEGER;
103 mt_params[4].integer.value = 0;
108 protocol = ACPI_SMBUS_PRTCL_BYTE;
109 if (read_write == I2C_SMBUS_WRITE) {
110 mt_params[3].type = ACPI_TYPE_INTEGER;
111 mt_params[3].integer.value = 0;
112 mt_params[4].type = ACPI_TYPE_INTEGER;
113 mt_params[4].integer.value = 0;
119 case I2C_SMBUS_BYTE_DATA:
120 protocol = ACPI_SMBUS_PRTCL_BYTE_DATA;
121 if (read_write == I2C_SMBUS_WRITE) {
122 mt_params[3].type = ACPI_TYPE_INTEGER;
123 mt_params[3].integer.value = 1;
124 mt_params[4].type = ACPI_TYPE_INTEGER;
125 mt_params[4].integer.value = data->byte;
129 case I2C_SMBUS_WORD_DATA:
130 protocol = ACPI_SMBUS_PRTCL_WORD_DATA;
131 if (read_write == I2C_SMBUS_WRITE) {
132 mt_params[3].type = ACPI_TYPE_INTEGER;
133 mt_params[3].integer.value = 2;
134 mt_params[4].type = ACPI_TYPE_INTEGER;
135 mt_params[4].integer.value = data->word;
139 case I2C_SMBUS_BLOCK_DATA:
140 protocol = ACPI_SMBUS_PRTCL_BLOCK_DATA;
141 if (read_write == I2C_SMBUS_WRITE) {
142 len = data->block[0];
143 if (len == 0 || len > I2C_SMBUS_BLOCK_MAX)
145 mt_params[3].type = ACPI_TYPE_INTEGER;
146 mt_params[3].integer.value = len;
147 mt_params[4].type = ACPI_TYPE_BUFFER;
148 mt_params[4].buffer.length = len;
149 mt_params[4].buffer.pointer = data->block + 1;
154 dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
158 if (read_write == I2C_SMBUS_READ) {
159 protocol |= ACPI_SMBUS_PRTCL_READ;
160 method = smbus_cmi->methods->mt_sbr;
163 protocol |= ACPI_SMBUS_PRTCL_WRITE;
164 method = smbus_cmi->methods->mt_sbw;
168 input.pointer = mt_params;
169 mt_params[0].type = ACPI_TYPE_INTEGER;
170 mt_params[0].integer.value = protocol;
171 mt_params[1].type = ACPI_TYPE_INTEGER;
172 mt_params[1].integer.value = addr;
173 mt_params[2].type = ACPI_TYPE_INTEGER;
174 mt_params[2].integer.value = command;
176 status = acpi_evaluate_object(smbus_cmi->handle, method, &input,
178 if (ACPI_FAILURE(status)) {
179 acpi_handle_err(smbus_cmi->handle,
180 "Failed to evaluate %s: %i\n", method, status);
184 pkg = buffer.pointer;
185 if (pkg && pkg->type == ACPI_TYPE_PACKAGE)
186 obj = pkg->package.elements;
188 acpi_handle_err(smbus_cmi->handle, "Invalid argument type\n");
192 if (obj == NULL || obj->type != ACPI_TYPE_INTEGER) {
193 acpi_handle_err(smbus_cmi->handle, "Invalid argument type\n");
198 result = obj->integer.value;
199 acpi_handle_debug(smbus_cmi->handle, "%s return status: %i\n", method,
203 case ACPI_SMBUS_STATUS_OK:
206 case ACPI_SMBUS_STATUS_BUSY:
209 case ACPI_SMBUS_STATUS_TIMEOUT:
212 case ACPI_SMBUS_STATUS_DNAK:
220 if (read_write == I2C_SMBUS_WRITE || size == I2C_SMBUS_QUICK)
223 obj = pkg->package.elements + 1;
224 if (obj->type != ACPI_TYPE_INTEGER) {
225 acpi_handle_err(smbus_cmi->handle, "Invalid argument type\n");
230 len = obj->integer.value;
231 obj = pkg->package.elements + 2;
234 case I2C_SMBUS_BYTE_DATA:
235 case I2C_SMBUS_WORD_DATA:
236 if (obj->type != ACPI_TYPE_INTEGER) {
237 acpi_handle_err(smbus_cmi->handle,
238 "Invalid argument type\n");
243 data->word = obj->integer.value;
245 data->byte = obj->integer.value;
247 case I2C_SMBUS_BLOCK_DATA:
248 if (obj->type != ACPI_TYPE_BUFFER) {
249 acpi_handle_err(smbus_cmi->handle,
250 "Invalid argument type\n");
254 if (len == 0 || len > I2C_SMBUS_BLOCK_MAX)
256 data->block[0] = len;
257 memcpy(data->block + 1, obj->buffer.pointer, len);
262 kfree(buffer.pointer);
263 dev_dbg(&adap->dev, "Transaction status: %i\n", result);
267 static u32 acpi_smbus_cmi_func(struct i2c_adapter *adapter)
269 struct acpi_smbus_cmi *smbus_cmi = adapter->algo_data;
272 ret = smbus_cmi->cap_read | smbus_cmi->cap_write ?
273 I2C_FUNC_SMBUS_QUICK : 0;
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;
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;
290 static const struct i2c_algorithm acpi_smbus_cmi_algorithm = {
291 .smbus_xfer = acpi_smbus_cmi_access,
292 .functionality = acpi_smbus_cmi_func,
296 static int acpi_smbus_cmi_add_cap(struct acpi_smbus_cmi *smbus_cmi,
299 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
300 struct acpi_handle *handle = smbus_cmi->handle;
301 union acpi_object *obj;
304 if (!strcmp(name, smbus_cmi->methods->mt_info)) {
305 status = acpi_evaluate_object(smbus_cmi->handle,
306 smbus_cmi->methods->mt_info,
308 if (ACPI_FAILURE(status)) {
309 acpi_handle_err(handle, "Failed to evaluate %s: %i\n",
310 smbus_cmi->methods->mt_info, status);
314 obj = buffer.pointer;
315 if (obj && obj->type == ACPI_TYPE_PACKAGE)
316 obj = obj->package.elements;
318 acpi_handle_err(handle, "Invalid argument type\n");
319 kfree(buffer.pointer);
323 if (obj->type != ACPI_TYPE_INTEGER) {
324 acpi_handle_err(handle, "Invalid argument type\n");
325 kfree(buffer.pointer);
328 acpi_handle_debug(handle, "SMBus CMI Version %x\n",
329 (int)obj->integer.value);
331 kfree(buffer.pointer);
332 smbus_cmi->cap_info = 1;
333 } else if (!strcmp(name, smbus_cmi->methods->mt_sbr))
334 smbus_cmi->cap_read = 1;
335 else if (!strcmp(name, smbus_cmi->methods->mt_sbw))
336 smbus_cmi->cap_write = 1;
338 acpi_handle_debug(handle, "Unsupported CMI method: %s\n", name);
343 static acpi_status acpi_smbus_cmi_query_methods(acpi_handle handle, u32 level,
344 void *context, void **return_value)
347 struct acpi_buffer buffer = { sizeof(node_name), node_name };
348 struct acpi_smbus_cmi *smbus_cmi = context;
351 status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
353 if (ACPI_SUCCESS(status))
354 acpi_smbus_cmi_add_cap(smbus_cmi, node_name);
359 static int smbus_cmi_probe(struct platform_device *device)
361 struct device *dev = &device->dev;
362 struct acpi_smbus_cmi *smbus_cmi;
365 smbus_cmi = kzalloc(sizeof(struct acpi_smbus_cmi), GFP_KERNEL);
369 smbus_cmi->handle = ACPI_HANDLE(dev);
370 smbus_cmi->methods = device_get_match_data(dev);
372 platform_set_drvdata(device, smbus_cmi);
374 smbus_cmi->cap_info = 0;
375 smbus_cmi->cap_read = 0;
376 smbus_cmi->cap_write = 0;
378 acpi_walk_namespace(ACPI_TYPE_METHOD, smbus_cmi->handle, 1,
379 acpi_smbus_cmi_query_methods, NULL, smbus_cmi, NULL);
381 if (smbus_cmi->cap_info == 0) {
386 snprintf(smbus_cmi->adapter.name, sizeof(smbus_cmi->adapter.name),
387 "SMBus CMI adapter %s", dev_name(dev));
388 smbus_cmi->adapter.owner = THIS_MODULE;
389 smbus_cmi->adapter.algo = &acpi_smbus_cmi_algorithm;
390 smbus_cmi->adapter.algo_data = smbus_cmi;
391 smbus_cmi->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
392 smbus_cmi->adapter.dev.parent = &device->dev;
394 ret = i2c_add_adapter(&smbus_cmi->adapter);
396 dev_err(&device->dev, "Couldn't register adapter!\n");
407 static void smbus_cmi_remove(struct platform_device *device)
409 struct acpi_smbus_cmi *smbus_cmi = platform_get_drvdata(device);
411 i2c_del_adapter(&smbus_cmi->adapter);
415 static struct platform_driver smbus_cmi_driver = {
416 .probe = smbus_cmi_probe,
417 .remove_new = smbus_cmi_remove,
420 .acpi_match_table = acpi_smbus_cmi_ids,
423 module_platform_driver(smbus_cmi_driver);
425 MODULE_LICENSE("GPL");
426 MODULE_AUTHOR("Crane Cai <crane.cai@amd.com>");
427 MODULE_DESCRIPTION("ACPI SMBus CMI driver");