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

[Weiyi Lu <weiyi.lu@mediatek.com>]

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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