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 (IS_ERR(c2port_class)) {
988		printk(KERN_ERR "c2port: failed to allocate class\n");
989		return PTR_ERR(c2port_class);
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");
1007