random: add tracepoints for easier debugging and verification
[linux-2.6.git] / drivers / char / bfin-otp.c
index 0a01329..44660f1 100644 (file)
@@ -1,8 +1,7 @@
 /*
  * 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
  *
@@ -86,9 +54,11 @@ static ssize_t bfin_otp_read(struct file *file, char __user *buff, size_t count,
        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;
                }
@@ -96,7 +66,7 @@ static ssize_t bfin_otp_read(struct file *file, char __user *buff, size_t count,
                        bytes_done = -EFAULT;
                        break;
                }
-               if (flags == OTP_UPPER_HALF)
+               if (flags & OTP_UPPER_HALF)
                        ++page;
                bytes_done += sizeof(content);
                *pos += sizeof(content);
@@ -108,14 +78,53 @@ static ssize_t bfin_otp_read(struct file *file, char __user *buff, size_t count,
 }
 
 #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;
@@ -123,20 +132,97 @@ static ssize_t bfin_otp_write(struct file *filp, const char __user *buff, size_t
        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,
+       .llseek         = default_llseek,
 };
 
 static struct miscdevice bfin_otp_misc_device = {