From: haojian.zhuang@linaro.org (Haojian Zhuang)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH RESEND] clk: divider: read before write for HIWORD mask
Date: Fri, 20 Dec 2013 11:50:17 +0800 [thread overview]
Message-ID: <1387511417-8573-1-git-send-email-haojian.zhuang@gmail.com> (raw)
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
next reply other threads:[~2013-12-20 3:50 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-12-20 3:50 Haojian Zhuang [this message]
2013-12-20 8:18 ` [PATCH RESEND] clk: divider: read before write for HIWORD mask Heiko Stübner
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