[PATCH] clk: divider: read before write for HIWORD mask
From: haojian.zhuang@linaro.org (Haojian Zhuang)
Date: 2013-12-11 01:29:07
Subsystem:
common clk framework, the rest · Maintainers:
Michael Turquette, Stephen Boyd, Linus Torvalds
When multiple dividers share one register, we need to read & mask register fist. Then we set the right value. For example, there're two mmc clock dividers shared in one registers. The clock register is HIWORD type. Signed-off-by: Haojian Zhuang <haojian.zhuang@gmail.com> --- drivers/clk/clk-divider.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c
index 8d3009e..e1ea289 100644
--- a/drivers/clk/clk-divider.c
+++ b/drivers/clk/clk-divider.c@@ -227,12 +227,10 @@ static int clk_divider_set_rate(struct clk_hw *hw, unsigned long rate, if (divider->lock) spin_lock_irqsave(divider->lock, flags); - if (divider->flags & CLK_DIVIDER_HIWORD_MASK) { - val = div_mask(divider) << (divider->shift + 16); - } else { - val = clk_readl(divider->reg); - val &= ~(div_mask(divider) << divider->shift); - } + val = clk_readl(divider->reg); + val &= ~(div_mask(divider) << divider->shift); + if (divider->flags & CLK_DIVIDER_HIWORD_MASK) + val |= div_mask(divider) << (divider->shift + 16); val |= value << divider->shift; clk_writel(val, divider->reg);
--
1.8.3.2