Linux 2.6.27.11
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / acpi / sbshc.c
bloba4e3767b8c64241c6bd1c11010f0c2001fd7e7c1
1 /*
2 * SMBus driver for ACPI Embedded Controller (v0.1)
4 * Copyright (c) 2007 Alexey Starikovskiy
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 */
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"
19 #define ACPI_SMB_HC_CLASS "smbus_host_controller"
20 #define ACPI_SMB_HC_DEVICE_NAME "ACPI SMBus HC"
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;
32 static int acpi_smbus_hc_add(struct acpi_device *device);
33 static int acpi_smbus_hc_remove(struct acpi_device *device, int type);
35 static const struct acpi_device_id sbs_device_ids[] = {
36 {"ACPI0001", 0},
37 {"ACPI0005", 0},
38 {"", 0},
41 MODULE_DEVICE_TABLE(acpi, sbs_device_ids);
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,
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;
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,
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 */
88 static inline int smb_hc_read(struct acpi_smb_hc *hc, u8 address, u8 *data)
90 return ec_read(hc->offset + address, data);
93 static inline int smb_hc_write(struct acpi_smb_hc *hc, u8 address, u8 data)
95 return ec_write(hc->offset + address, data);
98 static inline int smb_check_done(struct acpi_smb_hc *hc)
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);
105 static int wait_transaction_complete(struct acpi_smb_hc *hc, int timeout)
107 if (wait_event_timeout(hc->wait, smb_check_done(hc),
108 msecs_to_jiffies(timeout)))
109 return 0;
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.
115 if (smb_check_done(hc))
116 return 0;
117 else
118 return -ETIME;
121 static int acpi_smbus_transaction(struct acpi_smb_hc *hc, u8 protocol,
122 u8 address, u8 command, u8 *data, u8 length)
124 int ret = -EFAULT, i;
125 u8 temp, sz = 0;
127 if (!hc) {
128 printk(KERN_ERR PREFIX "host controller is not configured\n");
129 return ret;
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;
139 smb_hc_write(hc, ACPI_SMB_COMMAND, command);
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]);
145 smb_hc_write(hc, ACPI_SMB_ADDRESS, address << 1);
146 smb_hc_write(hc, ACPI_SMB_PROTOCOL, protocol);
148 * Wait for completion. Save the status code, data size,
149 * and data into the return package (if required by the protocol).
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;
167 sz &= 0x1f;
168 break;
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;
177 int acpi_smbus_read(struct acpi_smb_hc *hc, u8 protocol, u8 address,
178 u8 command, u8 *data)
180 return acpi_smbus_transaction(hc, protocol, address, command, data, 0);
183 EXPORT_SYMBOL_GPL(acpi_smbus_read);
185 int acpi_smbus_write(struct acpi_smb_hc *hc, u8 protocol, u8 address,
186 u8 command, u8 *data, u8 length)
188 return acpi_smbus_transaction(hc, protocol, address, command, data, length);
191 EXPORT_SYMBOL_GPL(acpi_smbus_write);
193 int acpi_smbus_register_callback(struct acpi_smb_hc *hc,
194 smbus_alarm_callback callback, void *context)
196 mutex_lock(&hc->lock);
197 hc->callback = callback;
198 hc->context = context;
199 mutex_unlock(&hc->lock);
200 return 0;
203 EXPORT_SYMBOL_GPL(acpi_smbus_register_callback);
205 int acpi_smbus_unregister_callback(struct acpi_smb_hc *hc)
207 mutex_lock(&hc->lock);
208 hc->callback = NULL;
209 hc->context = NULL;
210 mutex_unlock(&hc->lock);
211 return 0;
214 EXPORT_SYMBOL_GPL(acpi_smbus_unregister_callback);
216 static inline void acpi_smbus_callback(void *context)
218 struct acpi_smb_hc *hc = context;
219 if (hc->callback)
220 hc->callback(hc->context);
223 static int smbus_alarm(void *context)
225 struct acpi_smb_hc *hc = context;
226 union acpi_smb_status status;
227 u8 address;
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);
236 smb_hc_read(hc, ACPI_SMB_ALARM_ADDRESS, &address);
237 status.fields.alarm = 0;
238 smb_hc_write(hc, ACPI_SMB_STATUS, status.raw);
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:;
248 mutex_unlock(&hc->lock);
249 return 0;
252 typedef int (*acpi_ec_query_func) (void *data);
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);
258 static int acpi_smbus_hc_add(struct acpi_device *device)
260 int status;
261 unsigned long val;
262 struct acpi_smb_hc *hc;
264 if (!device)
265 return -EINVAL;
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;
273 strcpy(acpi_device_name(device), ACPI_SMB_HC_DEVICE_NAME);
274 strcpy(acpi_device_class(device), ACPI_SMB_HC_CLASS);
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);
282 hc->ec = acpi_driver_data(device->parent);
283 hc->offset = (val >> 8) & 0xff;
284 hc->query_bit = val & 0xff;
285 acpi_driver_data(device) = hc;
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);
291 return 0;
294 extern void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit);
296 static int acpi_smbus_hc_remove(struct acpi_device *device, int type)
298 struct acpi_smb_hc *hc;
300 if (!device)
301 return -EINVAL;
303 hc = acpi_driver_data(device);
304 acpi_ec_remove_query_handler(hc->ec, hc->query_bit);
305 kfree(hc);
306 acpi_driver_data(device) = NULL;
307 return 0;
310 static int __init acpi_smb_hc_init(void)
312 int result;
314 result = acpi_bus_register_driver(&acpi_smb_hc_driver);
315 if (result < 0)
316 return -ENODEV;
317 return 0;
320 static void __exit acpi_smb_hc_exit(void)
322 acpi_bus_unregister_driver(&acpi_smb_hc_driver);
325 module_init(acpi_smb_hc_init);
326 module_exit(acpi_smb_hc_exit);
328 MODULE_LICENSE("GPL");
329 MODULE_AUTHOR("Alexey Starikovskiy");
330 MODULE_DESCRIPTION("ACPI SMBus HC driver");