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 <nfraprado@collabora.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
Signed-off-by: Laura Nao <laura.nao@collabora.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

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) & BIT(pll->data->fenc_sta_bit));
+}
+
 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 +351,8 @@ 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;
+
 	init.name = data->name;
 	init.flags = (data->flags & PLL_AO) ? CLK_IS_CRITICAL : 0;
 	init.ops = pll_ops;
@@ -337,12 +375,13 @@ 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);
 

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 +74,7 @@ struct mtk_clk_pll {
 	void __iomem	*en_addr;
 	void __iomem	*en_set_addr;
 	void __iomem	*en_clr_addr;
+	void __iomem	*fenc_addr;
 	const struct mtk_pll_data *data;
 };
 
@@ -82,6 +85,7 @@ 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)
 {