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1/*
2 * Silicon Labs C2 port core Linux support
3 *
4 * Copyright (c) 2007 Rodolfo Giometti <giometti@linux.it>
5 * Copyright (c) 2007 Eurotech S.p.A. <info@eurotech.it>
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License version 2 as published by
9 * the Free Software Foundation
10 */
11
12#include <linux/module.h>
13#include <linux/init.h>
14#include <linux/device.h>
15#include <linux/errno.h>
16#include <linux/err.h>
17#include <linux/kernel.h>
18#include <linux/kmemcheck.h>
19#include <linux/ctype.h>
20#include <linux/delay.h>
21#include <linux/idr.h>
22#include <linux/sched.h>
23#include <linux/slab.h>
24
25#include <linux/c2port.h>
26
27#define DRIVER_NAME "c2port"
28#define DRIVER_VERSION "0.51.0"
29
30static DEFINE_SPINLOCK(c2port_idr_lock);
31static DEFINE_IDR(c2port_idr);
32
33/*
34 * Local variables
35 */
36
37static struct class *c2port_class;
38
39/*
40 * C2 registers & commands defines
41 */
42
43/* C2 registers */
44#define C2PORT_DEVICEID 0x00
45#define C2PORT_REVID 0x01
46#define C2PORT_FPCTL 0x02
47#define C2PORT_FPDAT 0xB4
48
49/* C2 interface commands */
50#define C2PORT_GET_VERSION 0x01
51#define C2PORT_DEVICE_ERASE 0x03
52#define C2PORT_BLOCK_READ 0x06
53#define C2PORT_BLOCK_WRITE 0x07
54#define C2PORT_PAGE_ERASE 0x08
55
56/* C2 status return codes */
57#define C2PORT_INVALID_COMMAND 0x00
58#define C2PORT_COMMAND_FAILED 0x02
59#define C2PORT_COMMAND_OK 0x0d
60
61/*
62 * C2 port low level signal managements
63 */
64
65static void c2port_reset(struct c2port_device *dev)
66{
67 struct c2port_ops *ops = dev->ops;
68
69 /* To reset the device we have to keep clock line low for at least
70 * 20us.
71 */
72 local_irq_disable();
73 ops->c2ck_set(dev, 0);
74 udelay(25);
75 ops->c2ck_set(dev, 1);
76 local_irq_enable();
77
78 udelay(1);
79}
80
81static void c2port_strobe_ck(struct c2port_device *dev)
82{
83 struct c2port_ops *ops = dev->ops;
84
85 /* During hi-low-hi transition we disable local IRQs to avoid
86 * interructions since C2 port specification says that it must be
87 * shorter than 5us, otherwise the microcontroller may consider
88 * it as a reset signal!
89 */
90 local_irq_disable();
91 ops->c2ck_set(dev, 0);
92 udelay(1);
93 ops->c2ck_set(dev, 1);
94 local_irq_enable();
95
96 udelay(1);
97}
98
99/*
100 * C2 port basic functions
101 */
102
103static void c2port_write_ar(struct c2port_device *dev, u8 addr)
104{
105 struct c2port_ops *ops = dev->ops;
106 int i;
107
108 /* START field */
109 c2port_strobe_ck(dev);
110
111 /* INS field (11b, LSB first) */
112 ops->c2d_dir(dev, 0);
113 ops->c2d_set(dev, 1);
114 c2port_strobe_ck(dev);
115 ops->c2d_set(dev, 1);
116 c2port_strobe_ck(dev);
117
118 /* ADDRESS field */
119 for (i = 0; i < 8; i++) {
120 ops->c2d_set(dev, addr & 0x01);
121 c2port_strobe_ck(dev);
122
123 addr >>= 1;
124 }
125
126 /* STOP field */
127 ops->c2d_dir(dev, 1);
128 c2port_strobe_ck(dev);
129}
130
131static int c2port_read_ar(struct c2port_device *dev, u8 *addr)
132{
133 struct c2port_ops *ops = dev->ops;
134 int i;
135
136 /* START field */
137 c2port_strobe_ck(dev);
138
139 /* INS field (10b, LSB first) */
140 ops->c2d_dir(dev, 0);
141 ops->c2d_set(dev, 0);
142 c2port_strobe_ck(dev);
143 ops->c2d_set(dev, 1);
144 c2port_strobe_ck(dev);
145
146 /* ADDRESS field */
147 ops->c2d_dir(dev, 1);
148 *addr = 0;
149 for (i = 0; i < 8; i++) {
150 *addr >>= 1; /* shift in 8-bit ADDRESS field LSB first */
151
152 c2port_strobe_ck(dev);
153 if (ops->c2d_get(dev))
154 *addr |= 0x80;
155 }
156
157 /* STOP field */
158 c2port_strobe_ck(dev);
159
160 return 0;
161}
162
163static int c2port_write_dr(struct c2port_device *dev, u8 data)
164{
165 struct c2port_ops *ops = dev->ops;
166 int timeout, i;
167
168 /* START field */
169 c2port_strobe_ck(dev);
170
171 /* INS field (01b, LSB first) */
172 ops->c2d_dir(dev, 0);
173 ops->c2d_set(dev, 1);
174 c2port_strobe_ck(dev);
175 ops->c2d_set(dev, 0);
176 c2port_strobe_ck(dev);
177
178 /* LENGTH field (00b, LSB first -> 1 byte) */
179 ops->c2d_set(dev, 0);
180 c2port_strobe_ck(dev);
181 ops->c2d_set(dev, 0);
182 c2port_strobe_ck(dev);
183
184 /* DATA field */
185 for (i = 0; i < 8; i++) {
186 ops->c2d_set(dev, data & 0x01);
187 c2port_strobe_ck(dev);
188
189 data >>= 1;
190 }
191
192 /* WAIT field */
193 ops->c2d_dir(dev, 1);
194 timeout = 20;
195 do {
196 c2port_strobe_ck(dev);
197 if (ops->c2d_get(dev))
198 break;
199
200 udelay(1);
201 } while (--timeout > 0);
202 if (timeout == 0)
203 return -EIO;
204
205 /* STOP field */
206 c2port_strobe_ck(dev);
207
208 return 0;
209}
210
211static int c2port_read_dr(struct c2port_device *dev, u8 *data)
212{
213 struct c2port_ops *ops = dev->ops;
214 int timeout, i;
215
216 /* START field */
217 c2port_strobe_ck(dev);
218
219 /* INS field (00b, LSB first) */
220 ops->c2d_dir(dev, 0);
221 ops->c2d_set(dev, 0);
222 c2port_strobe_ck(dev);
223 ops->c2d_set(dev, 0);
224 c2port_strobe_ck(dev);
225
226 /* LENGTH field (00b, LSB first -> 1 byte) */
227 ops->c2d_set(dev, 0);
228 c2port_strobe_ck(dev);
229 ops->c2d_set(dev, 0);
230 c2port_strobe_ck(dev);
231
232 /* WAIT field */
233 ops->c2d_dir(dev, 1);
234 timeout = 20;
235 do {
236 c2port_strobe_ck(dev);
237 if (ops->c2d_get(dev))
238 break;
239
240 udelay(1);
241 } while (--timeout > 0);
242 if (timeout == 0)
243 return -EIO;
244
245 /* DATA field */
246 *data = 0;
247 for (i = 0; i < 8; i++) {
248 *data >>= 1; /* shift in 8-bit DATA field LSB first */
249
250 c2port_strobe_ck(dev);
251 if (ops->c2d_get(dev))
252 *data |= 0x80;
253 }
254
255 /* STOP field */
256 c2port_strobe_ck(dev);
257
258 return 0;
259}
260
261static int c2port_poll_in_busy(struct c2port_device *dev)
262{
263 u8 addr;
264 int ret, timeout = 20;
265
266 do {
267 ret = (c2port_read_ar(dev, &addr));
268 if (ret < 0)
269 return -EIO;
270
271 if (!(addr & 0x02))
272 break;
273
274 udelay(1);
275 } while (--timeout > 0);
276 if (timeout == 0)
277 return -EIO;
278
279 return 0;
280}
281
282static int c2port_poll_out_ready(struct c2port_device *dev)
283{
284 u8 addr;
285 int ret, timeout = 10000; /* erase flash needs long time... */
286
287 do {
288 ret = (c2port_read_ar(dev, &addr));
289 if (ret < 0)
290 return -EIO;
291
292 if (addr & 0x01)
293 break;
294
295 udelay(1);
296 } while (--timeout > 0);
297 if (timeout == 0)
298 return -EIO;
299
300 return 0;
301}
302
303/*
304 * sysfs methods
305 */
306
307static ssize_t c2port_show_name(struct device *dev,
308 struct device_attribute *attr, char *buf)
309{
310 struct c2port_device *c2dev = dev_get_drvdata(dev);
311
312 return sprintf(buf, "%s\n", c2dev->name);
313}
314
315static ssize_t c2port_show_flash_blocks_num(struct device *dev,
316 struct device_attribute *attr, char *buf)
317{
318 struct c2port_device *c2dev = dev_get_drvdata(dev);
319 struct c2port_ops *ops = c2dev->ops;
320
321 return sprintf(buf, "%d\n", ops->blocks_num);
322}
323
324static ssize_t c2port_show_flash_block_size(struct device *dev,
325 struct device_attribute *attr, char *buf)
326{
327 struct c2port_device *c2dev = dev_get_drvdata(dev);
328 struct c2port_ops *ops = c2dev->ops;
329
330 return sprintf(buf, "%d\n", ops->block_size);
331}
332
333static ssize_t c2port_show_flash_size(struct device *dev,
334 struct device_attribute *attr, char *buf)
335{
336 struct c2port_device *c2dev = dev_get_drvdata(dev);
337 struct c2port_ops *ops = c2dev->ops;
338
339 return sprintf(buf, "%d\n", ops->blocks_num * ops->block_size);
340}
341
342static ssize_t c2port_show_access(struct device *dev,
343 struct device_attribute *attr, char *buf)
344{
345 struct c2port_device *c2dev = dev_get_drvdata(dev);
346
347 return sprintf(buf, "%d\n", c2dev->access);
348}
349
350static ssize_t c2port_store_access(struct device *dev,
351 struct device_attribute *attr,
352 const char *buf, size_t count)
353{
354 struct c2port_device *c2dev = dev_get_drvdata(dev);
355 struct c2port_ops *ops = c2dev->ops;
356 int status, ret;
357
358 ret = sscanf(buf, "%d", &status);
359 if (ret != 1)
360 return -EINVAL;
361
362 mutex_lock(&c2dev->mutex);
363
364 c2dev->access = !!status;
365
366 /* If access is "on" clock should be HIGH _before_ setting the line
367 * as output and data line should be set as INPUT anyway */
368 if (c2dev->access)
369 ops->c2ck_set(c2dev, 1);
370 ops->access(c2dev, c2dev->access);
371 if (c2dev->access)
372 ops->c2d_dir(c2dev, 1);
373
374 mutex_unlock(&c2dev->mutex);
375
376 return count;
377}
378
379static ssize_t c2port_store_reset(struct device *dev,
380 struct device_attribute *attr,
381 const char *buf, size_t count)
382{
383 struct c2port_device *c2dev = dev_get_drvdata(dev);
384
385 /* Check the device access status */
386 if (!c2dev->access)
387 return -EBUSY;
388
389 mutex_lock(&c2dev->mutex);
390
391 c2port_reset(c2dev);
392 c2dev->flash_access = 0;
393
394 mutex_unlock(&c2dev->mutex);
395
396 return count;
397}
398
399static ssize_t __c2port_show_dev_id(struct c2port_device *dev, char *buf)
400{
401 u8 data;
402 int ret;
403
404 /* Select DEVICEID register for C2 data register accesses */
405 c2port_write_ar(dev, C2PORT_DEVICEID);
406
407 /* Read and return the device ID register */
408 ret = c2port_read_dr(dev, &data);
409 if (ret < 0)
410 return ret;
411
412 return sprintf(buf, "%d\n", data);
413}
414
415static ssize_t c2port_show_dev_id(struct device *dev,
416 struct device_attribute *attr, char *buf)
417{
418 struct c2port_device *c2dev = dev_get_drvdata(dev);
419 ssize_t ret;
420
421 /* Check the device access status */
422 if (!c2dev->access)
423 return -EBUSY;
424
425 mutex_lock(&c2dev->mutex);
426 ret = __c2port_show_dev_id(c2dev, buf);
427 mutex_unlock(&c2dev->mutex);
428
429 if (ret < 0)
430 dev_err(dev, "cannot read from %s\n", c2dev->name);
431
432 return ret;
433}
434
435static ssize_t __c2port_show_rev_id(struct c2port_device *dev, char *buf)
436{
437 u8 data;
438 int ret;
439
440 /* Select REVID register for C2 data register accesses */
441 c2port_write_ar(dev, C2PORT_REVID);
442
443 /* Read and return the revision ID register */
444 ret = c2port_read_dr(dev, &data);
445 if (ret < 0)
446 return ret;
447
448 return sprintf(buf, "%d\n", data);
449}
450
451static ssize_t c2port_show_rev_id(struct device *dev,
452 struct device_attribute *attr, char *buf)
453{
454 struct c2port_device *c2dev = dev_get_drvdata(dev);
455 ssize_t ret;
456
457 /* Check the device access status */
458 if (!c2dev->access)
459 return -EBUSY;
460
461 mutex_lock(&c2dev->mutex);
462 ret = __c2port_show_rev_id(c2dev, buf);
463 mutex_unlock(&c2dev->mutex);
464
465 if (ret < 0)
466 dev_err(c2dev->dev, "cannot read from %s\n", c2dev->name);
467
468 return ret;
469}
470
471static ssize_t c2port_show_flash_access(struct device *dev,
472 struct device_attribute *attr, char *buf)
473{
474 struct c2port_device *c2dev = dev_get_drvdata(dev);
475
476 return sprintf(buf, "%d\n", c2dev->flash_access);
477}
478
479static ssize_t __c2port_store_flash_access(struct c2port_device *dev,
480 int status)
481{
482 int ret;
483
484 /* Check the device access status */
485 if (!dev->access)
486 return -EBUSY;
487
488 dev->flash_access = !!status;
489
490 /* If flash_access is off we have nothing to do... */
491 if (dev->flash_access == 0)
492 return 0;
493
494 /* Target the C2 flash programming control register for C2 data
495 * register access */
496 c2port_write_ar(dev, C2PORT_FPCTL);
497
498 /* Write the first keycode to enable C2 Flash programming */
499 ret = c2port_write_dr(dev, 0x02);
500 if (ret < 0)
501 return ret;
502
503 /* Write the second keycode to enable C2 Flash programming */
504 ret = c2port_write_dr(dev, 0x01);
505 if (ret < 0)
506 return ret;
507
508 /* Delay for at least 20ms to ensure the target is ready for
509 * C2 flash programming */
510 mdelay(25);
511
512 return 0;
513}
514
515static ssize_t c2port_store_flash_access(struct device *dev,
516 struct device_attribute *attr,
517 const char *buf, size_t count)
518{
519 struct c2port_device *c2dev = dev_get_drvdata(dev);
520 int status;
521 ssize_t ret;
522
523 ret = sscanf(buf, "%d", &status);
524 if (ret != 1)
525 return -EINVAL;
526
527 mutex_lock(&c2dev->mutex);
528 ret = __c2port_store_flash_access(c2dev, status);
529 mutex_unlock(&c2dev->mutex);
530
531 if (ret < 0) {
532 dev_err(c2dev->dev, "cannot enable %s flash programming\n",
533 c2dev->name);
534 return ret;
535 }
536
537 return count;
538}
539
540static ssize_t __c2port_write_flash_erase(struct c2port_device *dev)
541{
542 u8 status;
543 int ret;
544
545 /* Target the C2 flash programming data register for C2 data register
546 * access.
547 */
548 c2port_write_ar(dev, C2PORT_FPDAT);
549
550 /* Send device erase command */
551 c2port_write_dr(dev, C2PORT_DEVICE_ERASE);
552
553 /* Wait for input acknowledge */
554 ret = c2port_poll_in_busy(dev);
555 if (ret < 0)
556 return ret;
557
558 /* Should check status before starting FLASH access sequence */
559
560 /* Wait for status information */
561 ret = c2port_poll_out_ready(dev);
562 if (ret < 0)
563 return ret;
564
565 /* Read flash programming interface status */
566 ret = c2port_read_dr(dev, &status);
567 if (ret < 0)
568 return ret;
569 if (status != C2PORT_COMMAND_OK)
570 return -EBUSY;
571
572 /* Send a three-byte arming sequence to enable the device erase.
573 * If the sequence is not received correctly, the command will be
574 * ignored.
575 * Sequence is: 0xde, 0xad, 0xa5.
576 */
577 c2port_write_dr(dev, 0xde);
578 ret = c2port_poll_in_busy(dev);
579 if (ret < 0)
580 return ret;
581 c2port_write_dr(dev, 0xad);
582 ret = c2port_poll_in_busy(dev);
583 if (ret < 0)
584 return ret;
585 c2port_write_dr(dev, 0xa5);
586 ret = c2port_poll_in_busy(dev);
587 if (ret < 0)
588 return ret;
589
590 ret = c2port_poll_out_ready(dev);
591 if (ret < 0)
592 return ret;
593
594 return 0;
595}
596
597static ssize_t c2port_store_flash_erase(struct device *dev,
598 struct device_attribute *attr,
599 const char *buf, size_t count)
600{
601 struct c2port_device *c2dev = dev_get_drvdata(dev);
602 int ret;
603
604 /* Check the device and flash access status */
605 if (!c2dev->access || !c2dev->flash_access)
606 return -EBUSY;
607
608 mutex_lock(&c2dev->mutex);
609 ret = __c2port_write_flash_erase(c2dev);
610 mutex_unlock(&c2dev->mutex);
611
612 if (ret < 0) {
613 dev_err(c2dev->dev, "cannot erase %s flash\n", c2dev->name);
614 return ret;
615 }
616
617 return count;
618}
619
620static ssize_t __c2port_read_flash_data(struct c2port_device *dev,
621 char *buffer, loff_t offset, size_t count)
622{
623 struct c2port_ops *ops = dev->ops;
624 u8 status, nread = 128;
625 int i, ret;
626
627 /* Check for flash end */
628 if (offset >= ops->block_size * ops->blocks_num)
629 return 0;
630
631 if (ops->block_size * ops->blocks_num - offset < nread)
632 nread = ops->block_size * ops->blocks_num - offset;
633 if (count < nread)
634 nread = count;
635 if (nread == 0)
636 return nread;
637
638 /* Target the C2 flash programming data register for C2 data register
639 * access */
640 c2port_write_ar(dev, C2PORT_FPDAT);
641
642 /* Send flash block read command */
643 c2port_write_dr(dev, C2PORT_BLOCK_READ);
644
645 /* Wait for input acknowledge */
646 ret = c2port_poll_in_busy(dev);
647 if (ret < 0)
648 return ret;
649
650 /* Should check status before starting FLASH access sequence */
651
652 /* Wait for status information */
653 ret = c2port_poll_out_ready(dev);
654 if (ret < 0)
655 return ret;
656
657 /* Read flash programming interface status */
658 ret = c2port_read_dr(dev, &status);
659 if (ret < 0)
660 return ret;
661 if (status != C2PORT_COMMAND_OK)
662 return -EBUSY;
663
664 /* Send address high byte */
665 c2port_write_dr(dev, offset >> 8);
666 ret = c2port_poll_in_busy(dev);
667 if (ret < 0)
668 return ret;
669
670 /* Send address low byte */
671 c2port_write_dr(dev, offset & 0x00ff);
672 ret = c2port_poll_in_busy(dev);
673 if (ret < 0)
674 return ret;
675
676 /* Send address block size */
677 c2port_write_dr(dev, nread);
678 ret = c2port_poll_in_busy(dev);
679 if (ret < 0)
680 return ret;
681
682 /* Should check status before reading FLASH block */
683
684 /* Wait for status information */
685 ret = c2port_poll_out_ready(dev);
686 if (ret < 0)
687 return ret;
688
689 /* Read flash programming interface status */
690 ret = c2port_read_dr(dev, &status);
691 if (ret < 0)
692 return ret;
693 if (status != C2PORT_COMMAND_OK)
694 return -EBUSY;
695
696 /* Read flash block */
697 for (i = 0; i < nread; i++) {
698 ret = c2port_poll_out_ready(dev);
699 if (ret < 0)
700 return ret;
701
702 ret = c2port_read_dr(dev, buffer+i);
703 if (ret < 0)
704 return ret;
705 }
706
707 return nread;
708}
709
710static ssize_t c2port_read_flash_data(struct file *filp, struct kobject *kobj,
711 struct bin_attribute *attr,
712 char *buffer, loff_t offset, size_t count)
713{
714 struct c2port_device *c2dev =
715 dev_get_drvdata(container_of(kobj,
716 struct device, kobj));
717 ssize_t ret;
718
719 /* Check the device and flash access status */
720 if (!c2dev->access || !c2dev->flash_access)
721 return -EBUSY;
722
723 mutex_lock(&c2dev->mutex);
724 ret = __c2port_read_flash_data(c2dev, buffer, offset, count);
725 mutex_unlock(&c2dev->mutex);
726
727 if (ret < 0)
728 dev_err(c2dev->dev, "cannot read %s flash\n", c2dev->name);
729
730 return ret;
731}
732
733static ssize_t __c2port_write_flash_data(struct c2port_device *dev,
734 char *buffer, loff_t offset, size_t count)
735{
736 struct c2port_ops *ops = dev->ops;
737 u8 status, nwrite = 128;
738 int i, ret;
739
740 if (nwrite > count)
741 nwrite = count;
742 if (ops->block_size * ops->blocks_num - offset < nwrite)
743 nwrite = ops->block_size * ops->blocks_num - offset;
744
745 /* Check for flash end */
746 if (offset >= ops->block_size * ops->blocks_num)
747 return -EINVAL;
748
749 /* Target the C2 flash programming data register for C2 data register
750 * access */
751 c2port_write_ar(dev, C2PORT_FPDAT);
752
753 /* Send flash block write command */
754 c2port_write_dr(dev, C2PORT_BLOCK_WRITE);
755
756 /* Wait for input acknowledge */
757 ret = c2port_poll_in_busy(dev);
758 if (ret < 0)
759 return ret;
760
761 /* Should check status before starting FLASH access sequence */
762
763 /* Wait for status information */
764 ret = c2port_poll_out_ready(dev);
765 if (ret < 0)
766 return ret;
767
768 /* Read flash programming interface status */
769 ret = c2port_read_dr(dev, &status);
770 if (ret < 0)
771 return ret;
772 if (status != C2PORT_COMMAND_OK)
773 return -EBUSY;
774
775 /* Send address high byte */
776 c2port_write_dr(dev, offset >> 8);
777 ret = c2port_poll_in_busy(dev);
778 if (ret < 0)
779 return ret;
780
781 /* Send address low byte */
782 c2port_write_dr(dev, offset & 0x00ff);
783 ret = c2port_poll_in_busy(dev);
784 if (ret < 0)
785 return ret;
786
787 /* Send address block size */
788 c2port_write_dr(dev, nwrite);
789 ret = c2port_poll_in_busy(dev);
790 if (ret < 0)
791 return ret;
792
793 /* Should check status before writing FLASH block */
794
795 /* Wait for status information */
796 ret = c2port_poll_out_ready(dev);
797 if (ret < 0)
798 return ret;
799
800 /* Read flash programming interface status */
801 ret = c2port_read_dr(dev, &status);
802 if (ret < 0)
803 return ret;
804 if (status != C2PORT_COMMAND_OK)
805 return -EBUSY;
806
807 /* Write flash block */
808 for (i = 0; i < nwrite; i++) {
809 ret = c2port_write_dr(dev, *(buffer+i));
810 if (ret < 0)
811 return ret;
812
813 ret = c2port_poll_in_busy(dev);
814 if (ret < 0)
815 return ret;
816
817 }
818
819 /* Wait for last flash write to complete */
820 ret = c2port_poll_out_ready(dev);
821 if (ret < 0)
822 return ret;
823
824 return nwrite;
825}
826
827static ssize_t c2port_write_flash_data(struct file *filp, struct kobject *kobj,
828 struct bin_attribute *attr,
829 char *buffer, loff_t offset, size_t count)
830{
831 struct c2port_device *c2dev =
832 dev_get_drvdata(container_of(kobj,
833 struct device, kobj));
834 int ret;
835
836 /* Check the device access status */
837 if (!c2dev->access || !c2dev->flash_access)
838 return -EBUSY;
839
840 mutex_lock(&c2dev->mutex);
841 ret = __c2port_write_flash_data(c2dev, buffer, offset, count);
842 mutex_unlock(&c2dev->mutex);
843
844 if (ret < 0)
845 dev_err(c2dev->dev, "cannot write %s flash\n", c2dev->name);
846
847 return ret;
848}
849
850/*
851 * Class attributes
852 */
853
854static struct device_attribute c2port_attrs[] = {
855 __ATTR(name, 0444, c2port_show_name, NULL),
856 __ATTR(flash_blocks_num, 0444, c2port_show_flash_blocks_num, NULL),
857 __ATTR(flash_block_size, 0444, c2port_show_flash_block_size, NULL),
858 __ATTR(flash_size, 0444, c2port_show_flash_size, NULL),
859 __ATTR(access, 0644, c2port_show_access, c2port_store_access),
860 __ATTR(reset, 0200, NULL, c2port_store_reset),
861 __ATTR(dev_id, 0444, c2port_show_dev_id, NULL),
862 __ATTR(rev_id, 0444, c2port_show_rev_id, NULL),
863
864 __ATTR(flash_access, 0644, c2port_show_flash_access,
865 c2port_store_flash_access),
866 __ATTR(flash_erase, 0200, NULL, c2port_store_flash_erase),
867 __ATTR_NULL,
868};
869
870static struct bin_attribute c2port_bin_attrs = {
871 .attr = {
872 .name = "flash_data",
873 .mode = 0644
874 },
875 .read = c2port_read_flash_data,
876 .write = c2port_write_flash_data,
877 /* .size is computed at run-time */
878};
879
880/*
881 * Exported functions
882 */
883
884struct c2port_device *c2port_device_register(char *name,
885 struct c2port_ops *ops, void *devdata)
886{
887 struct c2port_device *c2dev;
888 int id, ret;
889
890 if (unlikely(!ops) || unlikely(!ops->access) || \
891 unlikely(!ops->c2d_dir) || unlikely(!ops->c2ck_set) || \
892 unlikely(!ops->c2d_get) || unlikely(!ops->c2d_set))
893 return ERR_PTR(-EINVAL);
894
895 c2dev = kmalloc(sizeof(struct c2port_device), GFP_KERNEL);
896 kmemcheck_annotate_bitfield(c2dev, flags);
897 if (unlikely(!c2dev))
898 return ERR_PTR(-ENOMEM);
899
900 ret = idr_pre_get(&c2port_idr, GFP_KERNEL);
901 if (!ret) {
902 ret = -ENOMEM;
903 goto error_idr_get_new;
904 }
905
906 spin_lock_irq(&c2port_idr_lock);
907 ret = idr_get_new(&c2port_idr, c2dev, &id);
908 spin_unlock_irq(&c2port_idr_lock);
909
910 if (ret < 0)
911 goto error_idr_get_new;
912 c2dev->id = id;
913
914 c2dev->dev = device_create(c2port_class, NULL, 0, c2dev,
915 "c2port%d", id);
916 if (unlikely(IS_ERR(c2dev->dev))) {
917 ret = PTR_ERR(c2dev->dev);
918 goto error_device_create;
919 }
920 dev_set_drvdata(c2dev->dev, c2dev);
921
922 strncpy(c2dev->name, name, C2PORT_NAME_LEN);
923 c2dev->ops = ops;
924 mutex_init(&c2dev->mutex);
925
926 /* Create binary file */
927 c2port_bin_attrs.size = ops->blocks_num * ops->block_size;
928 ret = device_create_bin_file(c2dev->dev, &c2port_bin_attrs);
929 if (unlikely(ret))
930 goto error_device_create_bin_file;
931
932 /* By default C2 port access is off */
933 c2dev->access = c2dev->flash_access = 0;
934 ops->access(c2dev, 0);
935
936 dev_info(c2dev->dev, "C2 port %s added\n", name);
937 dev_info(c2dev->dev, "%s flash has %d blocks x %d bytes "
938 "(%d bytes total)\n",
939 name, ops->blocks_num, ops->block_size,
940 ops->blocks_num * ops->block_size);
941
942 return c2dev;
943
944error_device_create_bin_file:
945 device_destroy(c2port_class, 0);
946
947error_device_create:
948 spin_lock_irq(&c2port_idr_lock);
949 idr_remove(&c2port_idr, id);
950 spin_unlock_irq(&c2port_idr_lock);
951
952error_idr_get_new:
953 kfree(c2dev);
954
955 return ERR_PTR(ret);
956}
957EXPORT_SYMBOL(c2port_device_register);
958
959void c2port_device_unregister(struct c2port_device *c2dev)
960{
961 if (!c2dev)
962 return;
963
964 dev_info(c2dev->dev, "C2 port %s removed\n", c2dev->name);
965
966 device_remove_bin_file(c2dev->dev, &c2port_bin_attrs);
967 spin_lock_irq(&c2port_idr_lock);
968 idr_remove(&c2port_idr, c2dev->id);
969 spin_unlock_irq(&c2port_idr_lock);
970
971 device_destroy(c2port_class, c2dev->id);
972
973 kfree(c2dev);
974}
975EXPORT_SYMBOL(c2port_device_unregister);
976
977/*
978 * Module stuff
979 */
980
981static int __init c2port_init(void)
982{
983 printk(KERN_INFO "Silicon Labs C2 port support v. " DRIVER_VERSION
984 " - (C) 2007 Rodolfo Giometti\n");
985
986 c2port_class = class_create(THIS_MODULE, "c2port");
987 if (!c2port_class) {
988 printk(KERN_ERR "c2port: failed to allocate class\n");
989 return -ENOMEM;
990 }
991 c2port_class->dev_attrs = c2port_attrs;
992
993 return 0;
994}
995
996static void __exit c2port_exit(void)
997{
998 class_destroy(c2port_class);
999}
1000
1001module_init(c2port_init);
1002module_exit(c2port_exit);
1003
1004MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
1005MODULE_DESCRIPTION("Silicon Labs C2 port support v. " DRIVER_VERSION);
1006MODULE_LICENSE("GPL");
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Silicon Labs C2 port core Linux support
4 *
5 * Copyright (c) 2007 Rodolfo Giometti <giometti@linux.it>
6 * Copyright (c) 2007 Eurotech S.p.A. <info@eurotech.it>
7 */
8
9#include <linux/module.h>
10#include <linux/init.h>
11#include <linux/device.h>
12#include <linux/errno.h>
13#include <linux/err.h>
14#include <linux/kernel.h>
15#include <linux/ctype.h>
16#include <linux/delay.h>
17#include <linux/idr.h>
18#include <linux/sched.h>
19#include <linux/slab.h>
20
21#include <linux/c2port.h>
22
23#define DRIVER_NAME "c2port"
24#define DRIVER_VERSION "0.51.0"
25
26static DEFINE_SPINLOCK(c2port_idr_lock);
27static DEFINE_IDR(c2port_idr);
28
29/*
30 * Local variables
31 */
32
33static struct class *c2port_class;
34
35/*
36 * C2 registers & commands defines
37 */
38
39/* C2 registers */
40#define C2PORT_DEVICEID 0x00
41#define C2PORT_REVID 0x01
42#define C2PORT_FPCTL 0x02
43#define C2PORT_FPDAT 0xB4
44
45/* C2 interface commands */
46#define C2PORT_GET_VERSION 0x01
47#define C2PORT_DEVICE_ERASE 0x03
48#define C2PORT_BLOCK_READ 0x06
49#define C2PORT_BLOCK_WRITE 0x07
50#define C2PORT_PAGE_ERASE 0x08
51
52/* C2 status return codes */
53#define C2PORT_INVALID_COMMAND 0x00
54#define C2PORT_COMMAND_FAILED 0x02
55#define C2PORT_COMMAND_OK 0x0d
56
57/*
58 * C2 port low level signal managements
59 */
60
61static void c2port_reset(struct c2port_device *dev)
62{
63 struct c2port_ops *ops = dev->ops;
64
65 /* To reset the device we have to keep clock line low for at least
66 * 20us.
67 */
68 local_irq_disable();
69 ops->c2ck_set(dev, 0);
70 udelay(25);
71 ops->c2ck_set(dev, 1);
72 local_irq_enable();
73
74 udelay(1);
75}
76
77static void c2port_strobe_ck(struct c2port_device *dev)
78{
79 struct c2port_ops *ops = dev->ops;
80
81 /* During hi-low-hi transition we disable local IRQs to avoid
82 * interructions since C2 port specification says that it must be
83 * shorter than 5us, otherwise the microcontroller may consider
84 * it as a reset signal!
85 */
86 local_irq_disable();
87 ops->c2ck_set(dev, 0);
88 udelay(1);
89 ops->c2ck_set(dev, 1);
90 local_irq_enable();
91
92 udelay(1);
93}
94
95/*
96 * C2 port basic functions
97 */
98
99static void c2port_write_ar(struct c2port_device *dev, u8 addr)
100{
101 struct c2port_ops *ops = dev->ops;
102 int i;
103
104 /* START field */
105 c2port_strobe_ck(dev);
106
107 /* INS field (11b, LSB first) */
108 ops->c2d_dir(dev, 0);
109 ops->c2d_set(dev, 1);
110 c2port_strobe_ck(dev);
111 ops->c2d_set(dev, 1);
112 c2port_strobe_ck(dev);
113
114 /* ADDRESS field */
115 for (i = 0; i < 8; i++) {
116 ops->c2d_set(dev, addr & 0x01);
117 c2port_strobe_ck(dev);
118
119 addr >>= 1;
120 }
121
122 /* STOP field */
123 ops->c2d_dir(dev, 1);
124 c2port_strobe_ck(dev);
125}
126
127static int c2port_read_ar(struct c2port_device *dev, u8 *addr)
128{
129 struct c2port_ops *ops = dev->ops;
130 int i;
131
132 /* START field */
133 c2port_strobe_ck(dev);
134
135 /* INS field (10b, LSB first) */
136 ops->c2d_dir(dev, 0);
137 ops->c2d_set(dev, 0);
138 c2port_strobe_ck(dev);
139 ops->c2d_set(dev, 1);
140 c2port_strobe_ck(dev);
141
142 /* ADDRESS field */
143 ops->c2d_dir(dev, 1);
144 *addr = 0;
145 for (i = 0; i < 8; i++) {
146 *addr >>= 1; /* shift in 8-bit ADDRESS field LSB first */
147
148 c2port_strobe_ck(dev);
149 if (ops->c2d_get(dev))
150 *addr |= 0x80;
151 }
152
153 /* STOP field */
154 c2port_strobe_ck(dev);
155
156 return 0;
157}
158
159static int c2port_write_dr(struct c2port_device *dev, u8 data)
160{
161 struct c2port_ops *ops = dev->ops;
162 int timeout, i;
163
164 /* START field */
165 c2port_strobe_ck(dev);
166
167 /* INS field (01b, LSB first) */
168 ops->c2d_dir(dev, 0);
169 ops->c2d_set(dev, 1);
170 c2port_strobe_ck(dev);
171 ops->c2d_set(dev, 0);
172 c2port_strobe_ck(dev);
173
174 /* LENGTH field (00b, LSB first -> 1 byte) */
175 ops->c2d_set(dev, 0);
176 c2port_strobe_ck(dev);
177 ops->c2d_set(dev, 0);
178 c2port_strobe_ck(dev);
179
180 /* DATA field */
181 for (i = 0; i < 8; i++) {
182 ops->c2d_set(dev, data & 0x01);
183 c2port_strobe_ck(dev);
184
185 data >>= 1;
186 }
187
188 /* WAIT field */
189 ops->c2d_dir(dev, 1);
190 timeout = 20;
191 do {
192 c2port_strobe_ck(dev);
193 if (ops->c2d_get(dev))
194 break;
195
196 udelay(1);
197 } while (--timeout > 0);
198 if (timeout == 0)
199 return -EIO;
200
201 /* STOP field */
202 c2port_strobe_ck(dev);
203
204 return 0;
205}
206
207static int c2port_read_dr(struct c2port_device *dev, u8 *data)
208{
209 struct c2port_ops *ops = dev->ops;
210 int timeout, i;
211
212 /* START field */
213 c2port_strobe_ck(dev);
214
215 /* INS field (00b, LSB first) */
216 ops->c2d_dir(dev, 0);
217 ops->c2d_set(dev, 0);
218 c2port_strobe_ck(dev);
219 ops->c2d_set(dev, 0);
220 c2port_strobe_ck(dev);
221
222 /* LENGTH field (00b, LSB first -> 1 byte) */
223 ops->c2d_set(dev, 0);
224 c2port_strobe_ck(dev);
225 ops->c2d_set(dev, 0);
226 c2port_strobe_ck(dev);
227
228 /* WAIT field */
229 ops->c2d_dir(dev, 1);
230 timeout = 20;
231 do {
232 c2port_strobe_ck(dev);
233 if (ops->c2d_get(dev))
234 break;
235
236 udelay(1);
237 } while (--timeout > 0);
238 if (timeout == 0)
239 return -EIO;
240
241 /* DATA field */
242 *data = 0;
243 for (i = 0; i < 8; i++) {
244 *data >>= 1; /* shift in 8-bit DATA field LSB first */
245
246 c2port_strobe_ck(dev);
247 if (ops->c2d_get(dev))
248 *data |= 0x80;
249 }
250
251 /* STOP field */
252 c2port_strobe_ck(dev);
253
254 return 0;
255}
256
257static int c2port_poll_in_busy(struct c2port_device *dev)
258{
259 u8 addr;
260 int ret, timeout = 20;
261
262 do {
263 ret = (c2port_read_ar(dev, &addr));
264 if (ret < 0)
265 return -EIO;
266
267 if (!(addr & 0x02))
268 break;
269
270 udelay(1);
271 } while (--timeout > 0);
272 if (timeout == 0)
273 return -EIO;
274
275 return 0;
276}
277
278static int c2port_poll_out_ready(struct c2port_device *dev)
279{
280 u8 addr;
281 int ret, timeout = 10000; /* erase flash needs long time... */
282
283 do {
284 ret = (c2port_read_ar(dev, &addr));
285 if (ret < 0)
286 return -EIO;
287
288 if (addr & 0x01)
289 break;
290
291 udelay(1);
292 } while (--timeout > 0);
293 if (timeout == 0)
294 return -EIO;
295
296 return 0;
297}
298
299/*
300 * sysfs methods
301 */
302
303static ssize_t c2port_show_name(struct device *dev,
304 struct device_attribute *attr, char *buf)
305{
306 struct c2port_device *c2dev = dev_get_drvdata(dev);
307
308 return sprintf(buf, "%s\n", c2dev->name);
309}
310static DEVICE_ATTR(name, 0444, c2port_show_name, NULL);
311
312static ssize_t c2port_show_flash_blocks_num(struct device *dev,
313 struct device_attribute *attr, char *buf)
314{
315 struct c2port_device *c2dev = dev_get_drvdata(dev);
316 struct c2port_ops *ops = c2dev->ops;
317
318 return sprintf(buf, "%d\n", ops->blocks_num);
319}
320static DEVICE_ATTR(flash_blocks_num, 0444, c2port_show_flash_blocks_num, NULL);
321
322static ssize_t c2port_show_flash_block_size(struct device *dev,
323 struct device_attribute *attr, char *buf)
324{
325 struct c2port_device *c2dev = dev_get_drvdata(dev);
326 struct c2port_ops *ops = c2dev->ops;
327
328 return sprintf(buf, "%d\n", ops->block_size);
329}
330static DEVICE_ATTR(flash_block_size, 0444, c2port_show_flash_block_size, NULL);
331
332static ssize_t c2port_show_flash_size(struct device *dev,
333 struct device_attribute *attr, char *buf)
334{
335 struct c2port_device *c2dev = dev_get_drvdata(dev);
336 struct c2port_ops *ops = c2dev->ops;
337
338 return sprintf(buf, "%d\n", ops->blocks_num * ops->block_size);
339}
340static DEVICE_ATTR(flash_size, 0444, c2port_show_flash_size, NULL);
341
342static ssize_t access_show(struct device *dev, struct device_attribute *attr,
343 char *buf)
344{
345 struct c2port_device *c2dev = dev_get_drvdata(dev);
346
347 return sprintf(buf, "%d\n", c2dev->access);
348}
349
350static ssize_t access_store(struct device *dev, struct device_attribute *attr,
351 const char *buf, size_t count)
352{
353 struct c2port_device *c2dev = dev_get_drvdata(dev);
354 struct c2port_ops *ops = c2dev->ops;
355 int status, ret;
356
357 ret = sscanf(buf, "%d", &status);
358 if (ret != 1)
359 return -EINVAL;
360
361 mutex_lock(&c2dev->mutex);
362
363 c2dev->access = !!status;
364
365 /* If access is "on" clock should be HIGH _before_ setting the line
366 * as output and data line should be set as INPUT anyway */
367 if (c2dev->access)
368 ops->c2ck_set(c2dev, 1);
369 ops->access(c2dev, c2dev->access);
370 if (c2dev->access)
371 ops->c2d_dir(c2dev, 1);
372
373 mutex_unlock(&c2dev->mutex);
374
375 return count;
376}
377static DEVICE_ATTR_RW(access);
378
379static ssize_t c2port_store_reset(struct device *dev,
380 struct device_attribute *attr,
381 const char *buf, size_t count)
382{
383 struct c2port_device *c2dev = dev_get_drvdata(dev);
384
385 /* Check the device access status */
386 if (!c2dev->access)
387 return -EBUSY;
388
389 mutex_lock(&c2dev->mutex);
390
391 c2port_reset(c2dev);
392 c2dev->flash_access = 0;
393
394 mutex_unlock(&c2dev->mutex);
395
396 return count;
397}
398static DEVICE_ATTR(reset, 0200, NULL, c2port_store_reset);
399
400static ssize_t __c2port_show_dev_id(struct c2port_device *dev, char *buf)
401{
402 u8 data;
403 int ret;
404
405 /* Select DEVICEID register for C2 data register accesses */
406 c2port_write_ar(dev, C2PORT_DEVICEID);
407
408 /* Read and return the device ID register */
409 ret = c2port_read_dr(dev, &data);
410 if (ret < 0)
411 return ret;
412
413 return sprintf(buf, "%d\n", data);
414}
415
416static ssize_t c2port_show_dev_id(struct device *dev,
417 struct device_attribute *attr, char *buf)
418{
419 struct c2port_device *c2dev = dev_get_drvdata(dev);
420 ssize_t ret;
421
422 /* Check the device access status */
423 if (!c2dev->access)
424 return -EBUSY;
425
426 mutex_lock(&c2dev->mutex);
427 ret = __c2port_show_dev_id(c2dev, buf);
428 mutex_unlock(&c2dev->mutex);
429
430 if (ret < 0)
431 dev_err(dev, "cannot read from %s\n", c2dev->name);
432
433 return ret;
434}
435static DEVICE_ATTR(dev_id, 0444, c2port_show_dev_id, NULL);
436
437static ssize_t __c2port_show_rev_id(struct c2port_device *dev, char *buf)
438{
439 u8 data;
440 int ret;
441
442 /* Select REVID register for C2 data register accesses */
443 c2port_write_ar(dev, C2PORT_REVID);
444
445 /* Read and return the revision ID register */
446 ret = c2port_read_dr(dev, &data);
447 if (ret < 0)
448 return ret;
449
450 return sprintf(buf, "%d\n", data);
451}
452
453static ssize_t c2port_show_rev_id(struct device *dev,
454 struct device_attribute *attr, char *buf)
455{
456 struct c2port_device *c2dev = dev_get_drvdata(dev);
457 ssize_t ret;
458
459 /* Check the device access status */
460 if (!c2dev->access)
461 return -EBUSY;
462
463 mutex_lock(&c2dev->mutex);
464 ret = __c2port_show_rev_id(c2dev, buf);
465 mutex_unlock(&c2dev->mutex);
466
467 if (ret < 0)
468 dev_err(c2dev->dev, "cannot read from %s\n", c2dev->name);
469
470 return ret;
471}
472static DEVICE_ATTR(rev_id, 0444, c2port_show_rev_id, NULL);
473
474static ssize_t c2port_show_flash_access(struct device *dev,
475 struct device_attribute *attr, char *buf)
476{
477 struct c2port_device *c2dev = dev_get_drvdata(dev);
478
479 return sprintf(buf, "%d\n", c2dev->flash_access);
480}
481
482static ssize_t __c2port_store_flash_access(struct c2port_device *dev,
483 int status)
484{
485 int ret;
486
487 /* Check the device access status */
488 if (!dev->access)
489 return -EBUSY;
490
491 dev->flash_access = !!status;
492
493 /* If flash_access is off we have nothing to do... */
494 if (dev->flash_access == 0)
495 return 0;
496
497 /* Target the C2 flash programming control register for C2 data
498 * register access */
499 c2port_write_ar(dev, C2PORT_FPCTL);
500
501 /* Write the first keycode to enable C2 Flash programming */
502 ret = c2port_write_dr(dev, 0x02);
503 if (ret < 0)
504 return ret;
505
506 /* Write the second keycode to enable C2 Flash programming */
507 ret = c2port_write_dr(dev, 0x01);
508 if (ret < 0)
509 return ret;
510
511 /* Delay for at least 20ms to ensure the target is ready for
512 * C2 flash programming */
513 mdelay(25);
514
515 return 0;
516}
517
518static ssize_t c2port_store_flash_access(struct device *dev,
519 struct device_attribute *attr,
520 const char *buf, size_t count)
521{
522 struct c2port_device *c2dev = dev_get_drvdata(dev);
523 int status;
524 ssize_t ret;
525
526 ret = sscanf(buf, "%d", &status);
527 if (ret != 1)
528 return -EINVAL;
529
530 mutex_lock(&c2dev->mutex);
531 ret = __c2port_store_flash_access(c2dev, status);
532 mutex_unlock(&c2dev->mutex);
533
534 if (ret < 0) {
535 dev_err(c2dev->dev, "cannot enable %s flash programming\n",
536 c2dev->name);
537 return ret;
538 }
539
540 return count;
541}
542static DEVICE_ATTR(flash_access, 0644, c2port_show_flash_access,
543 c2port_store_flash_access);
544
545static ssize_t __c2port_write_flash_erase(struct c2port_device *dev)
546{
547 u8 status;
548 int ret;
549
550 /* Target the C2 flash programming data register for C2 data register
551 * access.
552 */
553 c2port_write_ar(dev, C2PORT_FPDAT);
554
555 /* Send device erase command */
556 c2port_write_dr(dev, C2PORT_DEVICE_ERASE);
557
558 /* Wait for input acknowledge */
559 ret = c2port_poll_in_busy(dev);
560 if (ret < 0)
561 return ret;
562
563 /* Should check status before starting FLASH access sequence */
564
565 /* Wait for status information */
566 ret = c2port_poll_out_ready(dev);
567 if (ret < 0)
568 return ret;
569
570 /* Read flash programming interface status */
571 ret = c2port_read_dr(dev, &status);
572 if (ret < 0)
573 return ret;
574 if (status != C2PORT_COMMAND_OK)
575 return -EBUSY;
576
577 /* Send a three-byte arming sequence to enable the device erase.
578 * If the sequence is not received correctly, the command will be
579 * ignored.
580 * Sequence is: 0xde, 0xad, 0xa5.
581 */
582 c2port_write_dr(dev, 0xde);
583 ret = c2port_poll_in_busy(dev);
584 if (ret < 0)
585 return ret;
586 c2port_write_dr(dev, 0xad);
587 ret = c2port_poll_in_busy(dev);
588 if (ret < 0)
589 return ret;
590 c2port_write_dr(dev, 0xa5);
591 ret = c2port_poll_in_busy(dev);
592 if (ret < 0)
593 return ret;
594
595 ret = c2port_poll_out_ready(dev);
596 if (ret < 0)
597 return ret;
598
599 return 0;
600}
601
602static ssize_t c2port_store_flash_erase(struct device *dev,
603 struct device_attribute *attr,
604 const char *buf, size_t count)
605{
606 struct c2port_device *c2dev = dev_get_drvdata(dev);
607 int ret;
608
609 /* Check the device and flash access status */
610 if (!c2dev->access || !c2dev->flash_access)
611 return -EBUSY;
612
613 mutex_lock(&c2dev->mutex);
614 ret = __c2port_write_flash_erase(c2dev);
615 mutex_unlock(&c2dev->mutex);
616
617 if (ret < 0) {
618 dev_err(c2dev->dev, "cannot erase %s flash\n", c2dev->name);
619 return ret;
620 }
621
622 return count;
623}
624static DEVICE_ATTR(flash_erase, 0200, NULL, c2port_store_flash_erase);
625
626static ssize_t __c2port_read_flash_data(struct c2port_device *dev,
627 char *buffer, loff_t offset, size_t count)
628{
629 struct c2port_ops *ops = dev->ops;
630 u8 status, nread = 128;
631 int i, ret;
632
633 /* Check for flash end */
634 if (offset >= ops->block_size * ops->blocks_num)
635 return 0;
636
637 if (ops->block_size * ops->blocks_num - offset < nread)
638 nread = ops->block_size * ops->blocks_num - offset;
639 if (count < nread)
640 nread = count;
641 if (nread == 0)
642 return nread;
643
644 /* Target the C2 flash programming data register for C2 data register
645 * access */
646 c2port_write_ar(dev, C2PORT_FPDAT);
647
648 /* Send flash block read command */
649 c2port_write_dr(dev, C2PORT_BLOCK_READ);
650
651 /* Wait for input acknowledge */
652 ret = c2port_poll_in_busy(dev);
653 if (ret < 0)
654 return ret;
655
656 /* Should check status before starting FLASH access sequence */
657
658 /* Wait for status information */
659 ret = c2port_poll_out_ready(dev);
660 if (ret < 0)
661 return ret;
662
663 /* Read flash programming interface status */
664 ret = c2port_read_dr(dev, &status);
665 if (ret < 0)
666 return ret;
667 if (status != C2PORT_COMMAND_OK)
668 return -EBUSY;
669
670 /* Send address high byte */
671 c2port_write_dr(dev, offset >> 8);
672 ret = c2port_poll_in_busy(dev);
673 if (ret < 0)
674 return ret;
675
676 /* Send address low byte */
677 c2port_write_dr(dev, offset & 0x00ff);
678 ret = c2port_poll_in_busy(dev);
679 if (ret < 0)
680 return ret;
681
682 /* Send address block size */
683 c2port_write_dr(dev, nread);
684 ret = c2port_poll_in_busy(dev);
685 if (ret < 0)
686 return ret;
687
688 /* Should check status before reading FLASH block */
689
690 /* Wait for status information */
691 ret = c2port_poll_out_ready(dev);
692 if (ret < 0)
693 return ret;
694
695 /* Read flash programming interface status */
696 ret = c2port_read_dr(dev, &status);
697 if (ret < 0)
698 return ret;
699 if (status != C2PORT_COMMAND_OK)
700 return -EBUSY;
701
702 /* Read flash block */
703 for (i = 0; i < nread; i++) {
704 ret = c2port_poll_out_ready(dev);
705 if (ret < 0)
706 return ret;
707
708 ret = c2port_read_dr(dev, buffer+i);
709 if (ret < 0)
710 return ret;
711 }
712
713 return nread;
714}
715
716static ssize_t c2port_read_flash_data(struct file *filp, struct kobject *kobj,
717 struct bin_attribute *attr,
718 char *buffer, loff_t offset, size_t count)
719{
720 struct c2port_device *c2dev = dev_get_drvdata(kobj_to_dev(kobj));
721 ssize_t ret;
722
723 /* Check the device and flash access status */
724 if (!c2dev->access || !c2dev->flash_access)
725 return -EBUSY;
726
727 mutex_lock(&c2dev->mutex);
728 ret = __c2port_read_flash_data(c2dev, buffer, offset, count);
729 mutex_unlock(&c2dev->mutex);
730
731 if (ret < 0)
732 dev_err(c2dev->dev, "cannot read %s flash\n", c2dev->name);
733
734 return ret;
735}
736
737static ssize_t __c2port_write_flash_data(struct c2port_device *dev,
738 char *buffer, loff_t offset, size_t count)
739{
740 struct c2port_ops *ops = dev->ops;
741 u8 status, nwrite = 128;
742 int i, ret;
743
744 if (nwrite > count)
745 nwrite = count;
746 if (ops->block_size * ops->blocks_num - offset < nwrite)
747 nwrite = ops->block_size * ops->blocks_num - offset;
748
749 /* Check for flash end */
750 if (offset >= ops->block_size * ops->blocks_num)
751 return -EINVAL;
752
753 /* Target the C2 flash programming data register for C2 data register
754 * access */
755 c2port_write_ar(dev, C2PORT_FPDAT);
756
757 /* Send flash block write command */
758 c2port_write_dr(dev, C2PORT_BLOCK_WRITE);
759
760 /* Wait for input acknowledge */
761 ret = c2port_poll_in_busy(dev);
762 if (ret < 0)
763 return ret;
764
765 /* Should check status before starting FLASH access sequence */
766
767 /* Wait for status information */
768 ret = c2port_poll_out_ready(dev);
769 if (ret < 0)
770 return ret;
771
772 /* Read flash programming interface status */
773 ret = c2port_read_dr(dev, &status);
774 if (ret < 0)
775 return ret;
776 if (status != C2PORT_COMMAND_OK)
777 return -EBUSY;
778
779 /* Send address high byte */
780 c2port_write_dr(dev, offset >> 8);
781 ret = c2port_poll_in_busy(dev);
782 if (ret < 0)
783 return ret;
784
785 /* Send address low byte */
786 c2port_write_dr(dev, offset & 0x00ff);
787 ret = c2port_poll_in_busy(dev);
788 if (ret < 0)
789 return ret;
790
791 /* Send address block size */
792 c2port_write_dr(dev, nwrite);
793 ret = c2port_poll_in_busy(dev);
794 if (ret < 0)
795 return ret;
796
797 /* Should check status before writing FLASH block */
798
799 /* Wait for status information */
800 ret = c2port_poll_out_ready(dev);
801 if (ret < 0)
802 return ret;
803
804 /* Read flash programming interface status */
805 ret = c2port_read_dr(dev, &status);
806 if (ret < 0)
807 return ret;
808 if (status != C2PORT_COMMAND_OK)
809 return -EBUSY;
810
811 /* Write flash block */
812 for (i = 0; i < nwrite; i++) {
813 ret = c2port_write_dr(dev, *(buffer+i));
814 if (ret < 0)
815 return ret;
816
817 ret = c2port_poll_in_busy(dev);
818 if (ret < 0)
819 return ret;
820
821 }
822
823 /* Wait for last flash write to complete */
824 ret = c2port_poll_out_ready(dev);
825 if (ret < 0)
826 return ret;
827
828 return nwrite;
829}
830
831static ssize_t c2port_write_flash_data(struct file *filp, struct kobject *kobj,
832 struct bin_attribute *attr,
833 char *buffer, loff_t offset, size_t count)
834{
835 struct c2port_device *c2dev = dev_get_drvdata(kobj_to_dev(kobj));
836 int ret;
837
838 /* Check the device access status */
839 if (!c2dev->access || !c2dev->flash_access)
840 return -EBUSY;
841
842 mutex_lock(&c2dev->mutex);
843 ret = __c2port_write_flash_data(c2dev, buffer, offset, count);
844 mutex_unlock(&c2dev->mutex);
845
846 if (ret < 0)
847 dev_err(c2dev->dev, "cannot write %s flash\n", c2dev->name);
848
849 return ret;
850}
851/* size is computed at run-time */
852static BIN_ATTR(flash_data, 0644, c2port_read_flash_data,
853 c2port_write_flash_data, 0);
854
855/*
856 * Class attributes
857 */
858static struct attribute *c2port_attrs[] = {
859 &dev_attr_name.attr,
860 &dev_attr_flash_blocks_num.attr,
861 &dev_attr_flash_block_size.attr,
862 &dev_attr_flash_size.attr,
863 &dev_attr_access.attr,
864 &dev_attr_reset.attr,
865 &dev_attr_dev_id.attr,
866 &dev_attr_rev_id.attr,
867 &dev_attr_flash_access.attr,
868 &dev_attr_flash_erase.attr,
869 NULL,
870};
871
872static struct bin_attribute *c2port_bin_attrs[] = {
873 &bin_attr_flash_data,
874 NULL,
875};
876
877static const struct attribute_group c2port_group = {
878 .attrs = c2port_attrs,
879 .bin_attrs = c2port_bin_attrs,
880};
881
882static const struct attribute_group *c2port_groups[] = {
883 &c2port_group,
884 NULL,
885};
886
887/*
888 * Exported functions
889 */
890
891struct c2port_device *c2port_device_register(char *name,
892 struct c2port_ops *ops, void *devdata)
893{
894 struct c2port_device *c2dev;
895 int ret;
896
897 if (unlikely(!ops) || unlikely(!ops->access) || \
898 unlikely(!ops->c2d_dir) || unlikely(!ops->c2ck_set) || \
899 unlikely(!ops->c2d_get) || unlikely(!ops->c2d_set))
900 return ERR_PTR(-EINVAL);
901
902 c2dev = kzalloc(sizeof(struct c2port_device), GFP_KERNEL);
903 if (unlikely(!c2dev))
904 return ERR_PTR(-ENOMEM);
905
906 idr_preload(GFP_KERNEL);
907 spin_lock_irq(&c2port_idr_lock);
908 ret = idr_alloc(&c2port_idr, c2dev, 0, 0, GFP_NOWAIT);
909 spin_unlock_irq(&c2port_idr_lock);
910 idr_preload_end();
911
912 if (ret < 0)
913 goto error_idr_alloc;
914 c2dev->id = ret;
915
916 bin_attr_flash_data.size = ops->blocks_num * ops->block_size;
917
918 c2dev->dev = device_create(c2port_class, NULL, 0, c2dev,
919 "c2port%d", c2dev->id);
920 if (IS_ERR(c2dev->dev)) {
921 ret = PTR_ERR(c2dev->dev);
922 goto error_device_create;
923 }
924 dev_set_drvdata(c2dev->dev, c2dev);
925
926 strscpy(c2dev->name, name, sizeof(c2dev->name));
927 c2dev->ops = ops;
928 mutex_init(&c2dev->mutex);
929
930 /* By default C2 port access is off */
931 c2dev->access = c2dev->flash_access = 0;
932 ops->access(c2dev, 0);
933
934 dev_info(c2dev->dev, "C2 port %s added\n", name);
935 dev_info(c2dev->dev, "%s flash has %d blocks x %d bytes "
936 "(%d bytes total)\n",
937 name, ops->blocks_num, ops->block_size,
938 ops->blocks_num * ops->block_size);
939
940 return c2dev;
941
942error_device_create:
943 spin_lock_irq(&c2port_idr_lock);
944 idr_remove(&c2port_idr, c2dev->id);
945 spin_unlock_irq(&c2port_idr_lock);
946
947error_idr_alloc:
948 kfree(c2dev);
949
950 return ERR_PTR(ret);
951}
952EXPORT_SYMBOL(c2port_device_register);
953
954void c2port_device_unregister(struct c2port_device *c2dev)
955{
956 if (!c2dev)
957 return;
958
959 dev_info(c2dev->dev, "C2 port %s removed\n", c2dev->name);
960
961 spin_lock_irq(&c2port_idr_lock);
962 idr_remove(&c2port_idr, c2dev->id);
963 spin_unlock_irq(&c2port_idr_lock);
964
965 device_destroy(c2port_class, c2dev->id);
966
967 kfree(c2dev);
968}
969EXPORT_SYMBOL(c2port_device_unregister);
970
971/*
972 * Module stuff
973 */
974
975static int __init c2port_init(void)
976{
977 printk(KERN_INFO "Silicon Labs C2 port support v. " DRIVER_VERSION
978 " - (C) 2007 Rodolfo Giometti\n");
979
980 c2port_class = class_create("c2port");
981 if (IS_ERR(c2port_class)) {
982 printk(KERN_ERR "c2port: failed to allocate class\n");
983 return PTR_ERR(c2port_class);
984 }
985 c2port_class->dev_groups = c2port_groups;
986
987 return 0;
988}
989
990static void __exit c2port_exit(void)
991{
992 class_destroy(c2port_class);
993}
994
995module_init(c2port_init);
996module_exit(c2port_exit);
997
998MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
999MODULE_DESCRIPTION("Silicon Labs C2 port support v. " DRIVER_VERSION);
1000MODULE_LICENSE("GPL");