[v3,1/3] clk: meson: Support PLL with fixed fractional denominators

Commit Message

Chuan Liu via B4 Relay Sept. 9, 2024, 10:08 a.m. UTC

From: Chuan Liu <[e-mail]>

Some PLLS with fractional multipliers have fractional denominators with
fixed values, instead of the previous "(1 << pll-> frc.width)".

Signed-off-by: Chuan Liu <[e-mail]>
---
 drivers/clk/meson/clk-pll.c | 8 +++++---
 drivers/clk/meson/clk-pll.h | 1 +
 2 files changed, 6 insertions(+), 3 deletions(-)

Patch

diff --git a/drivers/clk/meson/clk-pll.c b/drivers/clk/meson/clk-pll.c
index bc570a2ff3a3..89f0f04a16ab 100644
--- a/drivers/clk/meson/clk-pll.c
+++ b/drivers/clk/meson/clk-pll.c
@@ -57,12 +57,13 @@  static unsigned long __pll_params_to_rate(unsigned long parent_rate,
 					  struct meson_clk_pll_data *pll)
 {
 	u64 rate = (u64)parent_rate * m;
+	unsigned int frac_max = pll->frac_max ? pll->frac_max :
+						(1 << pll->frac.width);
 
 	if (frac && MESON_PARM_APPLICABLE(&pll->frac)) {
 		u64 frac_rate = (u64)parent_rate * frac;
 
-		rate += DIV_ROUND_UP_ULL(frac_rate,
-					 (1 << pll->frac.width));
+		rate += DIV_ROUND_UP_ULL(frac_rate, frac_max);
 	}
 
 	return DIV_ROUND_UP_ULL(rate, n);
@@ -100,7 +101,8 @@  static unsigned int __pll_params_with_frac(unsigned long rate,
 					   unsigned int n,
 					   struct meson_clk_pll_data *pll)
 {
-	unsigned int frac_max = (1 << pll->frac.width);
+	unsigned int frac_max = pll->frac_max ? pll->frac_max :
+						(1 << pll->frac.width);
 	u64 val = (u64)rate * n;
 
 	/* Bail out if we are already over the requested rate */
diff --git a/drivers/clk/meson/clk-pll.h b/drivers/clk/meson/clk-pll.h
index 7b6b87274073..949157fb7bf5 100644
--- a/drivers/clk/meson/clk-pll.h
+++ b/drivers/clk/meson/clk-pll.h
@@ -43,6 +43,7 @@  struct meson_clk_pll_data {
 	unsigned int init_count;
 	const struct pll_params_table *table;
 	const struct pll_mult_range *range;
+	unsigned int frac_max;
 	u8 flags;
 };