ACPI: SBS: Host controller must initialize before SBS.
[linux-2.6.git] / drivers / acpi / sbshc.c
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;
110         else
111                 return -ETIME;
112 }
113
114 static int acpi_smbus_transaction(struct acpi_smb_hc *hc, u8 protocol,
115                                   u8 address, u8 command, u8 *data, u8 length)
116 {
117         int ret = -EFAULT, i;
118         u8 temp, sz = 0;
119
120         if (!hc) {
121                 printk(KERN_ERR PREFIX "host controller is not configured\n");
122                 return ret;
123         }
124
125         mutex_lock(&hc->lock);
126         if (smb_hc_read(hc, ACPI_SMB_PROTOCOL, &temp))
127                 goto end;
128         if (temp) {
129                 ret = -EBUSY;
130                 goto end;
131         }
132         smb_hc_write(hc, ACPI_SMB_COMMAND, command);
133         smb_hc_write(hc, ACPI_SMB_COMMAND, command);
134         if (!(protocol & 0x01)) {
135                 smb_hc_write(hc, ACPI_SMB_BLOCK_COUNT, length);
136                 for (i = 0; i < length; ++i)
137                         smb_hc_write(hc, ACPI_SMB_DATA + i, data[i]);
138         }
139         smb_hc_write(hc, ACPI_SMB_ADDRESS, address << 1);
140         smb_hc_write(hc, ACPI_SMB_PROTOCOL, protocol);
141         /*
142          * Wait for completion. Save the status code, data size,
143          * and data into the return package (if required by the protocol).
144          */
145         ret = wait_transaction_complete(hc, 1000);
146         if (ret || !(protocol & 0x01))
147                 goto end;
148         switch (protocol) {
149         case SMBUS_RECEIVE_BYTE:
150         case SMBUS_READ_BYTE:
151                 sz = 1;
152                 break;
153         case SMBUS_READ_WORD:
154                 sz = 2;
155                 break;
156         case SMBUS_READ_BLOCK:
157                 if (smb_hc_read(hc, ACPI_SMB_BLOCK_COUNT, &sz)) {
158                         ret = -EFAULT;
159                         goto end;
160                 }
161                 sz &= 0x1f;
162                 break;
163         }
164         for (i = 0; i < sz; ++i)
165                 smb_hc_read(hc, ACPI_SMB_DATA + i, &data[i]);
166       end:
167         mutex_unlock(&hc->lock);
168         return ret;
169 }
170
171 int acpi_smbus_read(struct acpi_smb_hc *hc, u8 protocol, u8 address,
172                     u8 command, u8 *data)
173 {
174         return acpi_smbus_transaction(hc, protocol, address, command, data, 0);
175 }
176
177 EXPORT_SYMBOL_GPL(acpi_smbus_read);
178
179 int acpi_smbus_write(struct acpi_smb_hc *hc, u8 protocol, u8 address,
180                      u8 command, u8 *data, u8 length)
181 {
182         return acpi_smbus_transaction(hc, protocol, address, command, data, length);
183 }
184
185 EXPORT_SYMBOL_GPL(acpi_smbus_write);
186
187 int acpi_smbus_register_callback(struct acpi_smb_hc *hc,
188                                  smbus_alarm_callback callback, void *context)
189 {
190         mutex_lock(&hc->lock);
191         hc->callback = callback;
192         hc->context = context;
193         mutex_unlock(&hc->lock);
194         return 0;
195 }
196
197 EXPORT_SYMBOL_GPL(acpi_smbus_register_callback);
198
199 int acpi_smbus_unregister_callback(struct acpi_smb_hc *hc)
200 {
201         mutex_lock(&hc->lock);
202         hc->callback = NULL;
203         hc->context = NULL;
204         mutex_unlock(&hc->lock);
205         return 0;
206 }
207
208 EXPORT_SYMBOL_GPL(acpi_smbus_unregister_callback);
209
210 static inline void acpi_smbus_callback(void *context)
211 {
212         struct acpi_smb_hc *hc = context;
213         if (hc->callback)
214                 hc->callback(hc->context);
215 }
216
217 static int smbus_alarm(void *context)
218 {
219         struct acpi_smb_hc *hc = context;
220         union acpi_smb_status status;
221         u8 address;
222         if (smb_hc_read(hc, ACPI_SMB_STATUS, &status.raw))
223                 return 0;
224         /* Check if it is only a completion notify */
225         if (status.fields.done)
226                 wake_up(&hc->wait);
227         if (!status.fields.alarm)
228                 return 0;
229         mutex_lock(&hc->lock);
230         smb_hc_read(hc, ACPI_SMB_ALARM_ADDRESS, &address);
231         status.fields.alarm = 0;
232         smb_hc_write(hc, ACPI_SMB_STATUS, status.raw);
233         /* We are only interested in events coming from known devices */
234         switch (address >> 1) {
235                 case ACPI_SBS_CHARGER:
236                 case ACPI_SBS_MANAGER:
237                 case ACPI_SBS_BATTERY:
238                         acpi_os_execute(OSL_GPE_HANDLER,
239                                         acpi_smbus_callback, hc);
240                 default:;
241         }
242         mutex_unlock(&hc->lock);
243         return 0;
244 }
245
246 typedef int (*acpi_ec_query_func) (void *data);
247
248 extern int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
249                               acpi_handle handle, acpi_ec_query_func func,
250                               void *data);
251
252 static int acpi_smbus_hc_add(struct acpi_device *device)
253 {
254         int status;
255         unsigned long val;
256         struct acpi_smb_hc *hc;
257
258         if (!device)
259                 return -EINVAL;
260
261         status = acpi_evaluate_integer(device->handle, "_EC", NULL, &val);
262         if (ACPI_FAILURE(status)) {
263                 printk(KERN_ERR PREFIX "error obtaining _EC.\n");
264                 return -EIO;
265         }
266
267         strcpy(acpi_device_name(device), ACPI_SMB_HC_DEVICE_NAME);
268         strcpy(acpi_device_class(device), ACPI_SMB_HC_CLASS);
269
270         hc = kzalloc(sizeof(struct acpi_smb_hc), GFP_KERNEL);
271         if (!hc)
272                 return -ENOMEM;
273         mutex_init(&hc->lock);
274         init_waitqueue_head(&hc->wait);
275
276         hc->ec = acpi_driver_data(device->parent);
277         hc->offset = (val >> 8) & 0xff;
278         hc->query_bit = val & 0xff;
279         acpi_driver_data(device) = hc;
280
281         acpi_ec_add_query_handler(hc->ec, hc->query_bit, NULL, smbus_alarm, hc);
282         printk(KERN_INFO PREFIX "SBS HC: EC = 0x%p, offset = 0x%0x, query_bit = 0x%0x\n",
283                 hc->ec, hc->offset, hc->query_bit);
284
285         return 0;
286 }
287
288 extern void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit);
289
290 static int acpi_smbus_hc_remove(struct acpi_device *device, int type)
291 {
292         struct acpi_smb_hc *hc;
293
294         if (!device)
295                 return -EINVAL;
296
297         hc = acpi_driver_data(device);
298         acpi_ec_remove_query_handler(hc->ec, hc->query_bit);
299         kfree(hc);
300         acpi_driver_data(device) = NULL;
301         return 0;
302 }
303
304 static int __init acpi_smb_hc_init(void)
305 {
306         int result;
307
308         result = acpi_bus_register_driver(&acpi_smb_hc_driver);
309         if (result < 0)
310                 return -ENODEV;
311         return 0;
312 }
313
314 static void __exit acpi_smb_hc_exit(void)
315 {
316         acpi_bus_unregister_driver(&acpi_smb_hc_driver);
317 }
318
319 module_init(acpi_smb_hc_init);
320 module_exit(acpi_smb_hc_exit);
321
322 MODULE_LICENSE("GPL");
323 MODULE_AUTHOR("Alexey Starikovskiy");
324 MODULE_DESCRIPTION("ACPI SMBus HC driver");