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barebox/arch/arm/mach-clps711x/clock.c

111 lines
2.4 KiB
C

/*
* Copyright (C) 2012 Alexander Shiyan <shc_work@mail.ru>
*
* 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 <common.h>
#include <init.h>
#include <sizes.h>
#include <asm/io.h>
#include <linux/clkdev.h>
#include <mach/clps711x.h>
#define CLPS711X_OSC_FREQ 3686400
#define CLPS711X_EXT_FREQ 13000000
static struct clk {
unsigned long rate;
} uart_clk, bus_clk, timer_clk;
unsigned long clk_get_rate(struct clk *clk)
{
return clk->rate;
}
EXPORT_SYMBOL(clk_get_rate);
int clk_enable(struct clk *clk)
{
/* Do nothing */
return 0;
}
EXPORT_SYMBOL(clk_enable);
void clk_disable(struct clk *clk)
{
/* Do nothing */
}
EXPORT_SYMBOL(clk_disable);
static int clocks_init(void)
{
int pll, cpu;
u32 tmp;
tmp = readl(PLLR) >> 24;
if (tmp)
pll = (CLPS711X_OSC_FREQ * tmp) / 2;
else
pll = 73728000; /* Default value for old CPUs */
tmp = readl(SYSFLG2);
if (tmp & SYSFLG2_CKMODE) {
cpu = CLPS711X_EXT_FREQ;
bus_clk.rate = CLPS711X_EXT_FREQ;
} else {
cpu = pll;
if (cpu >= 36864000)
bus_clk.rate = cpu / 2;
else
bus_clk.rate = 36864000 / 2;
}
uart_clk.rate = DIV_ROUND_CLOSEST(bus_clk.rate, 10);
if (tmp & SYSFLG2_CKMODE) {
tmp = readw(SYSCON2);
if (tmp & SYSCON2_OSTB)
timer_clk.rate = DIV_ROUND_CLOSEST(CLPS711X_EXT_FREQ, 26);
else
timer_clk.rate = DIV_ROUND_CLOSEST(CLPS711X_EXT_FREQ, 24);
} else
timer_clk.rate = DIV_ROUND_CLOSEST(cpu, 144);
tmp = readl(SYSCON1);
tmp &= ~SYSCON1_TC2M; /* Free running mode */
tmp |= SYSCON1_TC2S; /* High frequency source */
writel(tmp, SYSCON1);
return 0;
}
core_initcall(clocks_init);
static struct clk_lookup clocks_lookups[] = {
CLKDEV_CON_ID("bus", &bus_clk),
CLKDEV_DEV_ID("clps711x_serial0", &uart_clk),
CLKDEV_DEV_ID("clps711x_serial1", &uart_clk),
CLKDEV_DEV_ID("clps711x-cs", &timer_clk),
};
static int clkdev_init(void)
{
clkdev_add_table(clocks_lookups, ARRAY_SIZE(clocks_lookups));
return 0;
}
postcore_initcall(clkdev_init);
static const char *clps711x_clocksrc_name = "clps711x-cs";
static __init int clps711x_core_init(void)
{
add_generic_device(clps711x_clocksrc_name, DEVICE_ID_SINGLE, NULL,
TC2D, SZ_2, IORESOURCE_MEM, NULL);
return 0;
}
coredevice_initcall(clps711x_core_init);