[PATCH 13/21] clk: at91: sam9x7: add support for HW PLL freq dividers

[Varshini Rajendran <varshini.rajendran@microchip.com>]

Add support for hardware dividers for PLL IDs in sam9x7 Soc
PLL_ID_PLLA and PLL_ID_PLLA_DIV2 has /2 hardware dividers each

fcorepllack -----> HW Div = 2 -+--> fpllack
                               |
                               +--> HW Div = 2 ---> fplladiv2ck

Signed-off-by: Varshini Rajendran <varshini.rajendran@microchip.com>
---
 drivers/clk/at91/clk-sam9x60-pll.c | 38 ++++++++++++++++++++++++++----
 drivers/clk/at91/pmc.h             |  1 +
 2 files changed, 34 insertions(+), 5 deletions(-)

diff --git a/drivers/clk/at91/clk-sam9x60-pll.c b/drivers/clk/at91/clk-sam9x60-pll.c
index b3012641214c..76273ea74f8b 100644
--- a/drivers/clk/at91/clk-sam9x60-pll.c
+++ b/drivers/clk/at91/clk-sam9x60-pll.c
@@ -73,9 +73,15 @@ static unsigned long sam9x60_frac_pll_recalc_rate(struct clk_hw *hw,
 {
 	struct sam9x60_pll_core *core = to_sam9x60_pll_core(hw);
 	struct sam9x60_frac *frac = to_sam9x60_frac(core);
+	unsigned long freq;
 
-	return parent_rate * (frac->mul + 1) +
+	freq = parent_rate * (frac->mul + 1) +
 		DIV_ROUND_CLOSEST_ULL((u64)parent_rate * frac->frac, (1 << 22));
+
+	if (core->layout->div2)
+		freq >>= 1;
+
+	return freq;
 }
 
 static int sam9x60_frac_pll_set(struct sam9x60_pll_core *core)
@@ -432,6 +438,12 @@ static unsigned long sam9x60_div_pll_recalc_rate(struct clk_hw *hw,
 	return DIV_ROUND_CLOSEST_ULL(parent_rate, (div->div + 1));
 }
 
+static unsigned long sam9x60_fixed_div_pll_recalc_rate(struct clk_hw *hw,
+						       unsigned long parent_rate)
+{
+	return parent_rate >> 1;
+}
+
 static long sam9x60_div_pll_compute_div(struct sam9x60_pll_core *core,
 					unsigned long *parent_rate,
 					unsigned long rate)
@@ -606,6 +618,16 @@ static const struct clk_ops sam9x60_div_pll_ops_chg = {
 	.restore_context = sam9x60_div_pll_restore_context,
 };
 
+static const struct clk_ops sam9x60_fixed_div_pll_ops = {
+	.prepare = sam9x60_div_pll_prepare,
+	.unprepare = sam9x60_div_pll_unprepare,
+	.is_prepared = sam9x60_div_pll_is_prepared,
+	.recalc_rate = sam9x60_fixed_div_pll_recalc_rate,
+	.round_rate = sam9x60_div_pll_round_rate,
+	.save_context = sam9x60_div_pll_save_context,
+	.restore_context = sam9x60_div_pll_restore_context,
+};
+
 struct clk_hw * __init
 sam9x60_clk_register_frac_pll(struct regmap *regmap, spinlock_t *lock,
 			      const char *name, const char *parent_name,
@@ -718,10 +740,16 @@ sam9x60_clk_register_div_pll(struct regmap *regmap, spinlock_t *lock,
 	init.name = name;
 	init.parent_names = &parent_name;
 	init.num_parents = 1;
-	if (flags & CLK_SET_RATE_GATE)
-		init.ops = &sam9x60_div_pll_ops;
-	else
-		init.ops = &sam9x60_div_pll_ops_chg;
+
+	if (layout->div2) {
+		init.ops = &sam9x60_fixed_div_pll_ops;
+	} else {
+		if (flags & CLK_SET_RATE_GATE)
+			init.ops = &sam9x60_div_pll_ops;
+		else
+			init.ops = &sam9x60_div_pll_ops_chg;
+	}
+
 	init.flags = flags;
 
 	div->core.id = id;
diff --git a/drivers/clk/at91/pmc.h b/drivers/clk/at91/pmc.h
index 3e36dcc464c1..1dd01f30bdee 100644
--- a/drivers/clk/at91/pmc.h
+++ b/drivers/clk/at91/pmc.h
@@ -64,6 +64,7 @@ struct clk_pll_layout {
 	u8 frac_shift;
 	u8 div_shift;
 	u8 endiv_shift;
+	u8 div2;
 };
 
 extern const struct clk_pll_layout at91rm9200_pll_layout;
-- 
2.25.1