LXR linux/arch/arm/mach-mvebu/kirkwood-pm.c

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Power Management driver for Marvell Kirkwood SoCs
   4 *
   5 * Copyright (C) 2013 Ezequiel Garcia <ezequiel@free-electrons.com>
   6 * Copyright (C) 2010 Simon Guinot <sguinot@lacie.com>
   7 */
   8
   9#include <linux/kernel.h>
  10#include <linux/suspend.h>
  11#include <linux/io.h>
  12#include "kirkwood.h"
  13#include "kirkwood-pm.h"
  14
  15static void __iomem *ddr_operation_base;
  16static void __iomem *memory_pm_ctrl;
  17
  18static void kirkwood_low_power(void)
  19{
  20        u32 mem_pm_ctrl;
  21
  22        mem_pm_ctrl = readl(memory_pm_ctrl);
  23
  24        /* Set peripherals to low-power mode */
  25        writel_relaxed(~0, memory_pm_ctrl);
  26
  27        /* Set DDR in self-refresh */
  28        writel_relaxed(0x7, ddr_operation_base);
  29
  30        /*
  31         * Set CPU in wait-for-interrupt state.
  32         * This disables the CPU core clocks,
  33         * the array clocks, and also the L2 controller.
  34         */
  35        cpu_do_idle();
  36
  37        writel_relaxed(mem_pm_ctrl, memory_pm_ctrl);
  38}
  39
  40static int kirkwood_suspend_enter(suspend_state_t state)
  41{
  42        switch (state) {
  43        case PM_SUSPEND_STANDBY:
  44                kirkwood_low_power();
  45                break;
  46        default:
  47                return -EINVAL;
  48        }
  49        return 0;
  50}
  51
  52static int kirkwood_pm_valid_standby(suspend_state_t state)
  53{
  54        return state == PM_SUSPEND_STANDBY;
  55}
  56
  57static const struct platform_suspend_ops kirkwood_suspend_ops = {
  58        .enter = kirkwood_suspend_enter,
  59        .valid = kirkwood_pm_valid_standby,
  60};
  61
  62void __init kirkwood_pm_init(void)
  63{
  64        ddr_operation_base = ioremap(DDR_OPERATION_BASE, 4);
  65        memory_pm_ctrl = ioremap(MEMORY_PM_CTRL_PHYS, 4);
  66
  67        suspend_set_ops(&kirkwood_suspend_ops);
  68}
  69