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/*
* arch/arm/mach-ep93xx/clock.c
* Clock control for Cirrus EP93xx chips.
*
* Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
*
* 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.
*/
#include <linux/kernel.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/string.h>
#include <asm/div64.h>
#include <asm/hardware.h>
#include <asm/io.h>
struct clk {
char *name;
unsigned long rate;
int users;
u32 enable_reg;
u32 enable_mask;
};
static struct clk clk_pll1 = {
.name = "pll1",
};
static struct clk clk_f = {
.name = "fclk",
};
static struct clk clk_h = {
.name = "hclk",
};
static struct clk clk_p = {
.name = "pclk",
};
static struct clk clk_pll2 = {
.name = "pll2",
};
static struct clk clk_usb_host = {
.name = "usb_host",
.enable_reg = EP93XX_SYSCON_CLOCK_CONTROL,
.enable_mask = EP93XX_SYSCON_CLOCK_USH_EN,
};
static struct clk *clocks[] = {
&clk_pll1,
&clk_f,
&clk_h,
&clk_p,
&clk_pll2,
&clk_usb_host,
};
struct clk *clk_get(struct device *dev, const char *id)
{
int i;
for (i = 0; i < ARRAY_SIZE(clocks); i++) {
if (!strcmp(clocks[i]->name, id))
return clocks[i];
}
return ERR_PTR(-ENOENT);
}
int clk_enable(struct clk *clk)
{
if (!clk->users++ && clk->enable_reg) {
u32 value;
value = __raw_readl(clk->enable_reg);
__raw_writel(value | clk->enable_mask, clk->enable_reg);
}
return 0;
}
void clk_disable(struct clk *clk)
{
if (!--clk->users && clk->enable_reg) {
u32 value;
value = __raw_readl(clk->enable_reg);
__raw_writel(value & ~clk->enable_mask, clk->enable_reg);
}
}
unsigned long clk_get_rate(struct clk *clk)
{
return clk->rate;
}
void clk_put(struct clk *clk)
{
}
static char fclk_divisors[] = { 1, 2, 4, 8, 16, 1, 1, 1 };
static char hclk_divisors[] = { 1, 2, 4, 5, 6, 8, 16, 32 };
static char pclk_divisors[] = { 1, 2, 4, 8 };
/*
* PLL rate = 14.7456 MHz * (X1FBD + 1) * (X2FBD + 1) / (X2IPD + 1) / 2^PS
*/
static unsigned long calc_pll_rate(u32 config_word)
{
unsigned long long rate;
int i;
rate = 14745600;
rate *= ((config_word >> 11) & 0x1f) + 1; /* X1FBD */
rate *= ((config_word >> 5) & 0x3f) + 1; /* X2FBD */
do_div(rate, (config_word & 0x1f) + 1); /* X2IPD */
for (i = 0; i < ((config_word >> 16) & 3); i++) /* PS */
rate >>= 1;
return (unsigned long)rate;
}
void ep93xx_clock_init(void)
{
u32 value;
value = __raw_readl(EP93XX_SYSCON_CLOCK_SET1);
if (!(value & 0x00800000)) { /* PLL1 bypassed? */
clk_pll1.rate = 14745600;
} else {
clk_pll1.rate = calc_pll_rate(value);
}
clk_f.rate = clk_pll1.rate / fclk_divisors[(value >> 25) & 0x7];
clk_h.rate = clk_pll1.rate / hclk_divisors[(value >> 20) & 0x7];
clk_p.rate = clk_h.rate / pclk_divisors[(value >> 18) & 0x3];
value = __raw_readl(EP93XX_SYSCON_CLOCK_SET2);
if (!(value & 0x00080000)) { /* PLL2 bypassed? */
clk_pll2.rate = 14745600;
} else if (value & 0x00040000) { /* PLL2 enabled? */
clk_pll2.rate = calc_pll_rate(value);
} else {
clk_pll2.rate = 0;
}
clk_usb_host.rate = clk_pll2.rate / (((value >> 28) & 0xf) + 1);
printk(KERN_INFO "ep93xx: PLL1 running at %ld MHz, PLL2 at %ld MHz\n",
clk_pll1.rate / 1000000, clk_pll2.rate / 1000000);
printk(KERN_INFO "ep93xx: FCLK %ld MHz, HCLK %ld MHz, PCLK %ld MHz\n",
clk_f.rate / 1000000, clk_h.rate / 1000000,
clk_p.rate / 1000000);
}
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