/*
* Blackfin On-Chip OTP Memory Interface
- * Supports BF52x/BF54x
*
- * Copyright 2007-2008 Analog Devices Inc.
+ * Copyright 2007-2009 Analog Devices Inc.
*
* Enter bugs at http://blackfin.uclinux.org/
*
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/types.h>
+#include <mtd/mtd-abi.h>
#include <asm/blackfin.h>
+#include <asm/bfrom.h>
#include <asm/uaccess.h>
#define stamp(fmt, args...) pr_debug("%s:%i: " fmt "\n", __func__, __LINE__, ## args)
static DEFINE_MUTEX(bfin_otp_lock);
-/* OTP Boot ROM functions */
-#define _BOOTROM_OTP_COMMAND 0xEF000018
-#define _BOOTROM_OTP_READ 0xEF00001A
-#define _BOOTROM_OTP_WRITE 0xEF00001C
-
-static u32 (* const otp_command)(u32 command, u32 value) = (void *)_BOOTROM_OTP_COMMAND;
-static u32 (* const otp_read)(u32 page, u32 flags, u64 *page_content) = (void *)_BOOTROM_OTP_READ;
-static u32 (* const otp_write)(u32 page, u32 flags, u64 *page_content) = (void *)_BOOTROM_OTP_WRITE;
-
-/* otp_command(): defines for "command" */
-#define OTP_INIT 0x00000001
-#define OTP_CLOSE 0x00000002
-
-/* otp_{read,write}(): defines for "flags" */
-#define OTP_LOWER_HALF 0x00000000 /* select upper/lower 64-bit half (bit 0) */
-#define OTP_UPPER_HALF 0x00000001
-#define OTP_NO_ECC 0x00000010 /* do not use ECC */
-#define OTP_LOCK 0x00000020 /* sets page protection bit for page */
-#define OTP_ACCESS_READ 0x00001000
-#define OTP_ACCESS_READWRITE 0x00002000
-
-/* Return values for all functions */
-#define OTP_SUCCESS 0x00000000
-#define OTP_MASTER_ERROR 0x001
-#define OTP_WRITE_ERROR 0x003
-#define OTP_READ_ERROR 0x005
-#define OTP_ACC_VIO_ERROR 0x009
-#define OTP_DATA_MULT_ERROR 0x011
-#define OTP_ECC_MULT_ERROR 0x021
-#define OTP_PREV_WR_ERROR 0x041
-#define OTP_DATA_SB_WARN 0x100
-#define OTP_ECC_SB_WARN 0x200
-
/**
* bfin_otp_read - Read OTP pages
*
page = *pos / (sizeof(u64) * 2);
while (bytes_done < count) {
flags = (*pos % (sizeof(u64) * 2) ? OTP_UPPER_HALF : OTP_LOWER_HALF);
- stamp("processing page %i (%s)", page, (flags == OTP_UPPER_HALF ? "upper" : "lower"));
- ret = otp_read(page, flags, &content);
+ stamp("processing page %i (0x%x:%s)", page, flags,
+ (flags & OTP_UPPER_HALF ? "upper" : "lower"));
+ ret = bfrom_OtpRead(page, flags, &content);
if (ret & OTP_MASTER_ERROR) {
+ stamp("error from otp: 0x%x", ret);
bytes_done = -EIO;
break;
}
bytes_done = -EFAULT;
break;
}
- if (flags == OTP_UPPER_HALF)
+ if (flags & OTP_UPPER_HALF)
++page;
bytes_done += sizeof(content);
*pos += sizeof(content);
}
#ifdef CONFIG_BFIN_OTP_WRITE_ENABLE
+static bool allow_writes;
+
+/**
+ * bfin_otp_init_timing - setup OTP timing parameters
+ *
+ * Required before doing any write operation. Algorithms from HRM.
+ */
+static u32 bfin_otp_init_timing(void)
+{
+ u32 tp1, tp2, tp3, timing;
+
+ tp1 = get_sclk() / 1000000;
+ tp2 = (2 * get_sclk() / 10000000) << 8;
+ tp3 = (0x1401) << 15;
+ timing = tp1 | tp2 | tp3;
+ if (bfrom_OtpCommand(OTP_INIT, timing))
+ return 0;
+
+ return timing;
+}
+
+/**
+ * bfin_otp_deinit_timing - set timings to only allow reads
+ *
+ * Should be called after all writes are done.
+ */
+static void bfin_otp_deinit_timing(u32 timing)
+{
+ /* mask bits [31:15] so that any attempts to write fail */
+ bfrom_OtpCommand(OTP_CLOSE, 0);
+ bfrom_OtpCommand(OTP_INIT, timing & ~(-1 << 15));
+ bfrom_OtpCommand(OTP_CLOSE, 0);
+}
+
/**
- * bfin_otp_write - Write OTP pages
+ * bfin_otp_write - write OTP pages
*
* All writes must be in half page chunks (half page == 64 bits).
*/
static ssize_t bfin_otp_write(struct file *filp, const char __user *buff, size_t count, loff_t *pos)
{
- stampit();
+ ssize_t bytes_done;
+ u32 timing, page, base_flags, flags, ret;
+ u64 content;
+
+ if (!allow_writes)
+ return -EACCES;
if (count % sizeof(u64))
return -EMSGSIZE;
if (mutex_lock_interruptible(&bfin_otp_lock))
return -ERESTARTSYS;
- /* need otp_init() documentation before this can be implemented */
+ stampit();
+
+ timing = bfin_otp_init_timing();
+ if (timing == 0) {
+ mutex_unlock(&bfin_otp_lock);
+ return -EIO;
+ }
+
+ base_flags = OTP_CHECK_FOR_PREV_WRITE;
+
+ bytes_done = 0;
+ page = *pos / (sizeof(u64) * 2);
+ while (bytes_done < count) {
+ flags = base_flags | (*pos % (sizeof(u64) * 2) ? OTP_UPPER_HALF : OTP_LOWER_HALF);
+ stamp("processing page %i (0x%x:%s) from %p", page, flags,
+ (flags & OTP_UPPER_HALF ? "upper" : "lower"), buff + bytes_done);
+ if (copy_from_user(&content, buff + bytes_done, sizeof(content))) {
+ bytes_done = -EFAULT;
+ break;
+ }
+ ret = bfrom_OtpWrite(page, flags, &content);
+ if (ret & OTP_MASTER_ERROR) {
+ stamp("error from otp: 0x%x", ret);
+ bytes_done = -EIO;
+ break;
+ }
+ if (flags & OTP_UPPER_HALF)
+ ++page;
+ bytes_done += sizeof(content);
+ *pos += sizeof(content);
+ }
+
+ bfin_otp_deinit_timing(timing);
mutex_unlock(&bfin_otp_lock);
+ return bytes_done;
+}
+
+static long bfin_otp_ioctl(struct file *filp, unsigned cmd, unsigned long arg)
+{
+ stampit();
+
+ switch (cmd) {
+ case OTPLOCK: {
+ u32 timing;
+ int ret = -EIO;
+
+ if (!allow_writes)
+ return -EACCES;
+
+ if (mutex_lock_interruptible(&bfin_otp_lock))
+ return -ERESTARTSYS;
+
+ timing = bfin_otp_init_timing();
+ if (timing) {
+ u32 otp_result = bfrom_OtpWrite(arg, OTP_LOCK, NULL);
+ stamp("locking page %lu resulted in 0x%x", arg, otp_result);
+ if (!(otp_result & OTP_MASTER_ERROR))
+ ret = 0;
+
+ bfin_otp_deinit_timing(timing);
+ }
+
+ mutex_unlock(&bfin_otp_lock);
+
+ return ret;
+ }
+
+ case MEMLOCK:
+ allow_writes = false;
+ return 0;
+
+ case MEMUNLOCK:
+ allow_writes = true;
+ return 0;
+ }
+
return -EINVAL;
}
#else
# define bfin_otp_write NULL
+# define bfin_otp_ioctl NULL
#endif
-static struct file_operations bfin_otp_fops = {
- .owner = THIS_MODULE,
- .read = bfin_otp_read,
- .write = bfin_otp_write,
+static const struct file_operations bfin_otp_fops = {
+ .owner = THIS_MODULE,
+ .unlocked_ioctl = bfin_otp_ioctl,
+ .read = bfin_otp_read,
+ .write = bfin_otp_write,
};
static struct miscdevice bfin_otp_misc_device = {
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