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fuse: set i_nlink to sane value after mount
[linux-2.6/openmoko-kernel/knife-kernel.git] / drivers / i2c / busses / i2c-pasemi.c
blob58e32714afb5b881068c9ca096d8ec271a448cd7
1 /*
2 * Copyright (C) 2006-2007 PA Semi, Inc
3 *
4 * SMBus host driver for PA Semi PWRficient
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 version 2 as
8 * published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19
20 #include <linux/module.h>
21 #include <linux/pci.h>
22 #include <linux/kernel.h>
23 #include <linux/stddef.h>
24 #include <linux/sched.h>
25 #include <linux/i2c.h>
26 #include <linux/delay.h>
27 #include <asm/io.h>
28
29 static struct pci_driver pasemi_smb_driver;
30
31 struct pasemi_smbus {
32 struct pci_dev *dev;
33 struct i2c_adapter adapter;
34 unsigned long base;
35 int size;
36 };
37
38 /* Register offsets */
39 #define REG_MTXFIFO 0x00
40 #define REG_MRXFIFO 0x04
41 #define REG_SMSTA 0x14
42 #define REG_CTL 0x1c
43
44 /* Register defs */
45 #define MTXFIFO_READ 0x00000400
46 #define MTXFIFO_STOP 0x00000200
47 #define MTXFIFO_START 0x00000100
48 #define MTXFIFO_DATA_M 0x000000ff
49
50 #define MRXFIFO_EMPTY 0x00000100
51 #define MRXFIFO_DATA_M 0x000000ff
52
53 #define SMSTA_XEN 0x08000000
54
55 #define CTL_MRR 0x00000400
56 #define CTL_MTR 0x00000200
57 #define CTL_CLK_M 0x000000ff
58
59 #define CLK_100K_DIV 84
60 #define CLK_400K_DIV 21
61
62 static inline void reg_write(struct pasemi_smbus *smbus, int reg, int val)
63 {
64 dev_dbg(&smbus->dev->dev, "smbus write reg %lx val %08x\n",
65 smbus->base + reg, val);
66 outl(val, smbus->base + reg);
67 }
68
69 static inline int reg_read(struct pasemi_smbus *smbus, int reg)
70 {
71 int ret;
72 ret = inl(smbus->base + reg);
73 dev_dbg(&smbus->dev->dev, "smbus read reg %lx val %08x\n",
74 smbus->base + reg, ret);
75 return ret;
76 }
77
78 #define TXFIFO_WR(smbus, reg) reg_write((smbus), REG_MTXFIFO, (reg))
79 #define RXFIFO_RD(smbus) reg_read((smbus), REG_MRXFIFO)
80
81 static void pasemi_smb_clear(struct pasemi_smbus *smbus)
82 {
83 unsigned int status;
84
85 status = reg_read(smbus, REG_SMSTA);
86 reg_write(smbus, REG_SMSTA, status);
87 }
88
89 static unsigned int pasemi_smb_waitready(struct pasemi_smbus *smbus)
90 {
91 int timeout = 10;
92 unsigned int status;
93
94 status = reg_read(smbus, REG_SMSTA);
95
96 while (!(status & SMSTA_XEN) && timeout--) {
97 msleep(1);
98 status = reg_read(smbus, REG_SMSTA);
99 }
100
101 if (timeout < 0) {
102 dev_warn(&smbus->dev->dev, "Timeout, status 0x%08x\n", status);
103 reg_write(smbus, REG_SMSTA, status);
104 return -ETIME;
105 }
106
107 /* Clear XEN */
108 reg_write(smbus, REG_SMSTA, SMSTA_XEN);
109
110 return 0;
111 }
112
113 static int pasemi_i2c_xfer_msg(struct i2c_adapter *adapter,
114 struct i2c_msg *msg, int stop)
115 {
116 struct pasemi_smbus *smbus = adapter->algo_data;
117 int read, i, err;
118 u32 rd;
119
120 read = msg->flags & I2C_M_RD ? 1 : 0;
121
122 TXFIFO_WR(smbus, MTXFIFO_START | (msg->addr << 1) | read);
123
124 if (read) {
125 TXFIFO_WR(smbus, msg->len | MTXFIFO_READ |
126 (stop ? MTXFIFO_STOP : 0));
127
128 err = pasemi_smb_waitready(smbus);
129 if (err)
130 goto reset_out;
131
132 for (i = 0; i < msg->len; i++) {
133 rd = RXFIFO_RD(smbus);
134 if (rd & MRXFIFO_EMPTY) {
135 err = -ENODATA;
136 goto reset_out;
137 }
138 msg->buf[i] = rd & MRXFIFO_DATA_M;
139 }
140 } else {
141 for (i = 0; i < msg->len - 1; i++)
142 TXFIFO_WR(smbus, msg->buf[i]);
143
144 TXFIFO_WR(smbus, msg->buf[msg->len-1] |
145 (stop ? MTXFIFO_STOP : 0));
146 }
147
148 return 0;
149
150 reset_out:
151 reg_write(smbus, REG_CTL, (CTL_MTR | CTL_MRR |
152 (CLK_100K_DIV & CTL_CLK_M)));
153 return err;
154 }
155
156 static int pasemi_i2c_xfer(struct i2c_adapter *adapter,
157 struct i2c_msg *msgs, int num)
158 {
159 struct pasemi_smbus *smbus = adapter->algo_data;
160 int ret, i;
161
162 pasemi_smb_clear(smbus);
163
164 ret = 0;
165
166 for (i = 0; i < num && !ret; i++)
167 ret = pasemi_i2c_xfer_msg(adapter, &msgs[i], (i == (num - 1)));
168
169 return ret ? ret : num;
170 }
171
172 static int pasemi_smb_xfer(struct i2c_adapter *adapter,
173 u16 addr, unsigned short flags, char read_write, u8 command,
174 int size, union i2c_smbus_data *data)
175 {
176 struct pasemi_smbus *smbus = adapter->algo_data;
177 unsigned int rd;
178 int read_flag, err;
179 int len = 0, i;
180
181 /* All our ops take 8-bit shifted addresses */
182 addr <<= 1;
183 read_flag = read_write == I2C_SMBUS_READ;
184
185 pasemi_smb_clear(smbus);
186
187 switch (size) {
188 case I2C_SMBUS_QUICK:
189 TXFIFO_WR(smbus, addr | read_flag | MTXFIFO_START |
190 MTXFIFO_STOP);
191 break;
192 case I2C_SMBUS_BYTE:
193 TXFIFO_WR(smbus, addr | read_flag | MTXFIFO_START);
194 if (read_write)
195 TXFIFO_WR(smbus, 1 | MTXFIFO_STOP | MTXFIFO_READ);
196 else
197 TXFIFO_WR(smbus, MTXFIFO_STOP | command);
198 break;
199 case I2C_SMBUS_BYTE_DATA:
200 TXFIFO_WR(smbus, addr | MTXFIFO_START);
201 TXFIFO_WR(smbus, command);
202 if (read_write) {
203 TXFIFO_WR(smbus, addr | I2C_SMBUS_READ | MTXFIFO_START);
204 TXFIFO_WR(smbus, 1 | MTXFIFO_READ | MTXFIFO_STOP);
205 } else {
206 TXFIFO_WR(smbus, MTXFIFO_STOP | data->byte);
207 }
208 break;
209 case I2C_SMBUS_WORD_DATA:
210 TXFIFO_WR(smbus, addr | MTXFIFO_START);
211 TXFIFO_WR(smbus, command);
212 if (read_write) {
213 TXFIFO_WR(smbus, addr | I2C_SMBUS_READ | MTXFIFO_START);
214 TXFIFO_WR(smbus, 2 | MTXFIFO_READ | MTXFIFO_STOP);
215 } else {
216 TXFIFO_WR(smbus, data->word & MTXFIFO_DATA_M);
217 TXFIFO_WR(smbus, MTXFIFO_STOP | (data->word >> 8));
218 }
219 break;
220 case I2C_SMBUS_BLOCK_DATA:
221 TXFIFO_WR(smbus, addr | MTXFIFO_START);
222 TXFIFO_WR(smbus, command);
223 if (read_write) {
224 TXFIFO_WR(smbus, addr | I2C_SMBUS_READ | MTXFIFO_START);
225 TXFIFO_WR(smbus, 1 | MTXFIFO_READ);
226 rd = RXFIFO_RD(smbus);
227 len = min_t(u8, (rd & MRXFIFO_DATA_M),
228 I2C_SMBUS_BLOCK_MAX);
229 TXFIFO_WR(smbus, len | MTXFIFO_READ |
230 MTXFIFO_STOP);
231 } else {
232 len = min_t(u8, data->block[0], I2C_SMBUS_BLOCK_MAX);
233 TXFIFO_WR(smbus, len);
234 for (i = 1; i < len; i++)
235 TXFIFO_WR(smbus, data->block[i]);
236 TXFIFO_WR(smbus, data->block[len] | MTXFIFO_STOP);
237 }
238 break;
239 case I2C_SMBUS_PROC_CALL:
240 read_write = I2C_SMBUS_READ;
241 TXFIFO_WR(smbus, addr | MTXFIFO_START);
242 TXFIFO_WR(smbus, command);
243 TXFIFO_WR(smbus, data->word & MTXFIFO_DATA_M);
244 TXFIFO_WR(smbus, (data->word >> 8) & MTXFIFO_DATA_M);
245 TXFIFO_WR(smbus, addr | I2C_SMBUS_READ | MTXFIFO_START);
246 TXFIFO_WR(smbus, 2 | MTXFIFO_STOP | MTXFIFO_READ);
247 break;
248 case I2C_SMBUS_BLOCK_PROC_CALL:
249 len = min_t(u8, data->block[0], I2C_SMBUS_BLOCK_MAX - 1);
250 read_write = I2C_SMBUS_READ;
251 TXFIFO_WR(smbus, addr | MTXFIFO_START);
252 TXFIFO_WR(smbus, command);
253 TXFIFO_WR(smbus, len);
254 for (i = 1; i <= len; i++)
255 TXFIFO_WR(smbus, data->block[i]);
256 TXFIFO_WR(smbus, addr | I2C_SMBUS_READ);
257 TXFIFO_WR(smbus, MTXFIFO_READ | 1);
258 rd = RXFIFO_RD(smbus);
259 len = min_t(u8, (rd & MRXFIFO_DATA_M),
260 I2C_SMBUS_BLOCK_MAX - len);
261 TXFIFO_WR(smbus, len | MTXFIFO_READ | MTXFIFO_STOP);
262 break;
263
264 default:
265 dev_warn(&adapter->dev, "Unsupported transaction %d\n", size);
266 return -EINVAL;
267 }
268
269 err = pasemi_smb_waitready(smbus);
270 if (err)
271 goto reset_out;
272
273 if (read_write == I2C_SMBUS_WRITE)
274 return 0;
275
276 switch (size) {
277 case I2C_SMBUS_BYTE:
278 case I2C_SMBUS_BYTE_DATA:
279 rd = RXFIFO_RD(smbus);
280 if (rd & MRXFIFO_EMPTY) {
281 err = -ENODATA;
282 goto reset_out;
283 }
284 data->byte = rd & MRXFIFO_DATA_M;
285 break;
286 case I2C_SMBUS_WORD_DATA:
287 case I2C_SMBUS_PROC_CALL:
288 rd = RXFIFO_RD(smbus);
289 if (rd & MRXFIFO_EMPTY) {
290 err = -ENODATA;
291 goto reset_out;
292 }
293 data->word = rd & MRXFIFO_DATA_M;
294 rd = RXFIFO_RD(smbus);
295 if (rd & MRXFIFO_EMPTY) {
296 err = -ENODATA;
297 goto reset_out;
298 }
299 data->word |= (rd & MRXFIFO_DATA_M) << 8;
300 break;
301 case I2C_SMBUS_BLOCK_DATA:
302 case I2C_SMBUS_BLOCK_PROC_CALL:
303 data->block[0] = len;
304 for (i = 1; i <= len; i ++) {
305 rd = RXFIFO_RD(smbus);
306 if (rd & MRXFIFO_EMPTY) {
307 err = -ENODATA;
308 goto reset_out;
309 }
310 data->block[i] = rd & MRXFIFO_DATA_M;
311 }
312 break;
313 }
314
315 return 0;
316
317 reset_out:
318 reg_write(smbus, REG_CTL, (CTL_MTR | CTL_MRR |
319 (CLK_100K_DIV & CTL_CLK_M)));
320 return err;
321 }
322
323 static u32 pasemi_smb_func(struct i2c_adapter *adapter)
324 {
325 return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
326 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
327 I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_PROC_CALL |
328 I2C_FUNC_SMBUS_BLOCK_PROC_CALL | I2C_FUNC_I2C;
329 }
330
331 static const struct i2c_algorithm smbus_algorithm = {
332 .master_xfer = pasemi_i2c_xfer,
333 .smbus_xfer = pasemi_smb_xfer,
334 .functionality = pasemi_smb_func,
335 };
336
337 static int __devinit pasemi_smb_probe(struct pci_dev *dev,
338 const struct pci_device_id *id)
339 {
340 struct pasemi_smbus *smbus;
341 int error;
342
343 if (!(pci_resource_flags(dev, 0) & IORESOURCE_IO))
344 return -ENODEV;
345
346 smbus = kzalloc(sizeof(struct pasemi_smbus), GFP_KERNEL);
347 if (!smbus)
348 return -ENOMEM;
349
350 smbus->dev = dev;
351 smbus->base = pci_resource_start(dev, 0);
352 smbus->size = pci_resource_len(dev, 0);
353
354 if (!request_region(smbus->base, smbus->size,
355 pasemi_smb_driver.name)) {
356 error = -EBUSY;
357 goto out_kfree;
358 }
359
360 smbus->adapter.owner = THIS_MODULE;
361 snprintf(smbus->adapter.name, sizeof(smbus->adapter.name),
362 "PA Semi SMBus adapter at 0x%lx", smbus->base);
363 smbus->adapter.class = I2C_CLASS_HWMON;
364 smbus->adapter.algo = &smbus_algorithm;
365 smbus->adapter.algo_data = smbus;
366
367 /* set up the driverfs linkage to our parent device */
368 smbus->adapter.dev.parent = &dev->dev;
369
370 reg_write(smbus, REG_CTL, (CTL_MTR | CTL_MRR |
371 (CLK_100K_DIV & CTL_CLK_M)));
372
373 error = i2c_add_adapter(&smbus->adapter);
374 if (error)
375 goto out_release_region;
376
377 pci_set_drvdata(dev, smbus);
378
379 return 0;
380
381 out_release_region:
382 release_region(smbus->base, smbus->size);
383 out_kfree:
384 kfree(smbus);
385 return error;
386 }
387
388 static void __devexit pasemi_smb_remove(struct pci_dev *dev)
389 {
390 struct pasemi_smbus *smbus = pci_get_drvdata(dev);
391
392 i2c_del_adapter(&smbus->adapter);
393 release_region(smbus->base, smbus->size);
394 kfree(smbus);
395 }
396
397 static struct pci_device_id pasemi_smb_ids[] = {
398 { PCI_DEVICE(0x1959, 0xa003) },
399 { 0, }
400 };
401
402 MODULE_DEVICE_TABLE(pci, pasemi_smb_ids);
403
404 static struct pci_driver pasemi_smb_driver = {
405 .name = "i2c-pasemi",
406 .id_table = pasemi_smb_ids,
407 .probe = pasemi_smb_probe,
408 .remove = __devexit_p(pasemi_smb_remove),
409 };
410
411 static int __init pasemi_smb_init(void)
412 {
413 return pci_register_driver(&pasemi_smb_driver);
414 }
415
416 static void __exit pasemi_smb_exit(void)
417 {
418 pci_unregister_driver(&pasemi_smb_driver);
419 }
420
421 MODULE_LICENSE("GPL");
422 MODULE_AUTHOR ("Olof Johansson <olof@lixom.net>");
423 MODULE_DESCRIPTION("PA Semi PWRficient SMBus driver");
424
425 module_init(pasemi_smb_init);
426 module_exit(pasemi_smb_exit);
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