kernel-ark/arch/arm/plat-omap/include/mach/dmtimer.h
Paul Walmsley f248076c0d OMAP2/3 GPTIMER: allow system tick GPTIMER to be changed in board-*.c files
Add a function omap2_gp_clockevent_set_gptimer() for board-*.c files
to use in .init_irq functions to configure the system tick GPTIMER.
Practical choices at this point are GPTIMER1 or GPTIMER12.  Both of
these timers are in the WKUP powerdomain, and so are unaffected by
chip power management.  GPTIMER1 can use sys_clk as a source, for
applications where a high-resolution timer is more important than
power management.  GPTIMER12 has the special property that it has the
secure 32kHz oscillator as its source clock, which may be less prone
to glitches than the off-chip 32kHz oscillator.  But on HS devices, it
may not be available for Linux use.

It appears that most boards are fine with GPTIMER1, but BeagleBoard
should use GPTIMER12 when using a 32KiHz timer source, due to hardware bugs
in revisions B4 and below.  Modify board-omap3beagle.c to use GPTIMER12.

This patch originally used a Kbuild config option to select the GPTIMER,
but was changed to allow this to be specified in board-*.c files, per
Tony's request.

Kalle Vallo <kalle.valo@nokia.com> found a bug in an earlier version of
this patch - thanks Kalle.

Tested on Beagle rev B4 ES2.1, with and without CONFIG_OMAP_32K_TIMER, and
3430SDP.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Cc: Kalle Valo <kalle.valo@nokia.com>
2009-04-23 21:11:10 -06:00

85 lines
3.4 KiB
C

/*
* arch/arm/plat-omap/include/mach/dmtimer.h
*
* OMAP Dual-Mode Timers
*
* Copyright (C) 2005 Nokia Corporation
* Author: Lauri Leukkunen <lauri.leukkunen@nokia.com>
* PWM and clock framwork support by Timo Teras.
*
* 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 SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
* NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* 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.,
* 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#ifndef __ASM_ARCH_DMTIMER_H
#define __ASM_ARCH_DMTIMER_H
/* clock sources */
#define OMAP_TIMER_SRC_SYS_CLK 0x00
#define OMAP_TIMER_SRC_32_KHZ 0x01
#define OMAP_TIMER_SRC_EXT_CLK 0x02
/* timer interrupt enable bits */
#define OMAP_TIMER_INT_CAPTURE (1 << 2)
#define OMAP_TIMER_INT_OVERFLOW (1 << 1)
#define OMAP_TIMER_INT_MATCH (1 << 0)
/* trigger types */
#define OMAP_TIMER_TRIGGER_NONE 0x00
#define OMAP_TIMER_TRIGGER_OVERFLOW 0x01
#define OMAP_TIMER_TRIGGER_OVERFLOW_AND_COMPARE 0x02
struct omap_dm_timer;
struct clk;
int omap_dm_timer_init(void);
struct omap_dm_timer *omap_dm_timer_request(void);
struct omap_dm_timer *omap_dm_timer_request_specific(int timer_id);
void omap_dm_timer_free(struct omap_dm_timer *timer);
void omap_dm_timer_enable(struct omap_dm_timer *timer);
void omap_dm_timer_disable(struct omap_dm_timer *timer);
int omap_dm_timer_get_irq(struct omap_dm_timer *timer);
u32 omap_dm_timer_modify_idlect_mask(u32 inputmask);
struct clk *omap_dm_timer_get_fclk(struct omap_dm_timer *timer);
void omap_dm_timer_trigger(struct omap_dm_timer *timer);
void omap_dm_timer_start(struct omap_dm_timer *timer);
void omap_dm_timer_stop(struct omap_dm_timer *timer);
int omap_dm_timer_set_source(struct omap_dm_timer *timer, int source);
void omap_dm_timer_set_load(struct omap_dm_timer *timer, int autoreload, unsigned int value);
void omap_dm_timer_set_load_start(struct omap_dm_timer *timer, int autoreload, unsigned int value);
void omap_dm_timer_set_match(struct omap_dm_timer *timer, int enable, unsigned int match);
void omap_dm_timer_set_pwm(struct omap_dm_timer *timer, int def_on, int toggle, int trigger);
void omap_dm_timer_set_prescaler(struct omap_dm_timer *timer, int prescaler);
void omap_dm_timer_set_int_enable(struct omap_dm_timer *timer, unsigned int value);
unsigned int omap_dm_timer_read_status(struct omap_dm_timer *timer);
void omap_dm_timer_write_status(struct omap_dm_timer *timer, unsigned int value);
unsigned int omap_dm_timer_read_counter(struct omap_dm_timer *timer);
void omap_dm_timer_write_counter(struct omap_dm_timer *timer, unsigned int value);
int omap_dm_timers_active(void);
#endif /* __ASM_ARCH_DMTIMER_H */