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91087dfa AS |
1 | /* |
2 | * SMBus driver for ACPI Embedded Controller (v0.1) | |
3 | * | |
4 | * Copyright (c) 2007 Alexey Starikovskiy | |
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 <acpi/acpi_bus.h> | |
12 | #include <acpi/acpi_drivers.h> | |
13 | #include <acpi/actypes.h> | |
14 | #include <linux/wait.h> | |
15 | #include <linux/delay.h> | |
16 | #include <linux/interrupt.h> | |
17 | #include "sbshc.h" | |
18 | ||
19 | #define ACPI_SMB_HC_CLASS "smbus_host_controller" | |
20 | #define ACPI_SMB_HC_DEVICE_NAME "ACPI SMBus HC" | |
21 | ||
22 | struct acpi_smb_hc { | |
23 | struct acpi_ec *ec; | |
24 | struct mutex lock; | |
25 | wait_queue_head_t wait; | |
26 | u8 offset; | |
27 | u8 query_bit; | |
28 | smbus_alarm_callback callback; | |
29 | void *context; | |
30 | }; | |
31 | ||
32 | static int acpi_smbus_hc_add(struct acpi_device *device); | |
33 | static int acpi_smbus_hc_remove(struct acpi_device *device, int type); | |
34 | ||
35 | static const struct acpi_device_id sbs_device_ids[] = { | |
36 | {"ACPI0001", 0}, | |
37 | {"ACPI0005", 0}, | |
38 | {"", 0}, | |
39 | }; | |
40 | ||
41 | MODULE_DEVICE_TABLE(acpi, sbs_device_ids); | |
42 | ||
43 | static struct acpi_driver acpi_smb_hc_driver = { | |
44 | .name = "smbus_hc", | |
45 | .class = ACPI_SMB_HC_CLASS, | |
46 | .ids = sbs_device_ids, | |
47 | .ops = { | |
48 | .add = acpi_smbus_hc_add, | |
49 | .remove = acpi_smbus_hc_remove, | |
50 | }, | |
51 | }; | |
52 | ||
53 | union acpi_smb_status { | |
54 | u8 raw; | |
55 | struct { | |
56 | u8 status:5; | |
57 | u8 reserved:1; | |
58 | u8 alarm:1; | |
59 | u8 done:1; | |
60 | } fields; | |
61 | }; | |
62 | ||
63 | enum acpi_smb_status_codes { | |
64 | SMBUS_OK = 0, | |
65 | SMBUS_UNKNOWN_FAILURE = 0x07, | |
66 | SMBUS_DEVICE_ADDRESS_NACK = 0x10, | |
67 | SMBUS_DEVICE_ERROR = 0x11, | |
68 | SMBUS_DEVICE_COMMAND_ACCESS_DENIED = 0x12, | |
69 | SMBUS_UNKNOWN_ERROR = 0x13, | |
70 | SMBUS_DEVICE_ACCESS_DENIED = 0x17, | |
71 | SMBUS_TIMEOUT = 0x18, | |
72 | SMBUS_HOST_UNSUPPORTED_PROTOCOL = 0x19, | |
73 | SMBUS_BUSY = 0x1a, | |
74 | SMBUS_PEC_ERROR = 0x1f, | |
75 | }; | |
76 | ||
77 | enum acpi_smb_offset { | |
78 | ACPI_SMB_PROTOCOL = 0, /* protocol, PEC */ | |
79 | ACPI_SMB_STATUS = 1, /* status */ | |
80 | ACPI_SMB_ADDRESS = 2, /* address */ | |
81 | ACPI_SMB_COMMAND = 3, /* command */ | |
82 | ACPI_SMB_DATA = 4, /* 32 data registers */ | |
83 | ACPI_SMB_BLOCK_COUNT = 0x24, /* number of data bytes */ | |
84 | ACPI_SMB_ALARM_ADDRESS = 0x25, /* alarm address */ | |
85 | ACPI_SMB_ALARM_DATA = 0x26, /* 2 bytes alarm data */ | |
86 | }; | |
87 | ||
88 | static inline int smb_hc_read(struct acpi_smb_hc *hc, u8 address, u8 *data) | |
89 | { | |
90 | return ec_read(hc->offset + address, data); | |
91 | } | |
92 | ||
93 | static inline int smb_hc_write(struct acpi_smb_hc *hc, u8 address, u8 data) | |
94 | { | |
95 | return ec_write(hc->offset + address, data); | |
96 | } | |
97 | ||
98 | static inline int smb_check_done(struct acpi_smb_hc *hc) | |
99 | { | |
100 | union acpi_smb_status status = {.raw = 0}; | |
101 | smb_hc_read(hc, ACPI_SMB_STATUS, &status.raw); | |
102 | return status.fields.done && (status.fields.status == SMBUS_OK); | |
103 | } | |
104 | ||
105 | static int wait_transaction_complete(struct acpi_smb_hc *hc, int timeout) | |
106 | { | |
107 | if (wait_event_timeout(hc->wait, smb_check_done(hc), | |
108 | msecs_to_jiffies(timeout))) | |
109 | return 0; | |
266feefe ZY |
110 | /* |
111 | * After the timeout happens, OS will try to check the status of SMbus. | |
112 | * If the status is what OS expected, it will be regarded as the bogus | |
113 | * timeout. | |
114 | */ | |
115 | if (smb_check_done(hc)) | |
116 | return 0; | |
91087dfa AS |
117 | else |
118 | return -ETIME; | |
119 | } | |
120 | ||
e5685b9d AB |
121 | static int acpi_smbus_transaction(struct acpi_smb_hc *hc, u8 protocol, |
122 | u8 address, u8 command, u8 *data, u8 length) | |
91087dfa AS |
123 | { |
124 | int ret = -EFAULT, i; | |
125 | u8 temp, sz = 0; | |
126 | ||
bbafbecb AS |
127 | if (!hc) { |
128 | printk(KERN_ERR PREFIX "host controller is not configured\n"); | |
129 | return ret; | |
130 | } | |
131 | ||
91087dfa AS |
132 | mutex_lock(&hc->lock); |
133 | if (smb_hc_read(hc, ACPI_SMB_PROTOCOL, &temp)) | |
134 | goto end; | |
135 | if (temp) { | |
136 | ret = -EBUSY; | |
137 | goto end; | |
138 | } | |
139 | smb_hc_write(hc, ACPI_SMB_COMMAND, command); | |
91087dfa AS |
140 | if (!(protocol & 0x01)) { |
141 | smb_hc_write(hc, ACPI_SMB_BLOCK_COUNT, length); | |
142 | for (i = 0; i < length; ++i) | |
143 | smb_hc_write(hc, ACPI_SMB_DATA + i, data[i]); | |
144 | } | |
145 | smb_hc_write(hc, ACPI_SMB_ADDRESS, address << 1); | |
146 | smb_hc_write(hc, ACPI_SMB_PROTOCOL, protocol); | |
147 | /* | |
148 | * Wait for completion. Save the status code, data size, | |
149 | * and data into the return package (if required by the protocol). | |
150 | */ | |
151 | ret = wait_transaction_complete(hc, 1000); | |
152 | if (ret || !(protocol & 0x01)) | |
153 | goto end; | |
154 | switch (protocol) { | |
155 | case SMBUS_RECEIVE_BYTE: | |
156 | case SMBUS_READ_BYTE: | |
157 | sz = 1; | |
158 | break; | |
159 | case SMBUS_READ_WORD: | |
160 | sz = 2; | |
161 | break; | |
162 | case SMBUS_READ_BLOCK: | |
163 | if (smb_hc_read(hc, ACPI_SMB_BLOCK_COUNT, &sz)) { | |
164 | ret = -EFAULT; | |
165 | goto end; | |
166 | } | |
167 | sz &= 0x1f; | |
168 | break; | |
169 | } | |
170 | for (i = 0; i < sz; ++i) | |
171 | smb_hc_read(hc, ACPI_SMB_DATA + i, &data[i]); | |
172 | end: | |
173 | mutex_unlock(&hc->lock); | |
174 | return ret; | |
175 | } | |
176 | ||
177 | int acpi_smbus_read(struct acpi_smb_hc *hc, u8 protocol, u8 address, | |
178 | u8 command, u8 *data) | |
179 | { | |
180 | return acpi_smbus_transaction(hc, protocol, address, command, data, 0); | |
181 | } | |
182 | ||
183 | EXPORT_SYMBOL_GPL(acpi_smbus_read); | |
184 | ||
185 | int acpi_smbus_write(struct acpi_smb_hc *hc, u8 protocol, u8 address, | |
186 | u8 command, u8 *data, u8 length) | |
187 | { | |
188 | return acpi_smbus_transaction(hc, protocol, address, command, data, length); | |
189 | } | |
190 | ||
191 | EXPORT_SYMBOL_GPL(acpi_smbus_write); | |
192 | ||
193 | int acpi_smbus_register_callback(struct acpi_smb_hc *hc, | |
194 | smbus_alarm_callback callback, void *context) | |
195 | { | |
196 | mutex_lock(&hc->lock); | |
197 | hc->callback = callback; | |
198 | hc->context = context; | |
199 | mutex_unlock(&hc->lock); | |
200 | return 0; | |
201 | } | |
202 | ||
203 | EXPORT_SYMBOL_GPL(acpi_smbus_register_callback); | |
204 | ||
205 | int acpi_smbus_unregister_callback(struct acpi_smb_hc *hc) | |
206 | { | |
207 | mutex_lock(&hc->lock); | |
208 | hc->callback = NULL; | |
209 | hc->context = NULL; | |
210 | mutex_unlock(&hc->lock); | |
211 | return 0; | |
212 | } | |
213 | ||
214 | EXPORT_SYMBOL_GPL(acpi_smbus_unregister_callback); | |
215 | ||
c2d00f2d | 216 | static inline void acpi_smbus_callback(void *context) |
91087dfa AS |
217 | { |
218 | struct acpi_smb_hc *hc = context; | |
91087dfa AS |
219 | if (hc->callback) |
220 | hc->callback(hc->context); | |
221 | } | |
222 | ||
223 | static int smbus_alarm(void *context) | |
224 | { | |
225 | struct acpi_smb_hc *hc = context; | |
226 | union acpi_smb_status status; | |
c2d00f2d | 227 | u8 address; |
91087dfa AS |
228 | if (smb_hc_read(hc, ACPI_SMB_STATUS, &status.raw)) |
229 | return 0; | |
230 | /* Check if it is only a completion notify */ | |
231 | if (status.fields.done) | |
232 | wake_up(&hc->wait); | |
233 | if (!status.fields.alarm) | |
234 | return 0; | |
235 | mutex_lock(&hc->lock); | |
c2d00f2d | 236 | smb_hc_read(hc, ACPI_SMB_ALARM_ADDRESS, &address); |
09f1fb41 | 237 | status.fields.alarm = 0; |
91087dfa | 238 | smb_hc_write(hc, ACPI_SMB_STATUS, status.raw); |
c2d00f2d AS |
239 | /* We are only interested in events coming from known devices */ |
240 | switch (address >> 1) { | |
241 | case ACPI_SBS_CHARGER: | |
242 | case ACPI_SBS_MANAGER: | |
243 | case ACPI_SBS_BATTERY: | |
244 | acpi_os_execute(OSL_GPE_HANDLER, | |
245 | acpi_smbus_callback, hc); | |
246 | default:; | |
247 | } | |
91087dfa AS |
248 | mutex_unlock(&hc->lock); |
249 | return 0; | |
250 | } | |
251 | ||
252 | typedef int (*acpi_ec_query_func) (void *data); | |
253 | ||
254 | extern int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit, | |
255 | acpi_handle handle, acpi_ec_query_func func, | |
256 | void *data); | |
257 | ||
258 | static int acpi_smbus_hc_add(struct acpi_device *device) | |
259 | { | |
260 | int status; | |
27663c58 | 261 | unsigned long long val; |
91087dfa AS |
262 | struct acpi_smb_hc *hc; |
263 | ||
264 | if (!device) | |
265 | return -EINVAL; | |
266 | ||
267 | status = acpi_evaluate_integer(device->handle, "_EC", NULL, &val); | |
268 | if (ACPI_FAILURE(status)) { | |
269 | printk(KERN_ERR PREFIX "error obtaining _EC.\n"); | |
270 | return -EIO; | |
271 | } | |
272 | ||
273 | strcpy(acpi_device_name(device), ACPI_SMB_HC_DEVICE_NAME); | |
274 | strcpy(acpi_device_class(device), ACPI_SMB_HC_CLASS); | |
275 | ||
276 | hc = kzalloc(sizeof(struct acpi_smb_hc), GFP_KERNEL); | |
277 | if (!hc) | |
278 | return -ENOMEM; | |
279 | mutex_init(&hc->lock); | |
280 | init_waitqueue_head(&hc->wait); | |
281 | ||
282 | hc->ec = acpi_driver_data(device->parent); | |
283 | hc->offset = (val >> 8) & 0xff; | |
284 | hc->query_bit = val & 0xff; | |
db89b4f0 | 285 | device->driver_data = hc; |
91087dfa AS |
286 | |
287 | acpi_ec_add_query_handler(hc->ec, hc->query_bit, NULL, smbus_alarm, hc); | |
288 | printk(KERN_INFO PREFIX "SBS HC: EC = 0x%p, offset = 0x%0x, query_bit = 0x%0x\n", | |
289 | hc->ec, hc->offset, hc->query_bit); | |
290 | ||
291 | return 0; | |
292 | } | |
293 | ||
294 | extern void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit); | |
295 | ||
296 | static int acpi_smbus_hc_remove(struct acpi_device *device, int type) | |
297 | { | |
298 | struct acpi_smb_hc *hc; | |
299 | ||
300 | if (!device) | |
301 | return -EINVAL; | |
302 | ||
303 | hc = acpi_driver_data(device); | |
304 | acpi_ec_remove_query_handler(hc->ec, hc->query_bit); | |
305 | kfree(hc); | |
db89b4f0 | 306 | device->driver_data = NULL; |
91087dfa AS |
307 | return 0; |
308 | } | |
309 | ||
310 | static int __init acpi_smb_hc_init(void) | |
311 | { | |
312 | int result; | |
313 | ||
314 | result = acpi_bus_register_driver(&acpi_smb_hc_driver); | |
315 | if (result < 0) | |
316 | return -ENODEV; | |
317 | return 0; | |
318 | } | |
319 | ||
320 | static void __exit acpi_smb_hc_exit(void) | |
321 | { | |
322 | acpi_bus_unregister_driver(&acpi_smb_hc_driver); | |
323 | } | |
324 | ||
325 | module_init(acpi_smb_hc_init); | |
326 | module_exit(acpi_smb_hc_exit); | |
327 | ||
328 | MODULE_LICENSE("GPL"); | |
329 | MODULE_AUTHOR("Alexey Starikovskiy"); | |
330 | MODULE_DESCRIPTION("ACPI SMBus HC driver"); |