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drivers: clk: zynqmp: update divider round rate logic 

[ Upstream commit 1fe15be1fb ]

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.

Fixes: 3fde0e16d0 ("drivers: clk: Add ZynqMP clock driver")
Signed-off-by: Jay Buddhabhatti <jay.buddhabhatti@amd.com>
Link: https://lore.kernel.org/r/20231129112916.23125-3-jay.buddhabhatti@amd.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Jay Buddhabhatti 2023-11-29 03:29:16 -08:00 committed by Greg Kroah-Hartman
parent b61ca9c34c
commit c249ef9d09
1 changed files with 5 additions and 61 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

66
drivers/clk/zynqmp/divider.c
View File

@ -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 +128,7 @@ static long zynqmp_clk_divider_round_rate(struct clk_hw *hw,
u32 div_type = divider->div_type;
u32 bestdiv;
int ret;
u8 width;
/* if read only, just return current value */
if (divider->flags & CLK_DIVIDER_READ_ONLY) {
@ -193,23 +148,12 @@ 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);
width = fls(divider->max_div);
/*
* 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);
}
rate = divider_round_rate(hw, rate, prate, NULL, width, divider->flags);
if ((clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT) && divider->is_frac)
bestdiv = rate % *prate ? 1 : bestdiv;
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;
}