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Commit 5799ea12 authored by Heiko Stuebner's avatar Heiko Stuebner Committed by Kukjin Kim
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clk: samsung: add clock driver for external clock outputs 



This adds a driver for controlling the external clock outputs of
s3c24xx architectures including the dclk muxes and dividers.

The driver at the moment only supports the legacy non-dt boards using these
clock outputs. The clock-output control itself is part of the system-controller
mainly controlled by the pinctrl drivers. So it should most likely be
integrated there for dt platforms.

Signed-off-by: default avatarHeiko Stuebner <heiko@sntech.de>
Acked-by: default avatarMike Turquette <mturquette@linaro.org>
Signed-off-by: default avatarKukjin Kim <kgene.kim@samsung.com>
parent d8b53257

drivers/clk/samsung/Makefile

+1 −0
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@@ -8,6 +8,7 @@ obj-$(CONFIG_SOC_EXYNOS5250) += clk-exynos5250.o 
obj-$(CONFIG_SOC_EXYNOS5420)	+= clk-exynos5420.o

obj-$(CONFIG_SOC_EXYNOS5440)	+= clk-exynos5440.o

obj-$(CONFIG_ARCH_EXYNOS)	+= clk-exynos-audss.o

obj-$(CONFIG_S3C2410_COMMON_DCLK)+= clk-s3c2410-dclk.o

obj-$(CONFIG_S3C2412_COMMON_CLK)+= clk-s3c2412.o

obj-$(CONFIG_S3C2443_COMMON_CLK)+= clk-s3c2443.o

obj-$(CONFIG_ARCH_S3C64XX)	+= clk-s3c64xx.o

drivers/clk/samsung/clk-s3c2410-dclk.c

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+440 −0
Original line number Diff line number Diff line 
/*

 * Copyright (c) 2013 Heiko Stuebner <heiko@sntech.de>

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

 *

 * Common Clock Framework support for s3c24xx external clock output.

 */



#include <linux/platform_device.h>

#include <linux/module.h>

#include "clk.h"



/* legacy access to misccr, until dt conversion is finished */

#include <mach/hardware.h>

#include <mach/regs-gpio.h>



#define MUX_DCLK0	0

#define MUX_DCLK1	1

#define DIV_DCLK0	2

#define DIV_DCLK1	3

#define GATE_DCLK0	4

#define GATE_DCLK1	5

#define MUX_CLKOUT0	6

#define MUX_CLKOUT1	7

#define DCLK_MAX_CLKS	(MUX_CLKOUT1 + 1)



enum supported_socs {

	S3C2410,

	S3C2412,

	S3C2440,

	S3C2443,

};



struct s3c24xx_dclk_drv_data {

	const char **clkout0_parent_names;

	int clkout0_num_parents;

	const char **clkout1_parent_names;

	int clkout1_num_parents;

	const char **mux_parent_names;

	int mux_num_parents;

};



/*

 * Clock for output-parent selection in misccr

 */



struct s3c24xx_clkout {

	struct clk_hw		hw;

	u32			mask;

	u8			shift;

};



#define to_s3c24xx_clkout(_hw) container_of(_hw, struct s3c24xx_clkout, hw)



static u8 s3c24xx_clkout_get_parent(struct clk_hw *hw)

{

	struct s3c24xx_clkout *clkout = to_s3c24xx_clkout(hw);

	int num_parents = __clk_get_num_parents(hw->clk);

	u32 val;



	val = readl_relaxed(S3C24XX_MISCCR) >> clkout->shift;

	val >>= clkout->shift;

	val &= clkout->mask;



	if (val >= num_parents)

		return -EINVAL;



	return val;

}



static int s3c24xx_clkout_set_parent(struct clk_hw *hw, u8 index)

{

	struct s3c24xx_clkout *clkout = to_s3c24xx_clkout(hw);

	int ret = 0;



	s3c2410_modify_misccr((clkout->mask << clkout->shift),

			      (index << clkout->shift));



	return ret;

}



const struct clk_ops s3c24xx_clkout_ops = {

	.get_parent = s3c24xx_clkout_get_parent,

	.set_parent = s3c24xx_clkout_set_parent,

	.determine_rate = __clk_mux_determine_rate,

};



struct clk *s3c24xx_register_clkout(struct device *dev, const char *name,

		const char **parent_names, u8 num_parents,

		u8 shift, u32 mask)

{

	struct s3c24xx_clkout *clkout;

	struct clk *clk;

	struct clk_init_data init;



	/* allocate the clkout */

	clkout = kzalloc(sizeof(*clkout), GFP_KERNEL);

	if (!clkout)

		return ERR_PTR(-ENOMEM);



	init.name = name;

	init.ops = &s3c24xx_clkout_ops;

	init.flags = CLK_IS_BASIC;

	init.parent_names = parent_names;

	init.num_parents = num_parents;



	clkout->shift = shift;

	clkout->mask = mask;

	clkout->hw.init = &init;



	clk = clk_register(dev, &clkout->hw);



	return clk;

}



/*

 * dclk and clkout init

 */



struct s3c24xx_dclk {

	struct device *dev;

	void __iomem *base;

	struct clk_onecell_data clk_data;

	struct notifier_block dclk0_div_change_nb;

	struct notifier_block dclk1_div_change_nb;

	spinlock_t dclk_lock;

	unsigned long reg_save;

};



#define to_s3c24xx_dclk0(x) \

		container_of(x, struct s3c24xx_dclk, dclk0_div_change_nb)



#define to_s3c24xx_dclk1(x) \

		container_of(x, struct s3c24xx_dclk, dclk1_div_change_nb)



PNAME(dclk_s3c2410_p) = { "pclk", "uclk" };

PNAME(clkout0_s3c2410_p) = { "mpll", "upll", "fclk", "hclk", "pclk",

			     "gate_dclk0" };

PNAME(clkout1_s3c2410_p) = { "mpll", "upll", "fclk", "hclk", "pclk",

			     "gate_dclk1" };



PNAME(clkout0_s3c2412_p) = { "mpll", "upll", "rtc_clkout",

			     "hclk", "pclk", "gate_dclk0" };

PNAME(clkout1_s3c2412_p) = { "xti", "upll", "fclk", "hclk", "pclk",

			     "gate_dclk1" };



PNAME(clkout0_s3c2440_p) = { "xti", "upll", "fclk", "hclk", "pclk",

			     "gate_dclk0" };

PNAME(clkout1_s3c2440_p) = { "mpll", "upll", "rtc_clkout",

			     "hclk", "pclk", "gate_dclk1" };



PNAME(dclk_s3c2443_p) = { "pclk", "epll" };

PNAME(clkout0_s3c2443_p) = { "xti", "epll", "armclk", "hclk", "pclk",

			     "gate_dclk0" };

PNAME(clkout1_s3c2443_p) = { "dummy", "epll", "rtc_clkout",

			     "hclk", "pclk", "gate_dclk1" };



#define DCLKCON_DCLK_DIV_MASK		0xf

#define DCLKCON_DCLK0_DIV_SHIFT		4

#define DCLKCON_DCLK0_CMP_SHIFT		8

#define DCLKCON_DCLK1_DIV_SHIFT		20

#define DCLKCON_DCLK1_CMP_SHIFT		24



static void s3c24xx_dclk_update_cmp(struct s3c24xx_dclk *s3c24xx_dclk,

				    int div_shift, int cmp_shift)

{

	unsigned long flags = 0;

	u32 dclk_con, div, cmp;



	spin_lock_irqsave(&s3c24xx_dclk->dclk_lock, flags);



	dclk_con = readl_relaxed(s3c24xx_dclk->base);



	div = ((dclk_con >> div_shift) & DCLKCON_DCLK_DIV_MASK) + 1;

	cmp = ((div + 1) / 2) - 1;



	dclk_con &= ~(DCLKCON_DCLK_DIV_MASK << cmp_shift);

	dclk_con |= (cmp << cmp_shift);



	writel_relaxed(dclk_con, s3c24xx_dclk->base);



	spin_unlock_irqrestore(&s3c24xx_dclk->dclk_lock, flags);

}



static int s3c24xx_dclk0_div_notify(struct notifier_block *nb,

			       unsigned long event, void *data)

{

	struct s3c24xx_dclk *s3c24xx_dclk = to_s3c24xx_dclk0(nb);



	if (event == POST_RATE_CHANGE) {

		s3c24xx_dclk_update_cmp(s3c24xx_dclk,

			DCLKCON_DCLK0_DIV_SHIFT, DCLKCON_DCLK0_CMP_SHIFT);

	}



	return NOTIFY_DONE;

}



static int s3c24xx_dclk1_div_notify(struct notifier_block *nb,

			       unsigned long event, void *data)

{

	struct s3c24xx_dclk *s3c24xx_dclk = to_s3c24xx_dclk1(nb);



	if (event == POST_RATE_CHANGE) {

		s3c24xx_dclk_update_cmp(s3c24xx_dclk,

			DCLKCON_DCLK1_DIV_SHIFT, DCLKCON_DCLK1_CMP_SHIFT);

	}



	return NOTIFY_DONE;

}



#ifdef CONFIG_PM_SLEEP

static int s3c24xx_dclk_suspend(struct device *dev)

{

	struct platform_device *pdev = to_platform_device(dev);

	struct s3c24xx_dclk *s3c24xx_dclk = platform_get_drvdata(pdev);



	s3c24xx_dclk->reg_save = readl_relaxed(s3c24xx_dclk->base);

	return 0;

}



static int s3c24xx_dclk_resume(struct device *dev)

{

	struct platform_device *pdev = to_platform_device(dev);

	struct s3c24xx_dclk *s3c24xx_dclk = platform_get_drvdata(pdev);



	writel_relaxed(s3c24xx_dclk->reg_save, s3c24xx_dclk->base);

	return 0;

}

#endif



static SIMPLE_DEV_PM_OPS(s3c24xx_dclk_pm_ops,

			 s3c24xx_dclk_suspend, s3c24xx_dclk_resume);



static int s3c24xx_dclk_probe(struct platform_device *pdev)

{

	struct s3c24xx_dclk *s3c24xx_dclk;

	struct resource *mem;

	struct clk **clk_table;

	struct s3c24xx_dclk_drv_data *dclk_variant;

	int ret, i;



	s3c24xx_dclk = devm_kzalloc(&pdev->dev, sizeof(*s3c24xx_dclk),

				    GFP_KERNEL);

	if (!s3c24xx_dclk)

		return -ENOMEM;



	s3c24xx_dclk->dev = &pdev->dev;

	platform_set_drvdata(pdev, s3c24xx_dclk);

	spin_lock_init(&s3c24xx_dclk->dclk_lock);



	clk_table = devm_kzalloc(&pdev->dev,

				 sizeof(struct clk *) * DCLK_MAX_CLKS,

				 GFP_KERNEL);

	if (!clk_table)

		return -ENOMEM;



	s3c24xx_dclk->clk_data.clks = clk_table;

	s3c24xx_dclk->clk_data.clk_num = DCLK_MAX_CLKS;



	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	s3c24xx_dclk->base = devm_ioremap_resource(&pdev->dev, mem);

	if (IS_ERR(s3c24xx_dclk->base))

		return PTR_ERR(s3c24xx_dclk->base);



	dclk_variant = (struct s3c24xx_dclk_drv_data *)

				platform_get_device_id(pdev)->driver_data;





	clk_table[MUX_DCLK0] = clk_register_mux(&pdev->dev, "mux_dclk0",

				dclk_variant->mux_parent_names,

				dclk_variant->mux_num_parents, 0,

				s3c24xx_dclk->base, 1, 1, 0,

				&s3c24xx_dclk->dclk_lock);

	clk_table[MUX_DCLK1] = clk_register_mux(&pdev->dev, "mux_dclk1",

				dclk_variant->mux_parent_names,

				dclk_variant->mux_num_parents, 0,

				s3c24xx_dclk->base, 17, 1, 0,

				&s3c24xx_dclk->dclk_lock);



	clk_table[DIV_DCLK0] = clk_register_divider(&pdev->dev, "div_dclk0",

				"mux_dclk0", 0, s3c24xx_dclk->base,

				4, 4, 0, &s3c24xx_dclk->dclk_lock);

	clk_table[DIV_DCLK1] = clk_register_divider(&pdev->dev, "div_dclk1",

				"mux_dclk1", 0, s3c24xx_dclk->base,

				20, 4, 0, &s3c24xx_dclk->dclk_lock);



	clk_table[GATE_DCLK0] = clk_register_gate(&pdev->dev, "gate_dclk0",

				"div_dclk0", CLK_SET_RATE_PARENT,

				s3c24xx_dclk->base, 0, 0,

				&s3c24xx_dclk->dclk_lock);

	clk_table[GATE_DCLK1] = clk_register_gate(&pdev->dev, "gate_dclk1",

				"div_dclk1", CLK_SET_RATE_PARENT,

				s3c24xx_dclk->base, 16, 0,

				&s3c24xx_dclk->dclk_lock);



	clk_table[MUX_CLKOUT0] = s3c24xx_register_clkout(&pdev->dev,

				"clkout0", dclk_variant->clkout0_parent_names,

				dclk_variant->clkout0_num_parents, 4, 7);

	clk_table[MUX_CLKOUT1] = s3c24xx_register_clkout(&pdev->dev,

				"clkout1", dclk_variant->clkout1_parent_names,

				dclk_variant->clkout1_num_parents, 8, 7);



	for (i = 0; i < DCLK_MAX_CLKS; i++)

		if (IS_ERR(clk_table[i])) {

			dev_err(&pdev->dev, "clock %d failed to register\n", i);

			ret = PTR_ERR(clk_table[i]);

			goto err_clk_register;

		}



	ret = clk_register_clkdev(clk_table[MUX_DCLK0], "dclk0", NULL);

	if (!ret)

		ret = clk_register_clkdev(clk_table[MUX_DCLK1], "dclk1", NULL);

	if (!ret)

		ret = clk_register_clkdev(clk_table[MUX_CLKOUT0],

					  "clkout0", NULL);

	if (!ret)

		ret = clk_register_clkdev(clk_table[MUX_CLKOUT1],

					  "clkout1", NULL);

	if (ret) {

		dev_err(&pdev->dev, "failed to register aliases, %d\n", ret);

		goto err_clk_register;

	}



	s3c24xx_dclk->dclk0_div_change_nb.notifier_call =

						s3c24xx_dclk0_div_notify;



	s3c24xx_dclk->dclk1_div_change_nb.notifier_call =

						s3c24xx_dclk1_div_notify;



	ret = clk_notifier_register(clk_table[DIV_DCLK0],

				    &s3c24xx_dclk->dclk0_div_change_nb);

	if (ret)

		goto err_clk_register;



	ret = clk_notifier_register(clk_table[DIV_DCLK1],

				    &s3c24xx_dclk->dclk1_div_change_nb);

	if (ret)

		goto err_dclk_notify;



	return 0;



err_dclk_notify:

	clk_notifier_unregister(clk_table[DIV_DCLK0],

				&s3c24xx_dclk->dclk0_div_change_nb);

err_clk_register:

	for (i = 0; i < DCLK_MAX_CLKS; i++)

		if (clk_table[i] && !IS_ERR(clk_table[i]))

			clk_unregister(clk_table[i]);



	return ret;

}



static int s3c24xx_dclk_remove(struct platform_device *pdev)

{

	struct s3c24xx_dclk *s3c24xx_dclk = platform_get_drvdata(pdev);

	struct clk **clk_table = s3c24xx_dclk->clk_data.clks;

	int i;



	clk_notifier_unregister(clk_table[DIV_DCLK1],

				&s3c24xx_dclk->dclk1_div_change_nb);

	clk_notifier_unregister(clk_table[DIV_DCLK0],

				&s3c24xx_dclk->dclk0_div_change_nb);



	for (i = 0; i < DCLK_MAX_CLKS; i++)

		clk_unregister(clk_table[i]);



	return 0;

}



static struct s3c24xx_dclk_drv_data dclk_variants[] = {

	[S3C2410] = {

		.clkout0_parent_names = clkout0_s3c2410_p,

		.clkout0_num_parents = ARRAY_SIZE(clkout0_s3c2410_p),

		.clkout1_parent_names = clkout1_s3c2410_p,

		.clkout1_num_parents = ARRAY_SIZE(clkout1_s3c2410_p),

		.mux_parent_names = dclk_s3c2410_p,

		.mux_num_parents = ARRAY_SIZE(dclk_s3c2410_p),

	},

	[S3C2412] = {

		.clkout0_parent_names = clkout0_s3c2412_p,

		.clkout0_num_parents = ARRAY_SIZE(clkout0_s3c2412_p),

		.clkout1_parent_names = clkout1_s3c2412_p,

		.clkout1_num_parents = ARRAY_SIZE(clkout1_s3c2412_p),

		.mux_parent_names = dclk_s3c2410_p,

		.mux_num_parents = ARRAY_SIZE(dclk_s3c2410_p),

	},

	[S3C2440] = {

		.clkout0_parent_names = clkout0_s3c2440_p,

		.clkout0_num_parents = ARRAY_SIZE(clkout0_s3c2440_p),

		.clkout1_parent_names = clkout1_s3c2440_p,

		.clkout1_num_parents = ARRAY_SIZE(clkout1_s3c2440_p),

		.mux_parent_names = dclk_s3c2410_p,

		.mux_num_parents = ARRAY_SIZE(dclk_s3c2410_p),

	},

	[S3C2443] = {

		.clkout0_parent_names = clkout0_s3c2443_p,

		.clkout0_num_parents = ARRAY_SIZE(clkout0_s3c2443_p),

		.clkout1_parent_names = clkout1_s3c2443_p,

		.clkout1_num_parents = ARRAY_SIZE(clkout1_s3c2443_p),

		.mux_parent_names = dclk_s3c2443_p,

		.mux_num_parents = ARRAY_SIZE(dclk_s3c2443_p),

	},

};



static struct platform_device_id s3c24xx_dclk_driver_ids[] = {

	{

		.name		= "s3c2410-dclk",

		.driver_data	= (kernel_ulong_t)&dclk_variants[S3C2410],

	}, {

		.name		= "s3c2412-dclk",

		.driver_data	= (kernel_ulong_t)&dclk_variants[S3C2412],

	}, {

		.name		= "s3c2440-dclk",

		.driver_data	= (kernel_ulong_t)&dclk_variants[S3C2440],

	}, {

		.name		= "s3c2443-dclk",

		.driver_data	= (kernel_ulong_t)&dclk_variants[S3C2443],

	},

	{ }

};



MODULE_DEVICE_TABLE(platform, s3c24xx_dclk_driver_ids);



static struct platform_driver s3c24xx_dclk_driver = {

	.driver = {

		.name		= "s3c24xx-dclk",

		.owner		= THIS_MODULE,

		.pm		= &s3c24xx_dclk_pm_ops,

	},

	.probe = s3c24xx_dclk_probe,

	.remove = s3c24xx_dclk_remove,

	.id_table = s3c24xx_dclk_driver_ids,

};

module_platform_driver(s3c24xx_dclk_driver);



MODULE_LICENSE("GPL v2");

MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");

MODULE_DESCRIPTION("Driver for the S3C24XX external clock outputs");