/* linux/arch/arm/mach-s3c2410/clock.c
*
* Copyright (c) 2004-2005 Simtec Electronics
* Ben Dooks <ben@simtec.co.uk>
*
* S3C2410 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 <asm/hardware.h>
#include <asm/atomic.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <asm/arch/regs-clock.h>
#include "clock.h"
#include "cpu.h"
/* clock information */
static LIST_HEAD(clocks);
static DEFINE_MUTEX(clocks_mutex);
/* old functions */
void inline s3c24xx_clk_enable(unsigned int clocks, unsigned int enable)
{
unsigned long clkcon;
unsigned long flags;
local_irq_save(flags);
clkcon = __raw_readl(S3C2410_CLKCON);
clkcon &= ~clocks;
if (enable)
clkcon |= clocks;
/* ensure none of the special function bits set */
clkcon &= ~(S3C2410_CLKCON_IDLE|S3C2410_CLKCON_POWER);
__raw_writel(clkcon, S3C2410_CLKCON);
local_irq_restore(flags);
}
/* enable and disable calls for use with the clk struct */
static int clk_null_enable(struct clk *clk, int enable)
{
return 0;
}
int s3c24xx_clkcon_enable(struct clk *clk, int enable)
{
s3c24xx_clk_enable(clk->ctrlbit, 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))
return -EINVAL;
return (clk->enable)(clk, 1);
}
void clk_disable(struct clk *clk)
{
if (!IS_ERR(clk))
(clk->enable)(clk, 0);
}
unsigned long clk_get_rate(struct clk *clk)
{
if (IS_ERR(clk))
return 0;
if (clk->rate != 0)
return clk->rate;
while (clk->parent != NULL && clk->rate == 0)
clk = clk->parent;
return clk->rate;
}
long clk_round_rate(struct clk *clk, unsigned long rate)
{
return rate;
}
int clk_set_rate(struct clk *clk, unsigned long rate)
{
return -EINVAL;
}
struct clk *clk_get_parent(struct clk *clk)
{
return clk->parent;
}
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);
/* base clocks */
static struct clk clk_xtal = {
.name = "xtal",
.id = -1,
.rate = 0,
.parent = NULL,
.ctrlbit = 0,
};
static struct clk clk_f = {
.name = "fclk",
.id = -1,
.rate = 0,
.parent = NULL,
.ctrlbit = 0,
};
static struct clk clk_h = {
.name = "hclk",
.id = -1,
.rate = 0,
.parent = NULL,
.ctrlbit = 0,
};
static struct clk clk_p = {
.name = "pclk",
.id = -1,
.rate = 0,
.parent = NULL,
.ctrlbit = 0,
};
/* clocks that could be registered by external code */
struct clk s3c24xx_dclk0 = {
.name = "dclk0",
.id = -1,
};
struct clk s3c24xx_dclk1 = {
.name = "dclk1",
.id = -1,
};
struct clk s3c24xx_clkout0 = {
.name = "clkout0",
.id = -1,
};
struct clk s3c24xx_clkout1 = {
.name = "clkout1",
.id = -1,
};
struct clk s3c24xx_uclk = {
.name = "uclk",
.id = -1,
};
/* clock definitions */
static struct clk init_clocks[] = {
{
.name = "nand",
.id = -1,
.parent = &clk_h,
.enable = s3c24xx_clkcon_enable,
.ctrlbit = S3C2410_CLKCON_NAND,
}, {
.name = "lcd",
.id = -1,
.parent = &clk_h,
.enable = s3c24xx_clkcon_enable,
.ctrlbit = S3C2410_CLKCON_LCDC,
}, {
.name = "usb-host",
.id = -1,
.parent = &clk_h,
.enable = s3c24xx_clkcon_enable,
.ctrlbit = S3C2410_CLKCON_USBH,
}, {
.name = "usb-device",
.id = -1,
.parent = &clk_h,
.enable = s3c24xx_clkcon_enable,
.ctrlbit = S3C2410_CLKCON_USBD,
}, {
.name = "timers",
.id = -1,
.parent = &clk_p,
.enable = s3c24xx_clkcon_enable,
.ctrlbit = S3C2410_CLKCON_PWMT,
}, {
.name = "sdi",
.id = -1,
.parent = &clk_p,
.enable = s3c24xx_clkcon_enable,
.ctrlbit = S3C2410_CLKCON_SDI,
}, {
.name = "uart",
.id = 0,
.parent = &clk_p,
.enable = s3c24xx_clkcon_enable,
.ctrlbit = S3C2410_CLKCON_UART0,
}, {
.name = "uart",
.id = 1,
.parent = &clk_p,
.enable = s3c24xx_clkcon_enable,
.ctrlbit = S3C2410_CLKCON_UART1,
}, {
.name = "uart",
.id = 2,
.parent = &clk_p,
.enable = s3c24xx_clkcon_enable,
.ctrlbit = S3C2410_CLKCON_UART2,
}, {
.name = "gpio",
.id = -1,
.parent = &clk_p,
.enable = s3c24xx_clkcon_enable,
.ctrlbit = S3C2410_CLKCON_GPIO,
}, {
.name = "rtc",
.id = -1,
.parent = &clk_p,
.enable = s3c24xx_clkcon_enable,
.ctrlbit = S3C2410_CLKCON_RTC,
}, {
.name = "adc",
.id = -1,
.parent = &clk_p,
.enable = s3c24xx_clkcon_enable,
.ctrlbit = S3C2410_CLKCON_ADC,
}, {
.name = "i2c",
.id = -1,
.parent = &clk_p,
.enable = s3c24xx_clkcon_enable,
.ctrlbit = S3C2410_CLKCON_IIC,
}, {
.name = "iis",
.id = -1,
.parent = &clk_p,
.enable = s3c24xx_clkcon_enable,
.ctrlbit = S3C2410_CLKCON_IIS,
}, {
.name = "spi",
.id = -1,
.parent = &clk_p,
.enable = s3c24xx_clkcon_enable,
.ctrlbit = S3C2410_CLKCON_SPI,
}, {
.name = "watchdog",
.id = -1,
.parent = &clk_p,
.ctrlbit = 0,
}
};
/* 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;
}
/* initalise all the clocks */
int __init s3c24xx_setup_clocks(unsigned long xtal,
unsigned long fclk,
unsigned long hclk,
unsigned long pclk)
{
unsigned long clkslow = __raw_readl(S3C2410_CLKSLOW);
struct clk *clkp = init_clocks;
int ptr;
int ret;
printk(KERN_INFO "S3C2410 Clocks, (c) 2004 Simtec Electronics\n");
/* initialise the main system clocks */
clk_xtal.rate = xtal;
clk_h.rate = hclk;
clk_p.rate = pclk;
clk_f.rate = fclk;
/* We must be careful disabling the clocks we are not intending to
* be using at boot time, as subsytems such as the LCD which do
* their own DMA requests to the bus can cause the system to lockup
* if they where in the middle of requesting bus access.
*
* Disabling the LCD clock if the LCD is active is very dangerous,
* and therefore the bootloader should be careful to not enable
* the LCD clock if it is not needed.
*/
s3c24xx_clk_enable(S3C2410_CLKCON_NAND, 0);
s3c24xx_clk_enable(S3C2410_CLKCON_USBH, 0);
s3c24xx_clk_enable(S3C2410_CLKCON_USBD, 0);
s3c24xx_clk_enable(S3C2410_CLKCON_ADC, 0);
s3c24xx_clk_enable(S3C2410_CLKCON_IIC, 0);
s3c24xx_clk_enable(S3C2410_CLKCON_SPI, 0);
/* 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_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");
/* register clocks from clock array */
for (ptr = 0; ptr < ARRAY_SIZE(init_clocks); ptr++, clkp++) {
ret = s3c24xx_register_clock(clkp);
if (ret < 0) {
printk(KERN_ERR "Failed to register clock %s (%d)\n",
clkp->name, ret);
}
}
/* show the clock-slow value */
printk("CLOCK: Slow mode (%ld.%ld MHz), %s, MPLL %s, UPLL %s\n",
print_mhz(xtal / ( 2 * S3C2410_CLKSLOW_GET_SLOWVAL(clkslow))),
(clkslow & S3C2410_CLKSLOW_SLOW) ? "slow" : "fast",
(clkslow & S3C2410_CLKSLOW_MPLL_OFF) ? "off" : "on",
(clkslow & S3C2410_CLKSLOW_UCLK_OFF) ? "off" : "on");
return 0;
}
