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path: root/drivers/i2c/busses/i2c-scmi.c
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Diffstat (limited to 'drivers/i2c/busses/i2c-scmi.c')
-rw-r--r--drivers/i2c/busses/i2c-scmi.c430
1 files changed, 430 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-scmi.c b/drivers/i2c/busses/i2c-scmi.c
new file mode 100644
index 000000000000..276a046ac93f
--- /dev/null
+++ b/drivers/i2c/busses/i2c-scmi.c
@@ -0,0 +1,430 @@
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
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};
37
38static const struct smbus_methods_t smbus_methods = {
39 .mt_info = "_SBI",
40 .mt_sbr = "_SBR",
41 .mt_sbw = "_SBW",
42};
43
44static const struct acpi_device_id acpi_smbus_cmi_ids[] = {
45 {"SMBUS01", 0},
46 {"", 0}
47};
48
49#define ACPI_SMBUS_STATUS_OK 0x00
50#define ACPI_SMBUS_STATUS_FAIL 0x07
51#define ACPI_SMBUS_STATUS_DNAK 0x10
52#define ACPI_SMBUS_STATUS_DERR 0x11
53#define ACPI_SMBUS_STATUS_CMD_DENY 0x12
54#define ACPI_SMBUS_STATUS_UNKNOWN 0x13
55#define ACPI_SMBUS_STATUS_ACC_DENY 0x17
56#define ACPI_SMBUS_STATUS_TIMEOUT 0x18
57#define ACPI_SMBUS_STATUS_NOTSUP 0x19
58#define ACPI_SMBUS_STATUS_BUSY 0x1a
59#define ACPI_SMBUS_STATUS_PEC 0x1f
60
61#define ACPI_SMBUS_PRTCL_WRITE 0x00
62#define ACPI_SMBUS_PRTCL_READ 0x01
63#define ACPI_SMBUS_PRTCL_QUICK 0x02
64#define ACPI_SMBUS_PRTCL_BYTE 0x04
65#define ACPI_SMBUS_PRTCL_BYTE_DATA 0x06
66#define ACPI_SMBUS_PRTCL_WORD_DATA 0x08
67#define ACPI_SMBUS_PRTCL_BLOCK_DATA 0x0a
68
69
70static int
71acpi_smbus_cmi_access(struct i2c_adapter *adap, u16 addr, unsigned short flags,
72 char read_write, u8 command, int size,
73 union i2c_smbus_data *data)
74{
75 int result = 0;
76 struct acpi_smbus_cmi *smbus_cmi = adap->algo_data;
77 unsigned char protocol;
78 acpi_status status = 0;
79 struct acpi_object_list input;
80 union acpi_object mt_params[5];
81 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
82 union acpi_object *obj;
83 union acpi_object *pkg;
84 char *method;
85 int len = 0;
86
87 dev_dbg(&adap->dev, "access size: %d %s\n", size,
88 (read_write) ? "READ" : "WRITE");
89 switch (size) {
90 case I2C_SMBUS_QUICK:
91 protocol = ACPI_SMBUS_PRTCL_QUICK;
92 command = 0;
93 if (read_write == I2C_SMBUS_WRITE) {
94 mt_params[3].type = ACPI_TYPE_INTEGER;
95 mt_params[3].integer.value = 0;
96 mt_params[4].type = ACPI_TYPE_INTEGER;
97 mt_params[4].integer.value = 0;
98 }
99 break;
100
101 case I2C_SMBUS_BYTE:
102 protocol = ACPI_SMBUS_PRTCL_BYTE;
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 } else {
109 command = 0;
110 }
111 break;
112
113 case I2C_SMBUS_BYTE_DATA:
114 protocol = ACPI_SMBUS_PRTCL_BYTE_DATA;
115 if (read_write == I2C_SMBUS_WRITE) {
116 mt_params[3].type = ACPI_TYPE_INTEGER;
117 mt_params[3].integer.value = 1;
118 mt_params[4].type = ACPI_TYPE_INTEGER;
119 mt_params[4].integer.value = data->byte;
120 }
121 break;
122
123 case I2C_SMBUS_WORD_DATA:
124 protocol = ACPI_SMBUS_PRTCL_WORD_DATA;
125 if (read_write == I2C_SMBUS_WRITE) {
126 mt_params[3].type = ACPI_TYPE_INTEGER;
127 mt_params[3].integer.value = 2;
128 mt_params[4].type = ACPI_TYPE_INTEGER;
129 mt_params[4].integer.value = data->word;
130 }
131 break;
132
133 case I2C_SMBUS_BLOCK_DATA:
134 protocol = ACPI_SMBUS_PRTCL_BLOCK_DATA;
135 if (read_write == I2C_SMBUS_WRITE) {
136 len = data->block[0];
137 if (len == 0 || len > I2C_SMBUS_BLOCK_MAX)
138 return -EINVAL;
139 mt_params[3].type = ACPI_TYPE_INTEGER;
140 mt_params[3].integer.value = len;
141 mt_params[4].type = ACPI_TYPE_BUFFER;
142 mt_params[4].buffer.pointer = data->block + 1;
143 }
144 break;
145
146 default:
147 dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
148 return -EOPNOTSUPP;
149 }
150
151 if (read_write == I2C_SMBUS_READ) {
152 protocol |= ACPI_SMBUS_PRTCL_READ;
153 method = smbus_methods.mt_sbr;
154 input.count = 3;
155 } else {
156 protocol |= ACPI_SMBUS_PRTCL_WRITE;
157 method = smbus_methods.mt_sbw;
158 input.count = 5;
159 }
160
161 input.pointer = mt_params;
162 mt_params[0].type = ACPI_TYPE_INTEGER;
163 mt_params[0].integer.value = protocol;
164 mt_params[1].type = ACPI_TYPE_INTEGER;
165 mt_params[1].integer.value = addr;
166 mt_params[2].type = ACPI_TYPE_INTEGER;
167 mt_params[2].integer.value = command;
168
169 status = acpi_evaluate_object(smbus_cmi->handle, method, &input,
170 &buffer);
171 if (ACPI_FAILURE(status)) {
172 ACPI_ERROR((AE_INFO, "Evaluating %s: %i", method, status));
173 return -EIO;
174 }
175
176 pkg = buffer.pointer;
177 if (pkg && pkg->type == ACPI_TYPE_PACKAGE)
178 obj = pkg->package.elements;
179 else {
180 ACPI_ERROR((AE_INFO, "Invalid argument type"));
181 result = -EIO;
182 goto out;
183 }
184 if (obj == NULL || obj->type != ACPI_TYPE_INTEGER) {
185 ACPI_ERROR((AE_INFO, "Invalid argument type"));
186 result = -EIO;
187 goto out;
188 }
189
190 result = obj->integer.value;
191 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "%s return status: %i\n",
192 method, result));
193
194 switch (result) {
195 case ACPI_SMBUS_STATUS_OK:
196 result = 0;
197 break;
198 case ACPI_SMBUS_STATUS_BUSY:
199 result = -EBUSY;
200 goto out;
201 case ACPI_SMBUS_STATUS_TIMEOUT:
202 result = -ETIMEDOUT;
203 goto out;
204 case ACPI_SMBUS_STATUS_DNAK:
205 result = -ENXIO;
206 goto out;
207 default:
208 result = -EIO;
209 goto out;
210 }
211
212 if (read_write == I2C_SMBUS_WRITE || size == I2C_SMBUS_QUICK)
213 goto out;
214
215 obj = pkg->package.elements + 1;
216 if (obj == NULL || obj->type != ACPI_TYPE_INTEGER) {
217 ACPI_ERROR((AE_INFO, "Invalid argument type"));
218 result = -EIO;
219 goto out;
220 }
221
222 len = obj->integer.value;
223 obj = pkg->package.elements + 2;
224 switch (size) {
225 case I2C_SMBUS_BYTE:
226 case I2C_SMBUS_BYTE_DATA:
227 case I2C_SMBUS_WORD_DATA:
228 if (obj == NULL || obj->type != ACPI_TYPE_INTEGER) {
229 ACPI_ERROR((AE_INFO, "Invalid argument type"));
230 result = -EIO;
231 goto out;
232 }
233 if (len == 2)
234 data->word = obj->integer.value;
235 else
236 data->byte = obj->integer.value;
237 break;
238 case I2C_SMBUS_BLOCK_DATA:
239 if (obj == NULL || obj->type != ACPI_TYPE_BUFFER) {
240 ACPI_ERROR((AE_INFO, "Invalid argument type"));
241 result = -EIO;
242 goto out;
243 }
244 if (len == 0 || len > I2C_SMBUS_BLOCK_MAX)
245 return -EPROTO;
246 data->block[0] = len;
247 memcpy(data->block + 1, obj->buffer.pointer, len);
248 break;
249 }
250
251out:
252 kfree(buffer.pointer);
253 dev_dbg(&adap->dev, "Transaction status: %i\n", result);
254 return result;
255}
256
257static u32 acpi_smbus_cmi_func(struct i2c_adapter *adapter)
258{
259 struct acpi_smbus_cmi *smbus_cmi = adapter->algo_data;
260 u32 ret;
261
262 ret = smbus_cmi->cap_read | smbus_cmi->cap_write ?
263 I2C_FUNC_SMBUS_QUICK : 0;
264
265 ret |= smbus_cmi->cap_read ?
266 (I2C_FUNC_SMBUS_READ_BYTE |
267 I2C_FUNC_SMBUS_READ_BYTE_DATA |
268 I2C_FUNC_SMBUS_READ_WORD_DATA |
269 I2C_FUNC_SMBUS_READ_BLOCK_DATA) : 0;
270
271 ret |= smbus_cmi->cap_write ?
272 (I2C_FUNC_SMBUS_WRITE_BYTE |
273 I2C_FUNC_SMBUS_WRITE_BYTE_DATA |
274 I2C_FUNC_SMBUS_WRITE_WORD_DATA |
275 I2C_FUNC_SMBUS_WRITE_BLOCK_DATA) : 0;
276
277 return ret;
278}
279
280static const struct i2c_algorithm acpi_smbus_cmi_algorithm = {
281 .smbus_xfer = acpi_smbus_cmi_access,
282 .functionality = acpi_smbus_cmi_func,
283};
284
285
286static int acpi_smbus_cmi_add_cap(struct acpi_smbus_cmi *smbus_cmi,
287 const char *name)
288{
289 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
290 union acpi_object *obj;
291 acpi_status status;
292
293 if (!strcmp(name, smbus_methods.mt_info)) {
294 status = acpi_evaluate_object(smbus_cmi->handle,
295 smbus_methods.mt_info,
296 NULL, &buffer);
297 if (ACPI_FAILURE(status)) {
298 ACPI_ERROR((AE_INFO, "Evaluating %s: %i",
299 smbus_methods.mt_info, status));
300 return -EIO;
301 }
302
303 obj = buffer.pointer;
304 if (obj && obj->type == ACPI_TYPE_PACKAGE)
305 obj = obj->package.elements;
306 else {
307 ACPI_ERROR((AE_INFO, "Invalid argument type"));
308 kfree(buffer.pointer);
309 return -EIO;
310 }
311
312 if (obj->type != ACPI_TYPE_INTEGER) {
313 ACPI_ERROR((AE_INFO, "Invalid argument type"));
314 kfree(buffer.pointer);
315 return -EIO;
316 } else
317 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "SMBus CMI Version %x"
318 "\n", (int)obj->integer.value));
319
320 kfree(buffer.pointer);
321 smbus_cmi->cap_info = 1;
322 } else if (!strcmp(name, smbus_methods.mt_sbr))
323 smbus_cmi->cap_read = 1;
324 else if (!strcmp(name, smbus_methods.mt_sbw))
325 smbus_cmi->cap_write = 1;
326 else
327 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Unsupported CMI method: %s\n",
328 name));
329
330 return 0;
331}
332
333static acpi_status acpi_smbus_cmi_query_methods(acpi_handle handle, u32 level,
334 void *context, void **return_value)
335{
336 char node_name[5];
337 struct acpi_buffer buffer = { sizeof(node_name), node_name };
338 struct acpi_smbus_cmi *smbus_cmi = context;
339 acpi_status status;
340
341 status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
342
343 if (ACPI_SUCCESS(status))
344 acpi_smbus_cmi_add_cap(smbus_cmi, node_name);
345
346 return AE_OK;
347}
348
349static int acpi_smbus_cmi_add(struct acpi_device *device)
350{
351 struct acpi_smbus_cmi *smbus_cmi;
352
353 smbus_cmi = kzalloc(sizeof(struct acpi_smbus_cmi), GFP_KERNEL);
354 if (!smbus_cmi)
355 return -ENOMEM;
356
357 smbus_cmi->handle = device->handle;
358 strcpy(acpi_device_name(device), ACPI_SMBUS_HC_DEVICE_NAME);
359 strcpy(acpi_device_class(device), ACPI_SMBUS_HC_CLASS);
360 device->driver_data = smbus_cmi;
361 smbus_cmi->cap_info = 0;
362 smbus_cmi->cap_read = 0;
363 smbus_cmi->cap_write = 0;
364
365 acpi_walk_namespace(ACPI_TYPE_METHOD, smbus_cmi->handle, 1,
366 acpi_smbus_cmi_query_methods, smbus_cmi, NULL);
367
368 if (smbus_cmi->cap_info == 0)
369 goto err;
370
371 snprintf(smbus_cmi->adapter.name, sizeof(smbus_cmi->adapter.name),
372 "SMBus CMI adapter %s (%s)",
373 acpi_device_name(device),
374 acpi_device_uid(device));
375 smbus_cmi->adapter.owner = THIS_MODULE;
376 smbus_cmi->adapter.algo = &acpi_smbus_cmi_algorithm;
377 smbus_cmi->adapter.algo_data = smbus_cmi;
378 smbus_cmi->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
379 smbus_cmi->adapter.dev.parent = &device->dev;
380
381 if (i2c_add_adapter(&smbus_cmi->adapter)) {
382 dev_err(&device->dev, "Couldn't register adapter!\n");
383 goto err;
384 }
385
386 return 0;
387
388err:
389 kfree(smbus_cmi);
390 device->driver_data = NULL;
391 return -EIO;
392}
393
394static int acpi_smbus_cmi_remove(struct acpi_device *device, int type)
395{
396 struct acpi_smbus_cmi *smbus_cmi = acpi_driver_data(device);
397
398 i2c_del_adapter(&smbus_cmi->adapter);
399 kfree(smbus_cmi);
400 device->driver_data = NULL;
401
402 return 0;
403}
404
405static struct acpi_driver acpi_smbus_cmi_driver = {
406 .name = ACPI_SMBUS_HC_DEVICE_NAME,
407 .class = ACPI_SMBUS_HC_CLASS,
408 .ids = acpi_smbus_cmi_ids,
409 .ops = {
410 .add = acpi_smbus_cmi_add,
411 .remove = acpi_smbus_cmi_remove,
412 },
413};
414
415static int __init acpi_smbus_cmi_init(void)
416{
417 return acpi_bus_register_driver(&acpi_smbus_cmi_driver);
418}
419
420static void __exit acpi_smbus_cmi_exit(void)
421{
422 acpi_bus_unregister_driver(&acpi_smbus_cmi_driver);
423}
424
425module_init(acpi_smbus_cmi_init);
426module_exit(acpi_smbus_cmi_exit);
427
428MODULE_LICENSE("GPL");
429MODULE_AUTHOR("Crane Cai <crane.cai@amd.com>");
430MODULE_DESCRIPTION("ACPI SMBus CMI driver");
generated by cgit v1.2.2 (git 2.25.0) at 2025-01-04 10:45:55 -0500