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This client driver allows you to use a GPIO pin as a source for PPS
[linux-2.6/next.git] / drivers / i2c / busses / i2c-pasemi.c
blob837b8c1aa02a494ef92899c46ccaf67cb709f9c1
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 <linux/slab.h>
28 #include <linux/io.h>
29
30 static struct pci_driver pasemi_smb_driver;
31
32 struct pasemi_smbus {
33 struct pci_dev *dev;
34 struct i2c_adapter adapter;
35 unsigned long base;
36 int size;
37 };
38
39 /* Register offsets */
40 #define REG_MTXFIFO 0x00
41 #define REG_MRXFIFO 0x04
42 #define REG_SMSTA 0x14
43 #define REG_CTL 0x1c
44
45 /* Register defs */
46 #define MTXFIFO_READ 0x00000400
47 #define MTXFIFO_STOP 0x00000200
48 #define MTXFIFO_START 0x00000100
49 #define MTXFIFO_DATA_M 0x000000ff
50
51 #define MRXFIFO_EMPTY 0x00000100
52 #define MRXFIFO_DATA_M 0x000000ff
53
54 #define SMSTA_XEN 0x08000000
55 #define SMSTA_MTN 0x00200000
56
57 #define CTL_MRR 0x00000400
58 #define CTL_MTR 0x00000200
59 #define CTL_CLK_M 0x000000ff
60
61 #define CLK_100K_DIV 84
62 #define CLK_400K_DIV 21
63
64 static inline void reg_write(struct pasemi_smbus *smbus, int reg, int val)
65 {
66 dev_dbg(&smbus->dev->dev, "smbus write reg %lx val %08x\n",
67 smbus->base + reg, val);
68 outl(val, smbus->base + reg);
69 }
70
71 static inline int reg_read(struct pasemi_smbus *smbus, int reg)
72 {
73 int ret;
74 ret = inl(smbus->base + reg);
75 dev_dbg(&smbus->dev->dev, "smbus read reg %lx val %08x\n",
76 smbus->base + reg, ret);
77 return ret;
78 }
79
80 #define TXFIFO_WR(smbus, reg) reg_write((smbus), REG_MTXFIFO, (reg))
81 #define RXFIFO_RD(smbus) reg_read((smbus), REG_MRXFIFO)
82
83 static void pasemi_smb_clear(struct pasemi_smbus *smbus)
84 {
85 unsigned int status;
86
87 status = reg_read(smbus, REG_SMSTA);
88 reg_write(smbus, REG_SMSTA, status);
89 }
90
91 static int pasemi_smb_waitready(struct pasemi_smbus *smbus)
92 {
93 int timeout = 10;
94 unsigned int status;
95
96 status = reg_read(smbus, REG_SMSTA);
97
98 while (!(status & SMSTA_XEN) && timeout--) {
99 msleep(1);
100 status = reg_read(smbus, REG_SMSTA);
101 }
102
103 /* Got NACK? */
104 if (status & SMSTA_MTN)
105 return -ENXIO;
106
107 if (timeout < 0) {
108 dev_warn(&smbus->dev->dev, "Timeout, status 0x%08x\n", status);
109 reg_write(smbus, REG_SMSTA, status);
110 return -ETIME;
111 }
112
113 /* Clear XEN */
114 reg_write(smbus, REG_SMSTA, SMSTA_XEN);
115
116 return 0;
117 }
118
119 static int pasemi_i2c_xfer_msg(struct i2c_adapter *adapter,
120 struct i2c_msg *msg, int stop)
121 {
122 struct pasemi_smbus *smbus = adapter->algo_data;
123 int read, i, err;
124 u32 rd;
125
126 read = msg->flags & I2C_M_RD ? 1 : 0;
127
128 TXFIFO_WR(smbus, MTXFIFO_START | (msg->addr << 1) | read);
129
130 if (read) {
131 TXFIFO_WR(smbus, msg->len | MTXFIFO_READ |
132 (stop ? MTXFIFO_STOP : 0));
133
134 err = pasemi_smb_waitready(smbus);
135 if (err)
136 goto reset_out;
137
138 for (i = 0; i < msg->len; i++) {
139 rd = RXFIFO_RD(smbus);
140 if (rd & MRXFIFO_EMPTY) {
141 err = -ENODATA;
142 goto reset_out;
143 }
144 msg->buf[i] = rd & MRXFIFO_DATA_M;
145 }
146 } else {
147 for (i = 0; i < msg->len - 1; i++)
148 TXFIFO_WR(smbus, msg->buf[i]);
149
150 TXFIFO_WR(smbus, msg->buf[msg->len-1] |
151 (stop ? MTXFIFO_STOP : 0));
152 }
153
154 return 0;
155
156 reset_out:
157 reg_write(smbus, REG_CTL, (CTL_MTR | CTL_MRR |
158 (CLK_100K_DIV & CTL_CLK_M)));
159 return err;
160 }
161
162 static int pasemi_i2c_xfer(struct i2c_adapter *adapter,
163 struct i2c_msg *msgs, int num)
164 {
165 struct pasemi_smbus *smbus = adapter->algo_data;
166 int ret, i;
167
168 pasemi_smb_clear(smbus);
169
170 ret = 0;
171
172 for (i = 0; i < num && !ret; i++)
173 ret = pasemi_i2c_xfer_msg(adapter, &msgs[i], (i == (num - 1)));
174
175 return ret ? ret : num;
176 }
177
178 static int pasemi_smb_xfer(struct i2c_adapter *adapter,
179 u16 addr, unsigned short flags, char read_write, u8 command,
180 int size, union i2c_smbus_data *data)
181 {
182 struct pasemi_smbus *smbus = adapter->algo_data;
183 unsigned int rd;
184 int read_flag, err;
185 int len = 0, i;
186
187 /* All our ops take 8-bit shifted addresses */
188 addr <<= 1;
189 read_flag = read_write == I2C_SMBUS_READ;
190
191 pasemi_smb_clear(smbus);
192
193 switch (size) {
194 case I2C_SMBUS_QUICK:
195 TXFIFO_WR(smbus, addr | read_flag | MTXFIFO_START |
196 MTXFIFO_STOP);
197 break;
198 case I2C_SMBUS_BYTE:
199 TXFIFO_WR(smbus, addr | read_flag | MTXFIFO_START);
200 if (read_write)
201 TXFIFO_WR(smbus, 1 | MTXFIFO_STOP | MTXFIFO_READ);
202 else
203 TXFIFO_WR(smbus, MTXFIFO_STOP | command);
204 break;
205 case I2C_SMBUS_BYTE_DATA:
206 TXFIFO_WR(smbus, addr | MTXFIFO_START);
207 TXFIFO_WR(smbus, command);
208 if (read_write) {
209 TXFIFO_WR(smbus, addr | I2C_SMBUS_READ | MTXFIFO_START);
210 TXFIFO_WR(smbus, 1 | MTXFIFO_READ | MTXFIFO_STOP);
211 } else {
212 TXFIFO_WR(smbus, MTXFIFO_STOP | data->byte);
213 }
214 break;
215 case I2C_SMBUS_WORD_DATA:
216 TXFIFO_WR(smbus, addr | MTXFIFO_START);
217 TXFIFO_WR(smbus, command);
218 if (read_write) {
219 TXFIFO_WR(smbus, addr | I2C_SMBUS_READ | MTXFIFO_START);
220 TXFIFO_WR(smbus, 2 | MTXFIFO_READ | MTXFIFO_STOP);
221 } else {
222 TXFIFO_WR(smbus, data->word & MTXFIFO_DATA_M);
223 TXFIFO_WR(smbus, MTXFIFO_STOP | (data->word >> 8));
224 }
225 break;
226 case I2C_SMBUS_BLOCK_DATA:
227 TXFIFO_WR(smbus, addr | MTXFIFO_START);
228 TXFIFO_WR(smbus, command);
229 if (read_write) {
230 TXFIFO_WR(smbus, addr | I2C_SMBUS_READ | MTXFIFO_START);
231 TXFIFO_WR(smbus, 1 | MTXFIFO_READ);
232 rd = RXFIFO_RD(smbus);
233 len = min_t(u8, (rd & MRXFIFO_DATA_M),
234 I2C_SMBUS_BLOCK_MAX);
235 TXFIFO_WR(smbus, len | MTXFIFO_READ |
236 MTXFIFO_STOP);
237 } else {
238 len = min_t(u8, data->block[0], I2C_SMBUS_BLOCK_MAX);
239 TXFIFO_WR(smbus, len);
240 for (i = 1; i < len; i++)
241 TXFIFO_WR(smbus, data->block[i]);
242 TXFIFO_WR(smbus, data->block[len] | MTXFIFO_STOP);
243 }
244 break;
245 case I2C_SMBUS_PROC_CALL:
246 read_write = I2C_SMBUS_READ;
247 TXFIFO_WR(smbus, addr | MTXFIFO_START);
248 TXFIFO_WR(smbus, command);
249 TXFIFO_WR(smbus, data->word & MTXFIFO_DATA_M);
250 TXFIFO_WR(smbus, (data->word >> 8) & MTXFIFO_DATA_M);
251 TXFIFO_WR(smbus, addr | I2C_SMBUS_READ | MTXFIFO_START);
252 TXFIFO_WR(smbus, 2 | MTXFIFO_STOP | MTXFIFO_READ);
253 break;
254 case I2C_SMBUS_BLOCK_PROC_CALL:
255 len = min_t(u8, data->block[0], I2C_SMBUS_BLOCK_MAX - 1);
256 read_write = I2C_SMBUS_READ;
257 TXFIFO_WR(smbus, addr | MTXFIFO_START);
258 TXFIFO_WR(smbus, command);
259 TXFIFO_WR(smbus, len);
260 for (i = 1; i <= len; i++)
261 TXFIFO_WR(smbus, data->block[i]);
262 TXFIFO_WR(smbus, addr | I2C_SMBUS_READ);
263 TXFIFO_WR(smbus, MTXFIFO_READ | 1);
264 rd = RXFIFO_RD(smbus);
265 len = min_t(u8, (rd & MRXFIFO_DATA_M),
266 I2C_SMBUS_BLOCK_MAX - len);
267 TXFIFO_WR(smbus, len | MTXFIFO_READ | MTXFIFO_STOP);
268 break;
269
270 default:
271 dev_warn(&adapter->dev, "Unsupported transaction %d\n", size);
272 return -EINVAL;
273 }
274
275 err = pasemi_smb_waitready(smbus);
276 if (err)
277 goto reset_out;
278
279 if (read_write == I2C_SMBUS_WRITE)
280 return 0;
281
282 switch (size) {
283 case I2C_SMBUS_BYTE:
284 case I2C_SMBUS_BYTE_DATA:
285 rd = RXFIFO_RD(smbus);
286 if (rd & MRXFIFO_EMPTY) {
287 err = -ENODATA;
288 goto reset_out;
289 }
290 data->byte = rd & MRXFIFO_DATA_M;
291 break;
292 case I2C_SMBUS_WORD_DATA:
293 case I2C_SMBUS_PROC_CALL:
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;
300 rd = RXFIFO_RD(smbus);
301 if (rd & MRXFIFO_EMPTY) {
302 err = -ENODATA;
303 goto reset_out;
304 }
305 data->word |= (rd & MRXFIFO_DATA_M) << 8;
306 break;
307 case I2C_SMBUS_BLOCK_DATA:
308 case I2C_SMBUS_BLOCK_PROC_CALL:
309 data->block[0] = len;
310 for (i = 1; i <= len; i ++) {
311 rd = RXFIFO_RD(smbus);
312 if (rd & MRXFIFO_EMPTY) {
313 err = -ENODATA;
314 goto reset_out;
315 }
316 data->block[i] = rd & MRXFIFO_DATA_M;
317 }
318 break;
319 }
320
321 return 0;
322
323 reset_out:
324 reg_write(smbus, REG_CTL, (CTL_MTR | CTL_MRR |
325 (CLK_100K_DIV & CTL_CLK_M)));
326 return err;
327 }
328
329 static u32 pasemi_smb_func(struct i2c_adapter *adapter)
330 {
331 return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
332 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
333 I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_PROC_CALL |
334 I2C_FUNC_SMBUS_BLOCK_PROC_CALL | I2C_FUNC_I2C;
335 }
336
337 static const struct i2c_algorithm smbus_algorithm = {
338 .master_xfer = pasemi_i2c_xfer,
339 .smbus_xfer = pasemi_smb_xfer,
340 .functionality = pasemi_smb_func,
341 };
342
343 static int __devinit pasemi_smb_probe(struct pci_dev *dev,
344 const struct pci_device_id *id)
345 {
346 struct pasemi_smbus *smbus;
347 int error;
348
349 if (!(pci_resource_flags(dev, 0) & IORESOURCE_IO))
350 return -ENODEV;
351
352 smbus = kzalloc(sizeof(struct pasemi_smbus), GFP_KERNEL);
353 if (!smbus)
354 return -ENOMEM;
355
356 smbus->dev = dev;
357 smbus->base = pci_resource_start(dev, 0);
358 smbus->size = pci_resource_len(dev, 0);
359
360 if (!request_region(smbus->base, smbus->size,
361 pasemi_smb_driver.name)) {
362 error = -EBUSY;
363 goto out_kfree;
364 }
365
366 smbus->adapter.owner = THIS_MODULE;
367 snprintf(smbus->adapter.name, sizeof(smbus->adapter.name),
368 "PA Semi SMBus adapter at 0x%lx", smbus->base);
369 smbus->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
370 smbus->adapter.algo = &smbus_algorithm;
371 smbus->adapter.algo_data = smbus;
372 smbus->adapter.nr = PCI_FUNC(dev->devfn);
373
374 /* set up the sysfs linkage to our parent device */
375 smbus->adapter.dev.parent = &dev->dev;
376
377 reg_write(smbus, REG_CTL, (CTL_MTR | CTL_MRR |
378 (CLK_100K_DIV & CTL_CLK_M)));
379
380 error = i2c_add_numbered_adapter(&smbus->adapter);
381 if (error)
382 goto out_release_region;
383
384 pci_set_drvdata(dev, smbus);
385
386 return 0;
387
388 out_release_region:
389 release_region(smbus->base, smbus->size);
390 out_kfree:
391 kfree(smbus);
392 return error;
393 }
394
395 static void __devexit pasemi_smb_remove(struct pci_dev *dev)
396 {
397 struct pasemi_smbus *smbus = pci_get_drvdata(dev);
398
399 i2c_del_adapter(&smbus->adapter);
400 release_region(smbus->base, smbus->size);
401 kfree(smbus);
402 }
403
404 static const struct pci_device_id pasemi_smb_ids[] = {
405 { PCI_DEVICE(0x1959, 0xa003) },
406 { 0, }
407 };
408
409 MODULE_DEVICE_TABLE(pci, pasemi_smb_ids);
410
411 static struct pci_driver pasemi_smb_driver = {
412 .name = "i2c-pasemi",
413 .id_table = pasemi_smb_ids,
414 .probe = pasemi_smb_probe,
415 .remove = __devexit_p(pasemi_smb_remove),
416 };
417
418 static int __init pasemi_smb_init(void)
419 {
420 return pci_register_driver(&pasemi_smb_driver);
421 }
422
423 static void __exit pasemi_smb_exit(void)
424 {
425 pci_unregister_driver(&pasemi_smb_driver);
426 }
427
428 MODULE_LICENSE("GPL");
429 MODULE_AUTHOR ("Olof Johansson <olof@lixom.net>");
430 MODULE_DESCRIPTION("PA Semi PWRficient SMBus driver");
431
432 module_init(pasemi_smb_init);
433 module_exit(pasemi_smb_exit);
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