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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
22ACPI_MODULE_NAME("smbus_cmi");
23
24struct smbus_methods_t {
25 char *mt_info;
26 char *mt_sbr;
27 char *mt_sbw;
28};
29
30struct 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
39static const struct smbus_methods_t smbus_methods = {
40 .mt_info = "_SBI",
41 .mt_sbr = "_SBR",
42 .mt_sbw = "_SBW",
43};
44
45
46static const struct smbus_methods_t ibm_smbus_methods = {
47 .mt_info = "SBI_",
48 .mt_sbr = "SBR_",
49 .mt_sbw = "SBW_",
50};
51
52static 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};
57MODULE_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
80static int
81acpi_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
261out:
262 kfree(buffer.pointer);
263 dev_dbg(&adap->dev, "Transaction status: %i\n", result);
264 return result;
265}
266
267static 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
290static const struct i2c_algorithm acpi_smbus_cmi_algorithm = {
291 .smbus_xfer = acpi_smbus_cmi_access,
292 .functionality = acpi_smbus_cmi_func,
293};
294
295
296static 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
343static 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
359static 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
403err:
404 kfree(smbus_cmi);
405 device->driver_data = NULL;
406 return -EIO;
407}
408
409static 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
420static 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
430static int __init acpi_smbus_cmi_init(void)
431{
432 return acpi_bus_register_driver(&acpi_smbus_cmi_driver);
433}
434
435static void __exit acpi_smbus_cmi_exit(void)
436{
437 acpi_bus_unregister_driver(&acpi_smbus_cmi_driver);
438}
439
440module_init(acpi_smbus_cmi_init);
441module_exit(acpi_smbus_cmi_exit);
442
443MODULE_LICENSE("GPL");
444MODULE_AUTHOR("Crane Cai <crane.cai@amd.com>");
445MODULE_DESCRIPTION("ACPI SMBus CMI driver");
446
