i2c: Add support for nested i2c bus locking
[linux-2.6] / drivers / acpi / i2c_ec.c
1 /*
2  * SMBus driver for ACPI Embedded Controller ($Revision: 1.3 $)
3  *
4  * Copyright (c) 2002, 2005 Ducrot Bruno
5  * Copyright (c) 2005 Rich Townsend (tiny hacks & tweaks)
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation version 2.
10  */
11
12 #include <linux/version.h>
13 #include <linux/module.h>
14 #include <linux/slab.h>
15 #include <linux/kernel.h>
16 #include <linux/stddef.h>
17 #include <linux/sched.h>
18 #include <linux/init.h>
19 #include <linux/i2c.h>
20 #include <linux/acpi.h>
21 #include <linux/delay.h>
22
23 #include "i2c_ec.h"
24
25 #define xudelay(t)      udelay(t)
26 #define xmsleep(t)      msleep(t)
27
28 #define ACPI_EC_HC_COMPONENT    0x00080000
29 #define ACPI_EC_HC_CLASS        "ec_hc_smbus"
30 #define ACPI_EC_HC_HID          "ACPI0001"
31 #define ACPI_EC_HC_DRIVER_NAME  "ACPI EC HC smbus driver"
32 #define ACPI_EC_HC_DEVICE_NAME  "EC HC smbus"
33
34 #define _COMPONENT              ACPI_EC_HC_COMPONENT
35
36 ACPI_MODULE_NAME("acpi_smbus")
37
38 static int acpi_ec_hc_add(struct acpi_device *device);
39 static int acpi_ec_hc_remove(struct acpi_device *device, int type);
40
41 static struct acpi_driver acpi_ec_hc_driver = {
42         .name = ACPI_EC_HC_DRIVER_NAME,
43         .class = ACPI_EC_HC_CLASS,
44         .ids = ACPI_EC_HC_HID,
45         .ops = {
46                 .add = acpi_ec_hc_add,
47                 .remove = acpi_ec_hc_remove,
48                 },
49 };
50
51 /* Various bit mask for EC_SC (R) */
52 #define OBF             0x01
53 #define IBF             0x02
54 #define CMD             0x08
55 #define BURST           0x10
56 #define SCI_EVT         0x20
57 #define SMI_EVT         0x40
58
59 /* Commands for EC_SC (W) */
60 #define RD_EC           0x80
61 #define WR_EC           0x81
62 #define BE_EC           0x82
63 #define BD_EC           0x83
64 #define QR_EC           0x84
65
66 /*
67  * ACPI 2.0 chapter 13 SMBus 2.0 EC register model
68  */
69
70 #define ACPI_EC_SMB_PRTCL       0x00    /* protocol, PEC */
71 #define ACPI_EC_SMB_STS         0x01    /* status */
72 #define ACPI_EC_SMB_ADDR        0x02    /* address */
73 #define ACPI_EC_SMB_CMD         0x03    /* command */
74 #define ACPI_EC_SMB_DATA        0x04    /* 32 data registers */
75 #define ACPI_EC_SMB_BCNT        0x24    /* number of data bytes */
76 #define ACPI_EC_SMB_ALRM_A      0x25    /* alarm address */
77 #define ACPI_EC_SMB_ALRM_D      0x26    /* 2 bytes alarm data */
78
79 #define ACPI_EC_SMB_STS_DONE    0x80
80 #define ACPI_EC_SMB_STS_ALRM    0x40
81 #define ACPI_EC_SMB_STS_RES     0x20
82 #define ACPI_EC_SMB_STS_STATUS  0x1f
83
84 #define ACPI_EC_SMB_STATUS_OK           0x00
85 #define ACPI_EC_SMB_STATUS_FAIL         0x07
86 #define ACPI_EC_SMB_STATUS_DNAK         0x10
87 #define ACPI_EC_SMB_STATUS_DERR         0x11
88 #define ACPI_EC_SMB_STATUS_CMD_DENY     0x12
89 #define ACPI_EC_SMB_STATUS_UNKNOWN      0x13
90 #define ACPI_EC_SMB_STATUS_ACC_DENY     0x17
91 #define ACPI_EC_SMB_STATUS_TIMEOUT      0x18
92 #define ACPI_EC_SMB_STATUS_NOTSUP       0x19
93 #define ACPI_EC_SMB_STATUS_BUSY         0x1A
94 #define ACPI_EC_SMB_STATUS_PEC          0x1F
95
96 #define ACPI_EC_SMB_PRTCL_WRITE                 0x00
97 #define ACPI_EC_SMB_PRTCL_READ                  0x01
98 #define ACPI_EC_SMB_PRTCL_QUICK                 0x02
99 #define ACPI_EC_SMB_PRTCL_BYTE                  0x04
100 #define ACPI_EC_SMB_PRTCL_BYTE_DATA             0x06
101 #define ACPI_EC_SMB_PRTCL_WORD_DATA             0x08
102 #define ACPI_EC_SMB_PRTCL_BLOCK_DATA            0x0a
103 #define ACPI_EC_SMB_PRTCL_PROC_CALL             0x0c
104 #define ACPI_EC_SMB_PRTCL_BLOCK_PROC_CALL       0x0d
105 #define ACPI_EC_SMB_PRTCL_I2C_BLOCK_DATA        0x4a
106 #define ACPI_EC_SMB_PRTCL_PEC                   0x80
107
108 /* Length of pre/post transaction sleep (msec) */
109 #define ACPI_EC_SMB_TRANSACTION_SLEEP           1
110 #define ACPI_EC_SMB_ACCESS_SLEEP1               1
111 #define ACPI_EC_SMB_ACCESS_SLEEP2               10
112
113 static int acpi_ec_smb_read(struct acpi_ec_smbus *smbus, u8 address, u8 * data)
114 {
115         u8 val;
116         int err;
117
118         err = ec_read(smbus->base + address, &val);
119         if (!err) {
120                 *data = val;
121         }
122         xmsleep(ACPI_EC_SMB_TRANSACTION_SLEEP);
123         return (err);
124 }
125
126 static int acpi_ec_smb_write(struct acpi_ec_smbus *smbus, u8 address, u8 data)
127 {
128         int err;
129
130         err = ec_write(smbus->base + address, data);
131         return (err);
132 }
133
134 static int
135 acpi_ec_smb_access(struct i2c_adapter *adap, u16 addr, unsigned short flags,
136                    char read_write, u8 command, int size,
137                    union i2c_smbus_data *data)
138 {
139         struct acpi_ec_smbus *smbus = adap->algo_data;
140         unsigned char protocol, len = 0, pec, temp[2] = { 0, 0 };
141         int i;
142
143         if (read_write == I2C_SMBUS_READ) {
144                 protocol = ACPI_EC_SMB_PRTCL_READ;
145         } else {
146                 protocol = ACPI_EC_SMB_PRTCL_WRITE;
147         }
148         pec = (flags & I2C_CLIENT_PEC) ? ACPI_EC_SMB_PRTCL_PEC : 0;
149
150         switch (size) {
151
152         case I2C_SMBUS_QUICK:
153                 protocol |= ACPI_EC_SMB_PRTCL_QUICK;
154                 read_write = I2C_SMBUS_WRITE;
155                 break;
156
157         case I2C_SMBUS_BYTE:
158                 if (read_write == I2C_SMBUS_WRITE) {
159                         acpi_ec_smb_write(smbus, ACPI_EC_SMB_DATA, data->byte);
160                 }
161                 protocol |= ACPI_EC_SMB_PRTCL_BYTE;
162                 break;
163
164         case I2C_SMBUS_BYTE_DATA:
165                 acpi_ec_smb_write(smbus, ACPI_EC_SMB_CMD, command);
166                 if (read_write == I2C_SMBUS_WRITE) {
167                         acpi_ec_smb_write(smbus, ACPI_EC_SMB_DATA, data->byte);
168                 }
169                 protocol |= ACPI_EC_SMB_PRTCL_BYTE_DATA;
170                 break;
171
172         case I2C_SMBUS_WORD_DATA:
173                 acpi_ec_smb_write(smbus, ACPI_EC_SMB_CMD, command);
174                 if (read_write == I2C_SMBUS_WRITE) {
175                         acpi_ec_smb_write(smbus, ACPI_EC_SMB_DATA, data->word);
176                         acpi_ec_smb_write(smbus, ACPI_EC_SMB_DATA + 1,
177                                           data->word >> 8);
178                 }
179                 protocol |= ACPI_EC_SMB_PRTCL_WORD_DATA | pec;
180                 break;
181
182         case I2C_SMBUS_BLOCK_DATA:
183                 acpi_ec_smb_write(smbus, ACPI_EC_SMB_CMD, command);
184                 if (read_write == I2C_SMBUS_WRITE) {
185                         len = min_t(u8, data->block[0], 32);
186                         acpi_ec_smb_write(smbus, ACPI_EC_SMB_BCNT, len);
187                         for (i = 0; i < len; i++)
188                                 acpi_ec_smb_write(smbus, ACPI_EC_SMB_DATA + i,
189                                                   data->block[i + 1]);
190                 }
191                 protocol |= ACPI_EC_SMB_PRTCL_BLOCK_DATA | pec;
192                 break;
193
194         case I2C_SMBUS_I2C_BLOCK_DATA:
195                 len = min_t(u8, data->block[0], 32);
196                 acpi_ec_smb_write(smbus, ACPI_EC_SMB_CMD, command);
197                 acpi_ec_smb_write(smbus, ACPI_EC_SMB_BCNT, len);
198                 if (read_write == I2C_SMBUS_WRITE) {
199                         for (i = 0; i < len; i++) {
200                                 acpi_ec_smb_write(smbus, ACPI_EC_SMB_DATA + i,
201                                                   data->block[i + 1]);
202                         }
203                 }
204                 protocol |= ACPI_EC_SMB_PRTCL_I2C_BLOCK_DATA;
205                 break;
206
207         case I2C_SMBUS_PROC_CALL:
208                 acpi_ec_smb_write(smbus, ACPI_EC_SMB_CMD, command);
209                 acpi_ec_smb_write(smbus, ACPI_EC_SMB_DATA, data->word);
210                 acpi_ec_smb_write(smbus, ACPI_EC_SMB_DATA + 1, data->word >> 8);
211                 protocol = ACPI_EC_SMB_PRTCL_PROC_CALL | pec;
212                 read_write = I2C_SMBUS_READ;
213                 break;
214
215         case I2C_SMBUS_BLOCK_PROC_CALL:
216                 protocol |= pec;
217                 len = min_t(u8, data->block[0], 31);
218                 acpi_ec_smb_write(smbus, ACPI_EC_SMB_CMD, command);
219                 acpi_ec_smb_write(smbus, ACPI_EC_SMB_BCNT, len);
220                 for (i = 0; i < len; i++)
221                         acpi_ec_smb_write(smbus, ACPI_EC_SMB_DATA + i,
222                                           data->block[i + 1]);
223                 protocol = ACPI_EC_SMB_PRTCL_BLOCK_PROC_CALL | pec;
224                 read_write = I2C_SMBUS_READ;
225                 break;
226
227         default:
228                 ACPI_DEBUG_PRINT((ACPI_DB_WARN, "EC SMBus adapter: "
229                                   "Unsupported transaction %d\n", size));
230                 return (-1);
231         }
232
233         acpi_ec_smb_write(smbus, ACPI_EC_SMB_ADDR, addr << 1);
234         acpi_ec_smb_write(smbus, ACPI_EC_SMB_PRTCL, protocol);
235
236         acpi_ec_smb_read(smbus, ACPI_EC_SMB_STS, temp + 0);
237
238         if (~temp[0] & ACPI_EC_SMB_STS_DONE) {
239                 xudelay(500);
240                 acpi_ec_smb_read(smbus, ACPI_EC_SMB_STS, temp + 0);
241         }
242         if (~temp[0] & ACPI_EC_SMB_STS_DONE) {
243                 xmsleep(ACPI_EC_SMB_ACCESS_SLEEP2);
244                 acpi_ec_smb_read(smbus, ACPI_EC_SMB_STS, temp + 0);
245         }
246         if ((~temp[0] & ACPI_EC_SMB_STS_DONE)
247             || (temp[0] & ACPI_EC_SMB_STS_STATUS)) {
248                 return (-1);
249         }
250
251         if (read_write == I2C_SMBUS_WRITE) {
252                 return (0);
253         }
254
255         switch (size) {
256
257         case I2C_SMBUS_BYTE:
258         case I2C_SMBUS_BYTE_DATA:
259                 acpi_ec_smb_read(smbus, ACPI_EC_SMB_DATA, &data->byte);
260                 break;
261
262         case I2C_SMBUS_WORD_DATA:
263         case I2C_SMBUS_PROC_CALL:
264                 acpi_ec_smb_read(smbus, ACPI_EC_SMB_DATA, temp + 0);
265                 acpi_ec_smb_read(smbus, ACPI_EC_SMB_DATA + 1, temp + 1);
266                 data->word = (temp[1] << 8) | temp[0];
267                 break;
268
269         case I2C_SMBUS_BLOCK_DATA:
270         case I2C_SMBUS_BLOCK_PROC_CALL:
271                 len = 0;
272                 acpi_ec_smb_read(smbus, ACPI_EC_SMB_BCNT, &len);
273                 len = min_t(u8, len, 32);
274         case I2C_SMBUS_I2C_BLOCK_DATA:
275                 for (i = 0; i < len; i++)
276                         acpi_ec_smb_read(smbus, ACPI_EC_SMB_DATA + i,
277                                          data->block + i + 1);
278                 data->block[0] = len;
279                 break;
280         }
281
282         return (0);
283 }
284
285 static u32 acpi_ec_smb_func(struct i2c_adapter *adapter)
286 {
287
288         return (I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
289                 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
290                 I2C_FUNC_SMBUS_BLOCK_DATA |
291                 I2C_FUNC_SMBUS_PROC_CALL |
292                 I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
293                 I2C_FUNC_SMBUS_I2C_BLOCK | I2C_FUNC_SMBUS_HWPEC_CALC);
294 }
295
296 static const struct i2c_algorithm acpi_ec_smbus_algorithm = {
297         .smbus_xfer = acpi_ec_smb_access,
298         .functionality = acpi_ec_smb_func,
299 };
300
301 static int acpi_ec_hc_add(struct acpi_device *device)
302 {
303         int status;
304         unsigned long val;
305         struct acpi_ec_hc *ec_hc;
306         struct acpi_ec_smbus *smbus;
307
308         if (!device) {
309                 return -EINVAL;
310         }
311
312         ec_hc = kmalloc(sizeof(struct acpi_ec_hc), GFP_KERNEL);
313         if (!ec_hc) {
314                 return -ENOMEM;
315         }
316         memset(ec_hc, 0, sizeof(struct acpi_ec_hc));
317
318         smbus = kmalloc(sizeof(struct acpi_ec_smbus), GFP_KERNEL);
319         if (!smbus) {
320                 kfree(ec_hc);
321                 return -ENOMEM;
322         }
323         memset(smbus, 0, sizeof(struct acpi_ec_smbus));
324
325         ec_hc->handle = device->handle;
326         strcpy(acpi_device_name(device), ACPI_EC_HC_DEVICE_NAME);
327         strcpy(acpi_device_class(device), ACPI_EC_HC_CLASS);
328         acpi_driver_data(device) = ec_hc;
329
330         status = acpi_evaluate_integer(ec_hc->handle, "_EC", NULL, &val);
331         if (ACPI_FAILURE(status)) {
332                 ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Error obtaining _EC\n"));
333                 kfree(ec_hc);
334                 kfree(smbus);
335                 return -EIO;
336         }
337
338         smbus->ec = acpi_driver_data(device->parent);
339         smbus->base = (val & 0xff00ull) >> 8;
340         smbus->alert = val & 0xffull;
341
342         smbus->adapter.owner = THIS_MODULE;
343         smbus->adapter.algo = &acpi_ec_smbus_algorithm;
344         smbus->adapter.algo_data = smbus;
345
346         if (i2c_add_adapter(&smbus->adapter)) {
347                 ACPI_DEBUG_PRINT((ACPI_DB_WARN,
348                                   "EC SMBus adapter: Failed to register adapter\n"));
349                 kfree(smbus);
350                 kfree(ec_hc);
351                 return -EIO;
352         }
353
354         ec_hc->smbus = smbus;
355
356         printk(KERN_INFO PREFIX "%s [%s]\n",
357                acpi_device_name(device), acpi_device_bid(device));
358
359         return AE_OK;
360 }
361
362 static int acpi_ec_hc_remove(struct acpi_device *device, int type)
363 {
364         struct acpi_ec_hc *ec_hc;
365
366         if (!device) {
367                 return -EINVAL;
368         }
369         ec_hc = acpi_driver_data(device);
370
371         i2c_del_adapter(&ec_hc->smbus->adapter);
372         kfree(ec_hc->smbus);
373         kfree(ec_hc);
374
375         return AE_OK;
376 }
377
378 static int __init acpi_ec_hc_init(void)
379 {
380         int result;
381
382         result = acpi_bus_register_driver(&acpi_ec_hc_driver);
383         if (result < 0) {
384                 return -ENODEV;
385         }
386         return 0;
387 }
388
389 static void __exit acpi_ec_hc_exit(void)
390 {
391         acpi_bus_unregister_driver(&acpi_ec_hc_driver);
392 }
393
394 struct acpi_ec_hc *acpi_get_ec_hc(struct acpi_device *device)
395 {
396         return ((struct acpi_ec_hc *)acpi_driver_data(device->parent));
397 }
398
399 EXPORT_SYMBOL(acpi_get_ec_hc);
400
401 module_init(acpi_ec_hc_init);
402 module_exit(acpi_ec_hc_exit);
403
404 MODULE_LICENSE("GPL");
405 MODULE_AUTHOR("Ducrot Bruno");
406 MODULE_DESCRIPTION("ACPI EC SMBus driver");