diff options
Diffstat (limited to 'arch/arm/plat-samsung/clock.c')
| -rw-r--r-- | arch/arm/plat-samsung/clock.c | 409 | 
1 files changed, 409 insertions, 0 deletions
diff --git a/arch/arm/plat-samsung/clock.c b/arch/arm/plat-samsung/clock.c new file mode 100644 index 00000000000..1b25c9d8c40 --- /dev/null +++ b/arch/arm/plat-samsung/clock.c @@ -0,0 +1,409 @@ +/* linux/arch/arm/plat-s3c24xx/clock.c + * + * Copyright 2004-2005 Simtec Electronics + *	Ben Dooks <ben@simtec.co.uk> + * + * S3C24XX Core clock control support + * + * Based on, and code from linux/arch/arm/mach-versatile/clock.c + ** + **  Copyright (C) 2004 ARM Limited. + **  Written by Deep Blue Solutions Limited. + * + * + * 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. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA +*/ + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/list.h> +#include <linux/errno.h> +#include <linux/err.h> +#include <linux/platform_device.h> +#include <linux/sysdev.h> +#include <linux/interrupt.h> +#include <linux/ioport.h> +#include <linux/clk.h> +#include <linux/spinlock.h> +#include <linux/io.h> + +#include <mach/hardware.h> +#include <asm/irq.h> + +#include <plat/cpu-freq.h> + +#include <plat/clock.h> +#include <plat/cpu.h> + +/* clock information */ + +static LIST_HEAD(clocks); + +/* We originally used an mutex here, but some contexts (see resume) + * are calling functions such as clk_set_parent() with IRQs disabled + * causing an BUG to be triggered. + */ +DEFINE_SPINLOCK(clocks_lock); + +/* enable and disable calls for use with the clk struct */ + +static int clk_null_enable(struct clk *clk, int enable) +{ +	return 0; +} + +/* Clock API calls */ + +struct clk *clk_get(struct device *dev, const char *id) +{ +	struct clk *p; +	struct clk *clk = ERR_PTR(-ENOENT); +	int idno; + +	if (dev == NULL || dev->bus != &platform_bus_type) +		idno = -1; +	else +		idno = to_platform_device(dev)->id; + +	spin_lock(&clocks_lock); + +	list_for_each_entry(p, &clocks, list) { +		if (p->id == idno && +		    strcmp(id, p->name) == 0 && +		    try_module_get(p->owner)) { +			clk = p; +			break; +		} +	} + +	/* check for the case where a device was supplied, but the +	 * clock that was being searched for is not device specific */ + +	if (IS_ERR(clk)) { +		list_for_each_entry(p, &clocks, list) { +			if (p->id == -1 && strcmp(id, p->name) == 0 && +			    try_module_get(p->owner)) { +				clk = p; +				break; +			} +		} +	} + +	spin_unlock(&clocks_lock); +	return clk; +} + +void clk_put(struct clk *clk) +{ +	module_put(clk->owner); +} + +int clk_enable(struct clk *clk) +{ +	if (IS_ERR(clk) || clk == NULL) +		return -EINVAL; + +	clk_enable(clk->parent); + +	spin_lock(&clocks_lock); + +	if ((clk->usage++) == 0) +		(clk->enable)(clk, 1); + +	spin_unlock(&clocks_lock); +	return 0; +} + +void clk_disable(struct clk *clk) +{ +	if (IS_ERR(clk) || clk == NULL) +		return; + +	spin_lock(&clocks_lock); + +	if ((--clk->usage) == 0) +		(clk->enable)(clk, 0); + +	spin_unlock(&clocks_lock); +	clk_disable(clk->parent); +} + + +unsigned long clk_get_rate(struct clk *clk) +{ +	if (IS_ERR(clk)) +		return 0; + +	if (clk->rate != 0) +		return clk->rate; + +	if (clk->ops != NULL && clk->ops->get_rate != NULL) +		return (clk->ops->get_rate)(clk); + +	if (clk->parent != NULL) +		return clk_get_rate(clk->parent); + +	return clk->rate; +} + +long clk_round_rate(struct clk *clk, unsigned long rate) +{ +	if (!IS_ERR(clk) && clk->ops && clk->ops->round_rate) +		return (clk->ops->round_rate)(clk, rate); + +	return rate; +} + +int clk_set_rate(struct clk *clk, unsigned long rate) +{ +	int ret; + +	if (IS_ERR(clk)) +		return -EINVAL; + +	/* We do not default just do a clk->rate = rate as +	 * the clock may have been made this way by choice. +	 */ + +	WARN_ON(clk->ops == NULL); +	WARN_ON(clk->ops && clk->ops->set_rate == NULL); + +	if (clk->ops == NULL || clk->ops->set_rate == NULL) +		return -EINVAL; + +	spin_lock(&clocks_lock); +	ret = (clk->ops->set_rate)(clk, rate); +	spin_unlock(&clocks_lock); + +	return ret; +} + +struct clk *clk_get_parent(struct clk *clk) +{ +	return clk->parent; +} + +int clk_set_parent(struct clk *clk, struct clk *parent) +{ +	int ret = 0; + +	if (IS_ERR(clk)) +		return -EINVAL; + +	spin_lock(&clocks_lock); + +	if (clk->ops && clk->ops->set_parent) +		ret = (clk->ops->set_parent)(clk, parent); + +	spin_unlock(&clocks_lock); + +	return ret; +} + +EXPORT_SYMBOL(clk_get); +EXPORT_SYMBOL(clk_put); +EXPORT_SYMBOL(clk_enable); +EXPORT_SYMBOL(clk_disable); +EXPORT_SYMBOL(clk_get_rate); +EXPORT_SYMBOL(clk_round_rate); +EXPORT_SYMBOL(clk_set_rate); +EXPORT_SYMBOL(clk_get_parent); +EXPORT_SYMBOL(clk_set_parent); + +/* base clocks */ + +int clk_default_setrate(struct clk *clk, unsigned long rate) +{ +	clk->rate = rate; +	return 0; +} + +struct clk_ops clk_ops_def_setrate = { +	.set_rate	= clk_default_setrate, +}; + +struct clk clk_xtal = { +	.name		= "xtal", +	.id		= -1, +	.rate		= 0, +	.parent		= NULL, +	.ctrlbit	= 0, +}; + +struct clk clk_ext = { +	.name		= "ext", +	.id		= -1, +}; + +struct clk clk_epll = { +	.name		= "epll", +	.id		= -1, +}; + +struct clk clk_mpll = { +	.name		= "mpll", +	.id		= -1, +	.ops		= &clk_ops_def_setrate, +}; + +struct clk clk_upll = { +	.name		= "upll", +	.id		= -1, +	.parent		= NULL, +	.ctrlbit	= 0, +}; + +struct clk clk_f = { +	.name		= "fclk", +	.id		= -1, +	.rate		= 0, +	.parent		= &clk_mpll, +	.ctrlbit	= 0, +}; + +struct clk clk_h = { +	.name		= "hclk", +	.id		= -1, +	.rate		= 0, +	.parent		= NULL, +	.ctrlbit	= 0, +	.ops		= &clk_ops_def_setrate, +}; + +struct clk clk_p = { +	.name		= "pclk", +	.id		= -1, +	.rate		= 0, +	.parent		= NULL, +	.ctrlbit	= 0, +	.ops		= &clk_ops_def_setrate, +}; + +struct clk clk_usb_bus = { +	.name		= "usb-bus", +	.id		= -1, +	.rate		= 0, +	.parent		= &clk_upll, +}; + + +struct clk s3c24xx_uclk = { +	.name		= "uclk", +	.id		= -1, +}; + +/* initialise the clock system */ + +/** + * s3c24xx_register_clock() - register a clock + * @clk: The clock to register + * + * Add the specified clock to the list of clocks known by the system. + */ +int s3c24xx_register_clock(struct clk *clk) +{ +	if (clk->enable == NULL) +		clk->enable = clk_null_enable; + +	/* add to the list of available clocks */ + +	/* Quick check to see if this clock has already been registered. */ +	BUG_ON(clk->list.prev != clk->list.next); + +	spin_lock(&clocks_lock); +	list_add(&clk->list, &clocks); +	spin_unlock(&clocks_lock); + +	return 0; +} + +/** + * s3c24xx_register_clocks() - register an array of clock pointers + * @clks: Pointer to an array of struct clk pointers + * @nr_clks: The number of clocks in the @clks array. + * + * Call s3c24xx_register_clock() for all the clock pointers contained + * in the @clks list. Returns the number of failures. + */ +int s3c24xx_register_clocks(struct clk **clks, int nr_clks) +{ +	int fails = 0; + +	for (; nr_clks > 0; nr_clks--, clks++) { +		if (s3c24xx_register_clock(*clks) < 0) { +			struct clk *clk = *clks; +			printk(KERN_ERR "%s: failed to register %p: %s\n", +			       __func__, clk, clk->name); +			fails++; +		} +	} + +	return fails; +} + +/** + * s3c_register_clocks() - register an array of clocks + * @clkp: Pointer to the first clock in the array. + * @nr_clks: Number of clocks to register. + * + * Call s3c24xx_register_clock() on the @clkp array given, printing an + * error if it fails to register the clock (unlikely). + */ +void __init s3c_register_clocks(struct clk *clkp, int nr_clks) +{ +	int ret; + +	for (; nr_clks > 0; nr_clks--, clkp++) { +		ret = s3c24xx_register_clock(clkp); + +		if (ret < 0) { +			printk(KERN_ERR "Failed to register clock %s (%d)\n", +			       clkp->name, ret); +		} +	} +} + +/* initalise all the clocks */ + +int __init s3c24xx_register_baseclocks(unsigned long xtal) +{ +	printk(KERN_INFO "S3C24XX Clocks, Copyright 2004 Simtec Electronics\n"); + +	clk_xtal.rate = xtal; + +	/* register our clocks */ + +	if (s3c24xx_register_clock(&clk_xtal) < 0) +		printk(KERN_ERR "failed to register master xtal\n"); + +	if (s3c24xx_register_clock(&clk_mpll) < 0) +		printk(KERN_ERR "failed to register mpll clock\n"); + +	if (s3c24xx_register_clock(&clk_upll) < 0) +		printk(KERN_ERR "failed to register upll clock\n"); + +	if (s3c24xx_register_clock(&clk_f) < 0) +		printk(KERN_ERR "failed to register cpu fclk\n"); + +	if (s3c24xx_register_clock(&clk_h) < 0) +		printk(KERN_ERR "failed to register cpu hclk\n"); + +	if (s3c24xx_register_clock(&clk_p) < 0) +		printk(KERN_ERR "failed to register cpu pclk\n"); + +	return 0; +} +  |