2 * Flash memory interface rev.5 driver for the Intel
3 * Flash chips used on the NetWinder.
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
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...
17 #include <linux/module.h>
18 #include <linux/types.h>
20 #include <linux/errno.h>
22 #include <linux/delay.h>
23 #include <linux/proc_fs.h>
24 #include <linux/sched.h>
25 #include <linux/miscdevice.h>
26 #include <linux/spinlock.h>
27 #include <linux/rwsem.h>
28 #include <linux/init.h>
29 #include <linux/smp_lock.h>
31 #include <asm/hardware/dec21285.h>
34 #include <asm/mach-types.h>
35 #include <asm/system.h>
36 #include <asm/uaccess.h>
38 /*****************************************************************************/
39 #include <asm/nwflash.h>
41 #define NWFLASH_VERSION "6.4"
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);
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
53 static int flashdebug; //if set - we will display progress msgs
55 static int gbWriteEnable;
56 static int gbWriteBase64Enable;
57 static volatile unsigned char *FLASH_BASE;
58 static int gbFlashSize = KFLASH_SIZE;
59 static DECLARE_MUTEX(nwflash_sem);
61 extern spinlock_t gpio_lock;
64 * the delay routine - it is often required to let the flash "breeze"...
66 void flash_wait(int timeout)
68 current->state = TASK_INTERRUPTIBLE;
69 schedule_timeout(timeout);
72 static int get_flash_id(void)
74 volatile unsigned int c1, c2;
77 * try to get flash chip ID
81 *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x90;
83 c1 = *(volatile unsigned char *) FLASH_BASE;
87 * on 4 Meg flash the second byte is actually at offset 2...
90 c2 = *(volatile unsigned char *) (FLASH_BASE + 2);
92 c2 = *(volatile unsigned char *) (FLASH_BASE + 1);
97 * set it back to read mode
99 *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0xFF;
101 if (c2 == KFLASH_ID4)
102 gbFlashSize = KFLASH_SIZE4;
107 static int flash_ioctl(struct inode *inodep, struct file *filep, unsigned int cmd, unsigned long arg)
110 case CMD_WRITE_DISABLE:
111 gbWriteBase64Enable = 0;
115 case CMD_WRITE_ENABLE:
119 case CMD_WRITE_BASE64K_ENABLE:
120 gbWriteBase64Enable = 1;
124 gbWriteBase64Enable = 0;
131 static ssize_t flash_read(struct file *file, char __user *buf, size_t size,
134 unsigned long p = *ppos;
135 unsigned int count = size;
139 printk(KERN_DEBUG "flash_read: flash_read: offset=0x%lX, "
140 "buffer=%p, count=0x%X.\n", p, buf, count);
145 if (p < gbFlashSize) {
146 if (count > gbFlashSize - p)
147 count = gbFlashSize - p;
150 * We now lock against reads and writes. --rmk
152 if (down_interruptible(&nwflash_sem))
155 ret = copy_to_user(buf, (void *)(FLASH_BASE + p), count);
166 static ssize_t flash_write(struct file *file, const char __user *buf,
167 size_t size, loff_t * ppos)
169 unsigned long p = *ppos;
170 unsigned int count = size;
172 int nBlock, temp, rc;
176 printk("flash_write: offset=0x%lX, buffer=0x%p, count=0x%X.\n",
182 if (p < 64 * 1024 && (!gbWriteBase64Enable))
186 * check for out of range pos or count
188 if (p >= gbFlashSize)
189 return count ? -ENXIO : 0;
191 if (count > gbFlashSize - p)
192 count = gbFlashSize - p;
194 if (verify_area(VERIFY_READ, buf, count))
198 * We now lock against reads and writes. --rmk
200 if (down_interruptible(&nwflash_sem))
205 leds_event(led_claim);
206 leds_event(led_green_on);
208 nBlock = (int) p >> 16; //block # of 64K bytes
211 * # of 64K blocks to erase and write
213 temp = ((int) (p + count) >> 16) - nBlock + 1;
216 * write ends at exactly 64k boundary?
218 if (((int) (p + count) & 0xFFFF) == 0)
222 printk(KERN_DEBUG "flash_write: writing %d block(s) "
223 "starting at %d.\n", temp, nBlock);
225 for (; temp; temp--, nBlock++) {
227 printk(KERN_DEBUG "flash_write: erasing block %d.\n", nBlock);
230 * first we have to erase the block(s), where we will write...
236 rc = erase_block(nBlock);
238 } while (rc && i < 10);
241 printk(KERN_ERR "flash_write: erase error %x\n", rc);
245 printk(KERN_DEBUG "flash_write: writing offset %lX, "
246 "from buf %p, bytes left %X.\n", p, buf,
250 * write_block will limit write to space left in this block
252 rc = write_block(p, buf, count - written);
256 * if somehow write verify failed? Can't happen??
260 * retry up to 10 times
266 * else quit with error...
272 printk(KERN_ERR "flash_write: write error %X\n", rc);
281 printk(KERN_DEBUG "flash_write: written 0x%X bytes OK.\n", written);
285 * restore reg on exit
287 leds_event(led_release);
296 * The memory devices use the full 32/64 bits of the offset, and so we cannot
297 * check against negative addresses: they are ok. The return value is weird,
298 * though, in that case (0).
300 * also note that seeking relative to the "end of file" isn't supported:
301 * it has no meaning, so it returns -EINVAL.
303 static loff_t flash_llseek(struct file *file, loff_t offset, int orig)
309 printk(KERN_DEBUG "flash_llseek: offset=0x%X, orig=0x%X.\n",
310 (unsigned int) offset, orig);
319 if ((unsigned int) offset > gbFlashSize) {
324 file->f_pos = (unsigned int) offset;
328 if ((file->f_pos + offset) > gbFlashSize) {
332 if ((file->f_pos + offset) < 0) {
336 file->f_pos += offset;
348 * assume that main Write routine did the parameter checking...
349 * so just go ahead and erase, what requested!
352 static int erase_block(int nBlock)
354 volatile unsigned int c1;
355 volatile unsigned char *pWritePtr;
356 unsigned long timeout;
360 * orange LED == erase
362 leds_event(led_amber_on);
365 * reset footbridge to the correct offset 0 (...0..3)
367 *CSR_ROMWRITEREG = 0;
372 c1 = *(volatile unsigned char *) (FLASH_BASE + 0x8000);
376 * reset status if old errors
378 *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
382 * aim at the middle of a current block...
384 pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + 0x8000 + (nBlock << 16)));
394 *(volatile unsigned char *) pWritePtr = 0x20;
399 *(volatile unsigned char *) pWritePtr = 0xD0;
404 flash_wait(HZ / 100);
407 * wait while erasing in process (up to 10 sec)
409 timeout = jiffies + 10 * HZ;
411 while (!(c1 & 0x80) && time_before(jiffies, timeout)) {
412 flash_wait(HZ / 100);
416 c1 = *(volatile unsigned char *) (pWritePtr);
417 // printk("Flash_erase: status=%X.\n",c1);
421 * set flash for normal read access
424 // *(volatile unsigned char*)(FLASH_BASE+0x8000) = 0xFF;
425 *(volatile unsigned char *) pWritePtr = 0xFF; //back to normal operation
428 * check if erase errors were reported
431 printk(KERN_ERR "flash_erase: err at %p\n", pWritePtr);
436 *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
441 * just to make sure - verify if erased OK...
443 flash_wait(HZ / 100);
445 pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + (nBlock << 16)));
447 for (temp = 0; temp < 16 * 1024; temp++, pWritePtr += 4) {
448 if ((temp1 = *(volatile unsigned int *) pWritePtr) != 0xFFFFFFFF) {
449 printk(KERN_ERR "flash_erase: verify err at %p = %X\n",
460 * write_block will limit number of bytes written to the space in this block
462 static int write_block(unsigned long p, const char __user *buf, int count)
464 volatile unsigned int c1;
465 volatile unsigned int c2;
466 unsigned char *pWritePtr;
467 unsigned int uAddress;
469 unsigned long timeout;
470 unsigned long timeout1;
475 leds_event(led_amber_off);
476 leds_event(led_red_on);
478 pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + p));
481 * check if write will end in this block....
485 if (offset + count > 0x10000)
486 count = 0x10000 - offset;
489 * wait up to 30 sec for this block
491 timeout = jiffies + 30 * HZ;
493 for (offset = 0; offset < count; offset++, pWritePtr++) {
494 uAddress = (unsigned int) pWritePtr;
495 uAddress &= 0xFFFFFFFC;
496 if (__get_user(c2, buf + offset))
503 c1 = *(volatile unsigned char *) (FLASH_BASE + 0x8000);
506 * kick open the write gate
511 * program footbridge to the correct offset...0..3
513 *CSR_ROMWRITEREG = (unsigned int) pWritePtr & 3;
518 *(volatile unsigned char *) (uAddress) = 0x40;
523 *(volatile unsigned char *) (uAddress) = c2;
528 *(volatile unsigned char *) (FLASH_BASE + 0x10000) = 0x70;
533 * wait up to 1 sec for this byte
535 timeout1 = jiffies + 1 * HZ;
540 while (!(c1 & 0x80) && time_before(jiffies, timeout1))
541 c1 = *(volatile unsigned char *) (FLASH_BASE + 0x8000);
544 * if timeout getting status
546 if (time_after_eq(jiffies, timeout1)) {
551 *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
556 * switch on read access, as a default flash operation mode
562 *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0xFF;
565 * if hardware reports an error writing, and not timeout -
566 * reset the chip and retry
573 *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
578 if (time_before(jiffies, timeout)) {
580 printk(KERN_DEBUG "write_block: Retrying write at 0x%X)n",
581 pWritePtr - FLASH_BASE);
586 leds_event(led_amber_off);
590 flash_wait(HZ / 100);
594 leds_event(led_red_on);
598 printk(KERN_ERR "write_block: timeout at 0x%X\n",
599 pWritePtr - FLASH_BASE);
610 * green LED == read/verify
612 leds_event(led_amber_off);
613 leds_event(led_green_on);
615 flash_wait(HZ / 100);
617 pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + p));
619 for (offset = 0; offset < count; offset++) {
621 if (__get_user(c, buf))
624 if ((c1 = *pWritePtr++) != c) {
625 printk(KERN_ERR "write_block: verify error at 0x%X (%02X!=%02X)\n",
626 pWritePtr - FLASH_BASE, c1, c);
635 static void kick_open(void)
640 * we want to write a bit pattern XXX1 to Xilinx to enable
641 * the write gate, which will be open for about the next 2ms.
643 spin_lock_irqsave(&gpio_lock, flags);
645 spin_unlock_irqrestore(&gpio_lock, flags);
648 * let the ISA bus to catch on...
653 static struct file_operations flash_fops =
655 .owner = THIS_MODULE,
656 .llseek = flash_llseek,
658 .write = flash_write,
659 .ioctl = flash_ioctl,
662 static struct miscdevice flash_miscdev =
669 static int __init nwflash_init(void)
673 if (machine_is_netwinder()) {
676 FLASH_BASE = ioremap(DC21285_FLASH, KFLASH_SIZE4);
681 if ((id != KFLASH_ID) && (id != KFLASH_ID4)) {
683 iounmap((void *)FLASH_BASE);
684 printk("Flash: incorrect ID 0x%04X.\n", id);
688 printk("Flash ROM driver v.%s, flash device ID 0x%04X, size %d Mb.\n",
689 NWFLASH_VERSION, id, gbFlashSize / (1024 * 1024));
691 ret = misc_register(&flash_miscdev);
693 iounmap((void *)FLASH_BASE);
700 static void __exit nwflash_exit(void)
702 misc_deregister(&flash_miscdev);
703 iounmap((void *)FLASH_BASE);
706 MODULE_LICENSE("GPL");
708 MODULE_PARM(flashdebug, "i");
710 module_init(nwflash_init);
711 module_exit(nwflash_exit);