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  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/mutex.h>
 29#include <linux/jiffies.h>
 30
 31#include <asm/hardware/dec21285.h>
 32#include <asm/io.h>
 33#include <asm/mach-types.h>
 34#include <linux/uaccess.h>
 35
 36/*****************************************************************************/
 37#include <asm/nwflash.h>
 38
 39#define	NWFLASH_VERSION "6.4"
 40
 41static DEFINE_MUTEX(flash_mutex);
 42static void kick_open(void);
 43static int get_flash_id(void);
 44static int erase_block(int nBlock);
 45static int write_block(unsigned long p, const char __user *buf, int count);
 46
 47#define KFLASH_SIZE	1024*1024	//1 Meg
 48#define KFLASH_SIZE4	4*1024*1024	//4 Meg
 49#define KFLASH_ID	0x89A6		//Intel flash
 50#define KFLASH_ID4	0xB0D4		//Intel flash 4Meg
 51
 52static bool flashdebug;		//if set - we will display progress msgs
 53
 54static int gbWriteEnable;
 55static int gbWriteBase64Enable;
 56static volatile unsigned char *FLASH_BASE;
 57static int gbFlashSize = KFLASH_SIZE;
 58static DEFINE_MUTEX(nwflash_mutex);
 59
 60static int get_flash_id(void)
 61{
 62	volatile unsigned int c1, c2;
 63
 64	/*
 65	 * try to get flash chip ID
 66	 */
 67	kick_open();
 68	c2 = inb(0x80);
 69	*(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x90;
 70	udelay(15);
 71	c1 = *(volatile unsigned char *) FLASH_BASE;
 72	c2 = inb(0x80);
 73
 74	/*
 75	 * on 4 Meg flash the second byte is actually at offset 2...
 76	 */
 77	if (c1 == 0xB0)
 78		c2 = *(volatile unsigned char *) (FLASH_BASE + 2);
 79	else
 80		c2 = *(volatile unsigned char *) (FLASH_BASE + 1);
 81
 82	c2 += (c1 << 8);
 83
 84	/*
 85	 * set it back to read mode
 86	 */
 87	*(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0xFF;
 88
 89	if (c2 == KFLASH_ID4)
 90		gbFlashSize = KFLASH_SIZE4;
 91
 92	return c2;
 93}
 94
 95static long flash_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
 96{
 97	mutex_lock(&flash_mutex);
 98	switch (cmd) {
 99	case CMD_WRITE_DISABLE:
100		gbWriteBase64Enable = 0;
101		gbWriteEnable = 0;
102		break;
103
104	case CMD_WRITE_ENABLE:
105		gbWriteEnable = 1;
106		break;
107
108	case CMD_WRITE_BASE64K_ENABLE:
109		gbWriteBase64Enable = 1;
110		break;
111
112	default:
113		gbWriteBase64Enable = 0;
114		gbWriteEnable = 0;
115		mutex_unlock(&flash_mutex);
116		return -EINVAL;
117	}
118	mutex_unlock(&flash_mutex);
119	return 0;
120}
121
122static 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
142static 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	nBlock = (int) p >> 16;	//block # of 64K bytes
182
183	/*
184	 * # of 64K blocks to erase and write
185	 */
186	temp = ((int) (p + count) >> 16) - nBlock + 1;
187
188	/*
189	 * write ends at exactly 64k boundary?
190	 */
191	if (((int) (p + count) & 0xFFFF) == 0)
192		temp -= 1;
193
194	if (flashdebug)
195		printk(KERN_DEBUG "flash_write: writing %d block(s) "
196			"starting at %d.\n", temp, nBlock);
197
198	for (; temp; temp--, nBlock++) {
199		if (flashdebug)
200			printk(KERN_DEBUG "flash_write: erasing block %d.\n", nBlock);
201
202		/*
203		 * first we have to erase the block(s), where we will write...
204		 */
205		i = 0;
206		j = 0;
207	  RetryBlock:
208		do {
209			rc = erase_block(nBlock);
210			i++;
211		} while (rc && i < 10);
212
213		if (rc) {
214			printk(KERN_ERR "flash_write: erase error %x\n", rc);
215			break;
216		}
217		if (flashdebug)
218			printk(KERN_DEBUG "flash_write: writing offset %lX, "
219			       "from buf %p, bytes left %X.\n", p, buf,
220			       count - written);
221
222		/*
223		 * write_block will limit write to space left in this block
224		 */
225		rc = write_block(p, buf, count - written);
226		j++;
227
228		/*
229		 * if somehow write verify failed? Can't happen??
230		 */
231		if (!rc) {
232			/*
233			 * retry up to 10 times
234			 */
235			if (j < 10)
236				goto RetryBlock;
237			else
238				/*
239				 * else quit with error...
240				 */
241				rc = -1;
242
243		}
244		if (rc < 0) {
245			printk(KERN_ERR "flash_write: write error %X\n", rc);
246			break;
247		}
248		p += rc;
249		buf += rc;
250		written += rc;
251		*ppos += rc;
252
253		if (flashdebug)
254			printk(KERN_DEBUG "flash_write: written 0x%X bytes OK.\n", written);
255	}
256
257	mutex_unlock(&nwflash_mutex);
258
259	return written;
260}
261
262
263/*
264 * The memory devices use the full 32/64 bits of the offset, and so we cannot
265 * check against negative addresses: they are ok. The return value is weird,
266 * though, in that case (0).
267 *
268 * also note that seeking relative to the "end of file" isn't supported:
269 * it has no meaning, so it returns -EINVAL.
270 */
271static loff_t flash_llseek(struct file *file, loff_t offset, int orig)
272{
273	loff_t ret;
274
275	mutex_lock(&flash_mutex);
276	if (flashdebug)
277		printk(KERN_DEBUG "flash_llseek: offset=0x%X, orig=0x%X.\n",
278		       (unsigned int) offset, orig);
279
280	ret = no_seek_end_llseek_size(file, offset, orig, gbFlashSize);
281	mutex_unlock(&flash_mutex);
282	return ret;
283}
284
285
286/*
287 * assume that main Write routine did the parameter checking...
288 * so just go ahead and erase, what requested!
289 */
290
291static int erase_block(int nBlock)
292{
293	volatile unsigned int c1;
294	volatile unsigned char *pWritePtr;
295	unsigned long timeout;
296	int temp, temp1;
297
298	/*
299	 * reset footbridge to the correct offset 0 (...0..3)
300	 */
301	*CSR_ROMWRITEREG = 0;
302
303	/*
304	 * dummy ROM read
305	 */
306	c1 = *(volatile unsigned char *) (FLASH_BASE + 0x8000);
307
308	kick_open();
309	/*
310	 * reset status if old errors
311	 */
312	*(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
313
314	/*
315	 * erase a block...
316	 * aim at the middle of a current block...
317	 */
318	pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + 0x8000 + (nBlock << 16)));
319	/*
320	 * dummy read
321	 */
322	c1 = *pWritePtr;
323
324	kick_open();
325	/*
326	 * erase
327	 */
328	*(volatile unsigned char *) pWritePtr = 0x20;
329
330	/*
331	 * confirm
332	 */
333	*(volatile unsigned char *) pWritePtr = 0xD0;
334
335	/*
336	 * wait 10 ms
337	 */
338	msleep(10);
339
340	/*
341	 * wait while erasing in process (up to 10 sec)
342	 */
343	timeout = jiffies + 10 * HZ;
344	c1 = 0;
345	while (!(c1 & 0x80) && time_before(jiffies, timeout)) {
346		msleep(10);
347		/*
348		 * read any address
349		 */
350		c1 = *(volatile unsigned char *) (pWritePtr);
351		//              printk("Flash_erase: status=%X.\n",c1);
352	}
353
354	/*
355	 * set flash for normal read access
356	 */
357	kick_open();
358//      *(volatile unsigned char*)(FLASH_BASE+0x8000) = 0xFF;
359	*(volatile unsigned char *) pWritePtr = 0xFF;	//back to normal operation
360
361	/*
362	 * check if erase errors were reported
363	 */
364	if (c1 & 0x20) {
365		printk(KERN_ERR "flash_erase: err at %p\n", pWritePtr);
366
367		/*
368		 * reset error
369		 */
370		*(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
371		return -2;
372	}
373
374	/*
375	 * just to make sure - verify if erased OK...
376	 */
377	msleep(10);
378
379	pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + (nBlock << 16)));
380
381	for (temp = 0; temp < 16 * 1024; temp++, pWritePtr += 4) {
382		if ((temp1 = *(volatile unsigned int *) pWritePtr) != 0xFFFFFFFF) {
383			printk(KERN_ERR "flash_erase: verify err at %p = %X\n",
384			       pWritePtr, temp1);
385			return -1;
386		}
387	}
388
389	return 0;
390
391}
392
393/*
394 * write_block will limit number of bytes written to the space in this block
395 */
396static int write_block(unsigned long p, const char __user *buf, int count)
397{
398	volatile unsigned int c1;
399	volatile unsigned int c2;
400	unsigned char *pWritePtr;
401	unsigned int uAddress;
402	unsigned int offset;
403	unsigned long timeout;
404	unsigned long timeout1;
405
406	pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + p));
407
408	/*
409	 * check if write will end in this block....
410	 */
411	offset = p & 0xFFFF;
412
413	if (offset + count > 0x10000)
414		count = 0x10000 - offset;
415
416	/*
417	 * wait up to 30 sec for this block
418	 */
419	timeout = jiffies + 30 * HZ;
420
421	for (offset = 0; offset < count; offset++, pWritePtr++) {
422		uAddress = (unsigned int) pWritePtr;
423		uAddress &= 0xFFFFFFFC;
424		if (__get_user(c2, buf + offset))
425			return -EFAULT;
426
427	  WriteRetry:
428	  	/*
429	  	 * dummy read
430	  	 */
431		c1 = *(volatile unsigned char *) (FLASH_BASE + 0x8000);
432
433		/*
434		 * kick open the write gate
435		 */
436		kick_open();
437
438		/*
439		 * program footbridge to the correct offset...0..3
440		 */
441		*CSR_ROMWRITEREG = (unsigned int) pWritePtr & 3;
442
443		/*
444		 * write cmd
445		 */
446		*(volatile unsigned char *) (uAddress) = 0x40;
447
448		/*
449		 * data to write
450		 */
451		*(volatile unsigned char *) (uAddress) = c2;
452
453		/*
454		 * get status
455		 */
456		*(volatile unsigned char *) (FLASH_BASE + 0x10000) = 0x70;
457
458		c1 = 0;
459
460		/*
461		 * wait up to 1 sec for this byte
462		 */
463		timeout1 = jiffies + 1 * HZ;
464
465		/*
466		 * while not ready...
467		 */
468		while (!(c1 & 0x80) && time_before(jiffies, timeout1))
469			c1 = *(volatile unsigned char *) (FLASH_BASE + 0x8000);
470
471		/*
472		 * if timeout getting status
473		 */
474		if (time_after_eq(jiffies, timeout1)) {
475			kick_open();
476			/*
477			 * reset err
478			 */
479			*(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
480
481			goto WriteRetry;
482		}
483		/*
484		 * switch on read access, as a default flash operation mode
485		 */
486		kick_open();
487		/*
488		 * read access
489		 */
490		*(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0xFF;
491
492		/*
493		 * if hardware reports an error writing, and not timeout - 
494		 * reset the chip and retry
495		 */
496		if (c1 & 0x10) {
497			kick_open();
498			/*
499			 * reset err
500			 */
501			*(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
502
503			/*
504			 * before timeout?
505			 */
506			if (time_before(jiffies, timeout)) {
507				if (flashdebug)
508					printk(KERN_DEBUG "write_block: Retrying write at 0x%X)n",
509					       pWritePtr - FLASH_BASE);
510
511				/*
512				 * wait couple ms
513				 */
514				msleep(10);
515
516				goto WriteRetry;
517			} else {
518				printk(KERN_ERR "write_block: timeout at 0x%X\n",
519				       pWritePtr - FLASH_BASE);
520				/*
521				 * return error -2
522				 */
523				return -2;
524
525			}
526		}
527	}
528
529	msleep(10);
530
531	pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + p));
532
533	for (offset = 0; offset < count; offset++) {
534		char c, c1;
535		if (__get_user(c, buf))
536			return -EFAULT;
537		buf++;
538		if ((c1 = *pWritePtr++) != c) {
539			printk(KERN_ERR "write_block: verify error at 0x%X (%02X!=%02X)\n",
540			       pWritePtr - FLASH_BASE, c1, c);
541			return 0;
542		}
543	}
544
545	return count;
546}
547
548
549static void kick_open(void)
550{
551	unsigned long flags;
552
553	/*
554	 * we want to write a bit pattern XXX1 to Xilinx to enable
555	 * the write gate, which will be open for about the next 2ms.
556	 */
557	raw_spin_lock_irqsave(&nw_gpio_lock, flags);
558	nw_cpld_modify(CPLD_FLASH_WR_ENABLE, CPLD_FLASH_WR_ENABLE);
559	raw_spin_unlock_irqrestore(&nw_gpio_lock, flags);
560
561	/*
562	 * let the ISA bus to catch on...
563	 */
564	udelay(25);
565}
566
567static const struct file_operations flash_fops =
568{
569	.owner		= THIS_MODULE,
570	.llseek		= flash_llseek,
571	.read		= flash_read,
572	.write		= flash_write,
573	.unlocked_ioctl	= flash_ioctl,
574};
575
576static struct miscdevice flash_miscdev =
577{
578	FLASH_MINOR,
579	"nwflash",
580	&flash_fops
581};
582
583static int __init nwflash_init(void)
584{
585	int ret = -ENODEV;
586
587	if (machine_is_netwinder()) {
588		int id;
589
590		FLASH_BASE = ioremap(DC21285_FLASH, KFLASH_SIZE4);
591		if (!FLASH_BASE)
592			goto out;
593
594		id = get_flash_id();
595		if ((id != KFLASH_ID) && (id != KFLASH_ID4)) {
596			ret = -ENXIO;
597			iounmap((void *)FLASH_BASE);
598			printk("Flash: incorrect ID 0x%04X.\n", id);
599			goto out;
600		}
601
602		printk("Flash ROM driver v.%s, flash device ID 0x%04X, size %d Mb.\n",
603		       NWFLASH_VERSION, id, gbFlashSize / (1024 * 1024));
604
605		ret = misc_register(&flash_miscdev);
606		if (ret < 0) {
607			iounmap((void *)FLASH_BASE);
608		}
609	}
610out:
611	return ret;
612}
613
614static void __exit nwflash_exit(void)
615{
616	misc_deregister(&flash_miscdev);
617	iounmap((void *)FLASH_BASE);
618}
619
620MODULE_LICENSE("GPL");
621
622module_param(flashdebug, bool, 0644);
623
624module_init(nwflash_init);
625module_exit(nwflash_exit);
  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Flash memory interface rev.5 driver for the Intel
  4 * Flash chips used on the NetWinder.
  5 *
  6 * 20/08/2000	RMK	use __ioremap to map flash into virtual memory
  7 *			make a few more places use "volatile"
  8 * 22/05/2001	RMK	- Lock read against write
  9 *			- merge printk level changes (with mods) from Alan Cox.
 10 *			- use *ppos as the file position, not file->f_pos.
 11 *			- fix check for out of range pos and r/w size
 12 *
 13 * Please note that we are tampering with the only flash chip in the
 14 * machine, which contains the bootup code.  We therefore have the
 15 * power to convert these machines into doorstops...
 16 */
 17
 18#include <linux/module.h>
 19#include <linux/types.h>
 20#include <linux/fs.h>
 21#include <linux/errno.h>
 22#include <linux/mm.h>
 23#include <linux/delay.h>
 24#include <linux/proc_fs.h>
 25#include <linux/miscdevice.h>
 26#include <linux/spinlock.h>
 27#include <linux/rwsem.h>
 28#include <linux/init.h>
 29#include <linux/mutex.h>
 30#include <linux/jiffies.h>
 31
 32#include <asm/hardware/dec21285.h>
 33#include <asm/io.h>
 34#include <asm/mach-types.h>
 35#include <linux/uaccess.h>
 36
 37/*****************************************************************************/
 38#include <asm/nwflash.h>
 39
 40#define	NWFLASH_VERSION "6.4"
 41
 42static DEFINE_MUTEX(flash_mutex);
 43static void kick_open(void);
 44static int get_flash_id(void);
 45static int erase_block(int nBlock);
 46static 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
 53static bool flashdebug;		//if set - we will display progress msgs
 54
 55static int gbWriteEnable;
 56static int gbWriteBase64Enable;
 57static volatile unsigned char *FLASH_BASE;
 58static int gbFlashSize = KFLASH_SIZE;
 59static DEFINE_MUTEX(nwflash_mutex);
 60
 61static int get_flash_id(void)
 62{
 63	volatile unsigned int c1, c2;
 64
 65	/*
 66	 * try to get flash chip ID
 67	 */
 68	kick_open();
 69	c2 = inb(0x80);
 70	*(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x90;
 71	udelay(15);
 72	c1 = *(volatile unsigned char *) FLASH_BASE;
 73	c2 = inb(0x80);
 74
 75	/*
 76	 * on 4 Meg flash the second byte is actually at offset 2...
 77	 */
 78	if (c1 == 0xB0)
 79		c2 = *(volatile unsigned char *) (FLASH_BASE + 2);
 80	else
 81		c2 = *(volatile unsigned char *) (FLASH_BASE + 1);
 82
 83	c2 += (c1 << 8);
 84
 85	/*
 86	 * set it back to read mode
 87	 */
 88	*(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0xFF;
 89
 90	if (c2 == KFLASH_ID4)
 91		gbFlashSize = KFLASH_SIZE4;
 92
 93	return c2;
 94}
 95
 96static long flash_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
 97{
 98	mutex_lock(&flash_mutex);
 99	switch (cmd) {
100	case CMD_WRITE_DISABLE:
101		gbWriteBase64Enable = 0;
102		gbWriteEnable = 0;
103		break;
104
105	case CMD_WRITE_ENABLE:
106		gbWriteEnable = 1;
107		break;
108
109	case CMD_WRITE_BASE64K_ENABLE:
110		gbWriteBase64Enable = 1;
111		break;
112
113	default:
114		gbWriteBase64Enable = 0;
115		gbWriteEnable = 0;
116		mutex_unlock(&flash_mutex);
117		return -EINVAL;
118	}
119	mutex_unlock(&flash_mutex);
120	return 0;
121}
122
123static ssize_t flash_read(struct file *file, char __user *buf, size_t size,
124			  loff_t *ppos)
125{
126	ssize_t ret;
127
128	if (flashdebug)
129		printk(KERN_DEBUG "flash_read: flash_read: offset=0x%llx, "
130		       "buffer=%p, count=0x%zx.\n", *ppos, buf, size);
131	/*
132	 * We now lock against reads and writes. --rmk
133	 */
134	if (mutex_lock_interruptible(&nwflash_mutex))
135		return -ERESTARTSYS;
136
137	ret = simple_read_from_buffer(buf, size, ppos, (void *)FLASH_BASE, gbFlashSize);
138	mutex_unlock(&nwflash_mutex);
139
140	return ret;
141}
142
143static ssize_t flash_write(struct file *file, const char __user *buf,
144			   size_t size, loff_t * ppos)
145{
146	unsigned long p = *ppos;
147	unsigned int count = size;
148	int written;
149	int nBlock, temp, rc;
150	int i, j;
151
152	if (flashdebug)
153		printk("flash_write: offset=0x%lX, buffer=0x%p, count=0x%X.\n",
154		       p, buf, count);
155
156	if (!gbWriteEnable)
157		return -EINVAL;
158
159	if (p < 64 * 1024 && (!gbWriteBase64Enable))
160		return -EINVAL;
161
162	/*
163	 * check for out of range pos or count
164	 */
165	if (p >= gbFlashSize)
166		return count ? -ENXIO : 0;
167
168	if (count > gbFlashSize - p)
169		count = gbFlashSize - p;
170			
171	if (!access_ok(buf, count))
172		return -EFAULT;
173
174	/*
175	 * We now lock against reads and writes. --rmk
176	 */
177	if (mutex_lock_interruptible(&nwflash_mutex))
178		return -ERESTARTSYS;
179
180	written = 0;
181
182	nBlock = (int) p >> 16;	//block # of 64K bytes
183
184	/*
185	 * # of 64K blocks to erase and write
186	 */
187	temp = ((int) (p + count) >> 16) - nBlock + 1;
188
189	/*
190	 * write ends at exactly 64k boundary?
191	 */
192	if (((int) (p + count) & 0xFFFF) == 0)
193		temp -= 1;
194
195	if (flashdebug)
196		printk(KERN_DEBUG "flash_write: writing %d block(s) "
197			"starting at %d.\n", temp, nBlock);
198
199	for (; temp; temp--, nBlock++) {
200		if (flashdebug)
201			printk(KERN_DEBUG "flash_write: erasing block %d.\n", nBlock);
202
203		/*
204		 * first we have to erase the block(s), where we will write...
205		 */
206		i = 0;
207		j = 0;
208	  RetryBlock:
209		do {
210			rc = erase_block(nBlock);
211			i++;
212		} while (rc && i < 10);
213
214		if (rc) {
215			printk(KERN_ERR "flash_write: erase error %x\n", rc);
216			break;
217		}
218		if (flashdebug)
219			printk(KERN_DEBUG "flash_write: writing offset %lX, "
220			       "from buf %p, bytes left %X.\n", p, buf,
221			       count - written);
222
223		/*
224		 * write_block will limit write to space left in this block
225		 */
226		rc = write_block(p, buf, count - written);
227		j++;
228
229		/*
230		 * if somehow write verify failed? Can't happen??
231		 */
232		if (!rc) {
233			/*
234			 * retry up to 10 times
235			 */
236			if (j < 10)
237				goto RetryBlock;
238			else
239				/*
240				 * else quit with error...
241				 */
242				rc = -1;
243
244		}
245		if (rc < 0) {
246			printk(KERN_ERR "flash_write: write error %X\n", rc);
247			break;
248		}
249		p += rc;
250		buf += rc;
251		written += rc;
252		*ppos += rc;
253
254		if (flashdebug)
255			printk(KERN_DEBUG "flash_write: written 0x%X bytes OK.\n", written);
256	}
257
258	mutex_unlock(&nwflash_mutex);
259
260	return written;
261}
262
263
264/*
265 * The memory devices use the full 32/64 bits of the offset, and so we cannot
266 * check against negative addresses: they are ok. The return value is weird,
267 * though, in that case (0).
268 *
269 * also note that seeking relative to the "end of file" isn't supported:
270 * it has no meaning, so it returns -EINVAL.
271 */
272static loff_t flash_llseek(struct file *file, loff_t offset, int orig)
273{
274	loff_t ret;
275
276	mutex_lock(&flash_mutex);
277	if (flashdebug)
278		printk(KERN_DEBUG "flash_llseek: offset=0x%X, orig=0x%X.\n",
279		       (unsigned int) offset, orig);
280
281	ret = no_seek_end_llseek_size(file, offset, orig, gbFlashSize);
282	mutex_unlock(&flash_mutex);
283	return ret;
284}
285
286
287/*
288 * assume that main Write routine did the parameter checking...
289 * so just go ahead and erase, what requested!
290 */
291
292static int erase_block(int nBlock)
293{
294	volatile unsigned int c1;
295	volatile unsigned char *pWritePtr;
296	unsigned long timeout;
297	int temp, temp1;
298
299	/*
300	 * reset footbridge to the correct offset 0 (...0..3)
301	 */
302	*CSR_ROMWRITEREG = 0;
303
304	/*
305	 * dummy ROM read
306	 */
307	c1 = *(volatile unsigned char *) (FLASH_BASE + 0x8000);
308
309	kick_open();
310	/*
311	 * reset status if old errors
312	 */
313	*(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
314
315	/*
316	 * erase a block...
317	 * aim at the middle of a current block...
318	 */
319	pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + 0x8000 + (nBlock << 16)));
320	/*
321	 * dummy read
322	 */
323	c1 = *pWritePtr;
324
325	kick_open();
326	/*
327	 * erase
328	 */
329	*(volatile unsigned char *) pWritePtr = 0x20;
330
331	/*
332	 * confirm
333	 */
334	*(volatile unsigned char *) pWritePtr = 0xD0;
335
336	/*
337	 * wait 10 ms
338	 */
339	msleep(10);
340
341	/*
342	 * wait while erasing in process (up to 10 sec)
343	 */
344	timeout = jiffies + 10 * HZ;
345	c1 = 0;
346	while (!(c1 & 0x80) && time_before(jiffies, timeout)) {
347		msleep(10);
348		/*
349		 * read any address
350		 */
351		c1 = *(volatile unsigned char *) (pWritePtr);
352		//              printk("Flash_erase: status=%X.\n",c1);
353	}
354
355	/*
356	 * set flash for normal read access
357	 */
358	kick_open();
359//      *(volatile unsigned char*)(FLASH_BASE+0x8000) = 0xFF;
360	*(volatile unsigned char *) pWritePtr = 0xFF;	//back to normal operation
361
362	/*
363	 * check if erase errors were reported
364	 */
365	if (c1 & 0x20) {
366		printk(KERN_ERR "flash_erase: err at %p\n", pWritePtr);
367
368		/*
369		 * reset error
370		 */
371		*(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
372		return -2;
373	}
374
375	/*
376	 * just to make sure - verify if erased OK...
377	 */
378	msleep(10);
379
380	pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + (nBlock << 16)));
381
382	for (temp = 0; temp < 16 * 1024; temp++, pWritePtr += 4) {
383		if ((temp1 = *(volatile unsigned int *) pWritePtr) != 0xFFFFFFFF) {
384			printk(KERN_ERR "flash_erase: verify err at %p = %X\n",
385			       pWritePtr, temp1);
386			return -1;
387		}
388	}
389
390	return 0;
391
392}
393
394/*
395 * write_block will limit number of bytes written to the space in this block
396 */
397static int write_block(unsigned long p, const char __user *buf, int count)
398{
399	volatile unsigned int c1;
400	volatile unsigned int c2;
401	unsigned char *pWritePtr;
402	unsigned int uAddress;
403	unsigned int offset;
404	unsigned long timeout;
405	unsigned long timeout1;
406
407	pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + p));
408
409	/*
410	 * check if write will end in this block....
411	 */
412	offset = p & 0xFFFF;
413
414	if (offset + count > 0x10000)
415		count = 0x10000 - offset;
416
417	/*
418	 * wait up to 30 sec for this block
419	 */
420	timeout = jiffies + 30 * HZ;
421
422	for (offset = 0; offset < count; offset++, pWritePtr++) {
423		uAddress = (unsigned int) pWritePtr;
424		uAddress &= 0xFFFFFFFC;
425		if (__get_user(c2, buf + offset))
426			return -EFAULT;
427
428	  WriteRetry:
429	  	/*
430	  	 * dummy read
431	  	 */
432		c1 = *(volatile unsigned char *) (FLASH_BASE + 0x8000);
433
434		/*
435		 * kick open the write gate
436		 */
437		kick_open();
438
439		/*
440		 * program footbridge to the correct offset...0..3
441		 */
442		*CSR_ROMWRITEREG = (unsigned int) pWritePtr & 3;
443
444		/*
445		 * write cmd
446		 */
447		*(volatile unsigned char *) (uAddress) = 0x40;
448
449		/*
450		 * data to write
451		 */
452		*(volatile unsigned char *) (uAddress) = c2;
453
454		/*
455		 * get status
456		 */
457		*(volatile unsigned char *) (FLASH_BASE + 0x10000) = 0x70;
458
459		c1 = 0;
460
461		/*
462		 * wait up to 1 sec for this byte
463		 */
464		timeout1 = jiffies + 1 * HZ;
465
466		/*
467		 * while not ready...
468		 */
469		while (!(c1 & 0x80) && time_before(jiffies, timeout1))
470			c1 = *(volatile unsigned char *) (FLASH_BASE + 0x8000);
471
472		/*
473		 * if timeout getting status
474		 */
475		if (time_after_eq(jiffies, timeout1)) {
476			kick_open();
477			/*
478			 * reset err
479			 */
480			*(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
481
482			goto WriteRetry;
483		}
484		/*
485		 * switch on read access, as a default flash operation mode
486		 */
487		kick_open();
488		/*
489		 * read access
490		 */
491		*(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0xFF;
492
493		/*
494		 * if hardware reports an error writing, and not timeout - 
495		 * reset the chip and retry
496		 */
497		if (c1 & 0x10) {
498			kick_open();
499			/*
500			 * reset err
501			 */
502			*(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
503
504			/*
505			 * before timeout?
506			 */
507			if (time_before(jiffies, timeout)) {
508				if (flashdebug)
509					printk(KERN_DEBUG "write_block: Retrying write at 0x%X)n",
510					       pWritePtr - FLASH_BASE);
511
512				/*
513				 * wait couple ms
514				 */
515				msleep(10);
516
517				goto WriteRetry;
518			} else {
519				printk(KERN_ERR "write_block: timeout at 0x%X\n",
520				       pWritePtr - FLASH_BASE);
521				/*
522				 * return error -2
523				 */
524				return -2;
525
526			}
527		}
528	}
529
530	msleep(10);
531
532	pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + p));
533
534	for (offset = 0; offset < count; offset++) {
535		char c, c1;
536		if (__get_user(c, buf))
537			return -EFAULT;
538		buf++;
539		if ((c1 = *pWritePtr++) != c) {
540			printk(KERN_ERR "write_block: verify error at 0x%X (%02X!=%02X)\n",
541			       pWritePtr - FLASH_BASE, c1, c);
542			return 0;
543		}
544	}
545
546	return count;
547}
548
549
550static void kick_open(void)
551{
552	unsigned long flags;
553
554	/*
555	 * we want to write a bit pattern XXX1 to Xilinx to enable
556	 * the write gate, which will be open for about the next 2ms.
557	 */
558	raw_spin_lock_irqsave(&nw_gpio_lock, flags);
559	nw_cpld_modify(CPLD_FLASH_WR_ENABLE, CPLD_FLASH_WR_ENABLE);
560	raw_spin_unlock_irqrestore(&nw_gpio_lock, flags);
561
562	/*
563	 * let the ISA bus to catch on...
564	 */
565	udelay(25);
566}
567
568static const struct file_operations flash_fops =
569{
570	.owner		= THIS_MODULE,
571	.llseek		= flash_llseek,
572	.read		= flash_read,
573	.write		= flash_write,
574	.unlocked_ioctl	= flash_ioctl,
575};
576
577static struct miscdevice flash_miscdev =
578{
579	FLASH_MINOR,
580	"nwflash",
581	&flash_fops
582};
583
584static int __init nwflash_init(void)
585{
586	int ret = -ENODEV;
587
588	if (machine_is_netwinder()) {
589		int id;
590
591		FLASH_BASE = ioremap(DC21285_FLASH, KFLASH_SIZE4);
592		if (!FLASH_BASE)
593			goto out;
594
595		id = get_flash_id();
596		if ((id != KFLASH_ID) && (id != KFLASH_ID4)) {
597			ret = -ENXIO;
598			iounmap((void *)FLASH_BASE);
599			printk("Flash: incorrect ID 0x%04X.\n", id);
600			goto out;
601		}
602
603		printk("Flash ROM driver v.%s, flash device ID 0x%04X, size %d Mb.\n",
604		       NWFLASH_VERSION, id, gbFlashSize / (1024 * 1024));
605
606		ret = misc_register(&flash_miscdev);
607		if (ret < 0) {
608			iounmap((void *)FLASH_BASE);
609		}
610	}
611out:
612	return ret;
613}
614
615static void __exit nwflash_exit(void)
616{
617	misc_deregister(&flash_miscdev);
618	iounmap((void *)FLASH_BASE);
619}
620
621MODULE_LICENSE("GPL");
622
623module_param(flashdebug, bool, 0644);
624
625module_init(nwflash_init);
626module_exit(nwflash_exit);