linux-sg2042/arch/arm/mach-kirkwood/pm.c

77 lines
1.8 KiB
C

/*
* Power Management driver for Marvell Kirkwood SoCs
*
* Copyright (C) 2013 Ezequiel Garcia <ezequiel@free-electrons.com>
* Copyright (C) 2010 Simon Guinot <sguinot@lacie.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License,
* version 2 of the License.
*
* 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.
*/
#include <linux/kernel.h>
#include <linux/suspend.h>
#include <linux/io.h>
#include <mach/bridge-regs.h>
#include "common.h"
static void __iomem *ddr_operation_base;
static void __iomem *memory_pm_ctrl;
static void kirkwood_low_power(void)
{
u32 mem_pm_ctrl;
mem_pm_ctrl = readl(memory_pm_ctrl);
/* Set peripherals to low-power mode */
writel_relaxed(~0, memory_pm_ctrl);
/* Set DDR in self-refresh */
writel_relaxed(0x7, ddr_operation_base);
/*
* Set CPU in wait-for-interrupt state.
* This disables the CPU core clocks,
* the array clocks, and also the L2 controller.
*/
cpu_do_idle();
writel_relaxed(mem_pm_ctrl, memory_pm_ctrl);
}
static int kirkwood_suspend_enter(suspend_state_t state)
{
switch (state) {
case PM_SUSPEND_STANDBY:
kirkwood_low_power();
break;
default:
return -EINVAL;
}
return 0;
}
static int kirkwood_pm_valid_standby(suspend_state_t state)
{
return state == PM_SUSPEND_STANDBY;
}
static const struct platform_suspend_ops kirkwood_suspend_ops = {
.enter = kirkwood_suspend_enter,
.valid = kirkwood_pm_valid_standby,
};
void __init kirkwood_pm_init(void)
{
ddr_operation_base = ioremap(DDR_OPERATION_BASE, 4);
memory_pm_ctrl = ioremap(MEMORY_PM_CTRL_PHYS, 4);
suspend_set_ops(&kirkwood_suspend_ops);
}