linux/arch/mips/ath79/clock.c

184 lines
4.1 KiB
C

/*
* Atheros AR71XX/AR724X/AR913X common routines
*
* Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org>
*
* 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.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <asm/mach-ath79/ath79.h>
#include <asm/mach-ath79/ar71xx_regs.h>
#include "common.h"
#define AR71XX_BASE_FREQ 40000000
#define AR724X_BASE_FREQ 5000000
#define AR913X_BASE_FREQ 5000000
struct clk {
unsigned long rate;
};
static struct clk ath79_ref_clk;
static struct clk ath79_cpu_clk;
static struct clk ath79_ddr_clk;
static struct clk ath79_ahb_clk;
static struct clk ath79_wdt_clk;
static struct clk ath79_uart_clk;
static void __init ar71xx_clocks_init(void)
{
u32 pll;
u32 freq;
u32 div;
ath79_ref_clk.rate = AR71XX_BASE_FREQ;
pll = ath79_pll_rr(AR71XX_PLL_REG_CPU_CONFIG);
div = ((pll >> AR71XX_PLL_DIV_SHIFT) & AR71XX_PLL_DIV_MASK) + 1;
freq = div * ath79_ref_clk.rate;
div = ((pll >> AR71XX_CPU_DIV_SHIFT) & AR71XX_CPU_DIV_MASK) + 1;
ath79_cpu_clk.rate = freq / div;
div = ((pll >> AR71XX_DDR_DIV_SHIFT) & AR71XX_DDR_DIV_MASK) + 1;
ath79_ddr_clk.rate = freq / div;
div = (((pll >> AR71XX_AHB_DIV_SHIFT) & AR71XX_AHB_DIV_MASK) + 1) * 2;
ath79_ahb_clk.rate = ath79_cpu_clk.rate / div;
ath79_wdt_clk.rate = ath79_ahb_clk.rate;
ath79_uart_clk.rate = ath79_ahb_clk.rate;
}
static void __init ar724x_clocks_init(void)
{
u32 pll;
u32 freq;
u32 div;
ath79_ref_clk.rate = AR724X_BASE_FREQ;
pll = ath79_pll_rr(AR724X_PLL_REG_CPU_CONFIG);
div = ((pll >> AR724X_PLL_DIV_SHIFT) & AR724X_PLL_DIV_MASK);
freq = div * ath79_ref_clk.rate;
div = ((pll >> AR724X_PLL_REF_DIV_SHIFT) & AR724X_PLL_REF_DIV_MASK);
freq *= div;
ath79_cpu_clk.rate = freq;
div = ((pll >> AR724X_DDR_DIV_SHIFT) & AR724X_DDR_DIV_MASK) + 1;
ath79_ddr_clk.rate = freq / div;
div = (((pll >> AR724X_AHB_DIV_SHIFT) & AR724X_AHB_DIV_MASK) + 1) * 2;
ath79_ahb_clk.rate = ath79_cpu_clk.rate / div;
ath79_wdt_clk.rate = ath79_ahb_clk.rate;
ath79_uart_clk.rate = ath79_ahb_clk.rate;
}
static void __init ar913x_clocks_init(void)
{
u32 pll;
u32 freq;
u32 div;
ath79_ref_clk.rate = AR913X_BASE_FREQ;
pll = ath79_pll_rr(AR913X_PLL_REG_CPU_CONFIG);
div = ((pll >> AR913X_PLL_DIV_SHIFT) & AR913X_PLL_DIV_MASK);
freq = div * ath79_ref_clk.rate;
ath79_cpu_clk.rate = freq;
div = ((pll >> AR913X_DDR_DIV_SHIFT) & AR913X_DDR_DIV_MASK) + 1;
ath79_ddr_clk.rate = freq / div;
div = (((pll >> AR913X_AHB_DIV_SHIFT) & AR913X_AHB_DIV_MASK) + 1) * 2;
ath79_ahb_clk.rate = ath79_cpu_clk.rate / div;
ath79_wdt_clk.rate = ath79_ahb_clk.rate;
ath79_uart_clk.rate = ath79_ahb_clk.rate;
}
void __init ath79_clocks_init(void)
{
if (soc_is_ar71xx())
ar71xx_clocks_init();
else if (soc_is_ar724x())
ar724x_clocks_init();
else if (soc_is_ar913x())
ar913x_clocks_init();
else
BUG();
pr_info("Clocks: CPU:%lu.%03luMHz, DDR:%lu.%03luMHz, AHB:%lu.%03luMHz, "
"Ref:%lu.%03luMHz",
ath79_cpu_clk.rate / 1000000,
(ath79_cpu_clk.rate / 1000) % 1000,
ath79_ddr_clk.rate / 1000000,
(ath79_ddr_clk.rate / 1000) % 1000,
ath79_ahb_clk.rate / 1000000,
(ath79_ahb_clk.rate / 1000) % 1000,
ath79_ref_clk.rate / 1000000,
(ath79_ref_clk.rate / 1000) % 1000);
}
/*
* Linux clock API
*/
struct clk *clk_get(struct device *dev, const char *id)
{
if (!strcmp(id, "ref"))
return &ath79_ref_clk;
if (!strcmp(id, "cpu"))
return &ath79_cpu_clk;
if (!strcmp(id, "ddr"))
return &ath79_ddr_clk;
if (!strcmp(id, "ahb"))
return &ath79_ahb_clk;
if (!strcmp(id, "wdt"))
return &ath79_wdt_clk;
if (!strcmp(id, "uart"))
return &ath79_uart_clk;
return ERR_PTR(-ENOENT);
}
EXPORT_SYMBOL(clk_get);
int clk_enable(struct clk *clk)
{
return 0;
}
EXPORT_SYMBOL(clk_enable);
void clk_disable(struct clk *clk)
{
}
EXPORT_SYMBOL(clk_disable);
unsigned long clk_get_rate(struct clk *clk)
{
return clk->rate;
}
EXPORT_SYMBOL(clk_get_rate);
void clk_put(struct clk *clk)
{
}
EXPORT_SYMBOL(clk_put);