[PATCH RESEND 2/2] drivers: clk: zynqmp: update divider round rate logic
From: Jay Buddhabhatti <hidden>
Date: 2023-10-16 11:30:34
Also in:
linux-clk, lkml
Subsystem:
common clk framework, the rest · Maintainers:
Michael Turquette, Stephen Boyd, Linus Torvalds
Currently zynqmp divider round rate is considering single parent and calculating rate and parent rate accordingly. But if divider clock flag is set to SET_RATE_PARENT then its not trying to traverse through all parent rate and not selecting best parent rate from that. So use common divider_round_rate() which is traversing through all clock parents and its rate and calculating proper parent rate. Signed-off-by: Jay Buddhabhatti <redacted> --- drivers/clk/zynqmp/divider.c | 70 ++++++------------------------------ 1 file changed, 10 insertions(+), 60 deletions(-)
diff --git a/drivers/clk/zynqmp/divider.c b/drivers/clk/zynqmp/divider.c
index 33a3b2a22659..a42c183d7e5d 100644
--- a/drivers/clk/zynqmp/divider.c
+++ b/drivers/clk/zynqmp/divider.c@@ -110,52 +110,6 @@ static unsigned long zynqmp_clk_divider_recalc_rate(struct clk_hw *hw, return DIV_ROUND_UP_ULL(parent_rate, value); } -static void zynqmp_get_divider2_val(struct clk_hw *hw, - unsigned long rate, - struct zynqmp_clk_divider *divider, - u32 *bestdiv) -{ - int div1; - int div2; - long error = LONG_MAX; - unsigned long div1_prate; - struct clk_hw *div1_parent_hw; - struct zynqmp_clk_divider *pdivider; - struct clk_hw *div2_parent_hw = clk_hw_get_parent(hw); - - if (!div2_parent_hw) - return; - - pdivider = to_zynqmp_clk_divider(div2_parent_hw); - if (!pdivider) - return; - - div1_parent_hw = clk_hw_get_parent(div2_parent_hw); - if (!div1_parent_hw) - return; - - div1_prate = clk_hw_get_rate(div1_parent_hw); - *bestdiv = 1; - for (div1 = 1; div1 <= pdivider->max_div;) { - for (div2 = 1; div2 <= divider->max_div;) { - long new_error = ((div1_prate / div1) / div2) - rate; - - if (abs(new_error) < abs(error)) { - *bestdiv = div2; - error = new_error; - } - if (divider->flags & CLK_DIVIDER_POWER_OF_TWO) - div2 = div2 << 1; - else - div2++; - } - if (pdivider->flags & CLK_DIVIDER_POWER_OF_TWO) - div1 = div1 << 1; - else - div1++; - } -} - /** * zynqmp_clk_divider_round_rate() - Round rate of divider clock * @hw: handle between common and hardware-specific interfaces
@@ -174,6 +128,8 @@ static long zynqmp_clk_divider_round_rate(struct clk_hw *hw, u32 div_type = divider->div_type; u32 bestdiv; int ret; + u8 width = 0; + u16 max; /* if read only, just return current value */ if (divider->flags & CLK_DIVIDER_READ_ONLY) {
@@ -193,23 +149,17 @@ static long zynqmp_clk_divider_round_rate(struct clk_hw *hw, return DIV_ROUND_UP_ULL((u64)*prate, bestdiv); } - bestdiv = zynqmp_divider_get_val(*prate, rate, divider->flags); - - /* - * In case of two divisors, compute best divider values and return - * divider2 value based on compute value. div1 will be automatically - * set to optimum based on required total divider value. - */ - if (div_type == TYPE_DIV2 && - (clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT)) { - zynqmp_get_divider2_val(hw, rate, divider, &bestdiv); + max = divider->max_div; + while (max != 0) { + if ((max & 1) == 1) + width++; + max = max >> 1; } - if ((clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT) && divider->is_frac) - bestdiv = rate % *prate ? 1 : bestdiv; + rate = divider_round_rate(hw, rate, prate, NULL, width, divider->flags); - bestdiv = min_t(u32, bestdiv, divider->max_div); - *prate = rate * bestdiv; + if (divider->is_frac && (clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT) && (rate % *prate)) + *prate = rate; return rate; }
--
2.17.1
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel