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| author |   Tejas Patel <tejas.patel@xilinx.com> | 2019-12-04 22:35:59 -0800 |
|---|---|---|
| committer |   Stephen Boyd <sboyd@kernel.org> | 2020-01-23 13:25:37 -0800 |
| commit | 34bbe036170785bd288d8a74573ee8ad7946f4a1 (patch) | |
| tree | b1a8079be2cfff78ebc8c07e71e2bf08656a2f2f /drivers/clk | |
| parent | clk: zynqmp: Fix divider calculation (diff) | |
| download | linux-dev-34bbe036170785bd288d8a74573ee8ad7946f4a1.tar.xz linux-dev-34bbe036170785bd288d8a74573ee8ad7946f4a1.zip | |
clk: zynqmp: Add support for clock with CLK_DIVIDER_POWER_OF_TWO flag
Existing clock divider functions is not checking for
base of divider. So, if any clock divider is power of 2
then clock rate calculation will be wrong.
Add support to calculate divider value for the clocks
with CLK_DIVIDER_POWER_OF_TWO flag.
Signed-off-by: Tejas Patel <tejas.patel@xilinx.com>
Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>
Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Link: https://lkml.kernel.org/r/1575527759-26452-7-git-send-email-rajan.vaja@xilinx.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Diffstat (limited to 'drivers/clk')
| -rw-r--r-- | drivers/clk/zynqmp/divider.c | 36 |
1 files changed, 31 insertions, 5 deletions
diff --git a/drivers/clk/zynqmp/divider.c b/drivers/clk/zynqmp/divider.c index c6af0c454997..4be2cc76aa2e 100644 --- a/drivers/clk/zynqmp/divider.c +++ b/drivers/clk/zynqmp/divider.c @@ -2,7 +2,7 @@ /* * Zynq UltraScale+ MPSoC Divider support * - * Copyright (C) 2016-2018 Xilinx + * Copyright (C) 2016-2019 Xilinx * * Adjustable divider clock implementation */ @@ -45,9 +45,26 @@ struct zynqmp_clk_divider { }; static inline int zynqmp_divider_get_val(unsigned long parent_rate, - unsigned long rate) + unsigned long rate, u16 flags) { - return DIV_ROUND_CLOSEST(parent_rate, rate); + int up, down; + unsigned long up_rate, down_rate; + + if (flags & CLK_DIVIDER_POWER_OF_TWO) { + up = DIV_ROUND_UP_ULL((u64)parent_rate, rate); + down = DIV_ROUND_DOWN_ULL((u64)parent_rate, rate); + + up = __roundup_pow_of_two(up); + down = __rounddown_pow_of_two(down); + + up_rate = DIV_ROUND_UP_ULL((u64)parent_rate, up); + down_rate = DIV_ROUND_UP_ULL((u64)parent_rate, down); + + return (rate - up_rate) <= (down_rate - rate) ? up : down; + + } else { + return DIV_ROUND_CLOSEST(parent_rate, rate); + } } /** @@ -79,6 +96,9 @@ static unsigned long zynqmp_clk_divider_recalc_rate(struct clk_hw *hw, else value = div >> 16; + if (divider->flags & CLK_DIVIDER_POWER_OF_TWO) + value = 1 << value; + if (!value) { WARN(!(divider->flags & CLK_DIVIDER_ALLOW_ZERO), "%s: Zero divisor and CLK_DIVIDER_ALLOW_ZERO not set\n", @@ -157,10 +177,13 @@ static long zynqmp_clk_divider_round_rate(struct clk_hw *hw, else bestdiv = bestdiv >> 16; + if (divider->flags & CLK_DIVIDER_POWER_OF_TWO) + bestdiv = 1 << bestdiv; + return DIV_ROUND_UP_ULL((u64)*prate, bestdiv); } - bestdiv = zynqmp_divider_get_val(*prate, rate); + bestdiv = zynqmp_divider_get_val(*prate, rate, divider->flags); /* * In case of two divisors, compute best divider values and return @@ -198,7 +221,7 @@ static int zynqmp_clk_divider_set_rate(struct clk_hw *hw, unsigned long rate, int ret; const struct zynqmp_eemi_ops *eemi_ops = zynqmp_pm_get_eemi_ops(); - value = zynqmp_divider_get_val(parent_rate, rate); + value = zynqmp_divider_get_val(parent_rate, rate, divider->flags); if (div_type == TYPE_DIV1) { div = value & 0xFFFF; div |= 0xffff << 16; @@ -207,6 +230,9 @@ static int zynqmp_clk_divider_set_rate(struct clk_hw *hw, unsigned long rate, div |= value << 16; } + if (divider->flags & CLK_DIVIDER_POWER_OF_TWO) + div = __ffs(div); + ret = eemi_ops->clock_setdivider(clk_id, div); if (ret) |