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 } 69