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ARM: shmobile: r8a73a4: wait for completion when kicking the clock

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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 <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
This commit is contained in:
Guennadi Liakhovetski 2013-05-22 11:12:33 +02:00 committed by Simon Horman
parent 0b8eeba451
commit 8d27657286
1 changed files with 16 additions and 6 deletions
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22
arch/arm/mach-shmobile/clock-r8a73a4.c
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@ -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};