linux/arch/arm/plat-s3c24xx/clock.c

537 lines
11 KiB
C

/* linux/arch/arm/plat-s3c24xx/clock.c
*
* Copyright (c) 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/mutex.h>
#include <linux/delay.h>
#include <asm/hardware.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <asm/arch/regs-clock.h>
#include <asm/arch/regs-gpio.h>
#include <asm/plat-s3c24xx/clock.h>
#include <asm/plat-s3c24xx/cpu.h>
/* clock information */
static LIST_HEAD(clocks);
DEFINE_MUTEX(clocks_mutex);
/* 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;
mutex_lock(&clocks_mutex);
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;
}
}
}
mutex_unlock(&clocks_mutex);
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);
mutex_lock(&clocks_mutex);
if ((clk->usage++) == 0)
(clk->enable)(clk, 1);
mutex_unlock(&clocks_mutex);
return 0;
}
void clk_disable(struct clk *clk)
{
if (IS_ERR(clk) || clk == NULL)
return;
mutex_lock(&clocks_mutex);
if ((--clk->usage) == 0)
(clk->enable)(clk, 0);
mutex_unlock(&clocks_mutex);
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->get_rate != NULL)
return (clk->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->round_rate)
return (clk->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->set_rate == NULL);
if (clk->set_rate == NULL)
return -EINVAL;
mutex_lock(&clocks_mutex);
ret = (clk->set_rate)(clk, rate);
mutex_unlock(&clocks_mutex);
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;
mutex_lock(&clocks_mutex);
if (clk->set_parent)
ret = (clk->set_parent)(clk, parent);
mutex_unlock(&clocks_mutex);
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 */
static int clk_default_setrate(struct clk *clk, unsigned long rate)
{
clk->rate = rate;
return 0;
}
struct clk clk_xtal = {
.name = "xtal",
.id = -1,
.rate = 0,
.parent = NULL,
.ctrlbit = 0,
};
struct clk clk_mpll = {
.name = "mpll",
.id = -1,
.set_rate = clk_default_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,
.set_rate = clk_default_setrate,
};
struct clk clk_h = {
.name = "hclk",
.id = -1,
.rate = 0,
.parent = NULL,
.ctrlbit = 0,
.set_rate = clk_default_setrate,
};
struct clk clk_p = {
.name = "pclk",
.id = -1,
.rate = 0,
.parent = NULL,
.ctrlbit = 0,
.set_rate = clk_default_setrate,
};
struct clk clk_usb_bus = {
.name = "usb-bus",
.id = -1,
.rate = 0,
.parent = &clk_upll,
};
/* clocks that could be registered by external code */
static int s3c24xx_dclk_enable(struct clk *clk, int enable)
{
unsigned long dclkcon = __raw_readl(S3C24XX_DCLKCON);
if (enable)
dclkcon |= clk->ctrlbit;
else
dclkcon &= ~clk->ctrlbit;
__raw_writel(dclkcon, S3C24XX_DCLKCON);
return 0;
}
static int s3c24xx_dclk_setparent(struct clk *clk, struct clk *parent)
{
unsigned long dclkcon;
unsigned int uclk;
if (parent == &clk_upll)
uclk = 1;
else if (parent == &clk_p)
uclk = 0;
else
return -EINVAL;
clk->parent = parent;
dclkcon = __raw_readl(S3C24XX_DCLKCON);
if (clk->ctrlbit == S3C2410_DCLKCON_DCLK0EN) {
if (uclk)
dclkcon |= S3C2410_DCLKCON_DCLK0_UCLK;
else
dclkcon &= ~S3C2410_DCLKCON_DCLK0_UCLK;
} else {
if (uclk)
dclkcon |= S3C2410_DCLKCON_DCLK1_UCLK;
else
dclkcon &= ~S3C2410_DCLKCON_DCLK1_UCLK;
}
__raw_writel(dclkcon, S3C24XX_DCLKCON);
return 0;
}
static unsigned long s3c24xx_calc_div(struct clk *clk, unsigned long rate)
{
unsigned long div;
if ((rate == 0) || !clk->parent)
return 0;
div = clk_get_rate(clk->parent) / rate;
if (div < 2)
div = 2;
else if (div > 16)
div = 16;
return div;
}
static unsigned long s3c24xx_round_dclk_rate(struct clk *clk,
unsigned long rate)
{
unsigned long div = s3c24xx_calc_div(clk, rate);
if (div == 0)
return 0;
return clk_get_rate(clk->parent) / div;
}
static int s3c24xx_set_dclk_rate(struct clk *clk, unsigned long rate)
{
unsigned long mask, data, div = s3c24xx_calc_div(clk, rate);
if (div == 0)
return -EINVAL;
if (clk == &s3c24xx_dclk0) {
mask = S3C2410_DCLKCON_DCLK0_DIV_MASK |
S3C2410_DCLKCON_DCLK0_CMP_MASK;
data = S3C2410_DCLKCON_DCLK0_DIV(div) |
S3C2410_DCLKCON_DCLK0_CMP((div + 1) / 2);
} else if (clk == &s3c24xx_dclk1) {
mask = S3C2410_DCLKCON_DCLK1_DIV_MASK |
S3C2410_DCLKCON_DCLK1_CMP_MASK;
data = S3C2410_DCLKCON_DCLK1_DIV(div) |
S3C2410_DCLKCON_DCLK1_CMP((div + 1) / 2);
} else
return -EINVAL;
clk->rate = clk_get_rate(clk->parent) / div;
__raw_writel(((__raw_readl(S3C24XX_DCLKCON) & ~mask) | data),
S3C24XX_DCLKCON);
return clk->rate;
}
static int s3c24xx_clkout_setparent(struct clk *clk, struct clk *parent)
{
unsigned long mask;
unsigned long source;
/* calculate the MISCCR setting for the clock */
if (parent == &clk_xtal)
source = S3C2410_MISCCR_CLK0_MPLL;
else if (parent == &clk_upll)
source = S3C2410_MISCCR_CLK0_UPLL;
else if (parent == &clk_f)
source = S3C2410_MISCCR_CLK0_FCLK;
else if (parent == &clk_h)
source = S3C2410_MISCCR_CLK0_HCLK;
else if (parent == &clk_p)
source = S3C2410_MISCCR_CLK0_PCLK;
else if (clk == &s3c24xx_clkout0 && parent == &s3c24xx_dclk0)
source = S3C2410_MISCCR_CLK0_DCLK0;
else if (clk == &s3c24xx_clkout1 && parent == &s3c24xx_dclk1)
source = S3C2410_MISCCR_CLK0_DCLK0;
else
return -EINVAL;
clk->parent = parent;
if (clk == &s3c24xx_dclk0)
mask = S3C2410_MISCCR_CLK0_MASK;
else {
source <<= 4;
mask = S3C2410_MISCCR_CLK1_MASK;
}
s3c2410_modify_misccr(mask, source);
return 0;
}
/* external clock definitions */
struct clk s3c24xx_dclk0 = {
.name = "dclk0",
.id = -1,
.ctrlbit = S3C2410_DCLKCON_DCLK0EN,
.enable = s3c24xx_dclk_enable,
.set_parent = s3c24xx_dclk_setparent,
.set_rate = s3c24xx_set_dclk_rate,
.round_rate = s3c24xx_round_dclk_rate,
};
struct clk s3c24xx_dclk1 = {
.name = "dclk1",
.id = -1,
.ctrlbit = S3C2410_DCLKCON_DCLK0EN,
.enable = s3c24xx_dclk_enable,
.set_parent = s3c24xx_dclk_setparent,
.set_rate = s3c24xx_set_dclk_rate,
.round_rate = s3c24xx_round_dclk_rate,
};
struct clk s3c24xx_clkout0 = {
.name = "clkout0",
.id = -1,
.set_parent = s3c24xx_clkout_setparent,
};
struct clk s3c24xx_clkout1 = {
.name = "clkout1",
.id = -1,
.set_parent = s3c24xx_clkout_setparent,
};
struct clk s3c24xx_uclk = {
.name = "uclk",
.id = -1,
};
/* initialise the clock system */
int s3c24xx_register_clock(struct clk *clk)
{
clk->owner = THIS_MODULE;
if (clk->enable == NULL)
clk->enable = clk_null_enable;
/* add to the list of available clocks */
mutex_lock(&clocks_mutex);
list_add(&clk->list, &clocks);
mutex_unlock(&clocks_mutex);
return 0;
}
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)
fails++;
}
return fails;
}
/* initalise all the clocks */
int __init s3c24xx_setup_clocks(unsigned long xtal,
unsigned long fclk,
unsigned long hclk,
unsigned long pclk)
{
printk(KERN_INFO "S3C24XX Clocks, (c) 2004 Simtec Electronics\n");
/* initialise the main system clocks */
clk_xtal.rate = xtal;
clk_upll.rate = s3c2410_get_pll(__raw_readl(S3C2410_UPLLCON), xtal);
clk_mpll.rate = fclk;
clk_h.rate = hclk;
clk_p.rate = pclk;
clk_f.rate = fclk;
/* assume uart clocks are correctly setup */
/* 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;
}