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