From d1c3c959f2206dad0582876af2510aded4f9eac5 Mon Sep 17 00:00:00 2001 From: Guennadi Liakhovetski Date: Fri, 21 Jun 2013 09:10:35 +0200 Subject: [PATCH] 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 Acked-by: Kuninori Morimoto Signed-off-by: Simon Horman --- arch/arm/mach-shmobile/clock-r8a73a4.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) 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);