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Commit 5fba62ea authored by Boris BREZILLON's avatar Boris BREZILLON Committed by Nicolas Ferre
Browse files

clk: at91: add PMC system clocks 



This patch adds new at91 system clock implementation using common clk
framework.

Some peripherals need to enable a "system" clock in order to work properly.
Each system clock is given an id based on the bit position in SCER/SCDR
registers.

Signed-off-by: default avatarBoris BREZILLON <b.brezillon@overkiz.com>
Acked-by: default avatarMike Turquette <mturquette@linaro.org>
Signed-off-by: default avatarNicolas Ferre <nicolas.ferre@atmel.com>
parent e442d234

drivers/clk/at91/Makefile

+1 −0
Original line number Original line Diff line number Diff line
@@ -4,3 +4,4 @@ 




obj-y += pmc.o

obj-y += pmc.o

obj-y += clk-main.o clk-pll.o clk-plldiv.o clk-master.o

obj-y += clk-main.o clk-pll.o clk-plldiv.o clk-master.o

obj-y += clk-system.o

drivers/clk/at91/clk-system.c

0 → 100644
+135 −0
Original line number Original line Diff line number Diff line 
/*

 *  Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>

 *

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

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 */



#include <linux/clk-provider.h>

#include <linux/clkdev.h>

#include <linux/clk/at91_pmc.h>

#include <linux/of.h>

#include <linux/of_address.h>

#include <linux/io.h>



#include "pmc.h"



#define SYSTEM_MAX_ID		31



#define SYSTEM_MAX_NAME_SZ	32



#define to_clk_system(hw) container_of(hw, struct clk_system, hw)

struct clk_system {

	struct clk_hw hw;

	struct at91_pmc *pmc;

	u8 id;

};



static int clk_system_enable(struct clk_hw *hw)

{

	struct clk_system *sys = to_clk_system(hw);

	struct at91_pmc *pmc = sys->pmc;



	pmc_write(pmc, AT91_PMC_SCER, 1 << sys->id);

	return 0;

}



static void clk_system_disable(struct clk_hw *hw)

{

	struct clk_system *sys = to_clk_system(hw);

	struct at91_pmc *pmc = sys->pmc;



	pmc_write(pmc, AT91_PMC_SCDR, 1 << sys->id);

}



static int clk_system_is_enabled(struct clk_hw *hw)

{

	struct clk_system *sys = to_clk_system(hw);

	struct at91_pmc *pmc = sys->pmc;



	return !!(pmc_read(pmc, AT91_PMC_SCSR) & (1 << sys->id));

}



static const struct clk_ops system_ops = {

	.enable = clk_system_enable,

	.disable = clk_system_disable,

	.is_enabled = clk_system_is_enabled,

};



static struct clk * __init

at91_clk_register_system(struct at91_pmc *pmc, const char *name,

			 const char *parent_name, u8 id)

{

	struct clk_system *sys;

	struct clk *clk = NULL;

	struct clk_init_data init;



	if (!parent_name || id > SYSTEM_MAX_ID)

		return ERR_PTR(-EINVAL);



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

	if (!sys)

		return ERR_PTR(-ENOMEM);



	init.name = name;

	init.ops = &system_ops;

	init.parent_names = &parent_name;

	init.num_parents = 1;

	/*

	 * CLK_IGNORE_UNUSED is used to avoid ddrck switch off.

	 * TODO : we should implement a driver supporting at91 ddr controller

	 * (see drivers/memory) which would request and enable the ddrck clock.

	 * When this is done we will be able to remove CLK_IGNORE_UNUSED flag.

	 */

	init.flags = CLK_IGNORE_UNUSED;



	sys->id = id;

	sys->hw.init = &init;

	sys->pmc = pmc;



	clk = clk_register(NULL, &sys->hw);

	if (IS_ERR(clk))

		kfree(sys);



	return clk;

}



static void __init

of_at91_clk_sys_setup(struct device_node *np, struct at91_pmc *pmc)

{

	int num;

	u32 id;

	struct clk *clk;

	const char *name;

	struct device_node *sysclknp;

	const char *parent_name;



	num = of_get_child_count(np);

	if (num > (SYSTEM_MAX_ID + 1))

		return;



	for_each_child_of_node(np, sysclknp) {

		if (of_property_read_u32(sysclknp, "reg", &id))

			continue;



		if (of_property_read_string(np, "clock-output-names", &name))

			name = sysclknp->name;



		parent_name = of_clk_get_parent_name(sysclknp, 0);



		clk = at91_clk_register_system(pmc, name, parent_name, id);

		if (IS_ERR(clk))

			continue;



		of_clk_add_provider(sysclknp, of_clk_src_simple_get, clk);

	}

}



void __init of_at91rm9200_clk_sys_setup(struct device_node *np,

					struct at91_pmc *pmc)

{

	of_at91_clk_sys_setup(np, pmc);

}

drivers/clk/at91/pmc.c

+5 −0
Original line number Original line Diff line number Diff line
@@ -264,6 +264,11 @@ static const struct of_device_id pmc_clk_ids[] __initdata = { 
		.compatible = "atmel,at91sam9x5-clk-master",

		.compatible = "atmel,at91sam9x5-clk-master",

		.data = of_at91sam9x5_clk_master_setup,

		.data = of_at91sam9x5_clk_master_setup,

	},

	},

	/* System clocks */

	{

		.compatible = "atmel,at91rm9200-clk-system",

		.data = of_at91rm9200_clk_sys_setup,

	},

	{ /*sentinel*/ }

	{ /*sentinel*/ }

};

};

drivers/clk/at91/pmc.h

+3 −0
Original line number Original line Diff line number Diff line
@@ -77,4 +77,7 @@ extern void __init of_at91rm9200_clk_master_setup(struct device_node *np, 
extern void __init of_at91sam9x5_clk_master_setup(struct device_node *np,

extern void __init of_at91sam9x5_clk_master_setup(struct device_node *np,

						  struct at91_pmc *pmc);

						  struct at91_pmc *pmc);





extern void __init of_at91rm9200_clk_sys_setup(struct device_node *np,

					       struct at91_pmc *pmc);



#endif /* __PMC_H_ */
 
#endif /* __PMC_H_ */