Re: [PATCH v4 02/27] clk: mediatek: clk-pll: Add ops for PLLs using set/clr regs and FENC

MT8196 uses a combination of set/clr registers to control the PLL
enable state, along with a FENC bit to check the preparation status.
Add new set of PLL clock operations with support for set/clr enable and
FENC status logic.

Reviewed-by: Nícolas F. R. A. Prado <redacted>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Laura Nao <redacted>
---
 drivers/clk/mediatek/clk-pll.c | 42 +++++++++++++++++++++++++++++++++-
 drivers/clk/mediatek/clk-pll.h |  5 ++++
 2 files changed, 46 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/mediatek/clk-pll.c b/drivers/clk/mediatek/clk-pll.c
index 49ca25dd5418..8f46de77f42d 100644
--- a/drivers/clk/mediatek/clk-pll.c
+++ b/drivers/clk/mediatek/clk-pll.c

@@ -37,6 +37,13 @@ int mtk_pll_is_prepared(struct clk_hw *hw)
        return (readl(pll->en_addr) & BIT(pll->data->pll_en_bit)) != 0;
 }

+static int mtk_pll_fenc_is_prepared(struct clk_hw *hw)
+{
+       struct mtk_clk_pll *pll = to_mtk_clk_pll(hw);
+
+       return readl(pll->fenc_addr) & pll->fenc_mask;

+}
+
 static unsigned long __mtk_pll_recalc_rate(struct mtk_clk_pll *pll, u32 fin,
                u32 pcw, int postdiv)
 {

@@ -274,6 +281,25 @@ void mtk_pll_unprepare(struct clk_hw *hw)
        writel(r, pll->pwr_addr);
 }

+static int mtk_pll_prepare_setclr(struct clk_hw *hw)
+{
+       struct mtk_clk_pll *pll = to_mtk_clk_pll(hw);
+
+       writel(BIT(pll->data->pll_en_bit), pll->en_set_addr);
+
+       /* Wait 20us after enable for the PLL to stabilize */
+       udelay(20);
+
+       return 0;
+}
+
+static void mtk_pll_unprepare_setclr(struct clk_hw *hw)
+{
+       struct mtk_clk_pll *pll = to_mtk_clk_pll(hw);
+
+       writel(BIT(pll->data->pll_en_bit), pll->en_clr_addr);
+}
+
 const struct clk_ops mtk_pll_ops = {
        .is_prepared    = mtk_pll_is_prepared,
        .prepare        = mtk_pll_prepare,

@@ -283,6 +309,16 @@ const struct clk_ops mtk_pll_ops = {
        .set_rate       = mtk_pll_set_rate,
 };

+const struct clk_ops mtk_pll_fenc_clr_set_ops = {
+       .is_prepared    = mtk_pll_fenc_is_prepared,
+       .prepare        = mtk_pll_prepare_setclr,
+       .unprepare      = mtk_pll_unprepare_setclr,
+       .recalc_rate    = mtk_pll_recalc_rate,
+       .round_rate     = mtk_pll_round_rate,
+       .set_rate       = mtk_pll_set_rate,
+};
+EXPORT_SYMBOL_GPL(mtk_pll_fenc_clr_set_ops);
+
 struct clk_hw *mtk_clk_register_pll_ops(struct mtk_clk_pll *pll,
                                        const struct mtk_pll_data *data,
                                        void __iomem *base,

@@ -315,6 +351,9 @@ struct clk_hw *mtk_clk_register_pll_ops(struct mtk_clk_pll *pll,
        pll->hw.init = &init;
        pll->data = data;

+       pll->fenc_addr = base + data->fenc_sta_ofs;
+       pll->fenc_mask = BIT(data->fenc_sta_bit);
+
        init.name = data->name;
        init.flags = (data->flags & PLL_AO) ? CLK_IS_CRITICAL : 0;
        init.ops = pll_ops;

@@ -337,12 +376,13 @@ struct clk_hw *mtk_clk_register_pll(const struct mtk_pll_data *data,
 {
        struct mtk_clk_pll *pll;
        struct clk_hw *hw;
+       const struct clk_ops *pll_ops = data->ops ? data->ops : &mtk_pll_ops;

        pll = kzalloc(sizeof(*pll), GFP_KERNEL);
        if (!pll)
                return ERR_PTR(-ENOMEM);

-       hw = mtk_clk_register_pll_ops(pll, data, base, &mtk_pll_ops);
+       hw = mtk_clk_register_pll_ops(pll, data, base, pll_ops);
        if (IS_ERR(hw))
                kfree(pll);

diff --git a/drivers/clk/mediatek/clk-pll.h b/drivers/clk/mediatek/clk-pll.h
index c4d06bb11516..7fdc5267a2b5 100644
--- a/drivers/clk/mediatek/clk-pll.h
+++ b/drivers/clk/mediatek/clk-pll.h

@@ -29,6 +29,7 @@ struct mtk_pll_data {
        u32 reg;
        u32 pwr_reg;
        u32 en_mask;
+       u32 fenc_sta_ofs;
        u32 pd_reg;
        u32 tuner_reg;
        u32 tuner_en_reg;

@@ -51,6 +52,7 @@ struct mtk_pll_data {
        u32 en_clr_reg;
        u8 pll_en_bit; /* Assume 0, indicates BIT(0) by default */
        u8 pcw_chg_bit;
+       u8 fenc_sta_bit;
 };

 /*

@@ -72,6 +74,8 @@ struct mtk_clk_pll {
        void __iomem    *en_addr;
        void __iomem    *en_set_addr;
        void __iomem    *en_clr_addr;
+       void __iomem    *fenc_addr;
+       u32             fenc_mask;
        const struct mtk_pll_data *data;
 };

@@ -82,6 +86,7 @@ void mtk_clk_unregister_plls(const struct mtk_pll_data *plls, int num_plls,
                             struct clk_hw_onecell_data *clk_data);

 extern const struct clk_ops mtk_pll_ops;
+extern const struct clk_ops mtk_pll_fenc_clr_set_ops;

 static inline struct mtk_clk_pll *to_mtk_clk_pll(struct clk_hw *hw)
 {
--

2.39.5