clock-dclk.c
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/*
* Copyright (c) 2004-2008 Simtec Electronics
* Ben Dooks <ben@simtec.co.uk>
* http://armlinux.simtec.co.uk/
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* S3C24XX - definitions for DCLK and CLKOUT registers
*/
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <mach/regs-clock.h>
#include <mach/regs-gpio.h>
#include <plat/clock.h>
#include <plat/cpu.h>
/* 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_mpll)
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_clkout0)
mask = S3C2410_MISCCR_CLK0_MASK;
else {
source <<= 4;
mask = S3C2410_MISCCR_CLK1_MASK;
}
s3c2410_modify_misccr(mask, source);
return 0;
}
/* external clock definitions */
static struct clk_ops dclk_ops = {
.set_parent = s3c24xx_dclk_setparent,
.set_rate = s3c24xx_set_dclk_rate,
.round_rate = s3c24xx_round_dclk_rate,
};
struct clk s3c24xx_dclk0 = {
.name = "dclk0",
.ctrlbit = S3C2410_DCLKCON_DCLK0EN,
.enable = s3c24xx_dclk_enable,
.ops = &dclk_ops,
};
struct clk s3c24xx_dclk1 = {
.name = "dclk1",
.ctrlbit = S3C2410_DCLKCON_DCLK1EN,
.enable = s3c24xx_dclk_enable,
.ops = &dclk_ops,
};
static struct clk_ops clkout_ops = {
.set_parent = s3c24xx_clkout_setparent,
};
struct clk s3c24xx_clkout0 = {
.name = "clkout0",
.ops = &clkout_ops,
};
struct clk s3c24xx_clkout1 = {
.name = "clkout1",
.ops = &clkout_ops,
};