ARM: imx: pllv3 needs relock in .set_rate() call
The pllv3 nees relock not only when powering up but also when rate
changes. The patch creates a helper function clk_pllv3_wait_lock() and
moves the relock code from clk_pllv3_prepare() into there, so that
both .prepare() and .set_rate() hooks of pllv3 can call into the helper
for relocking.
Since relock is only needed when PLL is powered up while clk_set_rate()
could be called before clk is prepared, we need to add a check in
clk_pllv3_wait_lock() to skip the relock if PLL is not powered.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
diff --git a/arch/arm/mach-imx/clk-pllv3.c b/arch/arm/mach-imx/clk-pllv3.c
index c9ca191..df17362 100644
--- a/arch/arm/mach-imx/clk-pllv3.c
+++ b/arch/arm/mach-imx/clk-pllv3.c
@@ -46,10 +46,30 @@
#define to_clk_pllv3(_hw) container_of(_hw, struct clk_pllv3, hw)
+static int clk_pllv3_wait_lock(struct clk_pllv3 *pll)
+{
+ unsigned long timeout = jiffies + msecs_to_jiffies(10);
+ u32 val = readl_relaxed(pll->base) & BM_PLL_POWER;
+
+ /* No need to wait for lock when pll is not powered up */
+ if ((pll->powerup_set && !val) || (!pll->powerup_set && val))
+ return 0;
+
+ /* Wait for PLL to lock */
+ do {
+ if (readl_relaxed(pll->base) & BM_PLL_LOCK)
+ break;
+ if (time_after(jiffies, timeout))
+ break;
+ usleep_range(50, 500);
+ } while (1);
+
+ return readl_relaxed(pll->base) & BM_PLL_LOCK ? 0 : -ETIMEDOUT;
+}
+
static int clk_pllv3_prepare(struct clk_hw *hw)
{
struct clk_pllv3 *pll = to_clk_pllv3(hw);
- unsigned long timeout;
u32 val;
val = readl_relaxed(pll->base);
@@ -60,20 +80,7 @@
val &= ~BM_PLL_POWER;
writel_relaxed(val, pll->base);
- timeout = jiffies + msecs_to_jiffies(10);
- /* Wait for PLL to lock */
- do {
- if (readl_relaxed(pll->base) & BM_PLL_LOCK)
- break;
- if (time_after(jiffies, timeout))
- break;
- usleep_range(50, 500);
- } while (1);
-
- if (readl_relaxed(pll->base) & BM_PLL_LOCK)
- return 0;
- else
- return -ETIMEDOUT;
+ return clk_pllv3_wait_lock(pll);
}
static void clk_pllv3_unprepare(struct clk_hw *hw)
@@ -148,7 +155,7 @@
val |= div;
writel_relaxed(val, pll->base);
- return 0;
+ return clk_pllv3_wait_lock(pll);
}
static const struct clk_ops clk_pllv3_ops = {
@@ -204,7 +211,7 @@
val |= div;
writel_relaxed(val, pll->base);
- return 0;
+ return clk_pllv3_wait_lock(pll);
}
static const struct clk_ops clk_pllv3_sys_ops = {
@@ -278,7 +285,7 @@
writel_relaxed(mfn, pll->base + PLL_NUM_OFFSET);
writel_relaxed(mfd, pll->base + PLL_DENOM_OFFSET);
- return 0;
+ return clk_pllv3_wait_lock(pll);
}
static const struct clk_ops clk_pllv3_av_ops = {