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Alexey Starikovskiy91087df2007-09-26 19:43:28 +04001/*
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>
Alexey Starikovskiy91087df2007-09-26 19:43:28 +040013#include <linux/wait.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090014#include <linux/slab.h>
Alexey Starikovskiy91087df2007-09-26 19:43:28 +040015#include <linux/delay.h>
Paul Gortmakercc4b8592011-07-01 14:30:49 -040016#include <linux/module.h>
Alexey Starikovskiy91087df2007-09-26 19:43:28 +040017#include <linux/interrupt.h>
18#include "sbshc.h"
19
Len Browna192a952009-07-28 16:45:54 -040020#define PREFIX "ACPI: "
21
Dan Carpenter97c227c2010-04-27 14:06:05 -070022#define ACPI_SMB_HC_CLASS "smbus_host_ctl"
Alexey Starikovskiy91087df2007-09-26 19:43:28 +040023#define ACPI_SMB_HC_DEVICE_NAME "ACPI SMBus HC"
24
25struct acpi_smb_hc {
26 struct acpi_ec *ec;
27 struct mutex lock;
28 wait_queue_head_t wait;
29 u8 offset;
30 u8 query_bit;
31 smbus_alarm_callback callback;
32 void *context;
33};
34
35static int acpi_smbus_hc_add(struct acpi_device *device);
36static int acpi_smbus_hc_remove(struct acpi_device *device, int type);
37
38static const struct acpi_device_id sbs_device_ids[] = {
39 {"ACPI0001", 0},
40 {"ACPI0005", 0},
41 {"", 0},
42};
43
44MODULE_DEVICE_TABLE(acpi, sbs_device_ids);
45
46static struct acpi_driver acpi_smb_hc_driver = {
47 .name = "smbus_hc",
48 .class = ACPI_SMB_HC_CLASS,
49 .ids = sbs_device_ids,
50 .ops = {
51 .add = acpi_smbus_hc_add,
52 .remove = acpi_smbus_hc_remove,
53 },
54};
55
56union acpi_smb_status {
57 u8 raw;
58 struct {
59 u8 status:5;
60 u8 reserved:1;
61 u8 alarm:1;
62 u8 done:1;
63 } fields;
64};
65
66enum acpi_smb_status_codes {
67 SMBUS_OK = 0,
68 SMBUS_UNKNOWN_FAILURE = 0x07,
69 SMBUS_DEVICE_ADDRESS_NACK = 0x10,
70 SMBUS_DEVICE_ERROR = 0x11,
71 SMBUS_DEVICE_COMMAND_ACCESS_DENIED = 0x12,
72 SMBUS_UNKNOWN_ERROR = 0x13,
73 SMBUS_DEVICE_ACCESS_DENIED = 0x17,
74 SMBUS_TIMEOUT = 0x18,
75 SMBUS_HOST_UNSUPPORTED_PROTOCOL = 0x19,
76 SMBUS_BUSY = 0x1a,
77 SMBUS_PEC_ERROR = 0x1f,
78};
79
80enum acpi_smb_offset {
81 ACPI_SMB_PROTOCOL = 0, /* protocol, PEC */
82 ACPI_SMB_STATUS = 1, /* status */
83 ACPI_SMB_ADDRESS = 2, /* address */
84 ACPI_SMB_COMMAND = 3, /* command */
85 ACPI_SMB_DATA = 4, /* 32 data registers */
86 ACPI_SMB_BLOCK_COUNT = 0x24, /* number of data bytes */
87 ACPI_SMB_ALARM_ADDRESS = 0x25, /* alarm address */
88 ACPI_SMB_ALARM_DATA = 0x26, /* 2 bytes alarm data */
89};
90
91static inline int smb_hc_read(struct acpi_smb_hc *hc, u8 address, u8 *data)
92{
93 return ec_read(hc->offset + address, data);
94}
95
96static inline int smb_hc_write(struct acpi_smb_hc *hc, u8 address, u8 data)
97{
98 return ec_write(hc->offset + address, data);
99}
100
101static inline int smb_check_done(struct acpi_smb_hc *hc)
102{
103 union acpi_smb_status status = {.raw = 0};
104 smb_hc_read(hc, ACPI_SMB_STATUS, &status.raw);
105 return status.fields.done && (status.fields.status == SMBUS_OK);
106}
107
108static int wait_transaction_complete(struct acpi_smb_hc *hc, int timeout)
109{
110 if (wait_event_timeout(hc->wait, smb_check_done(hc),
111 msecs_to_jiffies(timeout)))
112 return 0;
Zhao Yakui266feef2008-08-26 13:57:34 +0800113 /*
114 * After the timeout happens, OS will try to check the status of SMbus.
115 * If the status is what OS expected, it will be regarded as the bogus
116 * timeout.
117 */
118 if (smb_check_done(hc))
119 return 0;
Alexey Starikovskiy91087df2007-09-26 19:43:28 +0400120 else
121 return -ETIME;
122}
123
Adrian Bunke5685b92007-10-24 18:24:42 +0200124static int acpi_smbus_transaction(struct acpi_smb_hc *hc, u8 protocol,
125 u8 address, u8 command, u8 *data, u8 length)
Alexey Starikovskiy91087df2007-09-26 19:43:28 +0400126{
127 int ret = -EFAULT, i;
128 u8 temp, sz = 0;
129
Alexey Starikovskiybbafbec2008-02-09 03:22:13 -0500130 if (!hc) {
131 printk(KERN_ERR PREFIX "host controller is not configured\n");
132 return ret;
133 }
134
Alexey Starikovskiy91087df2007-09-26 19:43:28 +0400135 mutex_lock(&hc->lock);
136 if (smb_hc_read(hc, ACPI_SMB_PROTOCOL, &temp))
137 goto end;
138 if (temp) {
139 ret = -EBUSY;
140 goto end;
141 }
142 smb_hc_write(hc, ACPI_SMB_COMMAND, command);
Alexey Starikovskiy91087df2007-09-26 19:43:28 +0400143 if (!(protocol & 0x01)) {
144 smb_hc_write(hc, ACPI_SMB_BLOCK_COUNT, length);
145 for (i = 0; i < length; ++i)
146 smb_hc_write(hc, ACPI_SMB_DATA + i, data[i]);
147 }
148 smb_hc_write(hc, ACPI_SMB_ADDRESS, address << 1);
149 smb_hc_write(hc, ACPI_SMB_PROTOCOL, protocol);
150 /*
151 * Wait for completion. Save the status code, data size,
152 * and data into the return package (if required by the protocol).
153 */
154 ret = wait_transaction_complete(hc, 1000);
155 if (ret || !(protocol & 0x01))
156 goto end;
157 switch (protocol) {
158 case SMBUS_RECEIVE_BYTE:
159 case SMBUS_READ_BYTE:
160 sz = 1;
161 break;
162 case SMBUS_READ_WORD:
163 sz = 2;
164 break;
165 case SMBUS_READ_BLOCK:
166 if (smb_hc_read(hc, ACPI_SMB_BLOCK_COUNT, &sz)) {
167 ret = -EFAULT;
168 goto end;
169 }
170 sz &= 0x1f;
171 break;
172 }
173 for (i = 0; i < sz; ++i)
174 smb_hc_read(hc, ACPI_SMB_DATA + i, &data[i]);
175 end:
176 mutex_unlock(&hc->lock);
177 return ret;
178}
179
180int acpi_smbus_read(struct acpi_smb_hc *hc, u8 protocol, u8 address,
181 u8 command, u8 *data)
182{
183 return acpi_smbus_transaction(hc, protocol, address, command, data, 0);
184}
185
186EXPORT_SYMBOL_GPL(acpi_smbus_read);
187
188int acpi_smbus_write(struct acpi_smb_hc *hc, u8 protocol, u8 address,
189 u8 command, u8 *data, u8 length)
190{
191 return acpi_smbus_transaction(hc, protocol, address, command, data, length);
192}
193
194EXPORT_SYMBOL_GPL(acpi_smbus_write);
195
196int acpi_smbus_register_callback(struct acpi_smb_hc *hc,
197 smbus_alarm_callback callback, void *context)
198{
199 mutex_lock(&hc->lock);
200 hc->callback = callback;
201 hc->context = context;
202 mutex_unlock(&hc->lock);
203 return 0;
204}
205
206EXPORT_SYMBOL_GPL(acpi_smbus_register_callback);
207
208int acpi_smbus_unregister_callback(struct acpi_smb_hc *hc)
209{
210 mutex_lock(&hc->lock);
211 hc->callback = NULL;
212 hc->context = NULL;
213 mutex_unlock(&hc->lock);
214 return 0;
215}
216
217EXPORT_SYMBOL_GPL(acpi_smbus_unregister_callback);
218
Alexey Starikovskiyc2d00f22007-12-08 13:02:40 +0300219static inline void acpi_smbus_callback(void *context)
Alexey Starikovskiy91087df2007-09-26 19:43:28 +0400220{
221 struct acpi_smb_hc *hc = context;
Alexey Starikovskiy91087df2007-09-26 19:43:28 +0400222 if (hc->callback)
223 hc->callback(hc->context);
224}
225
226static int smbus_alarm(void *context)
227{
228 struct acpi_smb_hc *hc = context;
229 union acpi_smb_status status;
Alexey Starikovskiyc2d00f22007-12-08 13:02:40 +0300230 u8 address;
Alexey Starikovskiy91087df2007-09-26 19:43:28 +0400231 if (smb_hc_read(hc, ACPI_SMB_STATUS, &status.raw))
232 return 0;
233 /* Check if it is only a completion notify */
234 if (status.fields.done)
235 wake_up(&hc->wait);
236 if (!status.fields.alarm)
237 return 0;
238 mutex_lock(&hc->lock);
Alexey Starikovskiyc2d00f22007-12-08 13:02:40 +0300239 smb_hc_read(hc, ACPI_SMB_ALARM_ADDRESS, &address);
Alexey Starikovskiy09f1fb42007-12-08 13:02:33 +0300240 status.fields.alarm = 0;
Alexey Starikovskiy91087df2007-09-26 19:43:28 +0400241 smb_hc_write(hc, ACPI_SMB_STATUS, status.raw);
Alexey Starikovskiyc2d00f22007-12-08 13:02:40 +0300242 /* We are only interested in events coming from known devices */
243 switch (address >> 1) {
244 case ACPI_SBS_CHARGER:
245 case ACPI_SBS_MANAGER:
246 case ACPI_SBS_BATTERY:
Alexey Starikovskiyf5347862009-12-30 15:53:03 +0300247 acpi_os_execute(OSL_NOTIFY_HANDLER,
Alexey Starikovskiyc2d00f22007-12-08 13:02:40 +0300248 acpi_smbus_callback, hc);
249 default:;
250 }
Alexey Starikovskiy91087df2007-09-26 19:43:28 +0400251 mutex_unlock(&hc->lock);
252 return 0;
253}
254
255typedef int (*acpi_ec_query_func) (void *data);
256
257extern int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
258 acpi_handle handle, acpi_ec_query_func func,
259 void *data);
260
261static int acpi_smbus_hc_add(struct acpi_device *device)
262{
263 int status;
Matthew Wilcox27663c52008-10-10 02:22:59 -0400264 unsigned long long val;
Alexey Starikovskiy91087df2007-09-26 19:43:28 +0400265 struct acpi_smb_hc *hc;
266
267 if (!device)
268 return -EINVAL;
269
270 status = acpi_evaluate_integer(device->handle, "_EC", NULL, &val);
271 if (ACPI_FAILURE(status)) {
272 printk(KERN_ERR PREFIX "error obtaining _EC.\n");
273 return -EIO;
274 }
275
276 strcpy(acpi_device_name(device), ACPI_SMB_HC_DEVICE_NAME);
277 strcpy(acpi_device_class(device), ACPI_SMB_HC_CLASS);
278
279 hc = kzalloc(sizeof(struct acpi_smb_hc), GFP_KERNEL);
280 if (!hc)
281 return -ENOMEM;
282 mutex_init(&hc->lock);
283 init_waitqueue_head(&hc->wait);
284
285 hc->ec = acpi_driver_data(device->parent);
286 hc->offset = (val >> 8) & 0xff;
287 hc->query_bit = val & 0xff;
Pavel Machekdb89b4f2008-09-22 14:37:34 -0700288 device->driver_data = hc;
Alexey Starikovskiy91087df2007-09-26 19:43:28 +0400289
290 acpi_ec_add_query_handler(hc->ec, hc->query_bit, NULL, smbus_alarm, hc);
291 printk(KERN_INFO PREFIX "SBS HC: EC = 0x%p, offset = 0x%0x, query_bit = 0x%0x\n",
292 hc->ec, hc->offset, hc->query_bit);
293
294 return 0;
295}
296
297extern void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit);
298
299static int acpi_smbus_hc_remove(struct acpi_device *device, int type)
300{
301 struct acpi_smb_hc *hc;
302
303 if (!device)
304 return -EINVAL;
305
306 hc = acpi_driver_data(device);
307 acpi_ec_remove_query_handler(hc->ec, hc->query_bit);
308 kfree(hc);
Pavel Machekdb89b4f2008-09-22 14:37:34 -0700309 device->driver_data = NULL;
Alexey Starikovskiy91087df2007-09-26 19:43:28 +0400310 return 0;
311}
312
313static int __init acpi_smb_hc_init(void)
314{
315 int result;
316
317 result = acpi_bus_register_driver(&acpi_smb_hc_driver);
318 if (result < 0)
319 return -ENODEV;
320 return 0;
321}
322
323static void __exit acpi_smb_hc_exit(void)
324{
325 acpi_bus_unregister_driver(&acpi_smb_hc_driver);
326}
327
328module_init(acpi_smb_hc_init);
329module_exit(acpi_smb_hc_exit);
330
331MODULE_LICENSE("GPL");
332MODULE_AUTHOR("Alexey Starikovskiy");
333MODULE_DESCRIPTION("ACPI SMBus HC driver");