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 *buf, int count);
47 static int flash_ioctl(struct inode *inodep, struct file *filep, unsigned int cmd, unsigned long arg);
48 static ssize_t flash_read(struct file *file, char *buf, size_t count, loff_t * ppos);
49 static ssize_t flash_write(struct file *file, const char *buf, size_t count, loff_t * ppos);
50 static loff_t flash_llseek(struct file *file, loff_t offset, int orig);
52 #define KFLASH_SIZE 1024*1024 //1 Meg
53 #define KFLASH_SIZE4 4*1024*1024 //4 Meg
54 #define KFLASH_ID 0x89A6 //Intel flash
55 #define KFLASH_ID4 0xB0D4 //Intel flash 4Meg
57 static int flashdebug; //if set - we will display progress msgs
59 static int gbWriteEnable;
60 static int gbWriteBase64Enable;
61 static volatile unsigned char *FLASH_BASE;
62 static int gbFlashSize = KFLASH_SIZE;
63 static DECLARE_MUTEX(nwflash_sem);
65 extern spinlock_t gpio_lock;
68 * the delay routine - it is often required to let the flash "breeze"...
70 void flash_wait(int timeout)
72 current->state = TASK_INTERRUPTIBLE;
73 schedule_timeout(timeout);
76 static int get_flash_id(void)
78 volatile unsigned int c1, c2;
81 * try to get flash chip ID
85 *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x90;
87 c1 = *(volatile unsigned char *) FLASH_BASE;
91 * on 4 Meg flash the second byte is actually at offset 2...
94 c2 = *(volatile unsigned char *) (FLASH_BASE + 2);
96 c2 = *(volatile unsigned char *) (FLASH_BASE + 1);
101 * set it back to read mode
103 *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0xFF;
105 if (c2 == KFLASH_ID4)
106 gbFlashSize = KFLASH_SIZE4;
111 static int flash_ioctl(struct inode *inodep, struct file *filep, unsigned int cmd, unsigned long arg)
114 case CMD_WRITE_DISABLE:
115 gbWriteBase64Enable = 0;
119 case CMD_WRITE_ENABLE:
123 case CMD_WRITE_BASE64K_ENABLE:
124 gbWriteBase64Enable = 1;
128 gbWriteBase64Enable = 0;
135 static ssize_t flash_read(struct file *file, char *buf, size_t size, loff_t * ppos)
137 unsigned long p = *ppos;
138 unsigned int count = size;
142 printk(KERN_DEBUG "flash_read: flash_read: offset=0x%lX, buffer=%p, count=0x%X.\n",
148 if (p < gbFlashSize) {
149 if (count > gbFlashSize - p)
150 count = gbFlashSize - p;
153 * We now lock against reads and writes. --rmk
155 if (down_interruptible(&nwflash_sem))
158 ret = copy_to_user(buf, (void *)(FLASH_BASE + p), count);
169 static ssize_t flash_write(struct file *file, const char *buf, size_t size, loff_t * ppos)
171 unsigned long p = *ppos;
172 unsigned int count = size;
174 int nBlock, temp, rc;
178 printk("flash_write: offset=0x%lX, buffer=0x%p, count=0x%X.\n",
184 if (p < 64 * 1024 && (!gbWriteBase64Enable))
188 * check for out of range pos or count
190 if (p >= gbFlashSize)
191 return count ? -ENXIO : 0;
193 if (count > gbFlashSize - p)
194 count = gbFlashSize - p;
196 if (verify_area(VERIFY_READ, buf, count))
200 * We now lock against reads and writes. --rmk
202 if (down_interruptible(&nwflash_sem))
207 leds_event(led_claim);
208 leds_event(led_green_on);
210 nBlock = (int) p >> 16; //block # of 64K bytes
213 * # of 64K blocks to erase and write
215 temp = ((int) (p + count) >> 16) - nBlock + 1;
218 * write ends at exactly 64k boundary?
220 if (((int) (p + count) & 0xFFFF) == 0)
224 printk(KERN_DEBUG "flash_write: writing %d block(s) "
225 "starting at %d.\n", temp, nBlock);
227 for (; temp; temp--, nBlock++) {
229 printk(KERN_DEBUG "flash_write: erasing block %d.\n", nBlock);
232 * first we have to erase the block(s), where we will write...
238 rc = erase_block(nBlock);
240 } while (rc && i < 10);
243 printk(KERN_ERR "flash_write: erase error %x\n", rc);
247 printk(KERN_DEBUG "flash_write: writing offset %lX, from buf "
248 "%p, bytes left %X.\n", p, buf, count - written);
251 * write_block will limit write to space left in this block
253 rc = write_block(p, buf, count - written);
257 * if somehow write verify failed? Can't happen??
261 * retry up to 10 times
267 * else quit with error...
273 printk(KERN_ERR "flash_write: write error %X\n", rc);
282 printk(KERN_DEBUG "flash_write: written 0x%X bytes OK.\n", written);
286 * restore reg on exit
288 leds_event(led_release);
297 * The memory devices use the full 32/64 bits of the offset, and so we cannot
298 * check against negative addresses: they are ok. The return value is weird,
299 * though, in that case (0).
301 * also note that seeking relative to the "end of file" isn't supported:
302 * it has no meaning, so it returns -EINVAL.
304 static loff_t flash_llseek(struct file *file, loff_t offset, int orig)
310 printk(KERN_DEBUG "flash_llseek: offset=0x%X, orig=0x%X.\n",
311 (unsigned int) offset, orig);
320 if ((unsigned int) offset > gbFlashSize) {
325 file->f_pos = (unsigned int) offset;
329 if ((file->f_pos + offset) > gbFlashSize) {
333 if ((file->f_pos + offset) < 0) {
337 file->f_pos += offset;
349 * assume that main Write routine did the parameter checking...
350 * so just go ahead and erase, what requested!
353 static int erase_block(int nBlock)
355 volatile unsigned int c1;
356 volatile unsigned char *pWritePtr;
357 unsigned long timeout;
361 * orange LED == erase
363 leds_event(led_amber_on);
366 * reset footbridge to the correct offset 0 (...0..3)
368 *CSR_ROMWRITEREG = 0;
373 c1 = *(volatile unsigned char *) (FLASH_BASE + 0x8000);
377 * reset status if old errors
379 *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
383 * aim at the middle of a current block...
385 pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + 0x8000 + (nBlock << 16)));
395 *(volatile unsigned char *) pWritePtr = 0x20;
400 *(volatile unsigned char *) pWritePtr = 0xD0;
405 flash_wait(HZ / 100);
408 * wait while erasing in process (up to 10 sec)
410 timeout = jiffies + 10 * HZ;
412 while (!(c1 & 0x80) && time_before(jiffies, timeout)) {
413 flash_wait(HZ / 100);
417 c1 = *(volatile unsigned char *) (pWritePtr);
418 // printk("Flash_erase: status=%X.\n",c1);
422 * set flash for normal read access
425 // *(volatile unsigned char*)(FLASH_BASE+0x8000) = 0xFF;
426 *(volatile unsigned char *) pWritePtr = 0xFF; //back to normal operation
429 * check if erase errors were reported
432 printk(KERN_ERR "flash_erase: err at %p\n", pWritePtr);
437 *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
442 * just to make sure - verify if erased OK...
444 flash_wait(HZ / 100);
446 pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + (nBlock << 16)));
448 for (temp = 0; temp < 16 * 1024; temp++, pWritePtr += 4) {
449 if ((temp1 = *(volatile unsigned int *) pWritePtr) != 0xFFFFFFFF) {
450 printk(KERN_ERR "flash_erase: verify err at %p = %X\n",
461 * write_block will limit number of bytes written to the space in this block
463 static int write_block(unsigned long p, const char *buf, int count)
465 volatile unsigned int c1;
466 volatile unsigned int c2;
467 unsigned char *pWritePtr;
468 unsigned int uAddress;
470 unsigned long timeout;
471 unsigned long timeout1;
476 leds_event(led_amber_off);
477 leds_event(led_red_on);
479 pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + p));
482 * check if write will end in this block....
486 if (offset + count > 0x10000)
487 count = 0x10000 - offset;
490 * wait up to 30 sec for this block
492 timeout = jiffies + 30 * HZ;
494 for (offset = 0; offset < count; offset++, pWritePtr++) {
495 uAddress = (unsigned int) pWritePtr;
496 uAddress &= 0xFFFFFFFC;
497 if (__get_user(c2, buf + offset))
504 c1 = *(volatile unsigned char *) (FLASH_BASE + 0x8000);
507 * kick open the write gate
512 * program footbridge to the correct offset...0..3
514 *CSR_ROMWRITEREG = (unsigned int) pWritePtr & 3;
519 *(volatile unsigned char *) (uAddress) = 0x40;
524 *(volatile unsigned char *) (uAddress) = c2;
529 *(volatile unsigned char *) (FLASH_BASE + 0x10000) = 0x70;
534 * wait up to 1 sec for this byte
536 timeout1 = jiffies + 1 * HZ;
541 while (!(c1 & 0x80) && time_before(jiffies, timeout1))
542 c1 = *(volatile unsigned char *) (FLASH_BASE + 0x8000);
545 * if timeout getting status
547 if (time_after_eq(jiffies, timeout1)) {
552 *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
557 * switch on read access, as a default flash operation mode
563 *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0xFF;
566 * if hardware reports an error writing, and not timeout -
567 * reset the chip and retry
574 *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
579 if (time_before(jiffies, timeout)) {
581 printk(KERN_DEBUG "write_block: Retrying write at 0x%X)n",
582 pWritePtr - FLASH_BASE);
587 leds_event(led_amber_off);
591 flash_wait(HZ / 100);
595 leds_event(led_red_on);
599 printk(KERN_ERR "write_block: timeout at 0x%X\n",
600 pWritePtr - FLASH_BASE);
611 * green LED == read/verify
613 leds_event(led_amber_off);
614 leds_event(led_green_on);
616 flash_wait(HZ / 100);
618 pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + p));
620 for (offset = 0; offset < count; offset++) {
622 if (__get_user(c, buf))
625 if ((c1 = *pWritePtr++) != c) {
626 printk(KERN_ERR "write_block: verify error at 0x%X (%02X!=%02X)\n",
627 pWritePtr - FLASH_BASE, c1, c);
636 static void kick_open(void)
641 * we want to write a bit pattern XXX1 to Xilinx to enable
642 * the write gate, which will be open for about the next 2ms.
644 spin_lock_irqsave(&gpio_lock, flags);
646 spin_unlock_irqrestore(&gpio_lock, flags);
649 * let the ISA bus to catch on...
654 static struct file_operations flash_fops =
656 .owner = THIS_MODULE,
657 .llseek = flash_llseek,
659 .write = flash_write,
660 .ioctl = flash_ioctl,
663 static struct miscdevice flash_miscdev =
670 static int __init nwflash_init(void)
674 if (machine_is_netwinder()) {
677 FLASH_BASE = ioremap(DC21285_FLASH, KFLASH_SIZE4);
682 if ((id != KFLASH_ID) && (id != KFLASH_ID4)) {
684 iounmap((void *)FLASH_BASE);
685 printk("Flash: incorrect ID 0x%04X.\n", id);
689 printk("Flash ROM driver v.%s, flash device ID 0x%04X, size %d Mb.\n",
690 NWFLASH_VERSION, id, gbFlashSize / (1024 * 1024));
692 ret = misc_register(&flash_miscdev);
694 iounmap((void *)FLASH_BASE);
701 static void __exit nwflash_exit(void)
703 misc_deregister(&flash_miscdev);
704 iounmap((void *)FLASH_BASE);
707 MODULE_LICENSE("GPL");
709 MODULE_PARM(flashdebug, "i");
711 module_init(nwflash_init);
712 module_exit(nwflash_exit);