From 8d27657286a1e9e6ee7adaf4d0638cefd708a6fa Mon Sep 17 00:00:00 2001 From: Guennadi Liakhovetski Date: Wed, 22 May 2013 11:12:33 +0200 Subject: [PATCH] ARM: shmobile: r8a73a4: wait for completion when kicking the clock To reconfigure clocks, controlled by FRQCRA and FRQCRB, a kick bit has to be set and to make sure the setting has taken effect, it has to be read back repeatedly until it is cleared by the hardware. This patch adds the waiting part, that was missing until now. Acked-by: Kuninori Morimoto Signed-off-by: Guennadi Liakhovetski Signed-off-by: Simon Horman --- arch/arm/mach-shmobile/clock-r8a73a4.c | 22 ++++++++++++++++------ 1 file changed, 16 insertions(+), 6 deletions(-) diff --git a/arch/arm/mach-shmobile/clock-r8a73a4.c b/arch/arm/mach-shmobile/clock-r8a73a4.c index 5f7fe628b8a1..d5176d0861b5 100644 --- a/arch/arm/mach-shmobile/clock-r8a73a4.c +++ b/arch/arm/mach-shmobile/clock-r8a73a4.c @@ -184,6 +184,21 @@ PLL_CLOCK(pll2h_clk, &main_div2_clk, pll_parent_main_extal, 3, 5, PLL2HCR, 5); SH_FIXED_RATIO_CLK(pll1_div2_clk, pll1_clk, div2); +static int frqcr_kick_do(struct clk *clk) +{ + int i; + + /* set KICK bit in FRQCRB to update hardware setting, check success */ + iowrite32(ioread32(CPG_MAP(FRQCRB)) | BIT(31), CPG_MAP(FRQCRB)); + for (i = 1000; i; i--) + if (ioread32(CPG_MAP(FRQCRB)) & BIT(31)) + cpu_relax(); + else + return 0; + + return -ETIMEDOUT; +} + static struct clk *main_clks[] = { &extalr_clk, &extal1_clk, @@ -205,12 +220,7 @@ static struct clk *main_clks[] = { /* DIV4 */ static void div4_kick(struct clk *clk) { - unsigned long value; - - /* set KICK bit in FRQCRB to update hardware setting */ - value = ioread32(CPG_MAP(FRQCRB)); - value |= (1 << 31); - iowrite32(value, CPG_MAP(FRQCRB)); + frqcr_kick_do(clk); } static int divisors[] = { 2, 3, 4, 6, 8, 12, 16, 18, 24, 0, 36, 48, 10}; -- 2.20.1