Commit 34bbe036 authored by Tejas Patel's avatar Tejas Patel Committed by Stephen Boyd
Browse files

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: default avatarTejas Patel <tejas.patel@xilinx.com>
Signed-off-by: default avatarRadhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>
Signed-off-by: default avatarRajan Vaja <rajan.vaja@xilinx.com>
Link: https://lkml.kernel.org/r/1575527759-26452-7-git-send-email-rajan.vaja@xilinx.com


Signed-off-by: default avatarStephen Boyd <sboyd@kernel.org>
parent 4ebd92d2

drivers/clk/zynqmp/divider.c

+31 −5
Original line number Diff line number Diff line
@@ -2,7 +2,7 @@ 
/*

 * Zynq UltraScale+ MPSoC Divider support

 *

 *  Copyright (C) 2016-2018 Xilinx

 *  Copyright (C) 2016-2019 Xilinx

 *

 * Adjustable divider clock implementation

 */
@@ -45,10 +45,27 @@ struct zynqmp_clk_divider { 
};



static inline int zynqmp_divider_get_val(unsigned long parent_rate,

					 unsigned long rate)

					 unsigned long rate, u16 flags)

{

	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);

	}

}



/**

 * zynqmp_clk_divider_recalc_rate() - Recalc rate of divider clock
@@ -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)