mx6: ocotp: add timeout to busy wait loop

[karo-tx-uboot.git] / drivers / misc / mxc_ocotp.c

diff --git a/drivers/misc/mxc_ocotp.c b/drivers/misc/mxc_ocotp.c
index 89737af9b73c417c61d55b5712d8c46f8b1ead4c..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 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);
+               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)
@@ -60,7 +71,7 @@ static int prepare_access(struct ocotp_regs **regs, u32 bank, u32 word,
        *regs = (struct ocotp_regs *)OCOTP_BASE_ADDR;
 
        if (bank >= ARRAY_SIZE((*regs)->bank) ||
-                       word >= ARRAY_SIZE((*regs)->bank[0].fuse_regs) >> 2 ||
+                       word >= ARRAY_SIZE((*regs)->bank[0].fuse_regs) ||
                        !assert) {
                printf("mxc_ocotp %s(): Invalid argument\n", caller);
                return -EINVAL;
@@ -68,8 +79,10 @@ static int prepare_access(struct ocotp_regs **regs, u32 bank, u32 word,
 
        enable_ocotp_clk(1);
 
-       wait_busy(*regs, 1);
-       clear_error(*regs);
+       if (wait_busy(*regs, 1))
+               clear_error(*regs);
+       else
+               return -ETIMEDOUT;
 
        return 0;
 }
@@ -80,7 +93,6 @@ static int finish_access(struct ocotp_regs *regs, const char *caller)
 
        err = !!(readl(&regs->ctrl) & BM_CTRL_ERROR);
        clear_error(regs);
-
        enable_ocotp_clk(0);
 
        if (err) {
@@ -156,8 +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);
-       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__);
 }