b097f494cc
Teach OMAP2 gp timer that HZ isn't always 100. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Tony Lindgren <tony@atomide.com>
77 lines
1.9 KiB
C
77 lines
1.9 KiB
C
/*
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* linux/arch/arm/mach-omap2/timer-gp.c
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*
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* OMAP2 GP timer support.
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*
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* Copyright (C) 2005 Nokia Corporation
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* Author: Paul Mundt <paul.mundt@nokia.com>
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* Juha Yrjölä <juha.yrjola@nokia.com>
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* OMAP Dual-mode timer framework support by Timo Teras
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*
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* Some parts based off of TI's 24xx code:
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*
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* Copyright (C) 2004 Texas Instruments, Inc.
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*
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* Roughly modelled after the OMAP1 MPU timer code.
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*/
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#include <linux/init.h>
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#include <linux/time.h>
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#include <linux/interrupt.h>
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#include <linux/err.h>
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#include <linux/clk.h>
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#include <linux/delay.h>
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#include <linux/irq.h>
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#include <asm/mach/time.h>
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#include <asm/arch/dmtimer.h>
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static struct omap_dm_timer *gptimer;
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static inline void omap2_gp_timer_start(unsigned long load_val)
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{
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omap_dm_timer_set_load(gptimer, 1, 0xffffffff - load_val);
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omap_dm_timer_set_int_enable(gptimer, OMAP_TIMER_INT_OVERFLOW);
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omap_dm_timer_start(gptimer);
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}
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static irqreturn_t omap2_gp_timer_interrupt(int irq, void *dev_id)
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{
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write_seqlock(&xtime_lock);
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omap_dm_timer_write_status(gptimer, OMAP_TIMER_INT_OVERFLOW);
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timer_tick();
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write_sequnlock(&xtime_lock);
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return IRQ_HANDLED;
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}
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static struct irqaction omap2_gp_timer_irq = {
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.name = "gp timer",
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.flags = IRQF_DISABLED | IRQF_TIMER,
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.handler = omap2_gp_timer_interrupt,
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};
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static void __init omap2_gp_timer_init(void)
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{
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u32 tick_period;
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omap_dm_timer_init();
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gptimer = omap_dm_timer_request_specific(1);
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BUG_ON(gptimer == NULL);
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omap_dm_timer_set_source(gptimer, OMAP_TIMER_SRC_SYS_CLK);
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tick_period = clk_get_rate(omap_dm_timer_get_fclk(gptimer)) / HZ;
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tick_period -= 1;
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setup_irq(omap_dm_timer_get_irq(gptimer), &omap2_gp_timer_irq);
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omap2_gp_timer_start(tick_period);
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}
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struct sys_timer omap_timer = {
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.init = omap2_gp_timer_init,
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};
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