Re: [PATCH v2 4/5] clk: mediatek: Add configurable enable control to mtk_pll_data

Weiyi Lu
2020-08-11T06:43:40Z

On Wed, 2020-07-29 at 18:58 +0800, Nicolas Boichat wrote:
> On Wed, Jul 29, 2020 at 4:44 PM Weiyi Lu <weiyi.lu@mediatek.com> wrote:
> >
> > In all MediaTek PLL design, bit0 of CON0 register is always
> > the enable bit.
> > However, there's a special case of usbpll on MT8192.
> > The enable bit of usbpll is moved to bit2 of other register.
> > Add configurable en_reg and pll_en_bit for enable control or
> > default 0 where pll data are static variables.
> > Hence, CON0_BASE_EN could also be removed.
> > And there might have another special case on other chips,
> > the enable bit is still on CON0 register but not at bit0.
> >
> > Signed-off-by: Weiyi Lu <weiyi.lu@mediatek.com>
> > ---
> > drivers/clk/mediatek/clk-mtk.h | 2 ++
> > drivers/clk/mediatek/clk-pll.c | 18 +++++++++++-------
> > 2 files changed, 13 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/clk/mediatek/clk-mtk.h b/drivers/clk/mediatek/clk-mtk.h
> > index c3d6756..810eb97 100644
> > --- a/drivers/clk/mediatek/clk-mtk.h
> > +++ b/drivers/clk/mediatek/clk-mtk.h
> > @@ -233,6 +233,8 @@ struct mtk_pll_data {
> > uint32_t pcw_chg_reg;
> > const struct mtk_pll_div_table *div_table;
> > const char *parent_name;
> > + uint32_t en_reg;
> > + uint8_t pll_en_bit;
> > };
> >
> > void mtk_clk_register_plls(struct device_node *node,
> > diff --git a/drivers/clk/mediatek/clk-pll.c b/drivers/clk/mediatek/clk-pll.c
> > index 3c79e1a..1434e99 100644
> > --- a/drivers/clk/mediatek/clk-pll.c
> > +++ b/drivers/clk/mediatek/clk-pll.c
> > @@ -16,7 +16,6 @@
> > #define REG_CON0 0
> > #define REG_CON1 4
> >
> > -#define CON0_BASE_EN BIT(0)
> > #define CON0_PWR_ON BIT(0)
> > #define CON0_ISO_EN BIT(1)
> > #define PCW_CHG_MASK BIT(31)
> > @@ -44,6 +43,7 @@ struct mtk_clk_pll {
> > void __iomem *tuner_en_addr;
> > void __iomem *pcw_addr;
> > void __iomem *pcw_chg_addr;
> > + void __iomem *en_addr;
> > const struct mtk_pll_data *data;
> > };
> >
> > @@ -56,7 +56,7 @@ static int mtk_pll_is_prepared(struct clk_hw *hw)
> > {
> > struct mtk_clk_pll *pll = to_mtk_clk_pll(hw);
> >
> > - return (readl(pll->base_addr + REG_CON0) & CON0_BASE_EN) != 0;
> > + return (readl(pll->en_addr) & BIT(pll->data->pll_en_bit)) != 0;
> > }
> >
> > static unsigned long __mtk_pll_recalc_rate(struct mtk_clk_pll *pll, u32 fin,
> > @@ -247,8 +247,8 @@ static int mtk_pll_prepare(struct clk_hw *hw)
> > writel(r, pll->pwr_addr);
> > udelay(1);
> >
> > - r = readl(pll->base_addr + REG_CON0) | CON0_BASE_EN;
> > - writel(r, pll->base_addr + REG_CON0);
> > + r = readl(pll->en_addr) | BIT(pll->data->pll_en_bit);
> > + writel(r, pll->en_addr);
> >
> > r = readl(pll->base_addr + REG_CON0) | pll->data->en_mask;
> > writel(r, pll->base_addr + REG_CON0);
> > @@ -283,9 +283,9 @@ static void mtk_pll_unprepare(struct clk_hw *hw)
> > r &= ~pll->data->en_mask;
> > writel(r, pll->base_addr + REG_CON0);
> >
> > - r = readl(pll->base_addr + REG_CON0);
> > - r &= ~CON0_BASE_EN;
> > - writel(r, pll->base_addr + REG_CON0);
> > + r = readl(pll->en_addr);
> > + r &= ~BIT(pll->data->pll_en_bit);
>
> 1 line, but that'll come naturally from the change I requested in the
> previous patch.
>

OK, I'll put it into one line in previous patch.

> > + writel(r, pll->en_addr);
> >
> > r = readl(pll->pwr_addr) | CON0_ISO_EN;
> > writel(r, pll->pwr_addr);
> > @@ -327,6 +327,10 @@ static struct clk *mtk_clk_register_pll(const struct mtk_pll_data *data,
> > pll->tuner_addr = base + data->tuner_reg;
> > if (data->tuner_en_reg)
> > pll->tuner_en_addr = base + data->tuner_en_reg;
> > + if (data->en_reg)
> > + pll->en_addr = base + data->en_reg;
> > + else
> > + pll->en_addr = pll->base_addr + REG_CON0;
>
> Don't you need to set pll->data->pll_en_bit to CON0_BASE_EN here?
> (which probably means that you need to add a pll->en_bit field to
> struct mtk_clk_pll)
>

Because all mtk_clk_pll data are static variables, en_bit would be 0 if
NO value assigned.

r = readl(pll->en_addr) | BIT(pll->data->pll_en_bit);
writel(r, pll->en_addr);

> > pll->hw.init = &init;
> > pll->data = data;
> >
> > --
> > 1.8.1.1.dirty
>
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