diff options
Diffstat (limited to 'drivers/char/nwflash.c')
| -rw-r--r-- | drivers/char/nwflash.c | 702 |
1 files changed, 702 insertions, 0 deletions
diff --git a/drivers/char/nwflash.c b/drivers/char/nwflash.c new file mode 100644 index 0000000..ca41d62 --- /dev/null +++ b/drivers/char/nwflash.c @@ -0,0 +1,702 @@ +/* + * Flash memory interface rev.5 driver for the Intel + * Flash chips used on the NetWinder. + * + * 20/08/2000 RMK use __ioremap to map flash into virtual memory + * make a few more places use "volatile" + * 22/05/2001 RMK - Lock read against write + * - merge printk level changes (with mods) from Alan Cox. + * - use *ppos as the file position, not file->f_pos. + * - fix check for out of range pos and r/w size + * + * Please note that we are tampering with the only flash chip in the + * machine, which contains the bootup code. We therefore have the + * power to convert these machines into doorstops... + */ + +#include <linux/module.h> +#include <linux/types.h> +#include <linux/fs.h> +#include <linux/errno.h> +#include <linux/mm.h> +#include <linux/delay.h> +#include <linux/proc_fs.h> +#include <linux/sched.h> +#include <linux/miscdevice.h> +#include <linux/spinlock.h> +#include <linux/rwsem.h> +#include <linux/init.h> +#include <linux/smp_lock.h> + +#include <asm/hardware/dec21285.h> +#include <asm/io.h> +#include <asm/leds.h> +#include <asm/mach-types.h> +#include <asm/system.h> +#include <asm/uaccess.h> + +/*****************************************************************************/ +#include <asm/nwflash.h> + +#define NWFLASH_VERSION "6.4" + +static void kick_open(void); +static int get_flash_id(void); +static int erase_block(int nBlock); +static int write_block(unsigned long p, const char __user *buf, int count); + +#define KFLASH_SIZE 1024*1024 //1 Meg +#define KFLASH_SIZE4 4*1024*1024 //4 Meg +#define KFLASH_ID 0x89A6 //Intel flash +#define KFLASH_ID4 0xB0D4 //Intel flash 4Meg + +static int flashdebug; //if set - we will display progress msgs + +static int gbWriteEnable; +static int gbWriteBase64Enable; +static volatile unsigned char *FLASH_BASE; +static int gbFlashSize = KFLASH_SIZE; +static DECLARE_MUTEX(nwflash_sem); + +extern spinlock_t gpio_lock; + +static int get_flash_id(void) +{ + volatile unsigned int c1, c2; + + /* + * try to get flash chip ID + */ + kick_open(); + c2 = inb(0x80); + *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x90; + udelay(15); + c1 = *(volatile unsigned char *) FLASH_BASE; + c2 = inb(0x80); + + /* + * on 4 Meg flash the second byte is actually at offset 2... + */ + if (c1 == 0xB0) + c2 = *(volatile unsigned char *) (FLASH_BASE + 2); + else + c2 = *(volatile unsigned char *) (FLASH_BASE + 1); + + c2 += (c1 << 8); + + /* + * set it back to read mode + */ + *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0xFF; + + if (c2 == KFLASH_ID4) + gbFlashSize = KFLASH_SIZE4; + + return c2; +} + +static int flash_ioctl(struct inode *inodep, struct file *filep, unsigned int cmd, unsigned long arg) +{ + switch (cmd) { + case CMD_WRITE_DISABLE: + gbWriteBase64Enable = 0; + gbWriteEnable = 0; + break; + + case CMD_WRITE_ENABLE: + gbWriteEnable = 1; + break; + + case CMD_WRITE_BASE64K_ENABLE: + gbWriteBase64Enable = 1; + break; + + default: + gbWriteBase64Enable = 0; + gbWriteEnable = 0; + return -EINVAL; + } + return 0; +} + +static ssize_t flash_read(struct file *file, char __user *buf, size_t size, + loff_t *ppos) +{ + unsigned long p = *ppos; + unsigned int count = size; + int ret = 0; + + if (flashdebug) + printk(KERN_DEBUG "flash_read: flash_read: offset=0x%lX, " + "buffer=%p, count=0x%X.\n", p, buf, count); + + if (count) + ret = -ENXIO; + + if (p < gbFlashSize) { + if (count > gbFlashSize - p) + count = gbFlashSize - p; + + /* + * We now lock against reads and writes. --rmk + */ + if (down_interruptible(&nwflash_sem)) + return -ERESTARTSYS; + + ret = copy_to_user(buf, (void *)(FLASH_BASE + p), count); + if (ret == 0) { + ret = count; + *ppos += count; + } else + ret = -EFAULT; + up(&nwflash_sem); + } + return ret; +} + +static ssize_t flash_write(struct file *file, const char __user *buf, + size_t size, loff_t * ppos) +{ + unsigned long p = *ppos; + unsigned int count = size; + int written; + int nBlock, temp, rc; + int i, j; + + if (flashdebug) + printk("flash_write: offset=0x%lX, buffer=0x%p, count=0x%X.\n", + p, buf, count); + + if (!gbWriteEnable) + return -EINVAL; + + if (p < 64 * 1024 && (!gbWriteBase64Enable)) + return -EINVAL; + + /* + * check for out of range pos or count + */ + if (p >= gbFlashSize) + return count ? -ENXIO : 0; + + if (count > gbFlashSize - p) + count = gbFlashSize - p; + + if (!access_ok(VERIFY_READ, buf, count)) + return -EFAULT; + + /* + * We now lock against reads and writes. --rmk + */ + if (down_interruptible(&nwflash_sem)) + return -ERESTARTSYS; + + written = 0; + + leds_event(led_claim); + leds_event(led_green_on); + + nBlock = (int) p >> 16; //block # of 64K bytes + + /* + * # of 64K blocks to erase and write + */ + temp = ((int) (p + count) >> 16) - nBlock + 1; + + /* + * write ends at exactly 64k boundary? + */ + if (((int) (p + count) & 0xFFFF) == 0) + temp -= 1; + + if (flashdebug) + printk(KERN_DEBUG "flash_write: writing %d block(s) " + "starting at %d.\n", temp, nBlock); + + for (; temp; temp--, nBlock++) { + if (flashdebug) + printk(KERN_DEBUG "flash_write: erasing block %d.\n", nBlock); + + /* + * first we have to erase the block(s), where we will write... + */ + i = 0; + j = 0; + RetryBlock: + do { + rc = erase_block(nBlock); + i++; + } while (rc && i < 10); + + if (rc) { + printk(KERN_ERR "flash_write: erase error %x\n", rc); + break; + } + if (flashdebug) + printk(KERN_DEBUG "flash_write: writing offset %lX, " + "from buf %p, bytes left %X.\n", p, buf, + count - written); + + /* + * write_block will limit write to space left in this block + */ + rc = write_block(p, buf, count - written); + j++; + + /* + * if somehow write verify failed? Can't happen?? + */ + if (!rc) { + /* + * retry up to 10 times + */ + if (j < 10) + goto RetryBlock; + else + /* + * else quit with error... + */ + rc = -1; + + } + if (rc < 0) { + printk(KERN_ERR "flash_write: write error %X\n", rc); + break; + } + p += rc; + buf += rc; + written += rc; + *ppos += rc; + + if (flashdebug) + printk(KERN_DEBUG "flash_write: written 0x%X bytes OK.\n", written); + } + + /* + * restore reg on exit + */ + leds_event(led_release); + + up(&nwflash_sem); + + return written; +} + + +/* + * The memory devices use the full 32/64 bits of the offset, and so we cannot + * check against negative addresses: they are ok. The return value is weird, + * though, in that case (0). + * + * also note that seeking relative to the "end of file" isn't supported: + * it has no meaning, so it returns -EINVAL. + */ +static loff_t flash_llseek(struct file *file, loff_t offset, int orig) +{ + loff_t ret; + + lock_kernel(); + if (flashdebug) + printk(KERN_DEBUG "flash_llseek: offset=0x%X, orig=0x%X.\n", + (unsigned int) offset, orig); + + switch (orig) { + case 0: + if (offset < 0) { + ret = -EINVAL; + break; + } + + if ((unsigned int) offset > gbFlashSize) { + ret = -EINVAL; + break; + } + + file->f_pos = (unsigned int) offset; + ret = file->f_pos; + break; + case 1: + if ((file->f_pos + offset) > gbFlashSize) { + ret = -EINVAL; + break; + } + if ((file->f_pos + offset) < 0) { + ret = -EINVAL; + break; + } + file->f_pos += offset; + ret = file->f_pos; + break; + default: + ret = -EINVAL; + } + unlock_kernel(); + return ret; +} + + +/* + * assume that main Write routine did the parameter checking... + * so just go ahead and erase, what requested! + */ + +static int erase_block(int nBlock) +{ + volatile unsigned int c1; + volatile unsigned char *pWritePtr; + unsigned long timeout; + int temp, temp1; + + /* + * orange LED == erase + */ + leds_event(led_amber_on); + + /* + * reset footbridge to the correct offset 0 (...0..3) + */ + *CSR_ROMWRITEREG = 0; + + /* + * dummy ROM read + */ + c1 = *(volatile unsigned char *) (FLASH_BASE + 0x8000); + + kick_open(); + /* + * reset status if old errors + */ + *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50; + + /* + * erase a block... + * aim at the middle of a current block... + */ + pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + 0x8000 + (nBlock << 16))); + /* + * dummy read + */ + c1 = *pWritePtr; + + kick_open(); + /* + * erase + */ + *(volatile unsigned char *) pWritePtr = 0x20; + + /* + * confirm + */ + *(volatile unsigned char *) pWritePtr = 0xD0; + + /* + * wait 10 ms + */ + msleep(10); + + /* + * wait while erasing in process (up to 10 sec) + */ + timeout = jiffies + 10 * HZ; + c1 = 0; + while (!(c1 & 0x80) && time_before(jiffies, timeout)) { + msleep(10); + /* + * read any address + */ + c1 = *(volatile unsigned char *) (pWritePtr); + // printk("Flash_erase: status=%X.\n",c1); + } + + /* + * set flash for normal read access + */ + kick_open(); +// *(volatile unsigned char*)(FLASH_BASE+0x8000) = 0xFF; + *(volatile unsigned char *) pWritePtr = 0xFF; //back to normal operation + + /* + * check if erase errors were reported + */ + if (c1 & 0x20) { + printk(KERN_ERR "flash_erase: err at %p\n", pWritePtr); + + /* + * reset error + */ + *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50; + return -2; + } + + /* + * just to make sure - verify if erased OK... + */ + msleep(10); + + pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + (nBlock << 16))); + + for (temp = 0; temp < 16 * 1024; temp++, pWritePtr += 4) { + if ((temp1 = *(volatile unsigned int *) pWritePtr) != 0xFFFFFFFF) { + printk(KERN_ERR "flash_erase: verify err at %p = %X\n", + pWritePtr, temp1); + return -1; + } + } + + return 0; + +} + +/* + * write_block will limit number of bytes written to the space in this block + */ +static int write_block(unsigned long p, const char __user *buf, int count) +{ + volatile unsigned int c1; + volatile unsigned int c2; + unsigned char *pWritePtr; + unsigned int uAddress; + unsigned int offset; + unsigned long timeout; + unsigned long timeout1; + + /* + * red LED == write + */ + leds_event(led_amber_off); + leds_event(led_red_on); + + pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + p)); + + /* + * check if write will end in this block.... + */ + offset = p & 0xFFFF; + + if (offset + count > 0x10000) + count = 0x10000 - offset; + + /* + * wait up to 30 sec for this block + */ + timeout = jiffies + 30 * HZ; + + for (offset = 0; offset < count; offset++, pWritePtr++) { + uAddress = (unsigned int) pWritePtr; + uAddress &= 0xFFFFFFFC; + if (__get_user(c2, buf + offset)) + return -EFAULT; + + WriteRetry: + /* + * dummy read + */ + c1 = *(volatile unsigned char *) (FLASH_BASE + 0x8000); + + /* + * kick open the write gate + */ + kick_open(); + + /* + * program footbridge to the correct offset...0..3 + */ + *CSR_ROMWRITEREG = (unsigned int) pWritePtr & 3; + + /* + * write cmd + */ + *(volatile unsigned char *) (uAddress) = 0x40; + + /* + * data to write + */ + *(volatile unsigned char *) (uAddress) = c2; + + /* + * get status + */ + *(volatile unsigned char *) (FLASH_BASE + 0x10000) = 0x70; + + c1 = 0; + + /* + * wait up to 1 sec for this byte + */ + timeout1 = jiffies + 1 * HZ; + + /* + * while not ready... + */ + while (!(c1 & 0x80) && time_before(jiffies, timeout1)) + c1 = *(volatile unsigned char *) (FLASH_BASE + 0x8000); + + /* + * if timeout getting status + */ + if (time_after_eq(jiffies, timeout1)) { + kick_open(); + /* + * reset err + */ + *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50; + + goto WriteRetry; + } + /* + * switch on read access, as a default flash operation mode + */ + kick_open(); + /* + * read access + */ + *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0xFF; + + /* + * if hardware reports an error writing, and not timeout - + * reset the chip and retry + */ + if (c1 & 0x10) { + kick_open(); + /* + * reset err + */ + *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50; + + /* + * before timeout? + */ + if (time_before(jiffies, timeout)) { + if (flashdebug) + printk(KERN_DEBUG "write_block: Retrying write at 0x%X)n", + pWritePtr - FLASH_BASE); + + /* + * no LED == waiting + */ + leds_event(led_amber_off); + /* + * wait couple ms + */ + msleep(10); + /* + * red LED == write + */ + leds_event(led_red_on); + + goto WriteRetry; + } else { + printk(KERN_ERR "write_block: timeout at 0x%X\n", + pWritePtr - FLASH_BASE); + /* + * return error -2 + */ + return -2; + + } + } + } + + /* + * green LED == read/verify + */ + leds_event(led_amber_off); + leds_event(led_green_on); + + msleep(10); + + pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + p)); + + for (offset = 0; offset < count; offset++) { + char c, c1; + if (__get_user(c, buf)) + return -EFAULT; + buf++; + if ((c1 = *pWritePtr++) != c) { + printk(KERN_ERR "write_block: verify error at 0x%X (%02X!=%02X)\n", + pWritePtr - FLASH_BASE, c1, c); + return 0; + } + } + + return count; +} + + +static void kick_open(void) +{ + unsigned long flags; + + /* + * we want to write a bit pattern XXX1 to Xilinx to enable + * the write gate, which will be open for about the next 2ms. + */ + spin_lock_irqsave(&gpio_lock, flags); + cpld_modify(1, 1); + spin_unlock_irqrestore(&gpio_lock, flags); + + /* + * let the ISA bus to catch on... + */ + udelay(25); +} + +static struct file_operations flash_fops = +{ + .owner = THIS_MODULE, + .llseek = flash_llseek, + .read = flash_read, + .write = flash_write, + .ioctl = flash_ioctl, +}; + +static struct miscdevice flash_miscdev = +{ + FLASH_MINOR, + "nwflash", + &flash_fops +}; + +static int __init nwflash_init(void) +{ + int ret = -ENODEV; + + if (machine_is_netwinder()) { + int id; + + FLASH_BASE = ioremap(DC21285_FLASH, KFLASH_SIZE4); + if (!FLASH_BASE) + goto out; + + id = get_flash_id(); + if ((id != KFLASH_ID) && (id != KFLASH_ID4)) { + ret = -ENXIO; + iounmap((void *)FLASH_BASE); + printk("Flash: incorrect ID 0x%04X.\n", id); + goto out; + } + + printk("Flash ROM driver v.%s, flash device ID 0x%04X, size %d Mb.\n", + NWFLASH_VERSION, id, gbFlashSize / (1024 * 1024)); + + ret = misc_register(&flash_miscdev); + if (ret < 0) { + iounmap((void *)FLASH_BASE); + } + } +out: + return ret; +} + +static void __exit nwflash_exit(void) +{ + misc_deregister(&flash_miscdev); + iounmap((void *)FLASH_BASE); +} + +MODULE_LICENSE("GPL"); + +module_param(flashdebug, bool, 0644); + +module_init(nwflash_init); +module_exit(nwflash_exit); |
