clk: qcom: support for 2 bit PLL post divider

Current PLL driver only supports 4 bit PLL post divider so
modified the PLL divider operations to support 2 bit PLL
post divider.
Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

drivers/clk/qcom/clk-alpha-pll.c

@@ -45,7 +45,7 @@
 
 #define PLL_USER_CTL(p)		((p)->offset + (p)->regs[PLL_OFF_USER_CTL])
 # define PLL_POST_DIV_SHIFT	8
-# define PLL_POST_DIV_MASK	0xf
+# define PLL_POST_DIV_MASK(p)	GENMASK((p)->width, 0)
 # define PLL_ALPHA_EN		BIT(24)
 # define PLL_ALPHA_MODE		BIT(25)
 # define PLL_VCO_SHIFT		20
@@ -750,7 +750,7 @@ clk_alpha_pll_postdiv_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
 	regmap_read(pll->clkr.regmap, PLL_USER_CTL(pll), &ctl);
 
 	ctl >>= PLL_POST_DIV_SHIFT;
-	ctl &= PLL_POST_DIV_MASK;
+	ctl &= PLL_POST_DIV_MASK(pll);
 
 	return parent_rate >> fls(ctl);
 }
@@ -764,13 +764,26 @@ static const struct clk_div_table clk_alpha_div_table[] = {
 	{ }
 };
 
+static const struct clk_div_table clk_alpha_2bit_div_table[] = {
+	{ 0x0, 1 },
+	{ 0x1, 2 },
+	{ 0x3, 4 },
+	{ }
+};
+
 static long
 clk_alpha_pll_postdiv_round_rate(struct clk_hw *hw, unsigned long rate,
 				 unsigned long *prate)
 {
 	struct clk_alpha_pll_postdiv *pll = to_clk_alpha_pll_postdiv(hw);
+	const struct clk_div_table *table;
+
+	if (pll->width == 2)
+		table = clk_alpha_2bit_div_table;
+	else
+		table = clk_alpha_div_table;
 
-	return divider_round_rate(hw, rate, prate, clk_alpha_div_table,
+	return divider_round_rate(hw, rate, prate, table,
 				  pll->width, CLK_DIVIDER_POWER_OF_TWO);
 }
 
@@ -784,7 +797,7 @@ static int clk_alpha_pll_postdiv_set_rate(struct clk_hw *hw, unsigned long rate,
 	div = DIV_ROUND_UP_ULL((u64)parent_rate, rate) - 1;
 
 	return regmap_update_bits(pll->clkr.regmap, PLL_USER_CTL(pll),
-				  PLL_POST_DIV_MASK << PLL_POST_DIV_SHIFT,
+				  PLL_POST_DIV_MASK(pll) << PLL_POST_DIV_SHIFT,
 				  div << PLL_POST_DIV_SHIFT);
 }