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