f69626c632
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
81 lines
2.1 KiB
C
81 lines
2.1 KiB
C
/**
|
|
* @file
|
|
* @brief Provide @ref clocksource functionality for OMAP
|
|
*
|
|
* FileName: arch/arm/mach-omap/s32k_clksource.c
|
|
*
|
|
* @ref clocksource provides a neat architecture. all we do is
|
|
* To loop in with Sync 32Khz clock ticking away at 32768hz on OMAP.
|
|
* Sync 32Khz clock is an always ON clock.
|
|
*
|
|
*/
|
|
/*
|
|
* (C) Copyright 2008
|
|
* Texas Instruments, <www.ti.com>
|
|
* Nishanth Menon <x0nishan@ti.com>
|
|
*
|
|
* 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.
|
|
*
|
|
* 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.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
|
|
* MA 02111-1307 USA
|
|
*/
|
|
|
|
#include <common.h>
|
|
#include <clock.h>
|
|
#include <init.h>
|
|
#include <asm/io.h>
|
|
#include <mach/silicon.h>
|
|
#include <mach/clocks.h>
|
|
#include <mach/timers.h>
|
|
#include <mach/sys_info.h>
|
|
#include <mach/syslib.h>
|
|
|
|
/**
|
|
* @brief Provide a simple clock read
|
|
*
|
|
* Nothing is simpler.. read direct from clock and provide it
|
|
* to the caller.
|
|
*
|
|
* @return S32K clock counter
|
|
*/
|
|
static uint64_t s32k_clocksource_read(void)
|
|
{
|
|
return readl(S32K_CR);
|
|
}
|
|
|
|
/* A bit obvious isn't it? */
|
|
static struct clocksource s32k_cs = {
|
|
.read = s32k_clocksource_read,
|
|
.mask = CLOCKSOURCE_MASK(32),
|
|
.shift = 10,
|
|
};
|
|
|
|
/**
|
|
* @brief Initialize the Clock
|
|
*
|
|
* There is nothing to do on OMAP as SYNC32K clock is
|
|
* always on, and we do a simple data structure initialization.
|
|
* 32K clock gives 32768 ticks a seconds
|
|
*
|
|
* @return result of @ref init_clock
|
|
*/
|
|
static int s32k_clocksource_init(void)
|
|
{
|
|
s32k_cs.mult = clocksource_hz2mult(S32K_FREQUENCY, s32k_cs.shift);
|
|
|
|
return init_clock(&s32k_cs);
|
|
}
|
|
|
|
/* Run me at boot time */
|
|
core_initcall(s32k_clocksource_init);
|