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x86/xen: resume timer irqs early
[linux/fpc-iii.git] / drivers / i2c / busses / i2c-viperboard.c
blobc68450cd8d5f3bf24834c2261238b5e18af58877
1 /*
2 * Nano River Technologies viperboard i2c master driver
3 *
4 * (C) 2012 by Lemonage GmbH
5 * Author: Lars Poeschel <poeschel@lemonage.de>
6 * All rights reserved.
7 *
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the
10 * Free Software Foundation; either version 2 of the License, or (at your
11 * option) any later version.
12 *
13 */
14
15 #include <linux/kernel.h>
16 #include <linux/errno.h>
17 #include <linux/module.h>
18 #include <linux/slab.h>
19 #include <linux/types.h>
20 #include <linux/mutex.h>
21 #include <linux/platform_device.h>
22
23 #include <linux/usb.h>
24 #include <linux/i2c.h>
25
26 #include <linux/mfd/viperboard.h>
27
28 struct vprbrd_i2c {
29 struct i2c_adapter i2c;
30 u8 bus_freq_param;
31 };
32
33 /* i2c bus frequency module parameter */
34 static u8 i2c_bus_param;
35 static unsigned int i2c_bus_freq = 100;
36 module_param(i2c_bus_freq, int, 0);
37 MODULE_PARM_DESC(i2c_bus_freq,
38 "i2c bus frequency in khz (default is 100) valid values: 10, 100, 200, 400, 1000, 3000, 6000");
39
40 static int vprbrd_i2c_status(struct i2c_adapter *i2c,
41 struct vprbrd_i2c_status *status, bool prev_error)
42 {
43 u16 bytes_xfer;
44 int ret;
45 struct vprbrd *vb = (struct vprbrd *)i2c->algo_data;
46
47 /* check for protocol error */
48 bytes_xfer = sizeof(struct vprbrd_i2c_status);
49
50 ret = usb_control_msg(vb->usb_dev, usb_rcvctrlpipe(vb->usb_dev, 0),
51 VPRBRD_USB_REQUEST_I2C, VPRBRD_USB_TYPE_IN, 0x0000, 0x0000,
52 status, bytes_xfer, VPRBRD_USB_TIMEOUT_MS);
53
54 if (ret != bytes_xfer)
55 prev_error = true;
56
57 if (prev_error) {
58 dev_err(&i2c->dev, "failure in usb communication\n");
59 return -EREMOTEIO;
60 }
61
62 dev_dbg(&i2c->dev, " status = %d\n", status->status);
63 if (status->status != 0x00) {
64 dev_err(&i2c->dev, "failure: i2c protocol error\n");
65 return -EPROTO;
66 }
67 return 0;
68 }
69
70 static int vprbrd_i2c_receive(struct usb_device *usb_dev,
71 struct vprbrd_i2c_read_msg *rmsg, int bytes_xfer)
72 {
73 int ret, bytes_actual;
74 int error = 0;
75
76 /* send the read request */
77 ret = usb_bulk_msg(usb_dev,
78 usb_sndbulkpipe(usb_dev, VPRBRD_EP_OUT), rmsg,
79 sizeof(struct vprbrd_i2c_read_hdr), &bytes_actual,
80 VPRBRD_USB_TIMEOUT_MS);
81
82 if ((ret < 0)
83 || (bytes_actual != sizeof(struct vprbrd_i2c_read_hdr))) {
84 dev_err(&usb_dev->dev, "failure transmitting usb\n");
85 error = -EREMOTEIO;
86 }
87
88 /* read the actual data */
89 ret = usb_bulk_msg(usb_dev,
90 usb_rcvbulkpipe(usb_dev, VPRBRD_EP_IN), rmsg,
91 bytes_xfer, &bytes_actual, VPRBRD_USB_TIMEOUT_MS);
92
93 if ((ret < 0) || (bytes_xfer != bytes_actual)) {
94 dev_err(&usb_dev->dev, "failure receiving usb\n");
95 error = -EREMOTEIO;
96 }
97 return error;
98 }
99
100 static int vprbrd_i2c_addr(struct usb_device *usb_dev,
101 struct vprbrd_i2c_addr_msg *amsg)
102 {
103 int ret, bytes_actual;
104
105 ret = usb_bulk_msg(usb_dev,
106 usb_sndbulkpipe(usb_dev, VPRBRD_EP_OUT), amsg,
107 sizeof(struct vprbrd_i2c_addr_msg), &bytes_actual,
108 VPRBRD_USB_TIMEOUT_MS);
109
110 if ((ret < 0) ||
111 (sizeof(struct vprbrd_i2c_addr_msg) != bytes_actual)) {
112 dev_err(&usb_dev->dev, "failure transmitting usb\n");
113 return -EREMOTEIO;
114 }
115 return 0;
116 }
117
118 static int vprbrd_i2c_read(struct vprbrd *vb, struct i2c_msg *msg)
119 {
120 int ret;
121 u16 remain_len, bytes_xfer, len1, len2,
122 start = 0x0000;
123 struct vprbrd_i2c_read_msg *rmsg =
124 (struct vprbrd_i2c_read_msg *)vb->buf;
125
126 remain_len = msg->len;
127 rmsg->header.cmd = VPRBRD_I2C_CMD_READ;
128 while (remain_len > 0) {
129 rmsg->header.addr = cpu_to_le16(start + 0x4000);
130 if (remain_len <= 255) {
131 len1 = remain_len;
132 len2 = 0x00;
133 rmsg->header.len0 = remain_len;
134 rmsg->header.len1 = 0x00;
135 rmsg->header.len2 = 0x00;
136 rmsg->header.len3 = 0x00;
137 rmsg->header.len4 = 0x00;
138 rmsg->header.len5 = 0x00;
139 remain_len = 0;
140 } else if (remain_len <= 510) {
141 len1 = remain_len;
142 len2 = 0x00;
143 rmsg->header.len0 = remain_len - 255;
144 rmsg->header.len1 = 0xff;
145 rmsg->header.len2 = 0x00;
146 rmsg->header.len3 = 0x00;
147 rmsg->header.len4 = 0x00;
148 rmsg->header.len5 = 0x00;
149 remain_len = 0;
150 } else if (remain_len <= 512) {
151 len1 = remain_len;
152 len2 = 0x00;
153 rmsg->header.len0 = remain_len - 510;
154 rmsg->header.len1 = 0xff;
155 rmsg->header.len2 = 0xff;
156 rmsg->header.len3 = 0x00;
157 rmsg->header.len4 = 0x00;
158 rmsg->header.len5 = 0x00;
159 remain_len = 0;
160 } else if (remain_len <= 767) {
161 len1 = 512;
162 len2 = remain_len - 512;
163 rmsg->header.len0 = 0x02;
164 rmsg->header.len1 = 0xff;
165 rmsg->header.len2 = 0xff;
166 rmsg->header.len3 = remain_len - 512;
167 rmsg->header.len4 = 0x00;
168 rmsg->header.len5 = 0x00;
169 bytes_xfer = remain_len;
170 remain_len = 0;
171 } else if (remain_len <= 1022) {
172 len1 = 512;
173 len2 = remain_len - 512;
174 rmsg->header.len0 = 0x02;
175 rmsg->header.len1 = 0xff;
176 rmsg->header.len2 = 0xff;
177 rmsg->header.len3 = remain_len - 767;
178 rmsg->header.len4 = 0xff;
179 rmsg->header.len5 = 0x00;
180 remain_len = 0;
181 } else if (remain_len <= 1024) {
182 len1 = 512;
183 len2 = remain_len - 512;
184 rmsg->header.len0 = 0x02;
185 rmsg->header.len1 = 0xff;
186 rmsg->header.len2 = 0xff;
187 rmsg->header.len3 = remain_len - 1022;
188 rmsg->header.len4 = 0xff;
189 rmsg->header.len5 = 0xff;
190 remain_len = 0;
191 } else {
192 len1 = 512;
193 len2 = 512;
194 rmsg->header.len0 = 0x02;
195 rmsg->header.len1 = 0xff;
196 rmsg->header.len2 = 0xff;
197 rmsg->header.len3 = 0x02;
198 rmsg->header.len4 = 0xff;
199 rmsg->header.len5 = 0xff;
200 remain_len -= 1024;
201 start += 1024;
202 }
203 rmsg->header.tf1 = cpu_to_le16(len1);
204 rmsg->header.tf2 = cpu_to_le16(len2);
205
206 /* first read transfer */
207 ret = vprbrd_i2c_receive(vb->usb_dev, rmsg, len1);
208 if (ret < 0)
209 return ret;
210 /* copy the received data */
211 memcpy(msg->buf + start, rmsg, len1);
212
213 /* second read transfer if neccessary */
214 if (len2 > 0) {
215 ret = vprbrd_i2c_receive(vb->usb_dev, rmsg, len2);
216 if (ret < 0)
217 return ret;
218 /* copy the received data */
219 memcpy(msg->buf + start + 512, rmsg, len2);
220 }
221 }
222 return 0;
223 }
224
225 static int vprbrd_i2c_write(struct vprbrd *vb, struct i2c_msg *msg)
226 {
227 int ret, bytes_actual;
228 u16 remain_len, bytes_xfer,
229 start = 0x0000;
230 struct vprbrd_i2c_write_msg *wmsg =
231 (struct vprbrd_i2c_write_msg *)vb->buf;
232
233 remain_len = msg->len;
234 wmsg->header.cmd = VPRBRD_I2C_CMD_WRITE;
235 wmsg->header.last = 0x00;
236 wmsg->header.chan = 0x00;
237 wmsg->header.spi = 0x0000;
238 while (remain_len > 0) {
239 wmsg->header.addr = cpu_to_le16(start + 0x4000);
240 if (remain_len > 503) {
241 wmsg->header.len1 = 0xff;
242 wmsg->header.len2 = 0xf8;
243 remain_len -= 503;
244 bytes_xfer = 503 + sizeof(struct vprbrd_i2c_write_hdr);
245 start += 503;
246 } else if (remain_len > 255) {
247 wmsg->header.len1 = 0xff;
248 wmsg->header.len2 = (remain_len - 255);
249 bytes_xfer = remain_len +
250 sizeof(struct vprbrd_i2c_write_hdr);
251 remain_len = 0;
252 } else {
253 wmsg->header.len1 = remain_len;
254 wmsg->header.len2 = 0x00;
255 bytes_xfer = remain_len +
256 sizeof(struct vprbrd_i2c_write_hdr);
257 remain_len = 0;
258 }
259 memcpy(wmsg->data, msg->buf + start,
260 bytes_xfer - sizeof(struct vprbrd_i2c_write_hdr));
261
262 ret = usb_bulk_msg(vb->usb_dev,
263 usb_sndbulkpipe(vb->usb_dev,
264 VPRBRD_EP_OUT), wmsg,
265 bytes_xfer, &bytes_actual, VPRBRD_USB_TIMEOUT_MS);
266 if ((ret < 0) || (bytes_xfer != bytes_actual))
267 return -EREMOTEIO;
268 }
269 return 0;
270 }
271
272 static int vprbrd_i2c_xfer(struct i2c_adapter *i2c, struct i2c_msg *msgs,
273 int num)
274 {
275 struct i2c_msg *pmsg;
276 int i, ret,
277 error = 0;
278 struct vprbrd *vb = (struct vprbrd *)i2c->algo_data;
279 struct vprbrd_i2c_addr_msg *amsg =
280 (struct vprbrd_i2c_addr_msg *)vb->buf;
281 struct vprbrd_i2c_status *smsg = (struct vprbrd_i2c_status *)vb->buf;
282
283 dev_dbg(&i2c->dev, "master xfer %d messages:\n", num);
284
285 for (i = 0 ; i < num ; i++) {
286 pmsg = &msgs[i];
287
288 dev_dbg(&i2c->dev,
289 " %d: %s (flags %d) %d bytes to 0x%02x\n",
290 i, pmsg->flags & I2C_M_RD ? "read" : "write",
291 pmsg->flags, pmsg->len, pmsg->addr);
292
293 /* msgs longer than 2048 bytes are not supported by adapter */
294 if (pmsg->len > 2048)
295 return -EINVAL;
296
297 mutex_lock(&vb->lock);
298 /* directly send the message */
299 if (pmsg->flags & I2C_M_RD) {
300 /* read data */
301 amsg->cmd = VPRBRD_I2C_CMD_ADDR;
302 amsg->unknown2 = 0x00;
303 amsg->unknown3 = 0x00;
304 amsg->addr = pmsg->addr;
305 amsg->unknown1 = 0x01;
306 amsg->len = cpu_to_le16(pmsg->len);
307 /* send the addr and len, we're interested to board */
308 ret = vprbrd_i2c_addr(vb->usb_dev, amsg);
309 if (ret < 0)
310 error = ret;
311
312 ret = vprbrd_i2c_read(vb, pmsg);
313 if (ret < 0)
314 error = ret;
315
316 ret = vprbrd_i2c_status(i2c, smsg, error);
317 if (ret < 0)
318 error = ret;
319 /* in case of protocol error, return the error */
320 if (error < 0)
321 goto error;
322 } else {
323 /* write data */
324 ret = vprbrd_i2c_write(vb, pmsg);
325
326 amsg->cmd = VPRBRD_I2C_CMD_ADDR;
327 amsg->unknown2 = 0x00;
328 amsg->unknown3 = 0x00;
329 amsg->addr = pmsg->addr;
330 amsg->unknown1 = 0x00;
331 amsg->len = cpu_to_le16(pmsg->len);
332 /* send the addr, the data goes to to board */
333 ret = vprbrd_i2c_addr(vb->usb_dev, amsg);
334 if (ret < 0)
335 error = ret;
336
337 ret = vprbrd_i2c_status(i2c, smsg, error);
338 if (ret < 0)
339 error = ret;
340
341 if (error < 0)
342 goto error;
343 }
344 mutex_unlock(&vb->lock);
345 }
346 return 0;
347 error:
348 mutex_unlock(&vb->lock);
349 return error;
350 }
351
352 static u32 vprbrd_i2c_func(struct i2c_adapter *i2c)
353 {
354 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
355 }
356
357 /* This is the actual algorithm we define */
358 static const struct i2c_algorithm vprbrd_algorithm = {
359 .master_xfer = vprbrd_i2c_xfer,
360 .functionality = vprbrd_i2c_func,
361 };
362
363 static int vprbrd_i2c_probe(struct platform_device *pdev)
364 {
365 struct vprbrd *vb = dev_get_drvdata(pdev->dev.parent);
366 struct vprbrd_i2c *vb_i2c;
367 int ret;
368 int pipe;
369
370 vb_i2c = kzalloc(sizeof(*vb_i2c), GFP_KERNEL);
371 if (vb_i2c == NULL)
372 return -ENOMEM;
373
374 /* setup i2c adapter description */
375 vb_i2c->i2c.owner = THIS_MODULE;
376 vb_i2c->i2c.class = I2C_CLASS_HWMON;
377 vb_i2c->i2c.algo = &vprbrd_algorithm;
378 vb_i2c->i2c.algo_data = vb;
379 /* save the param in usb capabable memory */
380 vb_i2c->bus_freq_param = i2c_bus_param;
381
382 snprintf(vb_i2c->i2c.name, sizeof(vb_i2c->i2c.name),
383 "viperboard at bus %03d device %03d",
384 vb->usb_dev->bus->busnum, vb->usb_dev->devnum);
385
386 /* setting the bus frequency */
387 if ((i2c_bus_param <= VPRBRD_I2C_FREQ_10KHZ)
388 && (i2c_bus_param >= VPRBRD_I2C_FREQ_6MHZ)) {
389 pipe = usb_sndctrlpipe(vb->usb_dev, 0);
390 ret = usb_control_msg(vb->usb_dev, pipe,
391 VPRBRD_USB_REQUEST_I2C_FREQ, VPRBRD_USB_TYPE_OUT,
392 0x0000, 0x0000, &vb_i2c->bus_freq_param, 1,
393 VPRBRD_USB_TIMEOUT_MS);
394 if (ret != 1) {
395 dev_err(&pdev->dev,
396 "failure setting i2c_bus_freq to %d\n", i2c_bus_freq);
397 ret = -EIO;
398 goto error;
399 }
400 } else {
401 dev_err(&pdev->dev,
402 "invalid i2c_bus_freq setting:%d\n", i2c_bus_freq);
403 ret = -EIO;
404 goto error;
405 }
406
407 vb_i2c->i2c.dev.parent = &pdev->dev;
408
409 /* attach to i2c layer */
410 i2c_add_adapter(&vb_i2c->i2c);
411
412 platform_set_drvdata(pdev, vb_i2c);
413
414 return 0;
415
416 error:
417 kfree(vb_i2c);
418 return ret;
419 }
420
421 static int vprbrd_i2c_remove(struct platform_device *pdev)
422 {
423 struct vprbrd_i2c *vb_i2c = platform_get_drvdata(pdev);
424
425 i2c_del_adapter(&vb_i2c->i2c);
426
427 return 0;
428 }
429
430 static struct platform_driver vprbrd_i2c_driver = {
431 .driver.name = "viperboard-i2c",
432 .driver.owner = THIS_MODULE,
433 .probe = vprbrd_i2c_probe,
434 .remove = vprbrd_i2c_remove,
435 };
436
437 static int __init vprbrd_i2c_init(void)
438 {
439 switch (i2c_bus_freq) {
440 case 6000:
441 i2c_bus_param = VPRBRD_I2C_FREQ_6MHZ;
442 break;
443 case 3000:
444 i2c_bus_param = VPRBRD_I2C_FREQ_3MHZ;
445 break;
446 case 1000:
447 i2c_bus_param = VPRBRD_I2C_FREQ_1MHZ;
448 break;
449 case 400:
450 i2c_bus_param = VPRBRD_I2C_FREQ_400KHZ;
451 break;
452 case 200:
453 i2c_bus_param = VPRBRD_I2C_FREQ_200KHZ;
454 break;
455 case 100:
456 i2c_bus_param = VPRBRD_I2C_FREQ_100KHZ;
457 break;
458 case 10:
459 i2c_bus_param = VPRBRD_I2C_FREQ_10KHZ;
460 break;
461 default:
462 pr_warn("invalid i2c_bus_freq (%d)\n", i2c_bus_freq);
463 i2c_bus_param = VPRBRD_I2C_FREQ_100KHZ;
464 }
465
466 return platform_driver_register(&vprbrd_i2c_driver);
467 }
468 subsys_initcall(vprbrd_i2c_init);
469
470 static void __exit vprbrd_i2c_exit(void)
471 {
472 platform_driver_unregister(&vprbrd_i2c_driver);
473 }
474 module_exit(vprbrd_i2c_exit);
475
476 MODULE_AUTHOR("Lars Poeschel <poeschel@lemonage.de>");
477 MODULE_DESCRIPTION("I2C master driver for Nano River Techs Viperboard");
478 MODULE_LICENSE("GPL");
479 MODULE_ALIAS("platform:viperboard-i2c");
Linux with added FPC-III support