diff mbox series

[v6,07/22] clk: mediatek: Fix asymmetrical PLL enable and disable control

Message ID 1608642587-15634-8-git-send-email-weiyi.lu@mediatek.com (mailing list archive)
State New, archived
Headers show
Series Mediatek MT8192 clock support | expand

Commit Message

Weiyi Lu Dec. 22, 2020, 1:09 p.m. UTC 
In fact, the en_mask is a combination of divider enable mask
and pll enable bit(bit0).
Before this patch, we enabled both divider mask and bit0 in prepare(),
but only cleared the bit0 in unprepare().
In the future, we hope en_mask will only be used as divider enable mask.
The enable register(CON0) will be set in 2 steps:
first is divider mask, and then bit0 during prepare(), and vice versa.
But considering backward compatibility, at this stage we allow en_mask
to be a combination or a pure divider enable mask.
And then we will make en_mask a pure divider enable mask in another
following patch series.

Signed-off-by: Weiyi Lu <weiyi.lu@mediatek.com>
---
 drivers/clk/mediatek/clk-pll.c | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

Comments

Ikjoon Jang Jan. 6, 2021, 10:35 a.m. UTC | #1 
On Tue, Dec 22, 2020 at 9:12 PM Weiyi Lu <weiyi.lu@mediatek.com> wrote:
>
> In fact, the en_mask is a combination of divider enable mask
> and pll enable bit(bit0).
> Before this patch, we enabled both divider mask and bit0 in prepare(),
> but only cleared the bit0 in unprepare().
> In the future, we hope en_mask will only be used as divider enable mask.
> The enable register(CON0) will be set in 2 steps:
> first is divider mask, and then bit0 during prepare(), and vice versa.
> But considering backward compatibility, at this stage we allow en_mask
> to be a combination or a pure divider enable mask.
> And then we will make en_mask a pure divider enable mask in another
> following patch series.
>
> Signed-off-by: Weiyi Lu <weiyi.lu@mediatek.com>

Reviewed-by: Ikjoon Jang <ikjn@chromium.org>

> ---
>  drivers/clk/mediatek/clk-pll.c | 20 ++++++++++++++++----
>  1 file changed, 16 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/clk/mediatek/clk-pll.c b/drivers/clk/mediatek/clk-pll.c
> index f440f2cd..11ed5d1 100644
> --- a/drivers/clk/mediatek/clk-pll.c
> +++ b/drivers/clk/mediatek/clk-pll.c
> @@ -238,6 +238,7 @@ static int mtk_pll_prepare(struct clk_hw *hw)
>  {
>         struct mtk_clk_pll *pll = to_mtk_clk_pll(hw);
>         u32 r;
> +       u32 div_en_mask;
>
>         r = readl(pll->pwr_addr) | CON0_PWR_ON;
>         writel(r, pll->pwr_addr);
> @@ -247,10 +248,15 @@ static int mtk_pll_prepare(struct clk_hw *hw)
>         writel(r, pll->pwr_addr);
>         udelay(1);
>
> -       r = readl(pll->base_addr + REG_CON0);
> -       r |= pll->data->en_mask;
> +       r = readl(pll->base_addr + REG_CON0) | CON0_BASE_EN;
>         writel(r, pll->base_addr + REG_CON0);
>
> +       div_en_mask = pll->data->en_mask & ~CON0_BASE_EN;
> +       if (div_en_mask) {
> +               r = readl(pll->base_addr + REG_CON0) | div_en_mask;
> +               writel(r, pll->base_addr + REG_CON0);
> +       }
> +
>         __mtk_pll_tuner_enable(pll);
>
>         udelay(20);
> @@ -268,6 +274,7 @@ static void mtk_pll_unprepare(struct clk_hw *hw)
>  {
>         struct mtk_clk_pll *pll = to_mtk_clk_pll(hw);
>         u32 r;
> +       u32 div_en_mask;
>
>         if (pll->data->flags & HAVE_RST_BAR) {
>                 r = readl(pll->base_addr + REG_CON0);
> @@ -277,8 +284,13 @@ static void mtk_pll_unprepare(struct clk_hw *hw)
>
>         __mtk_pll_tuner_disable(pll);
>
> -       r = readl(pll->base_addr + REG_CON0);
> -       r &= ~CON0_BASE_EN;
> +       div_en_mask = pll->data->en_mask & ~CON0_BASE_EN;
> +       if (div_en_mask) {
> +               r = readl(pll->base_addr + REG_CON0) & ~div_en_mask;
> +               writel(r, pll->base_addr + REG_CON0);
> +       }
> +
> +       r = readl(pll->base_addr + REG_CON0) & ~CON0_BASE_EN;
>         writel(r, pll->base_addr + REG_CON0);
>
>         r = readl(pll->pwr_addr) | CON0_ISO_EN;
> --
> 1.8.1.1.dirty
> _______________________________________________
> Linux-mediatek mailing list
> Linux-mediatek@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-mediatek
diff mbox series

Patch

diff --git a/drivers/clk/mediatek/clk-pll.c b/drivers/clk/mediatek/clk-pll.c
index f440f2cd..11ed5d1 100644
--- a/drivers/clk/mediatek/clk-pll.c
+++ b/drivers/clk/mediatek/clk-pll.c
@@ -238,6 +238,7 @@  static int mtk_pll_prepare(struct clk_hw *hw)
 {
 	struct mtk_clk_pll *pll = to_mtk_clk_pll(hw);
 	u32 r;
+	u32 div_en_mask;
 
 	r = readl(pll->pwr_addr) | CON0_PWR_ON;
 	writel(r, pll->pwr_addr);
@@ -247,10 +248,15 @@  static int mtk_pll_prepare(struct clk_hw *hw)
 	writel(r, pll->pwr_addr);
 	udelay(1);
 
-	r = readl(pll->base_addr + REG_CON0);
-	r |= pll->data->en_mask;
+	r = readl(pll->base_addr + REG_CON0) | CON0_BASE_EN;
 	writel(r, pll->base_addr + REG_CON0);
 
+	div_en_mask = pll->data->en_mask & ~CON0_BASE_EN;
+	if (div_en_mask) {
+		r = readl(pll->base_addr + REG_CON0) | div_en_mask;
+		writel(r, pll->base_addr + REG_CON0);
+	}
+
 	__mtk_pll_tuner_enable(pll);
 
 	udelay(20);
@@ -268,6 +274,7 @@  static void mtk_pll_unprepare(struct clk_hw *hw)
 {
 	struct mtk_clk_pll *pll = to_mtk_clk_pll(hw);
 	u32 r;
+	u32 div_en_mask;
 
 	if (pll->data->flags & HAVE_RST_BAR) {
 		r = readl(pll->base_addr + REG_CON0);
@@ -277,8 +284,13 @@  static void mtk_pll_unprepare(struct clk_hw *hw)
 
 	__mtk_pll_tuner_disable(pll);
 
-	r = readl(pll->base_addr + REG_CON0);
-	r &= ~CON0_BASE_EN;
+	div_en_mask = pll->data->en_mask & ~CON0_BASE_EN;
+	if (div_en_mask) {
+		r = readl(pll->base_addr + REG_CON0) & ~div_en_mask;
+		writel(r, pll->base_addr + REG_CON0);
+	}
+
+	r = readl(pll->base_addr + REG_CON0) & ~CON0_BASE_EN;
 	writel(r, pll->base_addr + REG_CON0);
 
 	r = readl(pll->pwr_addr) | CON0_ISO_EN;