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path: root/drivers/char/nwflash.c
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Diffstat (limited to 'drivers/char/nwflash.c')
-rw-r--r--drivers/char/nwflash.c654
1 files changed, 654 insertions, 0 deletions
diff --git a/drivers/char/nwflash.c b/drivers/char/nwflash.c
new file mode 100644
index 000000000..e371480d3
--- /dev/null
+++ b/drivers/char/nwflash.c
@@ -0,0 +1,654 @@
+/*
+ * 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/miscdevice.h>
+#include <linux/spinlock.h>
+#include <linux/rwsem.h>
+#include <linux/init.h>
+#include <linux/mutex.h>
+#include <linux/jiffies.h>
+
+#include <asm/hardware/dec21285.h>
+#include <asm/io.h>
+#include <asm/mach-types.h>
+#include <asm/uaccess.h>
+
+/*****************************************************************************/
+#include <asm/nwflash.h>
+
+#define NWFLASH_VERSION "6.4"
+
+static DEFINE_MUTEX(flash_mutex);
+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 bool 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 DEFINE_MUTEX(nwflash_mutex);
+
+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 long flash_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
+{
+ mutex_lock(&flash_mutex);
+ 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;
+ mutex_unlock(&flash_mutex);
+ return -EINVAL;
+ }
+ mutex_unlock(&flash_mutex);
+ return 0;
+}
+
+static ssize_t flash_read(struct file *file, char __user *buf, size_t size,
+ loff_t *ppos)
+{
+ ssize_t ret;
+
+ if (flashdebug)
+ printk(KERN_DEBUG "flash_read: flash_read: offset=0x%llx, "
+ "buffer=%p, count=0x%zx.\n", *ppos, buf, size);
+ /*
+ * We now lock against reads and writes. --rmk
+ */
+ if (mutex_lock_interruptible(&nwflash_mutex))
+ return -ERESTARTSYS;
+
+ ret = simple_read_from_buffer(buf, size, ppos, (void *)FLASH_BASE, gbFlashSize);
+ mutex_unlock(&nwflash_mutex);
+
+ 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 (mutex_lock_interruptible(&nwflash_mutex))
+ return -ERESTARTSYS;
+
+ written = 0;
+
+ 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);
+ }
+
+ mutex_unlock(&nwflash_mutex);
+
+ 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;
+
+ mutex_lock(&flash_mutex);
+ 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;
+ }
+ mutex_unlock(&flash_mutex);
+ 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;
+
+ /*
+ * 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;
+
+ 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);
+
+ /*
+ * wait couple ms
+ */
+ msleep(10);
+
+ goto WriteRetry;
+ } else {
+ printk(KERN_ERR "write_block: timeout at 0x%X\n",
+ pWritePtr - FLASH_BASE);
+ /*
+ * return error -2
+ */
+ return -2;
+
+ }
+ }
+ }
+
+ 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.
+ */
+ raw_spin_lock_irqsave(&nw_gpio_lock, flags);
+ nw_cpld_modify(CPLD_FLASH_WR_ENABLE, CPLD_FLASH_WR_ENABLE);
+ raw_spin_unlock_irqrestore(&nw_gpio_lock, flags);
+
+ /*
+ * let the ISA bus to catch on...
+ */
+ udelay(25);
+}
+
+static const struct file_operations flash_fops =
+{
+ .owner = THIS_MODULE,
+ .llseek = flash_llseek,
+ .read = flash_read,
+ .write = flash_write,
+ .unlocked_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);
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-19 10:59:15 +0000