1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * SMBus driver for ACPI SMBus CMI |
4 | * |
5 | * Copyright (C) 2009 Crane Cai <crane.cai@amd.com> |
6 | */ |
7 | |
8 | #include <linux/module.h> |
9 | #include <linux/platform_device.h> |
10 | #include <linux/slab.h> |
11 | #include <linux/kernel.h> |
12 | #include <linux/stddef.h> |
13 | #include <linux/i2c.h> |
14 | #include <linux/acpi.h> |
15 | |
16 | struct smbus_methods_t { |
17 | char *mt_info; |
18 | char *mt_sbr; |
19 | char *mt_sbw; |
20 | }; |
21 | |
22 | struct acpi_smbus_cmi { |
23 | acpi_handle handle; |
24 | struct i2c_adapter adapter; |
25 | u8 cap_info:1; |
26 | u8 cap_read:1; |
27 | u8 cap_write:1; |
28 | const struct smbus_methods_t *methods; |
29 | }; |
30 | |
31 | static const struct smbus_methods_t smbus_methods = { |
32 | .mt_info = "_SBI" , |
33 | .mt_sbr = "_SBR" , |
34 | .mt_sbw = "_SBW" , |
35 | }; |
36 | |
37 | /* Some IBM BIOSes omit the leading underscore */ |
38 | static const struct smbus_methods_t ibm_smbus_methods = { |
39 | .mt_info = "SBI_" , |
40 | .mt_sbr = "SBR_" , |
41 | .mt_sbw = "SBW_" , |
42 | }; |
43 | |
44 | static const struct acpi_device_id acpi_smbus_cmi_ids[] = { |
45 | {"SMBUS01" , (kernel_ulong_t)&smbus_methods}, |
46 | {ACPI_SMBUS_IBM_HID, (kernel_ulong_t)&ibm_smbus_methods}, |
47 | {ACPI_SMBUS_MS_HID, (kernel_ulong_t)&smbus_methods}, |
48 | {"" , 0} |
49 | }; |
50 | MODULE_DEVICE_TABLE(acpi, acpi_smbus_cmi_ids); |
51 | |
52 | #define ACPI_SMBUS_STATUS_OK 0x00 |
53 | #define ACPI_SMBUS_STATUS_FAIL 0x07 |
54 | #define ACPI_SMBUS_STATUS_DNAK 0x10 |
55 | #define ACPI_SMBUS_STATUS_DERR 0x11 |
56 | #define ACPI_SMBUS_STATUS_CMD_DENY 0x12 |
57 | #define ACPI_SMBUS_STATUS_UNKNOWN 0x13 |
58 | #define ACPI_SMBUS_STATUS_ACC_DENY 0x17 |
59 | #define ACPI_SMBUS_STATUS_TIMEOUT 0x18 |
60 | #define ACPI_SMBUS_STATUS_NOTSUP 0x19 |
61 | #define ACPI_SMBUS_STATUS_BUSY 0x1a |
62 | #define ACPI_SMBUS_STATUS_PEC 0x1f |
63 | |
64 | #define ACPI_SMBUS_PRTCL_WRITE 0x00 |
65 | #define ACPI_SMBUS_PRTCL_READ 0x01 |
66 | #define ACPI_SMBUS_PRTCL_QUICK 0x02 |
67 | #define ACPI_SMBUS_PRTCL_BYTE 0x04 |
68 | #define ACPI_SMBUS_PRTCL_BYTE_DATA 0x06 |
69 | #define ACPI_SMBUS_PRTCL_WORD_DATA 0x08 |
70 | #define ACPI_SMBUS_PRTCL_BLOCK_DATA 0x0a |
71 | |
72 | |
73 | static int |
74 | acpi_smbus_cmi_access(struct i2c_adapter *adap, u16 addr, unsigned short flags, |
75 | char read_write, u8 command, int size, |
76 | union i2c_smbus_data *data) |
77 | { |
78 | int result = 0; |
79 | struct acpi_smbus_cmi *smbus_cmi = adap->algo_data; |
80 | unsigned char protocol; |
81 | acpi_status status = 0; |
82 | struct acpi_object_list input; |
83 | union acpi_object mt_params[5]; |
84 | struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; |
85 | union acpi_object *obj; |
86 | union acpi_object *pkg; |
87 | char *method; |
88 | int len = 0; |
89 | |
90 | dev_dbg(&adap->dev, "access size: %d %s\n" , size, |
91 | (read_write) ? "READ" : "WRITE" ); |
92 | switch (size) { |
93 | case I2C_SMBUS_QUICK: |
94 | protocol = ACPI_SMBUS_PRTCL_QUICK; |
95 | command = 0; |
96 | if (read_write == I2C_SMBUS_WRITE) { |
97 | mt_params[3].type = ACPI_TYPE_INTEGER; |
98 | mt_params[3].integer.value = 0; |
99 | mt_params[4].type = ACPI_TYPE_INTEGER; |
100 | mt_params[4].integer.value = 0; |
101 | } |
102 | break; |
103 | |
104 | case I2C_SMBUS_BYTE: |
105 | protocol = ACPI_SMBUS_PRTCL_BYTE; |
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 | } else { |
112 | command = 0; |
113 | } |
114 | break; |
115 | |
116 | case I2C_SMBUS_BYTE_DATA: |
117 | protocol = ACPI_SMBUS_PRTCL_BYTE_DATA; |
118 | if (read_write == I2C_SMBUS_WRITE) { |
119 | mt_params[3].type = ACPI_TYPE_INTEGER; |
120 | mt_params[3].integer.value = 1; |
121 | mt_params[4].type = ACPI_TYPE_INTEGER; |
122 | mt_params[4].integer.value = data->byte; |
123 | } |
124 | break; |
125 | |
126 | case I2C_SMBUS_WORD_DATA: |
127 | protocol = ACPI_SMBUS_PRTCL_WORD_DATA; |
128 | if (read_write == I2C_SMBUS_WRITE) { |
129 | mt_params[3].type = ACPI_TYPE_INTEGER; |
130 | mt_params[3].integer.value = 2; |
131 | mt_params[4].type = ACPI_TYPE_INTEGER; |
132 | mt_params[4].integer.value = data->word; |
133 | } |
134 | break; |
135 | |
136 | case I2C_SMBUS_BLOCK_DATA: |
137 | protocol = ACPI_SMBUS_PRTCL_BLOCK_DATA; |
138 | if (read_write == I2C_SMBUS_WRITE) { |
139 | len = data->block[0]; |
140 | if (len == 0 || len > I2C_SMBUS_BLOCK_MAX) |
141 | return -EINVAL; |
142 | mt_params[3].type = ACPI_TYPE_INTEGER; |
143 | mt_params[3].integer.value = len; |
144 | mt_params[4].type = ACPI_TYPE_BUFFER; |
145 | mt_params[4].buffer.length = len; |
146 | mt_params[4].buffer.pointer = data->block + 1; |
147 | } |
148 | break; |
149 | |
150 | default: |
151 | dev_warn(&adap->dev, "Unsupported transaction %d\n" , size); |
152 | return -EOPNOTSUPP; |
153 | } |
154 | |
155 | if (read_write == I2C_SMBUS_READ) { |
156 | protocol |= ACPI_SMBUS_PRTCL_READ; |
157 | method = smbus_cmi->methods->mt_sbr; |
158 | input.count = 3; |
159 | } else { |
160 | protocol |= ACPI_SMBUS_PRTCL_WRITE; |
161 | method = smbus_cmi->methods->mt_sbw; |
162 | input.count = 5; |
163 | } |
164 | |
165 | input.pointer = mt_params; |
166 | mt_params[0].type = ACPI_TYPE_INTEGER; |
167 | mt_params[0].integer.value = protocol; |
168 | mt_params[1].type = ACPI_TYPE_INTEGER; |
169 | mt_params[1].integer.value = addr; |
170 | mt_params[2].type = ACPI_TYPE_INTEGER; |
171 | mt_params[2].integer.value = command; |
172 | |
173 | status = acpi_evaluate_object(object: smbus_cmi->handle, pathname: method, parameter_objects: &input, |
174 | return_object_buffer: &buffer); |
175 | if (ACPI_FAILURE(status)) { |
176 | acpi_handle_err(smbus_cmi->handle, |
177 | "Failed to evaluate %s: %i\n" , method, status); |
178 | return -EIO; |
179 | } |
180 | |
181 | pkg = buffer.pointer; |
182 | if (pkg && pkg->type == ACPI_TYPE_PACKAGE) |
183 | obj = pkg->package.elements; |
184 | else { |
185 | acpi_handle_err(smbus_cmi->handle, "Invalid argument type\n" ); |
186 | result = -EIO; |
187 | goto out; |
188 | } |
189 | if (obj == NULL || obj->type != ACPI_TYPE_INTEGER) { |
190 | acpi_handle_err(smbus_cmi->handle, "Invalid argument type\n" ); |
191 | result = -EIO; |
192 | goto out; |
193 | } |
194 | |
195 | result = obj->integer.value; |
196 | acpi_handle_debug(smbus_cmi->handle, "%s return status: %i\n" , method, |
197 | result); |
198 | |
199 | switch (result) { |
200 | case ACPI_SMBUS_STATUS_OK: |
201 | result = 0; |
202 | break; |
203 | case ACPI_SMBUS_STATUS_BUSY: |
204 | result = -EBUSY; |
205 | goto out; |
206 | case ACPI_SMBUS_STATUS_TIMEOUT: |
207 | result = -ETIMEDOUT; |
208 | goto out; |
209 | case ACPI_SMBUS_STATUS_DNAK: |
210 | result = -ENXIO; |
211 | goto out; |
212 | default: |
213 | result = -EIO; |
214 | goto out; |
215 | } |
216 | |
217 | if (read_write == I2C_SMBUS_WRITE || size == I2C_SMBUS_QUICK) |
218 | goto out; |
219 | |
220 | obj = pkg->package.elements + 1; |
221 | if (obj->type != ACPI_TYPE_INTEGER) { |
222 | acpi_handle_err(smbus_cmi->handle, "Invalid argument type\n" ); |
223 | result = -EIO; |
224 | goto out; |
225 | } |
226 | |
227 | len = obj->integer.value; |
228 | obj = pkg->package.elements + 2; |
229 | switch (size) { |
230 | case I2C_SMBUS_BYTE: |
231 | case I2C_SMBUS_BYTE_DATA: |
232 | case I2C_SMBUS_WORD_DATA: |
233 | if (obj->type != ACPI_TYPE_INTEGER) { |
234 | acpi_handle_err(smbus_cmi->handle, |
235 | "Invalid argument type\n" ); |
236 | result = -EIO; |
237 | goto out; |
238 | } |
239 | if (len == 2) |
240 | data->word = obj->integer.value; |
241 | else |
242 | data->byte = obj->integer.value; |
243 | break; |
244 | case I2C_SMBUS_BLOCK_DATA: |
245 | if (obj->type != ACPI_TYPE_BUFFER) { |
246 | acpi_handle_err(smbus_cmi->handle, |
247 | "Invalid argument type\n" ); |
248 | result = -EIO; |
249 | goto out; |
250 | } |
251 | if (len == 0 || len > I2C_SMBUS_BLOCK_MAX) |
252 | return -EPROTO; |
253 | data->block[0] = len; |
254 | memcpy(data->block + 1, obj->buffer.pointer, len); |
255 | break; |
256 | } |
257 | |
258 | out: |
259 | kfree(objp: buffer.pointer); |
260 | dev_dbg(&adap->dev, "Transaction status: %i\n" , result); |
261 | return result; |
262 | } |
263 | |
264 | static u32 acpi_smbus_cmi_func(struct i2c_adapter *adapter) |
265 | { |
266 | struct acpi_smbus_cmi *smbus_cmi = adapter->algo_data; |
267 | u32 ret; |
268 | |
269 | ret = smbus_cmi->cap_read | smbus_cmi->cap_write ? |
270 | I2C_FUNC_SMBUS_QUICK : 0; |
271 | |
272 | ret |= smbus_cmi->cap_read ? |
273 | (I2C_FUNC_SMBUS_READ_BYTE | |
274 | I2C_FUNC_SMBUS_READ_BYTE_DATA | |
275 | I2C_FUNC_SMBUS_READ_WORD_DATA | |
276 | I2C_FUNC_SMBUS_READ_BLOCK_DATA) : 0; |
277 | |
278 | ret |= smbus_cmi->cap_write ? |
279 | (I2C_FUNC_SMBUS_WRITE_BYTE | |
280 | I2C_FUNC_SMBUS_WRITE_BYTE_DATA | |
281 | I2C_FUNC_SMBUS_WRITE_WORD_DATA | |
282 | I2C_FUNC_SMBUS_WRITE_BLOCK_DATA) : 0; |
283 | |
284 | return ret; |
285 | } |
286 | |
287 | static const struct i2c_algorithm acpi_smbus_cmi_algorithm = { |
288 | .smbus_xfer = acpi_smbus_cmi_access, |
289 | .functionality = acpi_smbus_cmi_func, |
290 | }; |
291 | |
292 | |
293 | static int acpi_smbus_cmi_add_cap(struct acpi_smbus_cmi *smbus_cmi, |
294 | const char *name) |
295 | { |
296 | struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; |
297 | struct acpi_handle *handle = smbus_cmi->handle; |
298 | union acpi_object *obj; |
299 | acpi_status status; |
300 | |
301 | if (!strcmp(name, smbus_cmi->methods->mt_info)) { |
302 | status = acpi_evaluate_object(object: smbus_cmi->handle, |
303 | pathname: smbus_cmi->methods->mt_info, |
304 | NULL, return_object_buffer: &buffer); |
305 | if (ACPI_FAILURE(status)) { |
306 | acpi_handle_err(handle, "Failed to evaluate %s: %i\n" , |
307 | smbus_cmi->methods->mt_info, status); |
308 | return -EIO; |
309 | } |
310 | |
311 | obj = buffer.pointer; |
312 | if (obj && obj->type == ACPI_TYPE_PACKAGE) |
313 | obj = obj->package.elements; |
314 | else { |
315 | acpi_handle_err(handle, "Invalid argument type\n" ); |
316 | kfree(objp: buffer.pointer); |
317 | return -EIO; |
318 | } |
319 | |
320 | if (obj->type != ACPI_TYPE_INTEGER) { |
321 | acpi_handle_err(handle, "Invalid argument type\n" ); |
322 | kfree(objp: buffer.pointer); |
323 | return -EIO; |
324 | } else |
325 | acpi_handle_debug(handle, "SMBus CMI Version %x\n" , |
326 | (int)obj->integer.value); |
327 | |
328 | kfree(objp: buffer.pointer); |
329 | smbus_cmi->cap_info = 1; |
330 | } else if (!strcmp(name, smbus_cmi->methods->mt_sbr)) |
331 | smbus_cmi->cap_read = 1; |
332 | else if (!strcmp(name, smbus_cmi->methods->mt_sbw)) |
333 | smbus_cmi->cap_write = 1; |
334 | else |
335 | acpi_handle_debug(handle, "Unsupported CMI method: %s\n" , name); |
336 | |
337 | return 0; |
338 | } |
339 | |
340 | static acpi_status acpi_smbus_cmi_query_methods(acpi_handle handle, u32 level, |
341 | void *context, void **return_value) |
342 | { |
343 | char node_name[5]; |
344 | struct acpi_buffer buffer = { sizeof(node_name), node_name }; |
345 | struct acpi_smbus_cmi *smbus_cmi = context; |
346 | acpi_status status; |
347 | |
348 | status = acpi_get_name(object: handle, ACPI_SINGLE_NAME, ret_path_ptr: &buffer); |
349 | |
350 | if (ACPI_SUCCESS(status)) |
351 | acpi_smbus_cmi_add_cap(smbus_cmi, name: node_name); |
352 | |
353 | return AE_OK; |
354 | } |
355 | |
356 | static int smbus_cmi_probe(struct platform_device *device) |
357 | { |
358 | struct device *dev = &device->dev; |
359 | struct acpi_smbus_cmi *smbus_cmi; |
360 | int ret; |
361 | |
362 | smbus_cmi = kzalloc(size: sizeof(struct acpi_smbus_cmi), GFP_KERNEL); |
363 | if (!smbus_cmi) |
364 | return -ENOMEM; |
365 | |
366 | smbus_cmi->handle = ACPI_HANDLE(dev); |
367 | smbus_cmi->methods = device_get_match_data(dev); |
368 | |
369 | platform_set_drvdata(pdev: device, data: smbus_cmi); |
370 | |
371 | smbus_cmi->cap_info = 0; |
372 | smbus_cmi->cap_read = 0; |
373 | smbus_cmi->cap_write = 0; |
374 | |
375 | acpi_walk_namespace(ACPI_TYPE_METHOD, start_object: smbus_cmi->handle, max_depth: 1, |
376 | descending_callback: acpi_smbus_cmi_query_methods, NULL, context: smbus_cmi, NULL); |
377 | |
378 | if (smbus_cmi->cap_info == 0) { |
379 | ret = -ENODEV; |
380 | goto err; |
381 | } |
382 | |
383 | snprintf(buf: smbus_cmi->adapter.name, size: sizeof(smbus_cmi->adapter.name), |
384 | fmt: "SMBus CMI adapter %s" , dev_name(dev)); |
385 | smbus_cmi->adapter.owner = THIS_MODULE; |
386 | smbus_cmi->adapter.algo = &acpi_smbus_cmi_algorithm; |
387 | smbus_cmi->adapter.algo_data = smbus_cmi; |
388 | smbus_cmi->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_SPD; |
389 | smbus_cmi->adapter.dev.parent = &device->dev; |
390 | |
391 | ret = i2c_add_adapter(adap: &smbus_cmi->adapter); |
392 | if (ret) { |
393 | dev_err(&device->dev, "Couldn't register adapter!\n" ); |
394 | goto err; |
395 | } |
396 | |
397 | return 0; |
398 | |
399 | err: |
400 | kfree(objp: smbus_cmi); |
401 | return ret; |
402 | } |
403 | |
404 | static void smbus_cmi_remove(struct platform_device *device) |
405 | { |
406 | struct acpi_smbus_cmi *smbus_cmi = platform_get_drvdata(pdev: device); |
407 | |
408 | i2c_del_adapter(adap: &smbus_cmi->adapter); |
409 | kfree(objp: smbus_cmi); |
410 | } |
411 | |
412 | static struct platform_driver smbus_cmi_driver = { |
413 | .probe = smbus_cmi_probe, |
414 | .remove_new = smbus_cmi_remove, |
415 | .driver = { |
416 | .name = "smbus_cmi" , |
417 | .acpi_match_table = acpi_smbus_cmi_ids, |
418 | }, |
419 | }; |
420 | module_platform_driver(smbus_cmi_driver); |
421 | |
422 | MODULE_LICENSE("GPL" ); |
423 | MODULE_AUTHOR("Crane Cai <crane.cai@amd.com>" ); |
424 | MODULE_DESCRIPTION("ACPI SMBus CMI driver" ); |
425 | |