ACPI: SBS: Split host controller (ACPI0001) from SBS driver (ACPI0002)
[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 int acpi_smbus_transaction(struct acpi_smb_hc *hc, u8 protocol, u8 address,
115                     u8 command, u8 *data, u8 length)
116 {
117         int ret = -EFAULT, i;
118         u8 temp, sz = 0;
119
120         mutex_lock(&hc->lock);
121         if (smb_hc_read(hc, ACPI_SMB_PROTOCOL, &temp))
122                 goto end;
123         if (temp) {
124                 ret = -EBUSY;
125                 goto end;
126         }
127         smb_hc_write(hc, ACPI_SMB_COMMAND, command);
128         smb_hc_write(hc, ACPI_SMB_COMMAND, command);
129         if (!(protocol & 0x01)) {
130                 smb_hc_write(hc, ACPI_SMB_BLOCK_COUNT, length);
131                 for (i = 0; i < length; ++i)
132                         smb_hc_write(hc, ACPI_SMB_DATA + i, data[i]);
133         }
134         smb_hc_write(hc, ACPI_SMB_ADDRESS, address << 1);
135         smb_hc_write(hc, ACPI_SMB_PROTOCOL, protocol);
136         /*
137          * Wait for completion. Save the status code, data size,
138          * and data into the return package (if required by the protocol).
139          */
140         ret = wait_transaction_complete(hc, 1000);
141         if (ret || !(protocol & 0x01))
142                 goto end;
143         switch (protocol) {
144         case SMBUS_RECEIVE_BYTE:
145         case SMBUS_READ_BYTE:
146                 sz = 1;
147                 break;
148         case SMBUS_READ_WORD:
149                 sz = 2;
150                 break;
151         case SMBUS_READ_BLOCK:
152                 if (smb_hc_read(hc, ACPI_SMB_BLOCK_COUNT, &sz)) {
153                         ret = -EFAULT;
154                         goto end;
155                 }
156                 sz &= 0x1f;
157                 break;
158         }
159         for (i = 0; i < sz; ++i)
160                 smb_hc_read(hc, ACPI_SMB_DATA + i, &data[i]);
161       end:
162         mutex_unlock(&hc->lock);
163         return ret;
164 }
165
166 int acpi_smbus_read(struct acpi_smb_hc *hc, u8 protocol, u8 address,
167                     u8 command, u8 *data)
168 {
169         return acpi_smbus_transaction(hc, protocol, address, command, data, 0);
170 }
171
172 EXPORT_SYMBOL_GPL(acpi_smbus_read);
173
174 int acpi_smbus_write(struct acpi_smb_hc *hc, u8 protocol, u8 address,
175                      u8 command, u8 *data, u8 length)
176 {
177         return acpi_smbus_transaction(hc, protocol, address, command, data, length);
178 }
179
180 EXPORT_SYMBOL_GPL(acpi_smbus_write);
181
182 int acpi_smbus_register_callback(struct acpi_smb_hc *hc,
183                                  smbus_alarm_callback callback, void *context)
184 {
185         mutex_lock(&hc->lock);
186         hc->callback = callback;
187         hc->context = context;
188         mutex_unlock(&hc->lock);
189         return 0;
190 }
191
192 EXPORT_SYMBOL_GPL(acpi_smbus_register_callback);
193
194 int acpi_smbus_unregister_callback(struct acpi_smb_hc *hc)
195 {
196         mutex_lock(&hc->lock);
197         hc->callback = NULL;
198         hc->context = NULL;
199         mutex_unlock(&hc->lock);
200         return 0;
201 }
202
203 EXPORT_SYMBOL_GPL(acpi_smbus_unregister_callback);
204
205 static void acpi_smbus_callback(void *context)
206 {
207         struct acpi_smb_hc *hc = context;
208
209         if (hc->callback)
210                 hc->callback(hc->context);
211 }
212
213 static int smbus_alarm(void *context)
214 {
215         struct acpi_smb_hc *hc = context;
216         union acpi_smb_status status;
217         if (smb_hc_read(hc, ACPI_SMB_STATUS, &status.raw))
218                 return 0;
219         /* Check if it is only a completion notify */
220         if (status.fields.done)
221                 wake_up(&hc->wait);
222         if (!status.fields.alarm)
223                 return 0;
224         mutex_lock(&hc->lock);
225         smb_hc_write(hc, ACPI_SMB_STATUS, status.raw);
226         if (hc->callback)
227                 acpi_os_execute(OSL_GPE_HANDLER, acpi_smbus_callback, hc);
228         mutex_unlock(&hc->lock);
229         return 0;
230 }
231
232 typedef int (*acpi_ec_query_func) (void *data);
233
234 extern int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
235                               acpi_handle handle, acpi_ec_query_func func,
236                               void *data);
237
238 static int acpi_smbus_hc_add(struct acpi_device *device)
239 {
240         int status;
241         unsigned long val;
242         struct acpi_smb_hc *hc;
243
244         if (!device)
245                 return -EINVAL;
246
247         status = acpi_evaluate_integer(device->handle, "_EC", NULL, &val);
248         if (ACPI_FAILURE(status)) {
249                 printk(KERN_ERR PREFIX "error obtaining _EC.\n");
250                 return -EIO;
251         }
252
253         strcpy(acpi_device_name(device), ACPI_SMB_HC_DEVICE_NAME);
254         strcpy(acpi_device_class(device), ACPI_SMB_HC_CLASS);
255
256         hc = kzalloc(sizeof(struct acpi_smb_hc), GFP_KERNEL);
257         if (!hc)
258                 return -ENOMEM;
259         mutex_init(&hc->lock);
260         init_waitqueue_head(&hc->wait);
261
262         hc->ec = acpi_driver_data(device->parent);
263         hc->offset = (val >> 8) & 0xff;
264         hc->query_bit = val & 0xff;
265         acpi_driver_data(device) = hc;
266
267         acpi_ec_add_query_handler(hc->ec, hc->query_bit, NULL, smbus_alarm, hc);
268         printk(KERN_INFO PREFIX "SBS HC: EC = 0x%p, offset = 0x%0x, query_bit = 0x%0x\n",
269                 hc->ec, hc->offset, hc->query_bit);
270
271         return 0;
272 }
273
274 extern void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit);
275
276 static int acpi_smbus_hc_remove(struct acpi_device *device, int type)
277 {
278         struct acpi_smb_hc *hc;
279
280         if (!device)
281                 return -EINVAL;
282
283         hc = acpi_driver_data(device);
284         acpi_ec_remove_query_handler(hc->ec, hc->query_bit);
285         kfree(hc);
286         return 0;
287 }
288
289 static int __init acpi_smb_hc_init(void)
290 {
291         int result;
292
293         result = acpi_bus_register_driver(&acpi_smb_hc_driver);
294         if (result < 0)
295                 return -ENODEV;
296         return 0;
297 }
298
299 static void __exit acpi_smb_hc_exit(void)
300 {
301         acpi_bus_unregister_driver(&acpi_smb_hc_driver);
302 }
303
304 module_init(acpi_smb_hc_init);
305 module_exit(acpi_smb_hc_exit);
306
307 MODULE_LICENSE("GPL");
308 MODULE_AUTHOR("Alexey Starikovskiy");
309 MODULE_DESCRIPTION("ACPI SMBus HC driver");