mx6: ocotp: add timeout to busy wait loop

diff --git a/drivers/misc/mxc_ocotp.c b/drivers/misc/mxc_ocotp.c
index 4f222e6f991a28bf5418ba42e165eb67ee22ebd1..f468d9d5839fdf0ec68418f890235468f26b1378 100644 (file)
--- a/drivers/misc/mxc_ocotp.c
+++ b/drivers/misc/mxc_ocotp.c
@@ -42,11 +42,22 @@
 #define BF(value, field)               (((value) << BO_##field) & BM_##field)
 
 #define WRITE_POSTAMBLE_US             2
 #define BF(value, field)               (((value) << BO_##field) & BM_##field)
 
 #define WRITE_POSTAMBLE_US             2

+#define MXC_OTP_BUSY_TIMEOUT           1000

 
 

-static void wait_busy(struct ocotp_regs *regs, unsigned int delay_us)
+static bool wait_busy(struct ocotp_regs *regs, unsigned int delay_us)

 {
 {

-       while (readl(&regs->ctrl) & BM_CTRL_BUSY)
+       unsigned long start;
+       u32 reg;
+
+       start = get_timer_masked();
+       while ((reg = readl(&regs->ctrl)) & BM_CTRL_BUSY) {

                udelay(delay_us);
                udelay(delay_us);

+               if (get_timer(start) > MXC_OTP_BUSY_TIMEOUT)
+                       break;
+       }
+       if (!(reg & BM_CTRL_BUSY))
+               return 1;
+       return !(readl(&regs->ctrl) & BM_CTRL_BUSY);

 }
 
 static void clear_error(struct ocotp_regs *regs)
 }
 
 static void clear_error(struct ocotp_regs *regs)


@@ -68,8 +79,10 @@ static int prepare_access(struct ocotp_regs **regs, u32 bank, u32 word,
 
        enable_ocotp_clk(1);
 
 
        enable_ocotp_clk(1);
 

-       wait_busy(*regs, 1);
-       clear_error(*regs);
+       if (wait_busy(*regs, 1))
+               clear_error(*regs);
+       else
+               return -ETIMEDOUT;

 
        return 0;
 }
 
        return 0;
 }


@@ -155,8 +168,10 @@ int fuse_sense(u32 bank, u32 word, u32 *val)
 
        setup_direct_access(regs, bank, word, false);
        writel(BM_READ_CTRL_READ_FUSE, &regs->read_ctrl);
 
        setup_direct_access(regs, bank, word, false);
        writel(BM_READ_CTRL_READ_FUSE, &regs->read_ctrl);

-       wait_busy(regs, 1);
-       *val = readl(&regs->read_fuse_data);
+       if (wait_busy(regs, 1))
+               *val = readl(&regs->read_fuse_data);
+       else
+               *val = ~0;

 
        return finish_access(regs, __func__);
 }
 
        return finish_access(regs, __func__);
 }