linux/arch/arm/mach-s3c24xx/clock-s3c2440.c

210 lines
5.4 KiB
C

/* linux/arch/arm/mach-s3c2440/clock.c
*
* Copyright (c) 2004-2005 Simtec Electronics
* http://armlinux.simtec.co.uk/
* Ben Dooks <ben@simtec.co.uk>
*
* S3C2440 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/interrupt.h>
#include <linux/ioport.h>
#include <linux/mutex.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/serial_core.h>
#include <mach/hardware.h>
#include <linux/atomic.h>
#include <asm/irq.h>
#include <mach/regs-clock.h>
#include <plat/clock.h>
#include <plat/cpu.h>
#include <plat/regs-serial.h>
/* S3C2440 extended clock support */
static unsigned long s3c2440_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;
/* note, we remove the +/- 1 calculations for the divisor */
div = (parent_rate / rate) / 2;
if (div < 1)
div = 1;
else if (div > 16)
div = 16;
return parent_rate / (div * 2);
}
static int s3c2440_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 = s3c2440_camif_upll_round(clk, rate);
camdivn &= ~(S3C2440_CAMDIVN_CAMCLK_SEL | S3C2440_CAMDIVN_CAMCLK_MASK);
if (rate != parent_rate) {
camdivn |= S3C2440_CAMDIVN_CAMCLK_SEL;
camdivn |= (((parent_rate / rate) / 2) - 1);
}
__raw_writel(camdivn, S3C2440_CAMDIVN);
return 0;
}
static unsigned long s3c2440_camif_upll_getrate(struct clk *clk)
{
unsigned long parent_rate = clk_get_rate(clk->parent);
unsigned long camdivn = __raw_readl(S3C2440_CAMDIVN);
if (!(camdivn & S3C2440_CAMDIVN_CAMCLK_SEL))
return parent_rate;
camdivn &= S3C2440_CAMDIVN_CAMCLK_MASK;
return parent_rate / (camdivn + 1) / 2;
}
/* Extra S3C2440 clocks */
static struct clk s3c2440_clk_cam = {
.name = "camif",
.enable = s3c2410_clkcon_enable,
.ctrlbit = S3C2440_CLKCON_CAMERA,
};
static struct clk s3c2440_clk_cam_upll = {
.name = "camif-upll",
.ops = &(struct clk_ops) {
.set_rate = s3c2440_camif_upll_setrate,
.get_rate = s3c2440_camif_upll_getrate,
.round_rate = s3c2440_camif_upll_round,
},
};
static struct clk s3c2440_clk_ac97 = {
.name = "ac97",
.enable = s3c2410_clkcon_enable,
.ctrlbit = S3C2440_CLKCON_AC97,
};
static unsigned long s3c2440_fclk_n_getrate(struct clk *clk)
{
unsigned long ucon0, ucon1, ucon2, divisor;
/* the fun of calculating the uart divisors on the s3c2440 */
ucon0 = __raw_readl(S3C24XX_VA_UART0 + S3C2410_UCON);
ucon1 = __raw_readl(S3C24XX_VA_UART1 + S3C2410_UCON);
ucon2 = __raw_readl(S3C24XX_VA_UART2 + S3C2410_UCON);
ucon0 &= S3C2440_UCON0_DIVMASK;
ucon1 &= S3C2440_UCON1_DIVMASK;
ucon2 &= S3C2440_UCON2_DIVMASK;
if (ucon0 != 0)
divisor = (ucon0 >> S3C2440_UCON_DIVSHIFT) + 6;
else if (ucon1 != 0)
divisor = (ucon1 >> S3C2440_UCON_DIVSHIFT) + 21;
else if (ucon2 != 0)
divisor = (ucon2 >> S3C2440_UCON_DIVSHIFT) + 36;
else
/* manual calims 44, seems to be 9 */
divisor = 9;
return clk_get_rate(clk->parent) / divisor;
}
static struct clk s3c2440_clk_fclk_n = {
.name = "fclk_n",
.parent = &clk_f,
.ops = &(struct clk_ops) {
.get_rate = s3c2440_fclk_n_getrate,
},
};
static struct clk_lookup s3c2440_clk_lookup[] = {
CLKDEV_INIT(NULL, "clk_uart_baud1", &s3c24xx_uclk),
CLKDEV_INIT(NULL, "clk_uart_baud2", &clk_p),
CLKDEV_INIT(NULL, "clk_uart_baud3", &s3c2440_clk_fclk_n),
CLKDEV_INIT("s3c2440-camif", "camera", &s3c2440_clk_cam_upll),
};
static int __init_refok s3c2440_clk_add(struct device *dev, struct subsys_interface *sif)
{
struct clk *clock_upll;
struct clk *clock_h;
struct clk *clock_p;
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 "S3C2440: Failed to get parent clocks\n");
return -EINVAL;
}
s3c2440_clk_cam.parent = clock_h;
s3c2440_clk_ac97.parent = clock_p;
s3c2440_clk_cam_upll.parent = clock_upll;
s3c24xx_register_clock(&s3c2440_clk_fclk_n);
s3c24xx_register_clock(&s3c2440_clk_ac97);
s3c24xx_register_clock(&s3c2440_clk_cam);
s3c24xx_register_clock(&s3c2440_clk_cam_upll);
clkdev_add_table(s3c2440_clk_lookup, ARRAY_SIZE(s3c2440_clk_lookup));
clk_disable(&s3c2440_clk_ac97);
clk_disable(&s3c2440_clk_cam);
return 0;
}
static struct subsys_interface s3c2440_clk_interface = {
.name = "s3c2440_clk",
.subsys = &s3c2440_subsys,
.add_dev = s3c2440_clk_add,
};
static __init int s3c24xx_clk_init(void)
{
return subsys_interface_register(&s3c2440_clk_interface);
}
arch_initcall(s3c24xx_clk_init);