OpenCloudOS-Kernel/drivers/clk/versatile/clk-vexpress.c

143 lines
3.9 KiB
C

/*
* 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.
*
* 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.
*
* Copyright (C) 2012 ARM Limited
*/
#include <linux/clkdev.h>
#include <linux/clk-provider.h>
#include <linux/err.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/vexpress.h>
#include <asm/hardware/sp810.h>
static struct clk *vexpress_sp810_timerclken[4];
static DEFINE_SPINLOCK(vexpress_sp810_lock);
static void __init vexpress_sp810_init(void __iomem *base)
{
int i;
if (WARN_ON(!base))
return;
for (i = 0; i < ARRAY_SIZE(vexpress_sp810_timerclken); i++) {
char name[12];
const char *parents[] = {
"v2m:refclk32khz", /* REFCLK */
"v2m:refclk1mhz" /* TIMCLK */
};
snprintf(name, ARRAY_SIZE(name), "timerclken%d", i);
vexpress_sp810_timerclken[i] = clk_register_mux(NULL, name,
parents, 2, 0, base + SCCTRL,
SCCTRL_TIMERENnSEL_SHIFT(i), 1,
0, &vexpress_sp810_lock);
if (WARN_ON(IS_ERR(vexpress_sp810_timerclken[i])))
break;
}
}
static const char * const vexpress_clk_24mhz_periphs[] __initconst = {
"mb:uart0", "mb:uart1", "mb:uart2", "mb:uart3",
"mb:mmci", "mb:kmi0", "mb:kmi1"
};
void __init vexpress_clk_init(void __iomem *sp810_base)
{
struct clk *clk;
int i;
clk = clk_register_fixed_rate(NULL, "dummy_apb_pclk", NULL,
CLK_IS_ROOT, 0);
WARN_ON(clk_register_clkdev(clk, "apb_pclk", NULL));
clk = clk_register_fixed_rate(NULL, "v2m:clk_24mhz", NULL,
CLK_IS_ROOT, 24000000);
for (i = 0; i < ARRAY_SIZE(vexpress_clk_24mhz_periphs); i++)
WARN_ON(clk_register_clkdev(clk, NULL,
vexpress_clk_24mhz_periphs[i]));
clk = clk_register_fixed_rate(NULL, "v2m:refclk32khz", NULL,
CLK_IS_ROOT, 32768);
WARN_ON(clk_register_clkdev(clk, NULL, "v2m:wdt"));
clk = clk_register_fixed_rate(NULL, "v2m:refclk1mhz", NULL,
CLK_IS_ROOT, 1000000);
vexpress_sp810_init(sp810_base);
for (i = 0; i < ARRAY_SIZE(vexpress_sp810_timerclken); i++)
WARN_ON(clk_set_parent(vexpress_sp810_timerclken[i], clk));
WARN_ON(clk_register_clkdev(vexpress_sp810_timerclken[0],
"v2m-timer0", "sp804"));
WARN_ON(clk_register_clkdev(vexpress_sp810_timerclken[1],
"v2m-timer1", "sp804"));
}
#if defined(CONFIG_OF)
struct clk *vexpress_sp810_of_get(struct of_phandle_args *clkspec, void *data)
{
if (WARN_ON(clkspec->args_count != 1 || clkspec->args[0] >
ARRAY_SIZE(vexpress_sp810_timerclken)))
return NULL;
return vexpress_sp810_timerclken[clkspec->args[0]];
}
static const __initconst struct of_device_id vexpress_fixed_clk_match[] = {
{ .compatible = "fixed-clock", .data = of_fixed_clk_setup, },
{ .compatible = "arm,vexpress-osc", .data = vexpress_osc_of_setup, },
{}
};
void __init vexpress_clk_of_init(void)
{
struct device_node *node;
struct clk *clk;
struct clk *refclk, *timclk;
of_clk_init(vexpress_fixed_clk_match);
node = of_find_compatible_node(NULL, NULL, "arm,sp810");
vexpress_sp810_init(of_iomap(node, 0));
of_clk_add_provider(node, vexpress_sp810_of_get, NULL);
/* Select "better" (faster) parent for SP804 timers */
refclk = of_clk_get_by_name(node, "refclk");
timclk = of_clk_get_by_name(node, "timclk");
if (!WARN_ON(IS_ERR(refclk) || IS_ERR(timclk))) {
int i = 0;
if (clk_get_rate(refclk) > clk_get_rate(timclk))
clk = refclk;
else
clk = timclk;
for (i = 0; i < ARRAY_SIZE(vexpress_sp810_timerclken); i++)
WARN_ON(clk_set_parent(vexpress_sp810_timerclken[i],
clk));
}
WARN_ON(clk_register_clkdev(vexpress_sp810_timerclken[0],
"v2m-timer0", "sp804"));
WARN_ON(clk_register_clkdev(vexpress_sp810_timerclken[1],
"v2m-timer1", "sp804"));
}
#endif