Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes...
[linux-2.6.git] / drivers / i2c / busses / i2c-scmi.c
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
22 ACPI_MODULE_NAME("smbus_cmi");
23
24 struct smbus_methods_t {
25         char *mt_info;
26         char *mt_sbr;
27         char *mt_sbw;
28 };
29
30 struct 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
39 static 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 */
46 static const struct smbus_methods_t ibm_smbus_methods = {
47         .mt_info = "SBI_",
48         .mt_sbr  = "SBR_",
49         .mt_sbw  = "SBW_",
50 };
51
52 static 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 };
57 MODULE_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
80 static int
81 acpi_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
261 out:
262         kfree(buffer.pointer);
263         dev_dbg(&adap->dev, "Transaction status: %i\n", result);
264         return result;
265 }
266
267 static 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
290 static const struct i2c_algorithm acpi_smbus_cmi_algorithm = {
291         .smbus_xfer = acpi_smbus_cmi_access,
292         .functionality = acpi_smbus_cmi_func,
293 };
294
295
296 static 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
343 static 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
359 static 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
403 err:
404         kfree(smbus_cmi);
405         device->driver_data = NULL;
406         return -EIO;
407 }
408
409 static 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
420 static 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
430 static int __init acpi_smbus_cmi_init(void)
431 {
432         return acpi_bus_register_driver(&acpi_smbus_cmi_driver);
433 }
434
435 static void __exit acpi_smbus_cmi_exit(void)
436 {
437         acpi_bus_unregister_driver(&acpi_smbus_cmi_driver);
438 }
439
440 module_init(acpi_smbus_cmi_init);
441 module_exit(acpi_smbus_cmi_exit);
442
443 MODULE_LICENSE("GPL");
444 MODULE_AUTHOR("Crane Cai <crane.cai@amd.com>");
445 MODULE_DESCRIPTION("ACPI SMBus CMI driver");