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From:   Ikjoon Jang <ikjn@chromium.org>
Date:   Wed, 6 Jan 2021 18:37:59 +0800
Message-ID: <CAATdQgBvd_izVUZ7NiDeHzZsQ4rL0=3LZ04diO7HQXop5rxYsw@mail.gmail.com>
Subject: Re: [PATCH v6 08/22] clk: mediatek: Add configurable enable control
 to mtk_pll_data
To:     Weiyi Lu <weiyi.lu@mediatek.com>
Cc:     Matthias Brugger <matthias.bgg@gmail.com>,
        Rob Herring <robh@kernel.org>, Stephen Boyd <sboyd@kernel.org>,
        Nicolas Boichat <drinkcat@chromium.org>,
        srv_heupstream <srv_heupstream@mediatek.com>,
        open list <linux-kernel@vger.kernel.org>,
        Project_Global_Chrome_Upstream_Group@mediatek.com,
        "moderated list:ARM/Mediatek SoC support" 
        <linux-mediatek@lists.infradead.org>, linux-clk@vger.kernel.org,
        "moderated list:ARM/Mediatek SoC support" 
        <linux-arm-kernel@lists.infradead.org>
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Precedence: bulk

On Tue, Dec 22, 2020 at 9:11 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>

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

> ---
>  drivers/clk/mediatek/clk-mtk.h |  2 ++
>  drivers/clk/mediatek/clk-pll.c | 15 ++++++++++-----
>  2 files changed, 12 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/clk/mediatek/clk-mtk.h b/drivers/clk/mediatek/clk-mtk.h
> index c3d6756..c580663 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; /* Assume 0, indicates BIT(0) by default */
>  };
>
>  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 11ed5d1..7fb001a 100644
> --- a/drivers/clk/mediatek/clk-pll.c
> +++ b/drivers/clk/mediatek/clk-pll.c
> @@ -44,6 +44,7 @@ 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 +57,7 @@ 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,
> @@ -248,8 +249,8 @@ 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);
>
>         div_en_mask = pll->data->en_mask & ~CON0_BASE_EN;
>         if (div_en_mask) {
> @@ -290,8 +291,8 @@ static void mtk_pll_unprepare(struct clk_hw *hw)
>                 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->en_addr) & ~BIT(pll->data->pll_en_bit);
> +       writel(r, pll->en_addr);
>
>         r = readl(pll->pwr_addr) | CON0_ISO_EN;
>         writel(r, pll->pwr_addr);
> @@ -333,6 +334,10 @@ 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;
>         pll->hw.init = &init;
>         pll->data = data;
>
> --
> 1.8.1.1.dirty
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