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path: root/drivers/acpi/sbshc.c
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-rw-r--r--drivers/acpi/sbshc.c309
1 files changed, 309 insertions, 0 deletions
diff --git a/drivers/acpi/sbshc.c b/drivers/acpi/sbshc.c
new file mode 100644
index 000000000000..046d7c3ed356
--- /dev/null
+++ b/drivers/acpi/sbshc.c
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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 <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
22struct 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
32static int acpi_smbus_hc_add(struct acpi_device *device);
33static int acpi_smbus_hc_remove(struct acpi_device *device, int type);
34
35static const struct acpi_device_id sbs_device_ids[] = {
36 {"ACPI0001", 0},
37 {"ACPI0005", 0},
38 {"", 0},
39};
40
41MODULE_DEVICE_TABLE(acpi, sbs_device_ids);
42
43static 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
53union 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
63enum 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
77enum 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
88static 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
93static 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
98static 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
105static 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
114int 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
166int 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
172EXPORT_SYMBOL_GPL(acpi_smbus_read);
173
174int 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
180EXPORT_SYMBOL_GPL(acpi_smbus_write);
181
182int 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
192EXPORT_SYMBOL_GPL(acpi_smbus_register_callback);
193
194int 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
203EXPORT_SYMBOL_GPL(acpi_smbus_unregister_callback);
204
205static 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
213static 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
232typedef int (*acpi_ec_query_func) (void *data);
233
234extern 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
238static 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
274extern void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit);
275
276static 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
289static 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
299static void __exit acpi_smb_hc_exit(void)
300{
301 acpi_bus_unregister_driver(&acpi_smb_hc_driver);
302}
303
304module_init(acpi_smb_hc_init);
305module_exit(acpi_smb_hc_exit);
306
307MODULE_LICENSE("GPL");
308MODULE_AUTHOR("Alexey Starikovskiy");
309MODULE_DESCRIPTION("ACPI SMBus HC driver");