Merge commit 'v2.6.27-rc1' into x86/urgent
[linux-2.6] / drivers / char / nwflash.c
1 /*
2  * Flash memory interface rev.5 driver for the Intel
3  * Flash chips used on the NetWinder.
4  *
5  * 20/08/2000   RMK     use __ioremap to map flash into virtual memory
6  *                      make a few more places use "volatile"
7  * 22/05/2001   RMK     - Lock read against write
8  *                      - merge printk level changes (with mods) from Alan Cox.
9  *                      - use *ppos as the file position, not file->f_pos.
10  *                      - fix check for out of range pos and r/w size
11  *
12  * Please note that we are tampering with the only flash chip in the
13  * machine, which contains the bootup code.  We therefore have the
14  * power to convert these machines into doorstops...
15  */
16
17 #include <linux/module.h>
18 #include <linux/types.h>
19 #include <linux/fs.h>
20 #include <linux/errno.h>
21 #include <linux/mm.h>
22 #include <linux/delay.h>
23 #include <linux/proc_fs.h>
24 #include <linux/miscdevice.h>
25 #include <linux/spinlock.h>
26 #include <linux/rwsem.h>
27 #include <linux/init.h>
28 #include <linux/smp_lock.h>
29 #include <linux/mutex.h>
30
31 #include <asm/hardware/dec21285.h>
32 #include <asm/io.h>
33 #include <asm/leds.h>
34 #include <asm/mach-types.h>
35 #include <asm/system.h>
36 #include <asm/uaccess.h>
37
38 /*****************************************************************************/
39 #include <asm/nwflash.h>
40
41 #define NWFLASH_VERSION "6.4"
42
43 static void kick_open(void);
44 static int get_flash_id(void);
45 static int erase_block(int nBlock);
46 static int write_block(unsigned long p, const char __user *buf, int count);
47
48 #define KFLASH_SIZE     1024*1024       //1 Meg
49 #define KFLASH_SIZE4    4*1024*1024     //4 Meg
50 #define KFLASH_ID       0x89A6          //Intel flash
51 #define KFLASH_ID4      0xB0D4          //Intel flash 4Meg
52
53 static int flashdebug;          //if set - we will display progress msgs
54
55 static int gbWriteEnable;
56 static int gbWriteBase64Enable;
57 static volatile unsigned char *FLASH_BASE;
58 static int gbFlashSize = KFLASH_SIZE;
59 static DEFINE_MUTEX(nwflash_mutex);
60
61 extern spinlock_t gpio_lock;
62
63 static int get_flash_id(void)
64 {
65         volatile unsigned int c1, c2;
66
67         /*
68          * try to get flash chip ID
69          */
70         kick_open();
71         c2 = inb(0x80);
72         *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x90;
73         udelay(15);
74         c1 = *(volatile unsigned char *) FLASH_BASE;
75         c2 = inb(0x80);
76
77         /*
78          * on 4 Meg flash the second byte is actually at offset 2...
79          */
80         if (c1 == 0xB0)
81                 c2 = *(volatile unsigned char *) (FLASH_BASE + 2);
82         else
83                 c2 = *(volatile unsigned char *) (FLASH_BASE + 1);
84
85         c2 += (c1 << 8);
86
87         /*
88          * set it back to read mode
89          */
90         *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0xFF;
91
92         if (c2 == KFLASH_ID4)
93                 gbFlashSize = KFLASH_SIZE4;
94
95         return c2;
96 }
97
98 static int flash_ioctl(struct inode *inodep, struct file *filep, unsigned int cmd, unsigned long arg)
99 {
100         switch (cmd) {
101         case CMD_WRITE_DISABLE:
102                 gbWriteBase64Enable = 0;
103                 gbWriteEnable = 0;
104                 break;
105
106         case CMD_WRITE_ENABLE:
107                 gbWriteEnable = 1;
108                 break;
109
110         case CMD_WRITE_BASE64K_ENABLE:
111                 gbWriteBase64Enable = 1;
112                 break;
113
114         default:
115                 gbWriteBase64Enable = 0;
116                 gbWriteEnable = 0;
117                 return -EINVAL;
118         }
119         return 0;
120 }
121
122 static ssize_t flash_read(struct file *file, char __user *buf, size_t size,
123                           loff_t *ppos)
124 {
125         ssize_t ret;
126
127         if (flashdebug)
128                 printk(KERN_DEBUG "flash_read: flash_read: offset=0x%llx, "
129                        "buffer=%p, count=0x%zx.\n", *ppos, buf, size);
130         /*
131          * We now lock against reads and writes. --rmk
132          */
133         if (mutex_lock_interruptible(&nwflash_mutex))
134                 return -ERESTARTSYS;
135
136         ret = simple_read_from_buffer(buf, size, ppos, (void *)FLASH_BASE, gbFlashSize);
137         mutex_unlock(&nwflash_mutex);
138
139         return ret;
140 }
141
142 static ssize_t flash_write(struct file *file, const char __user *buf,
143                            size_t size, loff_t * ppos)
144 {
145         unsigned long p = *ppos;
146         unsigned int count = size;
147         int written;
148         int nBlock, temp, rc;
149         int i, j;
150
151         if (flashdebug)
152                 printk("flash_write: offset=0x%lX, buffer=0x%p, count=0x%X.\n",
153                        p, buf, count);
154
155         if (!gbWriteEnable)
156                 return -EINVAL;
157
158         if (p < 64 * 1024 && (!gbWriteBase64Enable))
159                 return -EINVAL;
160
161         /*
162          * check for out of range pos or count
163          */
164         if (p >= gbFlashSize)
165                 return count ? -ENXIO : 0;
166
167         if (count > gbFlashSize - p)
168                 count = gbFlashSize - p;
169                         
170         if (!access_ok(VERIFY_READ, buf, count))
171                 return -EFAULT;
172
173         /*
174          * We now lock against reads and writes. --rmk
175          */
176         if (mutex_lock_interruptible(&nwflash_mutex))
177                 return -ERESTARTSYS;
178
179         written = 0;
180
181         leds_event(led_claim);
182         leds_event(led_green_on);
183
184         nBlock = (int) p >> 16; //block # of 64K bytes
185
186         /*
187          * # of 64K blocks to erase and write
188          */
189         temp = ((int) (p + count) >> 16) - nBlock + 1;
190
191         /*
192          * write ends at exactly 64k boundary?
193          */
194         if (((int) (p + count) & 0xFFFF) == 0)
195                 temp -= 1;
196
197         if (flashdebug)
198                 printk(KERN_DEBUG "flash_write: writing %d block(s) "
199                         "starting at %d.\n", temp, nBlock);
200
201         for (; temp; temp--, nBlock++) {
202                 if (flashdebug)
203                         printk(KERN_DEBUG "flash_write: erasing block %d.\n", nBlock);
204
205                 /*
206                  * first we have to erase the block(s), where we will write...
207                  */
208                 i = 0;
209                 j = 0;
210           RetryBlock:
211                 do {
212                         rc = erase_block(nBlock);
213                         i++;
214                 } while (rc && i < 10);
215
216                 if (rc) {
217                         printk(KERN_ERR "flash_write: erase error %x\n", rc);
218                         break;
219                 }
220                 if (flashdebug)
221                         printk(KERN_DEBUG "flash_write: writing offset %lX, "
222                                "from buf %p, bytes left %X.\n", p, buf,
223                                count - written);
224
225                 /*
226                  * write_block will limit write to space left in this block
227                  */
228                 rc = write_block(p, buf, count - written);
229                 j++;
230
231                 /*
232                  * if somehow write verify failed? Can't happen??
233                  */
234                 if (!rc) {
235                         /*
236                          * retry up to 10 times
237                          */
238                         if (j < 10)
239                                 goto RetryBlock;
240                         else
241                                 /*
242                                  * else quit with error...
243                                  */
244                                 rc = -1;
245
246                 }
247                 if (rc < 0) {
248                         printk(KERN_ERR "flash_write: write error %X\n", rc);
249                         break;
250                 }
251                 p += rc;
252                 buf += rc;
253                 written += rc;
254                 *ppos += rc;
255
256                 if (flashdebug)
257                         printk(KERN_DEBUG "flash_write: written 0x%X bytes OK.\n", written);
258         }
259
260         /*
261          * restore reg on exit
262          */
263         leds_event(led_release);
264
265         mutex_unlock(&nwflash_mutex);
266
267         return written;
268 }
269
270
271 /*
272  * The memory devices use the full 32/64 bits of the offset, and so we cannot
273  * check against negative addresses: they are ok. The return value is weird,
274  * though, in that case (0).
275  *
276  * also note that seeking relative to the "end of file" isn't supported:
277  * it has no meaning, so it returns -EINVAL.
278  */
279 static loff_t flash_llseek(struct file *file, loff_t offset, int orig)
280 {
281         loff_t ret;
282
283         lock_kernel();
284         if (flashdebug)
285                 printk(KERN_DEBUG "flash_llseek: offset=0x%X, orig=0x%X.\n",
286                        (unsigned int) offset, orig);
287
288         switch (orig) {
289         case 0:
290                 if (offset < 0) {
291                         ret = -EINVAL;
292                         break;
293                 }
294
295                 if ((unsigned int) offset > gbFlashSize) {
296                         ret = -EINVAL;
297                         break;
298                 }
299
300                 file->f_pos = (unsigned int) offset;
301                 ret = file->f_pos;
302                 break;
303         case 1:
304                 if ((file->f_pos + offset) > gbFlashSize) {
305                         ret = -EINVAL;
306                         break;
307                 }
308                 if ((file->f_pos + offset) < 0) {
309                         ret = -EINVAL;
310                         break;
311                 }
312                 file->f_pos += offset;
313                 ret = file->f_pos;
314                 break;
315         default:
316                 ret = -EINVAL;
317         }
318         unlock_kernel();
319         return ret;
320 }
321
322
323 /*
324  * assume that main Write routine did the parameter checking...
325  * so just go ahead and erase, what requested!
326  */
327
328 static int erase_block(int nBlock)
329 {
330         volatile unsigned int c1;
331         volatile unsigned char *pWritePtr;
332         unsigned long timeout;
333         int temp, temp1;
334
335         /*
336          * orange LED == erase
337          */
338         leds_event(led_amber_on);
339
340         /*
341          * reset footbridge to the correct offset 0 (...0..3)
342          */
343         *CSR_ROMWRITEREG = 0;
344
345         /*
346          * dummy ROM read
347          */
348         c1 = *(volatile unsigned char *) (FLASH_BASE + 0x8000);
349
350         kick_open();
351         /*
352          * reset status if old errors
353          */
354         *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
355
356         /*
357          * erase a block...
358          * aim at the middle of a current block...
359          */
360         pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + 0x8000 + (nBlock << 16)));
361         /*
362          * dummy read
363          */
364         c1 = *pWritePtr;
365
366         kick_open();
367         /*
368          * erase
369          */
370         *(volatile unsigned char *) pWritePtr = 0x20;
371
372         /*
373          * confirm
374          */
375         *(volatile unsigned char *) pWritePtr = 0xD0;
376
377         /*
378          * wait 10 ms
379          */
380         msleep(10);
381
382         /*
383          * wait while erasing in process (up to 10 sec)
384          */
385         timeout = jiffies + 10 * HZ;
386         c1 = 0;
387         while (!(c1 & 0x80) && time_before(jiffies, timeout)) {
388                 msleep(10);
389                 /*
390                  * read any address
391                  */
392                 c1 = *(volatile unsigned char *) (pWritePtr);
393                 //              printk("Flash_erase: status=%X.\n",c1);
394         }
395
396         /*
397          * set flash for normal read access
398          */
399         kick_open();
400 //      *(volatile unsigned char*)(FLASH_BASE+0x8000) = 0xFF;
401         *(volatile unsigned char *) pWritePtr = 0xFF;   //back to normal operation
402
403         /*
404          * check if erase errors were reported
405          */
406         if (c1 & 0x20) {
407                 printk(KERN_ERR "flash_erase: err at %p\n", pWritePtr);
408
409                 /*
410                  * reset error
411                  */
412                 *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
413                 return -2;
414         }
415
416         /*
417          * just to make sure - verify if erased OK...
418          */
419         msleep(10);
420
421         pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + (nBlock << 16)));
422
423         for (temp = 0; temp < 16 * 1024; temp++, pWritePtr += 4) {
424                 if ((temp1 = *(volatile unsigned int *) pWritePtr) != 0xFFFFFFFF) {
425                         printk(KERN_ERR "flash_erase: verify err at %p = %X\n",
426                                pWritePtr, temp1);
427                         return -1;
428                 }
429         }
430
431         return 0;
432
433 }
434
435 /*
436  * write_block will limit number of bytes written to the space in this block
437  */
438 static int write_block(unsigned long p, const char __user *buf, int count)
439 {
440         volatile unsigned int c1;
441         volatile unsigned int c2;
442         unsigned char *pWritePtr;
443         unsigned int uAddress;
444         unsigned int offset;
445         unsigned long timeout;
446         unsigned long timeout1;
447
448         /*
449          * red LED == write
450          */
451         leds_event(led_amber_off);
452         leds_event(led_red_on);
453
454         pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + p));
455
456         /*
457          * check if write will end in this block....
458          */
459         offset = p & 0xFFFF;
460
461         if (offset + count > 0x10000)
462                 count = 0x10000 - offset;
463
464         /*
465          * wait up to 30 sec for this block
466          */
467         timeout = jiffies + 30 * HZ;
468
469         for (offset = 0; offset < count; offset++, pWritePtr++) {
470                 uAddress = (unsigned int) pWritePtr;
471                 uAddress &= 0xFFFFFFFC;
472                 if (__get_user(c2, buf + offset))
473                         return -EFAULT;
474
475           WriteRetry:
476                 /*
477                  * dummy read
478                  */
479                 c1 = *(volatile unsigned char *) (FLASH_BASE + 0x8000);
480
481                 /*
482                  * kick open the write gate
483                  */
484                 kick_open();
485
486                 /*
487                  * program footbridge to the correct offset...0..3
488                  */
489                 *CSR_ROMWRITEREG = (unsigned int) pWritePtr & 3;
490
491                 /*
492                  * write cmd
493                  */
494                 *(volatile unsigned char *) (uAddress) = 0x40;
495
496                 /*
497                  * data to write
498                  */
499                 *(volatile unsigned char *) (uAddress) = c2;
500
501                 /*
502                  * get status
503                  */
504                 *(volatile unsigned char *) (FLASH_BASE + 0x10000) = 0x70;
505
506                 c1 = 0;
507
508                 /*
509                  * wait up to 1 sec for this byte
510                  */
511                 timeout1 = jiffies + 1 * HZ;
512
513                 /*
514                  * while not ready...
515                  */
516                 while (!(c1 & 0x80) && time_before(jiffies, timeout1))
517                         c1 = *(volatile unsigned char *) (FLASH_BASE + 0x8000);
518
519                 /*
520                  * if timeout getting status
521                  */
522                 if (time_after_eq(jiffies, timeout1)) {
523                         kick_open();
524                         /*
525                          * reset err
526                          */
527                         *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
528
529                         goto WriteRetry;
530                 }
531                 /*
532                  * switch on read access, as a default flash operation mode
533                  */
534                 kick_open();
535                 /*
536                  * read access
537                  */
538                 *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0xFF;
539
540                 /*
541                  * if hardware reports an error writing, and not timeout - 
542                  * reset the chip and retry
543                  */
544                 if (c1 & 0x10) {
545                         kick_open();
546                         /*
547                          * reset err
548                          */
549                         *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
550
551                         /*
552                          * before timeout?
553                          */
554                         if (time_before(jiffies, timeout)) {
555                                 if (flashdebug)
556                                         printk(KERN_DEBUG "write_block: Retrying write at 0x%X)n",
557                                                pWritePtr - FLASH_BASE);
558
559                                 /*
560                                  * no LED == waiting
561                                  */
562                                 leds_event(led_amber_off);
563                                 /*
564                                  * wait couple ms
565                                  */
566                                 msleep(10);
567                                 /*
568                                  * red LED == write
569                                  */
570                                 leds_event(led_red_on);
571
572                                 goto WriteRetry;
573                         } else {
574                                 printk(KERN_ERR "write_block: timeout at 0x%X\n",
575                                        pWritePtr - FLASH_BASE);
576                                 /*
577                                  * return error -2
578                                  */
579                                 return -2;
580
581                         }
582                 }
583         }
584
585         /*
586          * green LED == read/verify
587          */
588         leds_event(led_amber_off);
589         leds_event(led_green_on);
590
591         msleep(10);
592
593         pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + p));
594
595         for (offset = 0; offset < count; offset++) {
596                 char c, c1;
597                 if (__get_user(c, buf))
598                         return -EFAULT;
599                 buf++;
600                 if ((c1 = *pWritePtr++) != c) {
601                         printk(KERN_ERR "write_block: verify error at 0x%X (%02X!=%02X)\n",
602                                pWritePtr - FLASH_BASE, c1, c);
603                         return 0;
604                 }
605         }
606
607         return count;
608 }
609
610
611 static void kick_open(void)
612 {
613         unsigned long flags;
614
615         /*
616          * we want to write a bit pattern XXX1 to Xilinx to enable
617          * the write gate, which will be open for about the next 2ms.
618          */
619         spin_lock_irqsave(&gpio_lock, flags);
620         cpld_modify(1, 1);
621         spin_unlock_irqrestore(&gpio_lock, flags);
622
623         /*
624          * let the ISA bus to catch on...
625          */
626         udelay(25);
627 }
628
629 static const struct file_operations flash_fops =
630 {
631         .owner          = THIS_MODULE,
632         .llseek         = flash_llseek,
633         .read           = flash_read,
634         .write          = flash_write,
635         .ioctl          = flash_ioctl,
636 };
637
638 static struct miscdevice flash_miscdev =
639 {
640         FLASH_MINOR,
641         "nwflash",
642         &flash_fops
643 };
644
645 static int __init nwflash_init(void)
646 {
647         int ret = -ENODEV;
648
649         if (machine_is_netwinder()) {
650                 int id;
651
652                 FLASH_BASE = ioremap(DC21285_FLASH, KFLASH_SIZE4);
653                 if (!FLASH_BASE)
654                         goto out;
655
656                 id = get_flash_id();
657                 if ((id != KFLASH_ID) && (id != KFLASH_ID4)) {
658                         ret = -ENXIO;
659                         iounmap((void *)FLASH_BASE);
660                         printk("Flash: incorrect ID 0x%04X.\n", id);
661                         goto out;
662                 }
663
664                 printk("Flash ROM driver v.%s, flash device ID 0x%04X, size %d Mb.\n",
665                        NWFLASH_VERSION, id, gbFlashSize / (1024 * 1024));
666
667                 ret = misc_register(&flash_miscdev);
668                 if (ret < 0) {
669                         iounmap((void *)FLASH_BASE);
670                 }
671         }
672 out:
673         return ret;
674 }
675
676 static void __exit nwflash_exit(void)
677 {
678         misc_deregister(&flash_miscdev);
679         iounmap((void *)FLASH_BASE);
680 }
681
682 MODULE_LICENSE("GPL");
683
684 module_param(flashdebug, bool, 0644);
685
686 module_init(nwflash_init);
687 module_exit(nwflash_exit);