/* 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>
#include <linux/serial_core.h>
#include <plat/regs-serial.h> /* for s3c24xx_uart_devs */
/* 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;
}
static int dev_is_s3c_uart(struct device *dev)
{
struct platform_device **pdev = s3c24xx_uart_devs;
int i;
for (i = 0; i < ARRAY_SIZE(s3c24xx_uart_devs); i++, pdev++)
if (*pdev && dev == &(*pdev)->dev)
return 1;
return 0;
}
/*
* Serial drivers call get_clock() very early, before platform bus
* has been set up, this requires a special check to let them get
* a proper clock
*/
static int dev_is_platform_device(struct device *dev)
{
return dev->bus == &platform_bus_type ||
(dev->bus == NULL && dev_is_s3c_uart(dev));
}
/* 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_is_platform_device(dev))
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);
}
}
}
/**
* s3c_disable_clocks() - disable an array of clocks
* @clkp: Pointer to the first clock in the array.
* @nr_clks: Number of clocks to register.
*
* for internal use only at initialisation time. disable the clocks in the
* @clkp array.
*/
void __init s3c_disable_clocks(struct clk *clkp, int nr_clks)
{
for (; nr_clks > 0; nr_clks--, clkp++)
(clkp->enable)(clkp, 0);
}
/* initialise 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;
}
