/* linux/arch/arm/mach-s3c2442/clock.c
*
* Copyright (c) 2004-2005 Simtec Electronics
* http://armlinux.simtec.co.uk/
* Ben Dooks <ben@simtec.co.uk>
*
* S3C2442 Clock support
*
* 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/device.h>
#include <linux/sysdev.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/mutex.h>
#include <linux/clk.h>
#include <asm/hardware.h>
#include <asm/atomic.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <asm/arch/regs-clock.h>
#include <asm/plat-s3c24xx/clock.h>
#include <asm/plat-s3c24xx/cpu.h>
/* S3C2442 extended clock support */
static unsigned long s3c2442_camif_upll_round(struct clk *clk,
unsigned long rate)
{
unsigned long parent_rate = clk_get_rate(clk->parent);
int div;
if (rate > parent_rate)
return parent_rate;
div = parent_rate / rate;
if (div == 3)
return parent_rate / 3;
/* note, we remove the +/- 1 calculations for the divisor */
div /= 2;
if (div < 1)
div = 1;
else if (div > 16)
div = 16;
return parent_rate / (div * 2);
}
static int s3c2442_camif_upll_setrate(struct clk *clk, unsigned long rate)
{
unsigned long parent_rate = clk_get_rate(clk->parent);
unsigned long camdivn = __raw_readl(S3C2440_CAMDIVN);
rate = s3c2442_camif_upll_round(clk, rate);
camdivn &= ~S3C2442_CAMDIVN_CAMCLK_DIV3;
if (rate == parent_rate) {
camdivn &= ~S3C2440_CAMDIVN_CAMCLK_SEL;
} else if ((parent_rate / rate) == 3) {
camdivn |= S3C2440_CAMDIVN_CAMCLK_SEL;
camdivn |= S3C2442_CAMDIVN_CAMCLK_DIV3;
} else {
camdivn &= ~S3C2440_CAMDIVN_CAMCLK_MASK;
camdivn |= S3C2440_CAMDIVN_CAMCLK_SEL;
camdivn |= (((parent_rate / rate) / 2) - 1);
}
__raw_writel(camdivn, S3C2440_CAMDIVN);
return 0;
}
/* Extra S3C2442 clocks */
static struct clk s3c2442_clk_cam = {
.name = "camif",
.id = -1,
.enable = s3c2410_clkcon_enable,
.ctrlbit = S3C2440_CLKCON_CAMERA,
};
static struct clk s3c2442_clk_cam_upll = {
.name = "camif-upll",
.id = -1,
.set_rate = s3c2442_camif_upll_setrate,
.round_rate = s3c2442_camif_upll_round,
};
static int s3c2442_clk_add(struct sys_device *sysdev)
{
unsigned long camdivn = __raw_readl(S3C2440_CAMDIVN);
unsigned long clkdivn;
struct clk *clock_h;
struct clk *clock_p;
struct clk *clock_upll;
printk("S3C2442: Clock Support, DVS %s\n",
(camdivn & S3C2440_CAMDIVN_DVSEN) ? "on" : "off");
clock_p = clk_get(NULL, "pclk");
clock_h = clk_get(NULL, "hclk");
clock_upll = clk_get(NULL, "upll");
if (IS_ERR(clock_p) || IS_ERR(clock_h) || IS_ERR(clock_upll)) {
printk(KERN_ERR "S3C2442: Failed to get parent clocks\n");
return -EINVAL;
}
/* check rate of UPLL, and if it is near 96MHz, then change
* to using half the UPLL rate for the system */
if (clk_get_rate(clock_upll) > (94 * MHZ)) {
clk_usb_bus.rate = clk_get_rate(clock_upll) / 2;
mutex_lock(&clocks_mutex);
clkdivn = __raw_readl(S3C2410_CLKDIVN);
clkdivn |= S3C2440_CLKDIVN_UCLK;
__raw_writel(clkdivn, S3C2410_CLKDIVN);
mutex_unlock(&clocks_mutex);
}
s3c2442_clk_cam.parent = clock_h;
s3c2442_clk_cam_upll.parent = clock_upll;
s3c24xx_register_clock(&s3c2442_clk_cam);
s3c24xx_register_clock(&s3c2442_clk_cam_upll);
clk_disable(&s3c2442_clk_cam);
return 0;
}
static struct sysdev_driver s3c2442_clk_driver = {
.add = s3c2442_clk_add,
};
static __init int s3c2442_clk_init(void)
{
return sysdev_driver_register(&s3c2442_sysclass, &s3c2442_clk_driver);
}
arch_initcall(s3c2442_clk_init);
