linux/arch/arm/mach-omap2/pm.c

/*
 * linux/arch/arm/mach-omap2/pm.c
 *
 * OMAP2 Power Management Routines
 *
 * Copyright (C) 2006 Nokia Corporation
 * Tony Lindgren <tony@atomide.com>
 *
 * Copyright (C) 2005 Texas Instruments, Inc.
 * Richard Woodruff <r-woodruff2@ti.com>
 *
 * Based on pm.c for omap1
 *
 * 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.
 */

#include <linux/pm.h>
#include <linux/sched.h>
#include <linux/proc_fs.h>
#include <linux/pm.h>
#include <linux/interrupt.h>
#include <linux/sysfs.h>
#include <linux/module.h>

#include <asm/io.h>
#include <asm/irq.h>
#include <asm/atomic.h>
#include <asm/mach/time.h>
#include <asm/mach/irq.h>
#include <asm/mach-types.h>

#include <asm/arch/irqs.h>
#include <asm/arch/clock.h>
#include <asm/arch/sram.h>
#include <asm/arch/pm.h>

static struct clk *vclk;
static void (*omap2_sram_idle)(void);
static void (*omap2_sram_suspend)(int dllctrl, int cpu_rev);
static void (*saved_idle)(void);

void omap2_pm_idle(void)
{
	local_irq_disable();
	local_fiq_disable();
	if (need_resched()) {
		local_fiq_enable();
		local_irq_enable();
		return;
	}

	/*
	 * Since an interrupt may set up a timer, we don't want to
	 * reprogram the hardware timer with interrupts enabled.
	 * Re-enable interrupts only after returning from idle.
	 */
	timer_dyn_reprogram();

	omap2_sram_idle();
	local_fiq_enable();
	local_irq_enable();
}

static int omap2_pm_prepare(suspend_state_t state)
{
	int error = 0;

	/* We cannot sleep in idle until we have resumed */
	saved_idle = pm_idle;
	pm_idle = NULL;

	switch (state)
	{
	case PM_SUSPEND_STANDBY:
	case PM_SUSPEND_MEM:
		break;

	case PM_SUSPEND_DISK:
		return -ENOTSUPP;

	default:
		return -EINVAL;
	}

	return error;
}

static int omap2_pm_enter(suspend_state_t state)
{
	switch (state)
	{
	case PM_SUSPEND_STANDBY:
	case PM_SUSPEND_MEM:
		/* FIXME: Add suspend */
		break;

	case PM_SUSPEND_DISK:
		return -ENOTSUPP;

	default:
		return -EINVAL;
	}

	return 0;
}

static int omap2_pm_finish(suspend_state_t state)
{
	pm_idle = saved_idle;
	return 0;
}

static struct pm_ops omap_pm_ops = {
	.pm_disk_mode	= 0,
	.prepare	= omap2_pm_prepare,
	.enter		= omap2_pm_enter,
	.finish		= omap2_pm_finish,
};

int __init omap2_pm_init(void)
{
	printk("Power Management for TI OMAP.\n");

	vclk = clk_get(NULL, "virt_prcm_set");
	if (IS_ERR(vclk)) {
		printk(KERN_ERR "Could not get PM vclk\n");
		return -ENODEV;
	}

	/*
	 * We copy the assembler sleep/wakeup routines to SRAM.
	 * These routines need to be in SRAM as that's the only
	 * memory the MPU can see when it wakes up.
	 */
	omap2_sram_idle = omap_sram_push(omap24xx_idle_loop_suspend,
					 omap24xx_idle_loop_suspend_sz);

	omap2_sram_suspend = omap_sram_push(omap24xx_cpu_suspend,
					    omap24xx_cpu_suspend_sz);

	pm_set_ops(&omap_pm_ops);
	pm_idle = omap2_pm_idle;

	return 0;
}

__initcall(omap2_pm_init);