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