linux/drivers/clk/versatile/clk-vexpress.c
Pawel Moll 6e973d2c43 clk: vexpress: Add separate SP810 driver
Factor out the SP810 clocking code into a separate driver,
selecting better (faster) parent at clk_prepare() time.
This is to avoid problems with clocking infrastructure
initialisation order, in particular to avoid dependency
of fixed clock being initialized before SP810. It also
makes vexpress platform OF-based clock initialisation code
unnecessary.

Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Tested-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
[mturquette@linaro.org: add .unprepare, FIXME comment, cleaned up code]
2013-04-18 11:41:10 -07:00

87 lines
2.4 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/amba/sp810.h>
#include <linux/clkdev.h>
#include <linux/clk-provider.h>
#include <linux/err.h>
#include <linux/vexpress.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"));
}