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
  15 static void __iomem *ddr_operation_base;
  16 static void __iomem *memory_pm_ctrl;
  17
  18 static 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
  40 static 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
  52 static int kirkwood_pm_valid_standby(suspend_state_t state)
  53 {
  54         return state == PM_SUSPEND_STANDBY;
  55 }
  56
  57 static const struct platform_suspend_ops kirkwood_suspend_ops = {
  58         .enter = kirkwood_suspend_enter,
  59         .valid = kirkwood_pm_valid_standby,
  60 };
  61
  62 void __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 }