diff options
author | Guennadi Liakhovetski <g.liakhovetski@gmx.de> | 2013-06-21 09:10:35 +0200 |
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committer | Simon Horman <horms+renesas@verge.net.au> | 2013-07-17 14:25:36 +0900 |
commit | d1c3c959f2206dad0582876af2510aded4f9eac5 (patch) | |
tree | 7b52af5e65df3f0434040c03a7235630edbfefd2 /arch/arm/mach-shmobile/clock-r8a73a4.c | |
parent | 181135e0b7f58735969619c89548f6a37cd0ee36 (diff) | |
download | linux-d1c3c959f2206dad0582876af2510aded4f9eac5.tar.bz2 |
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>
Diffstat (limited to 'arch/arm/mach-shmobile/clock-r8a73a4.c')
-rw-r--r-- | arch/arm/mach-shmobile/clock-r8a73a4.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/arch/arm/mach-shmobile/clock-r8a73a4.c b/arch/arm/mach-shmobile/clock-r8a73a4.c index 824789c26fb6..22f10ff40272 100644 --- a/arch/arm/mach-shmobile/clock-r8a73a4.c +++ b/arch/arm/mach-shmobile/clock-r8a73a4.c @@ -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); |