Commit b4054ac6 authored by Tomasz Figa's avatar Tomasz Figa Committed by Mike Turquette
Browse files

clk: samsung: pll: Add support for rate configuration of PLL45xx 



This patch implements round_rate and set_rate callbacks of PLL45xx
driver to allow reconfiguration of PLL at runtime.

Signed-off-by: default avatarTomasz Figa <t.figa@samsung.com>
Signed-off-by: default avatarKyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: default avatarSylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: default avatarMike Turquette <mturquette@linaro.org>
parent 52b06016

drivers/clk/samsung/clk-pll.c

+109 −1
Original line number Diff line number Diff line
@@ -10,9 +10,12 @@ 
*/



#include <linux/errno.h>

#include <linux/hrtimer.h>

#include "clk.h"

#include "clk-pll.h"



#define PLL_TIMEOUT_MS		10



struct samsung_clk_pll {

	struct clk_hw		hw;

	void __iomem		*lock_reg;
@@ -272,13 +275,20 @@ static const struct clk_ops samsung_pll36xx_clk_min_ops = { 
/*

 * PLL45xx Clock Type

 */

#define PLL4502_LOCK_FACTOR	400

#define PLL4508_LOCK_FACTOR	240



#define PLL45XX_MDIV_MASK	(0x3FF)

#define PLL45XX_PDIV_MASK	(0x3F)

#define PLL45XX_SDIV_MASK	(0x7)

#define PLL45XX_AFC_MASK	(0x1F)

#define PLL45XX_MDIV_SHIFT	(16)

#define PLL45XX_PDIV_SHIFT	(8)

#define PLL45XX_SDIV_SHIFT	(0)

#define PLL45XX_AFC_SHIFT	(0)



#define PLL45XX_ENABLE		BIT(31)

#define PLL45XX_LOCKED		BIT(29)



static unsigned long samsung_pll45xx_recalc_rate(struct clk_hw *hw,

				unsigned long parent_rate)
@@ -301,8 +311,101 @@ static unsigned long samsung_pll45xx_recalc_rate(struct clk_hw *hw, 
	return (unsigned long)fvco;

}



static bool samsung_pll45xx_mp_change(u32 pll_con0, u32 pll_con1,

				const struct samsung_pll_rate_table *rate)

{

	u32 old_mdiv, old_pdiv, old_afc;



	old_mdiv = (pll_con0 >> PLL45XX_MDIV_SHIFT) & PLL45XX_MDIV_MASK;

	old_pdiv = (pll_con0 >> PLL45XX_PDIV_SHIFT) & PLL45XX_PDIV_MASK;

	old_afc = (pll_con1 >> PLL45XX_AFC_SHIFT) & PLL45XX_AFC_MASK;



	return (old_mdiv != rate->mdiv || old_pdiv != rate->pdiv

		|| old_afc != rate->afc);

}



static int samsung_pll45xx_set_rate(struct clk_hw *hw, unsigned long drate,

					unsigned long prate)

{

	struct samsung_clk_pll *pll = to_clk_pll(hw);

	const struct samsung_pll_rate_table *rate;

	u32 con0, con1;

	ktime_t start;



	/* Get required rate settings from table */

	rate = samsung_get_pll_settings(pll, drate);

	if (!rate) {

		pr_err("%s: Invalid rate : %lu for pll clk %s\n", __func__,

			drate, __clk_get_name(hw->clk));

		return -EINVAL;

	}



	con0 = __raw_readl(pll->con_reg);

	con1 = __raw_readl(pll->con_reg + 0x4);



	if (!(samsung_pll45xx_mp_change(con0, con1, rate))) {

		/* If only s change, change just s value only*/

		con0 &= ~(PLL45XX_SDIV_MASK << PLL45XX_SDIV_SHIFT);

		con0 |= rate->sdiv << PLL45XX_SDIV_SHIFT;

		__raw_writel(con0, pll->con_reg);



		return 0;

	}



	/* Set PLL PMS values. */

	con0 &= ~((PLL45XX_MDIV_MASK << PLL45XX_MDIV_SHIFT) |

			(PLL45XX_PDIV_MASK << PLL45XX_PDIV_SHIFT) |

			(PLL45XX_SDIV_MASK << PLL45XX_SDIV_SHIFT));

	con0 |= (rate->mdiv << PLL45XX_MDIV_SHIFT) |

			(rate->pdiv << PLL45XX_PDIV_SHIFT) |

			(rate->sdiv << PLL45XX_SDIV_SHIFT);



	/* Set PLL AFC value. */

	con1 = __raw_readl(pll->con_reg + 0x4);

	con1 &= ~(PLL45XX_AFC_MASK << PLL45XX_AFC_SHIFT);

	con1 |= (rate->afc << PLL45XX_AFC_SHIFT);



	/* Set PLL lock time. */

	switch (pll->type) {

	case pll_4502:

		__raw_writel(rate->pdiv * PLL4502_LOCK_FACTOR, pll->lock_reg);

		break;

	case pll_4508:

		__raw_writel(rate->pdiv * PLL4508_LOCK_FACTOR, pll->lock_reg);

		break;

	default:

		break;

	};



	/* Set new configuration. */

	__raw_writel(con1, pll->con_reg + 0x4);

	__raw_writel(con0, pll->con_reg);



	/* Wait for locking. */

	start = ktime_get();

	while (!(__raw_readl(pll->con_reg) & PLL45XX_LOCKED)) {

		ktime_t delta = ktime_sub(ktime_get(), start);



		if (ktime_to_ms(delta) > PLL_TIMEOUT_MS) {

			pr_err("%s: could not lock PLL %s\n",

					__func__, __clk_get_name(hw->clk));

			return -EFAULT;

		}



		cpu_relax();

	}



	return 0;

}



static const struct clk_ops samsung_pll45xx_clk_ops = {

	.recalc_rate = samsung_pll45xx_recalc_rate,

	.round_rate = samsung_pll_round_rate,

	.set_rate = samsung_pll45xx_set_rate,

};



static const struct clk_ops samsung_pll45xx_clk_min_ops = {

	.recalc_rate = samsung_pll45xx_recalc_rate,

};



/*
@@ -591,8 +694,13 @@ static void __init _samsung_clk_register_pll(struct samsung_pll_clock *pll_clk, 
			init.ops = &samsung_pll35xx_clk_ops;

		break;

	case pll_4500:

		init.ops = &samsung_pll45xx_clk_min_ops;

		break;

	case pll_4502:

	case pll_4508:

		if (!pll->rate_table)

			init.ops = &samsung_pll45xx_clk_min_ops;

		else

			init.ops = &samsung_pll45xx_clk_ops;

		break;

	/* clk_ops for 36xx and 2650 are similar */

drivers/clk/samsung/clk-pll.h

+10 −0
Original line number Diff line number Diff line
@@ -41,6 +41,15 @@ enum samsung_pll_type { 
		.kdiv	=	(_k),				\

	}



#define PLL_45XX_RATE(_rate, _m, _p, _s, _afc)			\

	{							\

		.rate	=	(_rate),			\

		.mdiv	=	(_m),				\

		.pdiv	=	(_p),				\

		.sdiv	=	(_s),				\

		.afc	=	(_afc),				\

	}



/* NOTE: Rate table should be kept sorted in descending order. */



struct samsung_pll_rate_table {
@@ -49,6 +58,7 @@ struct samsung_pll_rate_table { 
	unsigned int mdiv;

	unsigned int sdiv;

	unsigned int kdiv;

	unsigned int afc;

};



enum pll46xx_type {

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