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.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_ERROR((AE_INFO, "Evaluating %s: %i", method, status));
186 return -EIO;
187 }
188
189 pkg = buffer.pointer;
190 if (pkg && pkg->type == ACPI_TYPE_PACKAGE)
191 obj = pkg->package.elements;
192 else {
193 ACPI_ERROR((AE_INFO, "Invalid argument type"));
194 result = -EIO;
195 goto out;
196 }
197 if (obj == NULL || obj->type != ACPI_TYPE_INTEGER) {
198 ACPI_ERROR((AE_INFO, "Invalid argument type"));
199 result = -EIO;
200 goto out;
201 }
202
203 result = obj->integer.value;
204 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "%s return status: %i\n",
205 method, result));
206
207 switch (result) {
208 case ACPI_SMBUS_STATUS_OK:
209 result = 0;
210 break;
211 case ACPI_SMBUS_STATUS_BUSY:
212 result = -EBUSY;
213 goto out;
214 case ACPI_SMBUS_STATUS_TIMEOUT:
215 result = -ETIMEDOUT;
216 goto out;
217 case ACPI_SMBUS_STATUS_DNAK:
218 result = -ENXIO;
219 goto out;
220 default:
221 result = -EIO;
222 goto out;
223 }
224
225 if (read_write == I2C_SMBUS_WRITE || size == I2C_SMBUS_QUICK)
226 goto out;
227
228 obj = pkg->package.elements + 1;
229 if (obj->type != ACPI_TYPE_INTEGER) {
230 ACPI_ERROR((AE_INFO, "Invalid argument type"));
231 result = -EIO;
232 goto out;
233 }
234
235 len = obj->integer.value;
236 obj = pkg->package.elements + 2;
237 switch (size) {
238 case I2C_SMBUS_BYTE:
239 case I2C_SMBUS_BYTE_DATA:
240 case I2C_SMBUS_WORD_DATA:
241 if (obj->type != ACPI_TYPE_INTEGER) {
242 ACPI_ERROR((AE_INFO, "Invalid argument type"));
243 result = -EIO;
244 goto out;
245 }
246 if (len == 2)
247 data->word = obj->integer.value;
248 else
249 data->byte = obj->integer.value;
250 break;
251 case I2C_SMBUS_BLOCK_DATA:
252 if (obj->type != ACPI_TYPE_BUFFER) {
253 ACPI_ERROR((AE_INFO, "Invalid argument type"));
254 result = -EIO;
255 goto out;
256 }
257 if (len == 0 || len > I2C_SMBUS_BLOCK_MAX)
258 return -EPROTO;
259 data->block[0] = len;
260 memcpy(data->block + 1, obj->buffer.pointer, len);
261 break;
262 }
263
264 out:
265 kfree(buffer.pointer);
266 dev_dbg(&adap->dev, "Transaction status: %i\n", result);
267 return result;
268 }
269
acpi_smbus_cmi_func(struct i2c_adapter * adapter)270 static u32 acpi_smbus_cmi_func(struct i2c_adapter *adapter)
271 {
272 struct acpi_smbus_cmi *smbus_cmi = adapter->algo_data;
273 u32 ret;
274
275 ret = smbus_cmi->cap_read | smbus_cmi->cap_write ?
276 I2C_FUNC_SMBUS_QUICK : 0;
277
278 ret |= smbus_cmi->cap_read ?
279 (I2C_FUNC_SMBUS_READ_BYTE |
280 I2C_FUNC_SMBUS_READ_BYTE_DATA |
281 I2C_FUNC_SMBUS_READ_WORD_DATA |
282 I2C_FUNC_SMBUS_READ_BLOCK_DATA) : 0;
283
284 ret |= smbus_cmi->cap_write ?
285 (I2C_FUNC_SMBUS_WRITE_BYTE |
286 I2C_FUNC_SMBUS_WRITE_BYTE_DATA |
287 I2C_FUNC_SMBUS_WRITE_WORD_DATA |
288 I2C_FUNC_SMBUS_WRITE_BLOCK_DATA) : 0;
289
290 return ret;
291 }
292
293 static const struct i2c_algorithm acpi_smbus_cmi_algorithm = {
294 .smbus_xfer = acpi_smbus_cmi_access,
295 .functionality = acpi_smbus_cmi_func,
296 };
297
298
acpi_smbus_cmi_add_cap(struct acpi_smbus_cmi * smbus_cmi,const char * name)299 static int acpi_smbus_cmi_add_cap(struct acpi_smbus_cmi *smbus_cmi,
300 const char *name)
301 {
302 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
303 union acpi_object *obj;
304 acpi_status status;
305
306 if (!strcmp(name, smbus_cmi->methods->mt_info)) {
307 status = acpi_evaluate_object(smbus_cmi->handle,
308 smbus_cmi->methods->mt_info,
309 NULL, &buffer);
310 if (ACPI_FAILURE(status)) {
311 ACPI_ERROR((AE_INFO, "Evaluating %s: %i",
312 smbus_cmi->methods->mt_info, status));
313 return -EIO;
314 }
315
316 obj = buffer.pointer;
317 if (obj && obj->type == ACPI_TYPE_PACKAGE)
318 obj = obj->package.elements;
319 else {
320 ACPI_ERROR((AE_INFO, "Invalid argument type"));
321 kfree(buffer.pointer);
322 return -EIO;
323 }
324
325 if (obj->type != ACPI_TYPE_INTEGER) {
326 ACPI_ERROR((AE_INFO, "Invalid argument type"));
327 kfree(buffer.pointer);
328 return -EIO;
329 } else
330 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "SMBus CMI Version %x"
331 "\n", (int)obj->integer.value));
332
333 kfree(buffer.pointer);
334 smbus_cmi->cap_info = 1;
335 } else if (!strcmp(name, smbus_cmi->methods->mt_sbr))
336 smbus_cmi->cap_read = 1;
337 else if (!strcmp(name, smbus_cmi->methods->mt_sbw))
338 smbus_cmi->cap_write = 1;
339 else
340 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Unsupported CMI method: %s\n",
341 name));
342
343 return 0;
344 }
345
acpi_smbus_cmi_query_methods(acpi_handle handle,u32 level,void * context,void ** return_value)346 static acpi_status acpi_smbus_cmi_query_methods(acpi_handle handle, u32 level,
347 void *context, void **return_value)
348 {
349 char node_name[5];
350 struct acpi_buffer buffer = { sizeof(node_name), node_name };
351 struct acpi_smbus_cmi *smbus_cmi = context;
352 acpi_status status;
353
354 status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
355
356 if (ACPI_SUCCESS(status))
357 acpi_smbus_cmi_add_cap(smbus_cmi, node_name);
358
359 return AE_OK;
360 }
361
acpi_smbus_cmi_add(struct acpi_device * device)362 static int acpi_smbus_cmi_add(struct acpi_device *device)
363 {
364 struct acpi_smbus_cmi *smbus_cmi;
365 const struct acpi_device_id *id;
366
367 smbus_cmi = kzalloc(sizeof(struct acpi_smbus_cmi), GFP_KERNEL);
368 if (!smbus_cmi)
369 return -ENOMEM;
370
371 smbus_cmi->handle = device->handle;
372 strcpy(acpi_device_name(device), ACPI_SMBUS_HC_DEVICE_NAME);
373 strcpy(acpi_device_class(device), ACPI_SMBUS_HC_CLASS);
374 device->driver_data = smbus_cmi;
375 smbus_cmi->cap_info = 0;
376 smbus_cmi->cap_read = 0;
377 smbus_cmi->cap_write = 0;
378
379 for (id = acpi_smbus_cmi_ids; id->id[0]; id++)
380 if (!strcmp(id->id, acpi_device_hid(device)))
381 smbus_cmi->methods =
382 (struct smbus_methods_t *) id->driver_data;
383
384 acpi_walk_namespace(ACPI_TYPE_METHOD, smbus_cmi->handle, 1,
385 acpi_smbus_cmi_query_methods, NULL, smbus_cmi, NULL);
386
387 if (smbus_cmi->cap_info == 0)
388 goto err;
389
390 snprintf(smbus_cmi->adapter.name, sizeof(smbus_cmi->adapter.name),
391 "SMBus CMI adapter %s",
392 acpi_device_name(device));
393 smbus_cmi->adapter.owner = THIS_MODULE;
394 smbus_cmi->adapter.algo = &acpi_smbus_cmi_algorithm;
395 smbus_cmi->adapter.algo_data = smbus_cmi;
396 smbus_cmi->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
397 smbus_cmi->adapter.dev.parent = &device->dev;
398
399 if (i2c_add_adapter(&smbus_cmi->adapter)) {
400 dev_err(&device->dev, "Couldn't register adapter!\n");
401 goto err;
402 }
403
404 return 0;
405
406 err:
407 kfree(smbus_cmi);
408 device->driver_data = NULL;
409 return -EIO;
410 }
411
acpi_smbus_cmi_remove(struct acpi_device * device)412 static int acpi_smbus_cmi_remove(struct acpi_device *device)
413 {
414 struct acpi_smbus_cmi *smbus_cmi = acpi_driver_data(device);
415
416 i2c_del_adapter(&smbus_cmi->adapter);
417 kfree(smbus_cmi);
418 device->driver_data = NULL;
419
420 return 0;
421 }
422
423 static struct acpi_driver acpi_smbus_cmi_driver = {
424 .name = ACPI_SMBUS_HC_DEVICE_NAME,
425 .class = ACPI_SMBUS_HC_CLASS,
426 .ids = acpi_smbus_cmi_ids,
427 .ops = {
428 .add = acpi_smbus_cmi_add,
429 .remove = acpi_smbus_cmi_remove,
430 },
431 };
432 module_acpi_driver(acpi_smbus_cmi_driver);
433
434 MODULE_LICENSE("GPL");
435 MODULE_AUTHOR("Crane Cai <crane.cai@amd.com>");
436 MODULE_DESCRIPTION("ACPI SMBus CMI driver");
437