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11#include <acpi/acpi_bus.h>
12#include <acpi/acpi_drivers.h>
13#include <linux/wait.h>
14#include <linux/slab.h>
15#include <linux/delay.h>
16#include <linux/interrupt.h>
17#include "sbshc.h"
18
19#define PREFIX "ACPI: "
20
21#define ACPI_SMB_HC_CLASS "smbus_host_ctl"
22#define ACPI_SMB_HC_DEVICE_NAME "ACPI SMBus HC"
23
24struct acpi_smb_hc {
25 struct acpi_ec *ec;
26 struct mutex lock;
27 wait_queue_head_t wait;
28 u8 offset;
29 u8 query_bit;
30 smbus_alarm_callback callback;
31 void *context;
32};
33
34static int acpi_smbus_hc_add(struct acpi_device *device);
35static int acpi_smbus_hc_remove(struct acpi_device *device, int type);
36
37static const struct acpi_device_id sbs_device_ids[] = {
38 {"ACPI0001", 0},
39 {"ACPI0005", 0},
40 {"", 0},
41};
42
43MODULE_DEVICE_TABLE(acpi, sbs_device_ids);
44
45static struct acpi_driver acpi_smb_hc_driver = {
46 .name = "smbus_hc",
47 .class = ACPI_SMB_HC_CLASS,
48 .ids = sbs_device_ids,
49 .ops = {
50 .add = acpi_smbus_hc_add,
51 .remove = acpi_smbus_hc_remove,
52 },
53};
54
55union acpi_smb_status {
56 u8 raw;
57 struct {
58 u8 status:5;
59 u8 reserved:1;
60 u8 alarm:1;
61 u8 done:1;
62 } fields;
63};
64
65enum acpi_smb_status_codes {
66 SMBUS_OK = 0,
67 SMBUS_UNKNOWN_FAILURE = 0x07,
68 SMBUS_DEVICE_ADDRESS_NACK = 0x10,
69 SMBUS_DEVICE_ERROR = 0x11,
70 SMBUS_DEVICE_COMMAND_ACCESS_DENIED = 0x12,
71 SMBUS_UNKNOWN_ERROR = 0x13,
72 SMBUS_DEVICE_ACCESS_DENIED = 0x17,
73 SMBUS_TIMEOUT = 0x18,
74 SMBUS_HOST_UNSUPPORTED_PROTOCOL = 0x19,
75 SMBUS_BUSY = 0x1a,
76 SMBUS_PEC_ERROR = 0x1f,
77};
78
79enum acpi_smb_offset {
80 ACPI_SMB_PROTOCOL = 0,
81 ACPI_SMB_STATUS = 1,
82 ACPI_SMB_ADDRESS = 2,
83 ACPI_SMB_COMMAND = 3,
84 ACPI_SMB_DATA = 4,
85 ACPI_SMB_BLOCK_COUNT = 0x24,
86 ACPI_SMB_ALARM_ADDRESS = 0x25,
87 ACPI_SMB_ALARM_DATA = 0x26,
88};
89
90static inline int smb_hc_read(struct acpi_smb_hc *hc, u8 address, u8 *data)
91{
92 return ec_read(hc->offset + address, data);
93}
94
95static inline int smb_hc_write(struct acpi_smb_hc *hc, u8 address, u8 data)
96{
97 return ec_write(hc->offset + address, data);
98}
99
100static inline int smb_check_done(struct acpi_smb_hc *hc)
101{
102 union acpi_smb_status status = {.raw = 0};
103 smb_hc_read(hc, ACPI_SMB_STATUS, &status.raw);
104 return status.fields.done && (status.fields.status == SMBUS_OK);
105}
106
107static int wait_transaction_complete(struct acpi_smb_hc *hc, int timeout)
108{
109 if (wait_event_timeout(hc->wait, smb_check_done(hc),
110 msecs_to_jiffies(timeout)))
111 return 0;
112
113
114
115
116
117 if (smb_check_done(hc))
118 return 0;
119 else
120 return -ETIME;
121}
122
123static int acpi_smbus_transaction(struct acpi_smb_hc *hc, u8 protocol,
124 u8 address, u8 command, u8 *data, u8 length)
125{
126 int ret = -EFAULT, i;
127 u8 temp, sz = 0;
128
129 if (!hc) {
130 printk(KERN_ERR PREFIX "host controller is not configured\n");
131 return ret;
132 }
133
134 mutex_lock(&hc->lock);
135 if (smb_hc_read(hc, ACPI_SMB_PROTOCOL, &temp))
136 goto end;
137 if (temp) {
138 ret = -EBUSY;
139 goto end;
140 }
141 smb_hc_write(hc, ACPI_SMB_COMMAND, command);
142 if (!(protocol & 0x01)) {
143 smb_hc_write(hc, ACPI_SMB_BLOCK_COUNT, length);
144 for (i = 0; i < length; ++i)
145 smb_hc_write(hc, ACPI_SMB_DATA + i, data[i]);
146 }
147 smb_hc_write(hc, ACPI_SMB_ADDRESS, address << 1);
148 smb_hc_write(hc, ACPI_SMB_PROTOCOL, protocol);
149
150
151
152
153 ret = wait_transaction_complete(hc, 1000);
154 if (ret || !(protocol & 0x01))
155 goto end;
156 switch (protocol) {
157 case SMBUS_RECEIVE_BYTE:
158 case SMBUS_READ_BYTE:
159 sz = 1;
160 break;
161 case SMBUS_READ_WORD:
162 sz = 2;
163 break;
164 case SMBUS_READ_BLOCK:
165 if (smb_hc_read(hc, ACPI_SMB_BLOCK_COUNT, &sz)) {
166 ret = -EFAULT;
167 goto end;
168 }
169 sz &= 0x1f;
170 break;
171 }
172 for (i = 0; i < sz; ++i)
173 smb_hc_read(hc, ACPI_SMB_DATA + i, &data[i]);
174 end:
175 mutex_unlock(&hc->lock);
176 return ret;
177}
178
179int acpi_smbus_read(struct acpi_smb_hc *hc, u8 protocol, u8 address,
180 u8 command, u8 *data)
181{
182 return acpi_smbus_transaction(hc, protocol, address, command, data, 0);
183}
184
185EXPORT_SYMBOL_GPL(acpi_smbus_read);
186
187int acpi_smbus_write(struct acpi_smb_hc *hc, u8 protocol, u8 address,
188 u8 command, u8 *data, u8 length)
189{
190 return acpi_smbus_transaction(hc, protocol, address, command, data, length);
191}
192
193EXPORT_SYMBOL_GPL(acpi_smbus_write);
194
195int acpi_smbus_register_callback(struct acpi_smb_hc *hc,
196 smbus_alarm_callback callback, void *context)
197{
198 mutex_lock(&hc->lock);
199 hc->callback = callback;
200 hc->context = context;
201 mutex_unlock(&hc->lock);
202 return 0;
203}
204
205EXPORT_SYMBOL_GPL(acpi_smbus_register_callback);
206
207int acpi_smbus_unregister_callback(struct acpi_smb_hc *hc)
208{
209 mutex_lock(&hc->lock);
210 hc->callback = NULL;
211 hc->context = NULL;
212 mutex_unlock(&hc->lock);
213 return 0;
214}
215
216EXPORT_SYMBOL_GPL(acpi_smbus_unregister_callback);
217
218static inline void acpi_smbus_callback(void *context)
219{
220 struct acpi_smb_hc *hc = context;
221 if (hc->callback)
222 hc->callback(hc->context);
223}
224
225static int smbus_alarm(void *context)
226{
227 struct acpi_smb_hc *hc = context;
228 union acpi_smb_status status;
229 u8 address;
230 if (smb_hc_read(hc, ACPI_SMB_STATUS, &status.raw))
231 return 0;
232
233 if (status.fields.done)
234 wake_up(&hc->wait);
235 if (!status.fields.alarm)
236 return 0;
237 mutex_lock(&hc->lock);
238 smb_hc_read(hc, ACPI_SMB_ALARM_ADDRESS, &address);
239 status.fields.alarm = 0;
240 smb_hc_write(hc, ACPI_SMB_STATUS, status.raw);
241
242 switch (address >> 1) {
243 case ACPI_SBS_CHARGER:
244 case ACPI_SBS_MANAGER:
245 case ACPI_SBS_BATTERY:
246 acpi_os_execute(OSL_NOTIFY_HANDLER,
247 acpi_smbus_callback, hc);
248 default:;
249 }
250 mutex_unlock(&hc->lock);
251 return 0;
252}
253
254typedef int (*acpi_ec_query_func) (void *data);
255
256extern int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
257 acpi_handle handle, acpi_ec_query_func func,
258 void *data);
259
260static int acpi_smbus_hc_add(struct acpi_device *device)
261{
262 int status;
263 unsigned long long val;
264 struct acpi_smb_hc *hc;
265
266 if (!device)
267 return -EINVAL;
268
269 status = acpi_evaluate_integer(device->handle, "_EC", NULL, &val);
270 if (ACPI_FAILURE(status)) {
271 printk(KERN_ERR PREFIX "error obtaining _EC.\n");
272 return -EIO;
273 }
274
275 strcpy(acpi_device_name(device), ACPI_SMB_HC_DEVICE_NAME);
276 strcpy(acpi_device_class(device), ACPI_SMB_HC_CLASS);
277
278 hc = kzalloc(sizeof(struct acpi_smb_hc), GFP_KERNEL);
279 if (!hc)
280 return -ENOMEM;
281 mutex_init(&hc->lock);
282 init_waitqueue_head(&hc->wait);
283
284 hc->ec = acpi_driver_data(device->parent);
285 hc->offset = (val >> 8) & 0xff;
286 hc->query_bit = val & 0xff;
287 device->driver_data = hc;
288
289 acpi_ec_add_query_handler(hc->ec, hc->query_bit, NULL, smbus_alarm, hc);
290 printk(KERN_INFO PREFIX "SBS HC: EC = 0x%p, offset = 0x%0x, query_bit = 0x%0x\n",
291 hc->ec, hc->offset, hc->query_bit);
292
293 return 0;
294}
295
296extern void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit);
297
298static int acpi_smbus_hc_remove(struct acpi_device *device, int type)
299{
300 struct acpi_smb_hc *hc;
301
302 if (!device)
303 return -EINVAL;
304
305 hc = acpi_driver_data(device);
306 acpi_ec_remove_query_handler(hc->ec, hc->query_bit);
307 kfree(hc);
308 device->driver_data = NULL;
309 return 0;
310}
311
312static int __init acpi_smb_hc_init(void)
313{
314 int result;
315
316 result = acpi_bus_register_driver(&acpi_smb_hc_driver);
317 if (result < 0)
318 return -ENODEV;
319 return 0;
320}
321
322static void __exit acpi_smb_hc_exit(void)
323{
324 acpi_bus_unregister_driver(&acpi_smb_hc_driver);
325}
326
327module_init(acpi_smb_hc_init);
328module_exit(acpi_smb_hc_exit);
329
330MODULE_LICENSE("GPL");
331MODULE_AUTHOR("Alexey Starikovskiy");
332MODULE_DESCRIPTION("ACPI SMBus HC driver");
333
