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authorGuennadi Liakhovetski <g.liakhovetski@gmx.de>2013-05-23 02:10:00 +0400
committerSimon Horman <horms+renesas@verge.net.au>2013-06-07 09:24:52 +0400
commit413bfd0e67894c930242482cd15ac09a800e2ab8 (patch)
treed23c871588e579baaf0e07cdabb63c55ca7caad1
parent3b207a45f909a73b6d7fbdcef49e9287ad7385af (diff)
downloadlinux-413bfd0e67894c930242482cd15ac09a800e2ab8.tar.xz
ARM: shmobile: sh73a0: div4 clocks must check the kick bit before changing rate
According to the datasheet, it is not allowed to change div4 clock rates if an earlier rate change operation is still in progress, as indicated by a set kick bit. Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com> Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
-rw-r--r--arch/arm/mach-shmobile/clock-sh73a0.c24
1 files changed, 19 insertions, 5 deletions
diff --git a/arch/arm/mach-shmobile/clock-sh73a0.c b/arch/arm/mach-shmobile/clock-sh73a0.c
index d05cf9039788..d9fd0336b910 100644
--- a/arch/arm/mach-shmobile/clock-sh73a0.c
+++ b/arch/arm/mach-shmobile/clock-sh73a0.c
@@ -257,7 +257,7 @@ static struct clk twd_clk = {
.ops = &twd_clk_ops,
};
-static struct sh_clk_ops zclk_ops;
+static struct sh_clk_ops zclk_ops, kicker_ops;
static const struct sh_clk_ops *div4_clk_ops;
static int zclk_set_rate(struct clk *clk, unsigned long rate)
@@ -324,18 +324,32 @@ static unsigned long zclk_recalc(struct clk *clk)
return clk_get_rate(clk->parent);
}
-static void zclk_extend(void)
+static int kicker_set_rate(struct clk *clk, unsigned long rate)
{
- div4_clk_ops = div4_clks[DIV4_Z].ops;
+ if (__raw_readl(FRQCRB) & (1 << 31))
+ return -EBUSY;
+
+ return div4_clk_ops->set_rate(clk, rate);
+}
+
+static void div4_clk_extend(void)
+{
+ int i;
+
+ div4_clk_ops = div4_clks[0].ops;
+ /* Add a kicker-busy check before changing the rate */
+ kicker_ops = *div4_clk_ops;
/* We extend the DIV4 clock with a 1:1 pass-through case */
zclk_ops = *div4_clk_ops;
+ kicker_ops.set_rate = kicker_set_rate;
zclk_ops.set_rate = zclk_set_rate;
zclk_ops.round_rate = zclk_round_rate;
zclk_ops.recalc = zclk_recalc;
- div4_clks[DIV4_Z].ops = &zclk_ops;
+ for (i = 0; i < DIV4_NR; i++)
+ div4_clks[i].ops = i == DIV4_Z ? &zclk_ops : &kicker_ops;
}
enum { DIV6_VCK1, DIV6_VCK2, DIV6_VCK3, DIV6_ZB1,
@@ -697,7 +711,7 @@ void __init sh73a0_clock_init(void)
if (!ret) {
ret = sh_clk_div4_register(div4_clks, DIV4_NR, &div4_table);
if (!ret)
- zclk_extend();
+ div4_clk_extend();
}
if (!ret)