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
acpi_smbus_cmi_access(struct i2c_adapter * adap,u16 addr,unsigned short flags,char read_write,u8 command,int size,union i2c_smbus_data * data)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.length = len;
156 mt_params[4].buffer.pointer = data->block + 1;
157 }
158 break;
159
160 default:
161 dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
162 return -EOPNOTSUPP;
163 }
164
165 if (read_write == I2C_SMBUS_READ) {
166 protocol |= ACPI_SMBUS_PRTCL_READ;
167 method = smbus_cmi->methods->mt_sbr;
168 input.count = 3;
169 } else {
170 protocol |= ACPI_SMBUS_PRTCL_WRITE;
171 method = smbus_cmi->methods->mt_sbw;
172 input.count = 5;
173 }
174
175 input.pointer = mt_params;
176 mt_params[0].type = ACPI_TYPE_INTEGER;
177 mt_params[0].integer.value = protocol;
178 mt_params[1].type = ACPI_TYPE_INTEGER;
179 mt_params[1].integer.value = addr;
180 mt_params[2].type = ACPI_TYPE_INTEGER;
181 mt_params[2].integer.value = command;
182
183 status = acpi_evaluate_object(smbus_cmi->handle, method, &input,
184 &buffer);
185 if (ACPI_FAILURE(status)) {
186 ACPI_ERROR((AE_INFO, "Evaluating %s: %i", 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_ERROR((AE_INFO, "Invalid argument type"));
195 result = -EIO;
196 goto out;
197 }
198 if (obj == NULL || obj->type != ACPI_TYPE_INTEGER) {
199 ACPI_ERROR((AE_INFO, "Invalid argument type"));
200 result = -EIO;
201 goto out;
202 }
203
204 result = obj->integer.value;
205 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "%s return status: %i\n",
206 method, 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_ERROR((AE_INFO, "Invalid argument type"));
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_ERROR((AE_INFO, "Invalid argument type"));
244 result = -EIO;
245 goto out;
246 }
247 if (len == 2)
248 data->word = obj->integer.value;
249 else
250 data->byte = obj->integer.value;
251 break;
252 case I2C_SMBUS_BLOCK_DATA:
253 if (obj->type != ACPI_TYPE_BUFFER) {
254 ACPI_ERROR((AE_INFO, "Invalid argument type"));
255 result = -EIO;
256 goto out;
257 }
258 if (len == 0 || len > I2C_SMBUS_BLOCK_MAX)
259 return -EPROTO;
260 data->block[0] = len;
261 memcpy(data->block + 1, obj->buffer.pointer, len);
262 break;
263 }
264
265 out:
266 kfree(buffer.pointer);
267 dev_dbg(&adap->dev, "Transaction status: %i\n", result);
268 return result;
269 }
270
acpi_smbus_cmi_func(struct i2c_adapter * adapter)271 static u32 acpi_smbus_cmi_func(struct i2c_adapter *adapter)
272 {
273 struct acpi_smbus_cmi *smbus_cmi = adapter->algo_data;
274 u32 ret;
275
276 ret = smbus_cmi->cap_read | smbus_cmi->cap_write ?
277 I2C_FUNC_SMBUS_QUICK : 0;
278
279 ret |= smbus_cmi->cap_read ?
280 (I2C_FUNC_SMBUS_READ_BYTE |
281 I2C_FUNC_SMBUS_READ_BYTE_DATA |
282 I2C_FUNC_SMBUS_READ_WORD_DATA |
283 I2C_FUNC_SMBUS_READ_BLOCK_DATA) : 0;
284
285 ret |= smbus_cmi->cap_write ?
286 (I2C_FUNC_SMBUS_WRITE_BYTE |
287 I2C_FUNC_SMBUS_WRITE_BYTE_DATA |
288 I2C_FUNC_SMBUS_WRITE_WORD_DATA |
289 I2C_FUNC_SMBUS_WRITE_BLOCK_DATA) : 0;
290
291 return ret;
292 }
293
294 static const struct i2c_algorithm acpi_smbus_cmi_algorithm = {
295 .smbus_xfer = acpi_smbus_cmi_access,
296 .functionality = acpi_smbus_cmi_func,
297 };
298
299
acpi_smbus_cmi_add_cap(struct acpi_smbus_cmi * smbus_cmi,const char * name)300 static int acpi_smbus_cmi_add_cap(struct acpi_smbus_cmi *smbus_cmi,
301 const char *name)
302 {
303 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
304 union acpi_object *obj;
305 acpi_status status;
306
307 if (!strcmp(name, smbus_cmi->methods->mt_info)) {
308 status = acpi_evaluate_object(smbus_cmi->handle,
309 smbus_cmi->methods->mt_info,
310 NULL, &buffer);
311 if (ACPI_FAILURE(status)) {
312 ACPI_ERROR((AE_INFO, "Evaluating %s: %i",
313 smbus_cmi->methods->mt_info, status));
314 return -EIO;
315 }
316
317 obj = buffer.pointer;
318 if (obj && obj->type == ACPI_TYPE_PACKAGE)
319 obj = obj->package.elements;
320 else {
321 ACPI_ERROR((AE_INFO, "Invalid argument type"));
322 kfree(buffer.pointer);
323 return -EIO;
324 }
325
326 if (obj->type != ACPI_TYPE_INTEGER) {
327 ACPI_ERROR((AE_INFO, "Invalid argument type"));
328 kfree(buffer.pointer);
329 return -EIO;
330 } else
331 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "SMBus CMI Version %x"
332 "\n", (int)obj->integer.value));
333
334 kfree(buffer.pointer);
335 smbus_cmi->cap_info = 1;
336 } else if (!strcmp(name, smbus_cmi->methods->mt_sbr))
337 smbus_cmi->cap_read = 1;
338 else if (!strcmp(name, smbus_cmi->methods->mt_sbw))
339 smbus_cmi->cap_write = 1;
340 else
341 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Unsupported CMI method: %s\n",
342 name));
343
344 return 0;
345 }
346
acpi_smbus_cmi_query_methods(acpi_handle handle,u32 level,void * context,void ** return_value)347 static acpi_status acpi_smbus_cmi_query_methods(acpi_handle handle, u32 level,
348 void *context, void **return_value)
349 {
350 char node_name[5];
351 struct acpi_buffer buffer = { sizeof(node_name), node_name };
352 struct acpi_smbus_cmi *smbus_cmi = context;
353 acpi_status status;
354
355 status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
356
357 if (ACPI_SUCCESS(status))
358 acpi_smbus_cmi_add_cap(smbus_cmi, node_name);
359
360 return AE_OK;
361 }
362
acpi_smbus_cmi_add(struct acpi_device * device)363 static int acpi_smbus_cmi_add(struct acpi_device *device)
364 {
365 struct acpi_smbus_cmi *smbus_cmi;
366 const struct acpi_device_id *id;
367 int ret;
368
369 smbus_cmi = kzalloc(sizeof(struct acpi_smbus_cmi), GFP_KERNEL);
370 if (!smbus_cmi)
371 return -ENOMEM;
372
373 smbus_cmi->handle = device->handle;
374 strcpy(acpi_device_name(device), ACPI_SMBUS_HC_DEVICE_NAME);
375 strcpy(acpi_device_class(device), ACPI_SMBUS_HC_CLASS);
376 device->driver_data = smbus_cmi;
377 smbus_cmi->cap_info = 0;
378 smbus_cmi->cap_read = 0;
379 smbus_cmi->cap_write = 0;
380
381 for (id = acpi_smbus_cmi_ids; id->id[0]; id++)
382 if (!strcmp(id->id, acpi_device_hid(device)))
383 smbus_cmi->methods =
384 (struct smbus_methods_t *) id->driver_data;
385
386 acpi_walk_namespace(ACPI_TYPE_METHOD, smbus_cmi->handle, 1,
387 acpi_smbus_cmi_query_methods, NULL, smbus_cmi, NULL);
388
389 if (smbus_cmi->cap_info == 0) {
390 ret = -ENODEV;
391 goto err;
392 }
393
394 snprintf(smbus_cmi->adapter.name, sizeof(smbus_cmi->adapter.name),
395 "SMBus CMI adapter %s",
396 acpi_device_name(device));
397 smbus_cmi->adapter.owner = THIS_MODULE;
398 smbus_cmi->adapter.algo = &acpi_smbus_cmi_algorithm;
399 smbus_cmi->adapter.algo_data = smbus_cmi;
400 smbus_cmi->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
401 smbus_cmi->adapter.dev.parent = &device->dev;
402
403 ret = i2c_add_adapter(&smbus_cmi->adapter);
404 if (ret) {
405 dev_err(&device->dev, "Couldn't register adapter!\n");
406 goto err;
407 }
408
409 return 0;
410
411 err:
412 kfree(smbus_cmi);
413 device->driver_data = NULL;
414 return ret;
415 }
416
acpi_smbus_cmi_remove(struct acpi_device * device)417 static int acpi_smbus_cmi_remove(struct acpi_device *device)
418 {
419 struct acpi_smbus_cmi *smbus_cmi = acpi_driver_data(device);
420
421 i2c_del_adapter(&smbus_cmi->adapter);
422 kfree(smbus_cmi);
423 device->driver_data = NULL;
424
425 return 0;
426 }
427
428 static struct acpi_driver acpi_smbus_cmi_driver = {
429 .name = ACPI_SMBUS_HC_DEVICE_NAME,
430 .class = ACPI_SMBUS_HC_CLASS,
431 .ids = acpi_smbus_cmi_ids,
432 .ops = {
433 .add = acpi_smbus_cmi_add,
434 .remove = acpi_smbus_cmi_remove,
435 },
436 };
437 module_acpi_driver(acpi_smbus_cmi_driver);
438
439 MODULE_LICENSE("GPL");
440 MODULE_AUTHOR("Crane Cai <crane.cai@amd.com>");
441 MODULE_DESCRIPTION("ACPI SMBus CMI driver");
442