[PATCH] clk: mediatek: Add MT8173 MMPLL change rate support

[James Liao]

MT8173 MMPLL frequency settings are different from common PLLs.
It needs different post divider settings for some ranges of frequency.
This patch add support for MT8173 MMPLL frequency setting, includes:

1. Add div-rate table for PLLs.
2. Increase the max ost divider setting from 3 (/8) to 4 (/16).
3. Write postdiv and pcw settings at the same time.

Signed-off-by: James Liao <jamesjj.liao at mediatek.com>
---
 drivers/clk/mediatek/clk-mt8173.c | 24 +++++++++++++++++++++---
 drivers/clk/mediatek/clk-mtk.h    |  1 +
 drivers/clk/mediatek/clk-pll.c    | 37 +++++++++++++++++++++++++------------
 3 files changed, 47 insertions(+), 15 deletions(-)

diff --git a/drivers/clk/mediatek/clk-mt8173.c b/drivers/clk/mediatek/clk-mt8173.c
index 357b080..821de7d 100644
--- a/drivers/clk/mediatek/clk-mt8173.c
+++ b/drivers/clk/mediatek/clk-mt8173.c
@@ -779,8 +779,9 @@ CLK_OF_DECLARE(mtk_pericfg, "mediatek,mt8173-pericfg", mtk_pericfg_init);
 
 #define CON0_MT8173_RST_BAR	BIT(24)
 
-#define PLL(_id, _name, _reg, _pwr_reg, _en_mask, _flags, _pcwbits, _pd_reg, _pd_shift, \
-			_tuner_reg, _pcw_reg, _pcw_shift) { \
+#define PLL_B(_id, _name, _reg, _pwr_reg, _en_mask, _flags, _pcwbits,	\
+			_pd_reg, _pd_shift, _tuner_reg, _pcw_reg,	\
+			_pcw_shift, _div_rate) {			\
 		.id = _id,						\
 		.name = _name,						\
 		.reg = _reg,						\
@@ -795,14 +796,31 @@ CLK_OF_DECLARE(mtk_pericfg, "mediatek,mt8173-pericfg", mtk_pericfg_init);
 		.tuner_reg = _tuner_reg,				\
 		.pcw_reg = _pcw_reg,					\
 		.pcw_shift = _pcw_shift,				\
+		.div_rate = _div_rate,					\
 	}
 
+#define PLL(_id, _name, _reg, _pwr_reg, _en_mask, _flags, _pcwbits,	\
+			_pd_reg, _pd_shift, _tuner_reg, _pcw_reg,	\
+			_pcw_shift)					\
+		PLL_B(_id, _name, _reg, _pwr_reg, _en_mask, _flags, _pcwbits, \
+			_pd_reg, _pd_shift, _tuner_reg, _pcw_reg, _pcw_shift, \
+			NULL)
+
+const unsigned long mmpll_div_rate[] = {
+	MT8173_PLL_FMAX,
+	1000000000,
+	702000000,
+	253500000,
+	126750000,
+	0,
+};
+
 static const struct mtk_pll_data plls[] = {
 	PLL(CLK_APMIXED_ARMCA15PLL, "armca15pll", 0x200, 0x20c, 0x00000001, 0, 21, 0x204, 24, 0x0, 0x204, 0),
 	PLL(CLK_APMIXED_ARMCA7PLL, "armca7pll", 0x210, 0x21c, 0x00000001, 0, 21, 0x214, 24, 0x0, 0x214, 0),
 	PLL(CLK_APMIXED_MAINPLL, "mainpll", 0x220, 0x22c, 0xf0000101, HAVE_RST_BAR, 21, 0x220, 4, 0x0, 0x224, 0),
 	PLL(CLK_APMIXED_UNIVPLL, "univpll", 0x230, 0x23c, 0xfe000001, HAVE_RST_BAR, 7, 0x230, 4, 0x0, 0x234, 14),
-	PLL(CLK_APMIXED_MMPLL, "mmpll", 0x240, 0x24c, 0x00000001, 0, 21, 0x244, 24, 0x0, 0x244, 0),
+	PLL_B(CLK_APMIXED_MMPLL, "mmpll", 0x240, 0x24c, 0x00000001, 0, 21, 0x244, 24, 0x0, 0x244, 0, mmpll_div_rate),
 	PLL(CLK_APMIXED_MSDCPLL, "msdcpll", 0x250, 0x25c, 0x00000001, 0, 21, 0x250, 4, 0x0, 0x254, 0),
 	PLL(CLK_APMIXED_VENCPLL, "vencpll", 0x260, 0x26c, 0x00000001, 0, 21, 0x260, 4, 0x0, 0x264, 0),
 	PLL(CLK_APMIXED_TVDPLL, "tvdpll", 0x270, 0x27c, 0x00000001, 0, 21, 0x270, 4, 0x0, 0x274, 0),
diff --git a/drivers/clk/mediatek/clk-mtk.h b/drivers/clk/mediatek/clk-mtk.h
index 61035b9..645af7c 100644
--- a/drivers/clk/mediatek/clk-mtk.h
+++ b/drivers/clk/mediatek/clk-mtk.h
@@ -150,6 +150,7 @@ struct mtk_pll_data {
 	int pcwbits;
 	uint32_t pcw_reg;
 	int pcw_shift;
+	const unsigned long *div_rate;
 };
 
 void __init 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 44409e9..4680a09 100644
--- a/drivers/clk/mediatek/clk-pll.c
+++ b/drivers/clk/mediatek/clk-pll.c
@@ -90,20 +90,23 @@ static unsigned long __mtk_pll_recalc_rate(struct mtk_clk_pll *pll, u32 fin,
 static void mtk_pll_set_rate_regs(struct mtk_clk_pll *pll, u32 pcw,
 		int postdiv)
 {
-	u32 con1, pd, val;
+	u32 con1, val;
 	int pll_en;
 
-	/* set postdiv */
-	pd = readl(pll->pd_addr);
-	pd &= ~(POSTDIV_MASK << pll->data->pd_shift);
-	pd |= (ffs(postdiv) - 1) << pll->data->pd_shift;
-	writel(pd, pll->pd_addr);
-
 	pll_en = readl(pll->base_addr + REG_CON0) & CON0_BASE_EN;
 
-	/* set pcw */
-	val = readl(pll->pcw_addr);
+	/* set postdiv */
+	val = readl(pll->pd_addr);
+	val &= ~(POSTDIV_MASK << pll->data->pd_shift);
+	val |= (ffs(postdiv) - 1) << pll->data->pd_shift;
+
+	/* postdiv and pcw need to set at the same time if on same register */
+	if (pll->pd_addr != pll->pcw_addr) {
+		writel(val, pll->pd_addr);
+		val = readl(pll->pcw_addr);
+	}
 
+	/* set pcw */
 	val &= ~GENMASK(pll->data->pcw_shift + pll->data->pcwbits - 1,
 			pll->data->pcw_shift);
 	val |= pcw << pll->data->pcw_shift;
@@ -135,16 +138,26 @@ static void mtk_pll_calc_values(struct mtk_clk_pll *pll, u32 *pcw, u32 *postdiv,
 		u32 freq, u32 fin)
 {
 	unsigned long fmin = 1000 * MHZ;
+	const unsigned long *div_rate = pll->data->div_rate;
 	u64 _pcw;
 	u32 val;
 
 	if (freq > pll->data->fmax)
 		freq = pll->data->fmax;
 
-	for (val = 0; val < 4; val++) {
+	if (div_rate) {
+		for (val = 1; div_rate[val] != 0; val++) {
+			if (freq > div_rate[val])
+				break;
+		}
+		val--;
 		*postdiv = 1 << val;
-		if (freq * *postdiv >= fmin)
-			break;
+	} else {
+		for (val = 0; val < 5; val++) {
+			*postdiv = 1 << val;
+			if ((u64)freq * *postdiv >= fmin)
+				break;
+		}
 	}
 
 	/* _pcw = freq * postdiv / fin * 2^pcwfbits */
-- 
1.8.1.1.dirty