2 * Silicon Labs C2 port core Linux support
4 * Copyright (c) 2007 Rodolfo Giometti <giometti@linux.it>
5 * Copyright (c) 2007 Eurotech S.p.A. <info@eurotech.it>
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
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>
24 #include <linux/c2port.h>
26 #define DRIVER_NAME "c2port"
27 #define DRIVER_VERSION "0.51.0"
29 static DEFINE_SPINLOCK(c2port_idr_lock);
30 static DEFINE_IDR(c2port_idr);
36 static struct class *c2port_class;
39 * C2 registers & commands defines
43 #define C2PORT_DEVICEID 0x00
44 #define C2PORT_REVID 0x01
45 #define C2PORT_FPCTL 0x02
46 #define C2PORT_FPDAT 0xB4
48 /* C2 interface commands */
49 #define C2PORT_GET_VERSION 0x01
50 #define C2PORT_DEVICE_ERASE 0x03
51 #define C2PORT_BLOCK_READ 0x06
52 #define C2PORT_BLOCK_WRITE 0x07
53 #define C2PORT_PAGE_ERASE 0x08
55 /* C2 status return codes */
56 #define C2PORT_INVALID_COMMAND 0x00
57 #define C2PORT_COMMAND_FAILED 0x02
58 #define C2PORT_COMMAND_OK 0x0d
61 * C2 port low level signal managements
64 static void c2port_reset(struct c2port_device *dev)
66 struct c2port_ops *ops = dev->ops;
68 /* To reset the device we have to keep clock line low for at least
72 ops->c2ck_set(dev, 0);
74 ops->c2ck_set(dev, 1);
80 static void c2port_strobe_ck(struct c2port_device *dev)
82 struct c2port_ops *ops = dev->ops;
84 /* During hi-low-hi transition we disable local IRQs to avoid
85 * interructions since C2 port specification says that it must be
86 * shorter than 5us, otherwise the microcontroller may consider
87 * it as a reset signal!
90 ops->c2ck_set(dev, 0);
92 ops->c2ck_set(dev, 1);
99 * C2 port basic functions
102 static void c2port_write_ar(struct c2port_device *dev, u8 addr)
104 struct c2port_ops *ops = dev->ops;
108 c2port_strobe_ck(dev);
110 /* INS field (11b, LSB first) */
111 ops->c2d_dir(dev, 0);
112 ops->c2d_set(dev, 1);
113 c2port_strobe_ck(dev);
114 ops->c2d_set(dev, 1);
115 c2port_strobe_ck(dev);
118 for (i = 0; i < 8; i++) {
119 ops->c2d_set(dev, addr & 0x01);
120 c2port_strobe_ck(dev);
126 ops->c2d_dir(dev, 1);
127 c2port_strobe_ck(dev);
130 static int c2port_read_ar(struct c2port_device *dev, u8 *addr)
132 struct c2port_ops *ops = dev->ops;
136 c2port_strobe_ck(dev);
138 /* INS field (10b, LSB first) */
139 ops->c2d_dir(dev, 0);
140 ops->c2d_set(dev, 0);
141 c2port_strobe_ck(dev);
142 ops->c2d_set(dev, 1);
143 c2port_strobe_ck(dev);
146 ops->c2d_dir(dev, 1);
148 for (i = 0; i < 8; i++) {
149 *addr >>= 1; /* shift in 8-bit ADDRESS field LSB first */
151 c2port_strobe_ck(dev);
152 if (ops->c2d_get(dev))
157 c2port_strobe_ck(dev);
162 static int c2port_write_dr(struct c2port_device *dev, u8 data)
164 struct c2port_ops *ops = dev->ops;
168 c2port_strobe_ck(dev);
170 /* INS field (01b, LSB first) */
171 ops->c2d_dir(dev, 0);
172 ops->c2d_set(dev, 1);
173 c2port_strobe_ck(dev);
174 ops->c2d_set(dev, 0);
175 c2port_strobe_ck(dev);
177 /* LENGTH field (00b, LSB first -> 1 byte) */
178 ops->c2d_set(dev, 0);
179 c2port_strobe_ck(dev);
180 ops->c2d_set(dev, 0);
181 c2port_strobe_ck(dev);
184 for (i = 0; i < 8; i++) {
185 ops->c2d_set(dev, data & 0x01);
186 c2port_strobe_ck(dev);
192 ops->c2d_dir(dev, 1);
195 c2port_strobe_ck(dev);
196 if (ops->c2d_get(dev))
200 } while (--timeout > 0);
205 c2port_strobe_ck(dev);
210 static int c2port_read_dr(struct c2port_device *dev, u8 *data)
212 struct c2port_ops *ops = dev->ops;
216 c2port_strobe_ck(dev);
218 /* INS field (00b, LSB first) */
219 ops->c2d_dir(dev, 0);
220 ops->c2d_set(dev, 0);
221 c2port_strobe_ck(dev);
222 ops->c2d_set(dev, 0);
223 c2port_strobe_ck(dev);
225 /* LENGTH field (00b, LSB first -> 1 byte) */
226 ops->c2d_set(dev, 0);
227 c2port_strobe_ck(dev);
228 ops->c2d_set(dev, 0);
229 c2port_strobe_ck(dev);
232 ops->c2d_dir(dev, 1);
235 c2port_strobe_ck(dev);
236 if (ops->c2d_get(dev))
240 } while (--timeout > 0);
246 for (i = 0; i < 8; i++) {
247 *data >>= 1; /* shift in 8-bit DATA field LSB first */
249 c2port_strobe_ck(dev);
250 if (ops->c2d_get(dev))
255 c2port_strobe_ck(dev);
260 static int c2port_poll_in_busy(struct c2port_device *dev)
263 int ret, timeout = 20;
266 ret = (c2port_read_ar(dev, &addr));
274 } while (--timeout > 0);
281 static int c2port_poll_out_ready(struct c2port_device *dev)
284 int ret, timeout = 10000; /* erase flash needs long time... */
287 ret = (c2port_read_ar(dev, &addr));
295 } while (--timeout > 0);
306 static ssize_t c2port_show_name(struct device *dev,
307 struct device_attribute *attr, char *buf)
309 struct c2port_device *c2dev = dev_get_drvdata(dev);
311 return sprintf(buf, "%s\n", c2dev->name);
314 static ssize_t c2port_show_flash_blocks_num(struct device *dev,
315 struct device_attribute *attr, char *buf)
317 struct c2port_device *c2dev = dev_get_drvdata(dev);
318 struct c2port_ops *ops = c2dev->ops;
320 return sprintf(buf, "%d\n", ops->blocks_num);
323 static ssize_t c2port_show_flash_block_size(struct device *dev,
324 struct device_attribute *attr, char *buf)
326 struct c2port_device *c2dev = dev_get_drvdata(dev);
327 struct c2port_ops *ops = c2dev->ops;
329 return sprintf(buf, "%d\n", ops->block_size);
332 static ssize_t c2port_show_flash_size(struct device *dev,
333 struct device_attribute *attr, char *buf)
335 struct c2port_device *c2dev = dev_get_drvdata(dev);
336 struct c2port_ops *ops = c2dev->ops;
338 return sprintf(buf, "%d\n", ops->blocks_num * ops->block_size);
341 static ssize_t c2port_show_access(struct device *dev,
342 struct device_attribute *attr, char *buf)
344 struct c2port_device *c2dev = dev_get_drvdata(dev);
346 return sprintf(buf, "%d\n", c2dev->access);
349 static ssize_t c2port_store_access(struct device *dev,
350 struct device_attribute *attr,
351 const char *buf, size_t count)
353 struct c2port_device *c2dev = dev_get_drvdata(dev);
354 struct c2port_ops *ops = c2dev->ops;
357 ret = sscanf(buf, "%d", &status);
361 mutex_lock(&c2dev->mutex);
363 c2dev->access = !!status;
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 */
368 ops->c2ck_set(c2dev, 1);
369 ops->access(c2dev, c2dev->access);
371 ops->c2d_dir(c2dev, 1);
373 mutex_unlock(&c2dev->mutex);
378 static ssize_t c2port_store_reset(struct device *dev,
379 struct device_attribute *attr,
380 const char *buf, size_t count)
382 struct c2port_device *c2dev = dev_get_drvdata(dev);
384 /* Check the device access status */
388 mutex_lock(&c2dev->mutex);
391 c2dev->flash_access = 0;
393 mutex_unlock(&c2dev->mutex);
398 static ssize_t __c2port_show_dev_id(struct c2port_device *dev, char *buf)
403 /* Select DEVICEID register for C2 data register accesses */
404 c2port_write_ar(dev, C2PORT_DEVICEID);
406 /* Read and return the device ID register */
407 ret = c2port_read_dr(dev, &data);
411 return sprintf(buf, "%d\n", data);
414 static ssize_t c2port_show_dev_id(struct device *dev,
415 struct device_attribute *attr, char *buf)
417 struct c2port_device *c2dev = dev_get_drvdata(dev);
420 /* Check the device access status */
424 mutex_lock(&c2dev->mutex);
425 ret = __c2port_show_dev_id(c2dev, buf);
426 mutex_unlock(&c2dev->mutex);
429 dev_err(dev, "cannot read from %s\n", c2dev->name);
434 static ssize_t __c2port_show_rev_id(struct c2port_device *dev, char *buf)
439 /* Select REVID register for C2 data register accesses */
440 c2port_write_ar(dev, C2PORT_REVID);
442 /* Read and return the revision ID register */
443 ret = c2port_read_dr(dev, &data);
447 return sprintf(buf, "%d\n", data);
450 static ssize_t c2port_show_rev_id(struct device *dev,
451 struct device_attribute *attr, char *buf)
453 struct c2port_device *c2dev = dev_get_drvdata(dev);
456 /* Check the device access status */
460 mutex_lock(&c2dev->mutex);
461 ret = __c2port_show_rev_id(c2dev, buf);
462 mutex_unlock(&c2dev->mutex);
465 dev_err(c2dev->dev, "cannot read from %s\n", c2dev->name);
470 static ssize_t c2port_show_flash_access(struct device *dev,
471 struct device_attribute *attr, char *buf)
473 struct c2port_device *c2dev = dev_get_drvdata(dev);
475 return sprintf(buf, "%d\n", c2dev->flash_access);
478 static ssize_t __c2port_store_flash_access(struct c2port_device *dev,
483 /* Check the device access status */
487 dev->flash_access = !!status;
489 /* If flash_access is off we have nothing to do... */
490 if (dev->flash_access == 0)
493 /* Target the C2 flash programming control register for C2 data
495 c2port_write_ar(dev, C2PORT_FPCTL);
497 /* Write the first keycode to enable C2 Flash programming */
498 ret = c2port_write_dr(dev, 0x02);
502 /* Write the second keycode to enable C2 Flash programming */
503 ret = c2port_write_dr(dev, 0x01);
507 /* Delay for at least 20ms to ensure the target is ready for
508 * C2 flash programming */
514 static ssize_t c2port_store_flash_access(struct device *dev,
515 struct device_attribute *attr,
516 const char *buf, size_t count)
518 struct c2port_device *c2dev = dev_get_drvdata(dev);
522 ret = sscanf(buf, "%d", &status);
526 mutex_lock(&c2dev->mutex);
527 ret = __c2port_store_flash_access(c2dev, status);
528 mutex_unlock(&c2dev->mutex);
531 dev_err(c2dev->dev, "cannot enable %s flash programming\n",
539 static ssize_t __c2port_write_flash_erase(struct c2port_device *dev)
544 /* Target the C2 flash programming data register for C2 data register
547 c2port_write_ar(dev, C2PORT_FPDAT);
549 /* Send device erase command */
550 c2port_write_dr(dev, C2PORT_DEVICE_ERASE);
552 /* Wait for input acknowledge */
553 ret = c2port_poll_in_busy(dev);
557 /* Should check status before starting FLASH access sequence */
559 /* Wait for status information */
560 ret = c2port_poll_out_ready(dev);
564 /* Read flash programming interface status */
565 ret = c2port_read_dr(dev, &status);
568 if (status != C2PORT_COMMAND_OK)
571 /* Send a three-byte arming sequence to enable the device erase.
572 * If the sequence is not received correctly, the command will be
574 * Sequence is: 0xde, 0xad, 0xa5.
576 c2port_write_dr(dev, 0xde);
577 ret = c2port_poll_in_busy(dev);
580 c2port_write_dr(dev, 0xad);
581 ret = c2port_poll_in_busy(dev);
584 c2port_write_dr(dev, 0xa5);
585 ret = c2port_poll_in_busy(dev);
589 ret = c2port_poll_out_ready(dev);
596 static ssize_t c2port_store_flash_erase(struct device *dev,
597 struct device_attribute *attr,
598 const char *buf, size_t count)
600 struct c2port_device *c2dev = dev_get_drvdata(dev);
603 /* Check the device and flash access status */
604 if (!c2dev->access || !c2dev->flash_access)
607 mutex_lock(&c2dev->mutex);
608 ret = __c2port_write_flash_erase(c2dev);
609 mutex_unlock(&c2dev->mutex);
612 dev_err(c2dev->dev, "cannot erase %s flash\n", c2dev->name);
619 static ssize_t __c2port_read_flash_data(struct c2port_device *dev,
620 char *buffer, loff_t offset, size_t count)
622 struct c2port_ops *ops = dev->ops;
623 u8 status, nread = 128;
626 /* Check for flash end */
627 if (offset >= ops->block_size * ops->blocks_num)
630 if (ops->block_size * ops->blocks_num - offset < nread)
631 nread = ops->block_size * ops->blocks_num - offset;
637 /* Target the C2 flash programming data register for C2 data register
639 c2port_write_ar(dev, C2PORT_FPDAT);
641 /* Send flash block read command */
642 c2port_write_dr(dev, C2PORT_BLOCK_READ);
644 /* Wait for input acknowledge */
645 ret = c2port_poll_in_busy(dev);
649 /* Should check status before starting FLASH access sequence */
651 /* Wait for status information */
652 ret = c2port_poll_out_ready(dev);
656 /* Read flash programming interface status */
657 ret = c2port_read_dr(dev, &status);
660 if (status != C2PORT_COMMAND_OK)
663 /* Send address high byte */
664 c2port_write_dr(dev, offset >> 8);
665 ret = c2port_poll_in_busy(dev);
669 /* Send address low byte */
670 c2port_write_dr(dev, offset & 0x00ff);
671 ret = c2port_poll_in_busy(dev);
675 /* Send address block size */
676 c2port_write_dr(dev, nread);
677 ret = c2port_poll_in_busy(dev);
681 /* Should check status before reading FLASH block */
683 /* Wait for status information */
684 ret = c2port_poll_out_ready(dev);
688 /* Read flash programming interface status */
689 ret = c2port_read_dr(dev, &status);
692 if (status != C2PORT_COMMAND_OK)
695 /* Read flash block */
696 for (i = 0; i < nread; i++) {
697 ret = c2port_poll_out_ready(dev);
701 ret = c2port_read_dr(dev, buffer+i);
709 static ssize_t c2port_read_flash_data(struct kobject *kobj,
710 struct bin_attribute *attr,
711 char *buffer, loff_t offset, size_t count)
713 struct c2port_device *c2dev =
714 dev_get_drvdata(container_of(kobj,
715 struct device, kobj));
718 /* Check the device and flash access status */
719 if (!c2dev->access || !c2dev->flash_access)
722 mutex_lock(&c2dev->mutex);
723 ret = __c2port_read_flash_data(c2dev, buffer, offset, count);
724 mutex_unlock(&c2dev->mutex);
727 dev_err(c2dev->dev, "cannot read %s flash\n", c2dev->name);
732 static ssize_t __c2port_write_flash_data(struct c2port_device *dev,
733 char *buffer, loff_t offset, size_t count)
735 struct c2port_ops *ops = dev->ops;
736 u8 status, nwrite = 128;
741 if (ops->block_size * ops->blocks_num - offset < nwrite)
742 nwrite = ops->block_size * ops->blocks_num - offset;
744 /* Check for flash end */
745 if (offset >= ops->block_size * ops->blocks_num)
748 /* Target the C2 flash programming data register for C2 data register
750 c2port_write_ar(dev, C2PORT_FPDAT);
752 /* Send flash block write command */
753 c2port_write_dr(dev, C2PORT_BLOCK_WRITE);
755 /* Wait for input acknowledge */
756 ret = c2port_poll_in_busy(dev);
760 /* Should check status before starting FLASH access sequence */
762 /* Wait for status information */
763 ret = c2port_poll_out_ready(dev);
767 /* Read flash programming interface status */
768 ret = c2port_read_dr(dev, &status);
771 if (status != C2PORT_COMMAND_OK)
774 /* Send address high byte */
775 c2port_write_dr(dev, offset >> 8);
776 ret = c2port_poll_in_busy(dev);
780 /* Send address low byte */
781 c2port_write_dr(dev, offset & 0x00ff);
782 ret = c2port_poll_in_busy(dev);
786 /* Send address block size */
787 c2port_write_dr(dev, nwrite);
788 ret = c2port_poll_in_busy(dev);
792 /* Should check status before writing FLASH block */
794 /* Wait for status information */
795 ret = c2port_poll_out_ready(dev);
799 /* Read flash programming interface status */
800 ret = c2port_read_dr(dev, &status);
803 if (status != C2PORT_COMMAND_OK)
806 /* Write flash block */
807 for (i = 0; i < nwrite; i++) {
808 ret = c2port_write_dr(dev, *(buffer+i));
812 ret = c2port_poll_in_busy(dev);
818 /* Wait for last flash write to complete */
819 ret = c2port_poll_out_ready(dev);
826 static ssize_t c2port_write_flash_data(struct kobject *kobj,
827 struct bin_attribute *attr,
828 char *buffer, loff_t offset, size_t count)
830 struct c2port_device *c2dev =
831 dev_get_drvdata(container_of(kobj,
832 struct device, kobj));
835 /* Check the device access status */
836 if (!c2dev->access || !c2dev->flash_access)
839 mutex_lock(&c2dev->mutex);
840 ret = __c2port_write_flash_data(c2dev, buffer, offset, count);
841 mutex_unlock(&c2dev->mutex);
844 dev_err(c2dev->dev, "cannot write %s flash\n", c2dev->name);
853 static struct device_attribute c2port_attrs[] = {
854 __ATTR(name, 0444, c2port_show_name, NULL),
855 __ATTR(flash_blocks_num, 0444, c2port_show_flash_blocks_num, NULL),
856 __ATTR(flash_block_size, 0444, c2port_show_flash_block_size, NULL),
857 __ATTR(flash_size, 0444, c2port_show_flash_size, NULL),
858 __ATTR(access, 0644, c2port_show_access, c2port_store_access),
859 __ATTR(reset, 0200, NULL, c2port_store_reset),
860 __ATTR(dev_id, 0444, c2port_show_dev_id, NULL),
861 __ATTR(rev_id, 0444, c2port_show_rev_id, NULL),
863 __ATTR(flash_access, 0644, c2port_show_flash_access,
864 c2port_store_flash_access),
865 __ATTR(flash_erase, 0200, NULL, c2port_store_flash_erase),
869 static struct bin_attribute c2port_bin_attrs = {
871 .name = "flash_data",
874 .read = c2port_read_flash_data,
875 .write = c2port_write_flash_data,
876 /* .size is computed at run-time */
883 struct c2port_device *c2port_device_register(char *name,
884 struct c2port_ops *ops, void *devdata)
886 struct c2port_device *c2dev;
889 if (unlikely(!ops) || unlikely(!ops->access) || \
890 unlikely(!ops->c2d_dir) || unlikely(!ops->c2ck_set) || \
891 unlikely(!ops->c2d_get) || unlikely(!ops->c2d_set))
892 return ERR_PTR(-EINVAL);
894 c2dev = kmalloc(sizeof(struct c2port_device), GFP_KERNEL);
895 kmemcheck_annotate_bitfield(c2dev, flags);
896 if (unlikely(!c2dev))
897 return ERR_PTR(-ENOMEM);
899 ret = idr_pre_get(&c2port_idr, GFP_KERNEL);
902 goto error_idr_get_new;
905 spin_lock_irq(&c2port_idr_lock);
906 ret = idr_get_new(&c2port_idr, c2dev, &id);
907 spin_unlock_irq(&c2port_idr_lock);
910 goto error_idr_get_new;
913 c2dev->dev = device_create(c2port_class, NULL, 0, c2dev,
915 if (unlikely(IS_ERR(c2dev->dev))) {
916 ret = PTR_ERR(c2dev->dev);
917 goto error_device_create;
919 dev_set_drvdata(c2dev->dev, c2dev);
921 strncpy(c2dev->name, name, C2PORT_NAME_LEN);
923 mutex_init(&c2dev->mutex);
925 /* Create binary file */
926 c2port_bin_attrs.size = ops->blocks_num * ops->block_size;
927 ret = device_create_bin_file(c2dev->dev, &c2port_bin_attrs);
929 goto error_device_create_bin_file;
931 /* By default C2 port access is off */
932 c2dev->access = c2dev->flash_access = 0;
933 ops->access(c2dev, 0);
935 dev_info(c2dev->dev, "C2 port %s added\n", name);
936 dev_info(c2dev->dev, "%s flash has %d blocks x %d bytes "
937 "(%d bytes total)\n",
938 name, ops->blocks_num, ops->block_size,
939 ops->blocks_num * ops->block_size);
943 error_device_create_bin_file:
944 device_destroy(c2port_class, 0);
947 spin_lock_irq(&c2port_idr_lock);
948 idr_remove(&c2port_idr, id);
949 spin_unlock_irq(&c2port_idr_lock);
956 EXPORT_SYMBOL(c2port_device_register);
958 void c2port_device_unregister(struct c2port_device *c2dev)
963 dev_info(c2dev->dev, "C2 port %s removed\n", c2dev->name);
965 device_remove_bin_file(c2dev->dev, &c2port_bin_attrs);
966 spin_lock_irq(&c2port_idr_lock);
967 idr_remove(&c2port_idr, c2dev->id);
968 spin_unlock_irq(&c2port_idr_lock);
970 device_destroy(c2port_class, c2dev->id);
974 EXPORT_SYMBOL(c2port_device_unregister);
980 static int __init c2port_init(void)
982 printk(KERN_INFO "Silicon Labs C2 port support v. " DRIVER_VERSION
983 " - (C) 2007 Rodolfo Giometti\n");
985 c2port_class = class_create(THIS_MODULE, "c2port");
987 printk(KERN_ERR "c2port: failed to allocate class\n");
990 c2port_class->dev_attrs = c2port_attrs;
995 static void __exit c2port_exit(void)
997 class_destroy(c2port_class);
1000 module_init(c2port_init);
1001 module_exit(c2port_exit);
1003 MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
1004 MODULE_DESCRIPTION("Silicon Labs C2 port support v. " DRIVER_VERSION);
1005 MODULE_LICENSE("GPL");