arm/mach-mvebu/kirkwood-pm.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Power Management driver for Marvell Kirkwood SoCs
0004  *
0005  * Copyright (C) 2013 Ezequiel Garcia <ezequiel@free-electrons.com>
0006  * Copyright (C) 2010 Simon Guinot <sguinot@lacie.com>
0007  */
0008
0009 #include <linux/kernel.h>
0010 #include <linux/suspend.h>
0011 #include <linux/io.h>
0012 #include "kirkwood.h"
0013 #include "kirkwood-pm.h"
0014
0015 static void __iomem *ddr_operation_base;
0016 static void __iomem *memory_pm_ctrl;
0017
0018 static void kirkwood_low_power(void)
0019 {
0020     u32 mem_pm_ctrl;
0021
0022     mem_pm_ctrl = readl(memory_pm_ctrl);
0023
0024     /* Set peripherals to low-power mode */
0025     writel_relaxed(~0, memory_pm_ctrl);
0026
0027     /* Set DDR in self-refresh */
0028     writel_relaxed(0x7, ddr_operation_base);
0029
0030     /*
0031      * Set CPU in wait-for-interrupt state.
0032      * This disables the CPU core clocks,
0033      * the array clocks, and also the L2 controller.
0034      */
0035     cpu_do_idle();
0036
0037     writel_relaxed(mem_pm_ctrl, memory_pm_ctrl);
0038 }
0039
0040 static int kirkwood_suspend_enter(suspend_state_t state)
0041 {
0042     switch (state) {
0043     case PM_SUSPEND_STANDBY:
0044         kirkwood_low_power();
0045         break;
0046     default:
0047         return -EINVAL;
0048     }
0049     return 0;
0050 }
0051
0052 static int kirkwood_pm_valid_standby(suspend_state_t state)
0053 {
0054     return state == PM_SUSPEND_STANDBY;
0055 }
0056
0057 static const struct platform_suspend_ops kirkwood_suspend_ops = {
0058     .enter = kirkwood_suspend_enter,
0059     .valid = kirkwood_pm_valid_standby,
0060 };
0061
0062 void __init kirkwood_pm_init(void)
0063 {
0064     ddr_operation_base = ioremap(DDR_OPERATION_BASE, 4);
0065     memory_pm_ctrl = ioremap(MEMORY_PM_CTRL_PHYS, 4);
0066
0067     suspend_set_ops(&kirkwood_suspend_ops);
0068 }