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ARM: shmobile: r8a73a4: safeguard against wrong clk_set_rate() uses 

clk_set_rate() should only be called with exact rates, returned by
clk_round_rate(). However, it is still good to verify, that the value,
passed to clock's .set_rate() method is at least valid. This patch adds
such a check for the Z-clock on r8a73a4.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
This commit is contained in:
Guennadi Liakhovetski 2013-06-21 09:10:35 +02:00 committed by Simon Horman
parent 181135e0b7
commit d1c3c959f2
1 changed files with 13 additions and 1 deletions
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14
arch/arm/mach-shmobile/clock-r8a73a4.c
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@ -225,16 +225,28 @@ static int zclk_set_rate(struct clk *clk, unsigned long rate)
goto done;
}
frqcrc = clk->mapped_reg + (FRQCRC - (u32)clk->enable_reg);
/*
* Users are supposed to first call clk_set_rate() only with
* clk_round_rate() results. So, we don't fix wrong rates here, but
* guard against them anyway
*/
p_rate = clk_get_rate(clk->parent);
if (rate == p_rate) {
val = 0;
} else {
step = DIV_ROUND_CLOSEST(p_rate, 32);
if (rate > p_rate || rate < step) {
ret = -EINVAL;
goto done;
}
val = 32 - rate / step;
}
frqcrc = clk->mapped_reg + (FRQCRC - (u32)clk->enable_reg);
iowrite32((ioread32(frqcrc) & ~(clk->div_mask << clk->enable_bit)) |
(val << clk->enable_bit), frqcrc);