mxs: spl: adjust delay after setting CLKCTRL_PLL0CTRL0_POWER to what the hardware...

[karo-tx-uboot.git] / arch / arm / cpu / arm926ejs / mxs / spl_power_init.c

diff --git a/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c b/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c
index 3d26b8d1b37525c924f96d7dd8e1056be19baab6..6d6d416bcf00a07a2d2caae5823ba9dbc2d58ff4 100644 (file)
--- a/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c
+++ b/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c
@@ -114,19 +114,16 @@ static void mxs_power_clock2pll(void)
 
        debug("SPL: Switching CPU core clock source to PLL\n");
 
 
        debug("SPL: Switching CPU core clock source to PLL\n");
 

-       /*
-        * TODO: Are we really? It looks like we turn on PLL0, but we then
-        * set the CLKCTRL_CLKSEQ_BYPASS_CPU bit of the (which was already
-        * set by mxs_power_clock2xtal()). Clearing this bit here seems to
-        * introduce some instability (causing the CPU core to hang). Maybe
-        * we aren't giving PLL0 enough time to stabilise?
-        */

        writel(CLKCTRL_PLL0CTRL0_POWER,
                &clkctrl_regs->hw_clkctrl_pll0ctrl0_set);
        writel(CLKCTRL_PLL0CTRL0_POWER,
                &clkctrl_regs->hw_clkctrl_pll0ctrl0_set);

-       udelay(100);
+       /*
+        * The PLL is documented to lock within 10 µs from setting
+        * the POWER bit.
+        */
+       udelay(15);

 
        /*
 
        /*

-        * TODO: Should the PLL0 FORCE_LOCK bit be set here followed be a
+        * TODO: Should the PLL0 FORCE_LOCK bit be set here followed by a

         * wait on the PLL0 LOCK bit?
         */
        writel(CLKCTRL_CLKSEQ_BYPASS_CPU,
         * wait on the PLL0 LOCK bit?
         */
        writel(CLKCTRL_CLKSEQ_BYPASS_CPU,