Thread (27 messages) 27 messages, 3 authors, 2019-02-27

Re: [PATCH v4 01/12] clk: mediatek: Disable tuner_en before change PLL rate

From: Matthias Brugger <matthias.bgg@gmail.com>
Date: 2019-02-26 15:59:57
Also in: linux-clk, linux-mediatek, lkml, stable


On 01/02/2019 09:30, Weiyi Lu wrote:
quoted hunk ↗ jump to hunk
From: Owen Chen <redacted>

PLLs with tuner_en bit, such as APLL1, need to disable
tuner_en before apply new frequency settings, or the new frequency
settings (pcw) will not be applied.
The tuner_en bit will be disabled during changing PLL rate
and be restored after new settings applied.
Another minor change is to correct the macro name of pcw change bit
to CON1_PCW_CHG because PCW_CHG(BIT31) is on CON1.

Fixes: e2f744a82d725 (clk: mediatek: Add MT2712 clock support)
Cc: <redacted>
Signed-off-by: Owen Chen <redacted>
---
 drivers/clk/mediatek/clk-pll.c | 33 +++++++++++++++++++++++++++++++--
 1 file changed, 31 insertions(+), 2 deletions(-)
diff --git a/drivers/clk/mediatek/clk-pll.c b/drivers/clk/mediatek/clk-pll.c
index f54e4015b0b1..f0ff5f535c7e 100644
--- a/drivers/clk/mediatek/clk-pll.c
+++ b/drivers/clk/mediatek/clk-pll.c
@@ -27,7 +27,7 @@
 #define CON0_BASE_EN		BIT(0)
 #define CON0_PWR_ON		BIT(0)
 #define CON0_ISO_EN		BIT(1)
-#define CON0_PCW_CHG		BIT(31)
+#define CON1_PCW_CHG		BIT(31)
 
 #define AUDPLL_TUNER_EN		BIT(31)
 
@@ -93,9 +93,31 @@ static void mtk_pll_set_rate_regs(struct mtk_clk_pll *pll, u32 pcw,
 {
 	u32 con1, val;
 	int pll_en;
+	u32 tuner_en = 0;
+	u32 tuner_en_mask;
+	void __iomem *tuner_en_addr = NULL;
 
 	pll_en = readl(pll->base_addr + REG_CON0) & CON0_BASE_EN;
 
+	/* disable tuner */
+	if (pll->tuner_en_addr) {
+		tuner_en_addr = pll->tuner_en_addr;
+		tuner_en_mask = BIT(pll->data->tuner_en_bit);
+	} else if (pll->tuner_addr) {
+		tuner_en_addr = pll->tuner_addr;
+		tuner_en_mask = AUDPLL_TUNER_EN;
+	}
+
+	if (tuner_en_addr) {
+		val = readl(tuner_en_addr);
+		tuner_en = val & tuner_en_mask;
+
+		if (tuner_en) {
+			val &= ~tuner_en_mask;
+			writel(val, tuner_en_addr);
+		}
+	}
+
Why don't we use a flag here, it would make the code easier to understand.
I think it would also help if you put this code in a separate function.

Regards,
Matthias

quoted hunk ↗ jump to hunk
 	/* set postdiv */
 	val = readl(pll->pd_addr);
 	val &= ~(POSTDIV_MASK << pll->data->pd_shift);
@@ -116,12 +138,19 @@ static void mtk_pll_set_rate_regs(struct mtk_clk_pll *pll, u32 pcw,
 	con1 = readl(pll->base_addr + REG_CON1);
 
 	if (pll_en)
-		con1 |= CON0_PCW_CHG;
+		con1 |= CON1_PCW_CHG;
 
 	writel(con1, pll->base_addr + REG_CON1);
 	if (pll->tuner_addr)
 		writel(con1 + 1, pll->tuner_addr);
 
+	/* restore tuner_en */
+	if (tuner_en_addr && tuner_en) {
+		val = readl(tuner_en_addr);
+		val |= tuner_en_mask;
+		writel(val, tuner_en_addr);
+	}
+
 	if (pll_en)
 		udelay(20);
 }
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