clk: mediatek: Add configurable enable control to mtk_pll_data

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.

Reviewed-by: Ikjoon Jang <ikjn@chromium.org>
Signed-off-by: Weiyi Lu <weiyi.lu@mediatek.com>
Signed-off-by: Chun-Jie Chen <chun-jie.chen@mediatek.com>
Link: https://lore.kernel.org/r/20210726105719.15793-8-chun-jie.chen@mediatek.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

drivers/clk/mediatek/clk-mtk.h

@@ -213,13 +213,13 @@ struct mtk_pll_div_table {
 struct mtk_pll_data {
 	int id;
 	const char *name;
-	uint32_t reg;
-	uint32_t pwr_reg;
-	uint32_t en_mask;
-	uint32_t pd_reg;
-	uint32_t tuner_reg;
-	uint32_t tuner_en_reg;
-	uint8_t tuner_en_bit;
+	u32 reg;
+	u32 pwr_reg;
+	u32 en_mask;
+	u32 pd_reg;
+	u32 tuner_reg;
+	u32 tuner_en_reg;
+	u8 tuner_en_bit;
 	int pd_shift;
 	unsigned int flags;
 	const struct clk_ops *ops;
@@ -228,11 +228,13 @@ struct mtk_pll_data {
 	unsigned long fmax;
 	int pcwbits;
 	int pcwibits;
-	uint32_t pcw_reg;
+	u32 pcw_reg;
 	int pcw_shift;
-	uint32_t pcw_chg_reg;
+	u32 pcw_chg_reg;
 	const struct mtk_pll_div_table *div_table;
 	const char *parent_name;
+	u32 en_reg;
+	u8 pll_en_bit; /* Assume 0, indicates BIT(0) by default */
 };
 
 void mtk_clk_register_plls(struct device_node *node,

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;