linux/arch/arm/mach-mx5/pm-imx5.c
Dinh Nguyen f9e9fc2736 ARM: mx51: Add support for low power suspend on MX51
Adds initial low power suspend functionality to MX51.
Supports "mem" and "standby" modes.

Tested on mx51-babbage.

Signed-off-by: Dinh Nguyen <Dinh.Nguyen@freescale.com>
Tested-by: Arnaud Patard <arnaud.patard@rtp-net.org>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2011-07-07 10:01:10 +02:00

73 lines
1.6 KiB
C

/*
* Copyright (C) 2011 Freescale Semiconductor, Inc. All Rights Reserved.
*
* The code contained herein is licensed under the GNU General Public
* License. You may obtain a copy of the GNU General Public License
* Version 2 or later at the following locations:
*
* http://www.opensource.org/licenses/gpl-license.html
* http://www.gnu.org/copyleft/gpl.html
*/
#include <linux/suspend.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/err.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
#include <mach/system.h>
#include "crm_regs.h"
static struct clk *gpc_dvfs_clk;
static int mx5_suspend_enter(suspend_state_t state)
{
clk_enable(gpc_dvfs_clk);
switch (state) {
case PM_SUSPEND_MEM:
mx5_cpu_lp_set(STOP_POWER_OFF);
break;
case PM_SUSPEND_STANDBY:
mx5_cpu_lp_set(WAIT_UNCLOCKED_POWER_OFF);
break;
default:
return -EINVAL;
}
if (state == PM_SUSPEND_MEM) {
local_flush_tlb_all();
flush_cache_all();
/*clear the EMPGC0/1 bits */
__raw_writel(0, MXC_SRPG_EMPGC0_SRPGCR);
__raw_writel(0, MXC_SRPG_EMPGC1_SRPGCR);
}
cpu_do_idle();
clk_disable(gpc_dvfs_clk);
return 0;
}
static int mx5_pm_valid(suspend_state_t state)
{
return (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX);
}
static const struct platform_suspend_ops mx5_suspend_ops = {
.valid = mx5_pm_valid,
.enter = mx5_suspend_enter,
};
static int __init mx5_pm_init(void)
{
if (gpc_dvfs_clk == NULL)
gpc_dvfs_clk = clk_get(NULL, "gpc_dvfs");
if (!IS_ERR(gpc_dvfs_clk)) {
if (cpu_is_mx51())
suspend_set_ops(&mx5_suspend_ops);
} else
return -EPERM;
return 0;
}
device_initcall(mx5_pm_init);