xref: /OK3568_Linux_fs/kernel/arch/arm/mach-mvebu/kirkwood-pm.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-only
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun  * Power Management driver for Marvell Kirkwood SoCs
4*4882a593Smuzhiyun  *
5*4882a593Smuzhiyun  * Copyright (C) 2013 Ezequiel Garcia <ezequiel@free-electrons.com>
6*4882a593Smuzhiyun  * Copyright (C) 2010 Simon Guinot <sguinot@lacie.com>
7*4882a593Smuzhiyun  */
8*4882a593Smuzhiyun 
9*4882a593Smuzhiyun #include <linux/kernel.h>
10*4882a593Smuzhiyun #include <linux/suspend.h>
11*4882a593Smuzhiyun #include <linux/io.h>
12*4882a593Smuzhiyun #include "kirkwood.h"
13*4882a593Smuzhiyun #include "kirkwood-pm.h"
14*4882a593Smuzhiyun 
15*4882a593Smuzhiyun static void __iomem *ddr_operation_base;
16*4882a593Smuzhiyun static void __iomem *memory_pm_ctrl;
17*4882a593Smuzhiyun 
kirkwood_low_power(void)18*4882a593Smuzhiyun static void kirkwood_low_power(void)
19*4882a593Smuzhiyun {
20*4882a593Smuzhiyun 	u32 mem_pm_ctrl;
21*4882a593Smuzhiyun 
22*4882a593Smuzhiyun 	mem_pm_ctrl = readl(memory_pm_ctrl);
23*4882a593Smuzhiyun 
24*4882a593Smuzhiyun 	/* Set peripherals to low-power mode */
25*4882a593Smuzhiyun 	writel_relaxed(~0, memory_pm_ctrl);
26*4882a593Smuzhiyun 
27*4882a593Smuzhiyun 	/* Set DDR in self-refresh */
28*4882a593Smuzhiyun 	writel_relaxed(0x7, ddr_operation_base);
29*4882a593Smuzhiyun 
30*4882a593Smuzhiyun 	/*
31*4882a593Smuzhiyun 	 * Set CPU in wait-for-interrupt state.
32*4882a593Smuzhiyun 	 * This disables the CPU core clocks,
33*4882a593Smuzhiyun 	 * the array clocks, and also the L2 controller.
34*4882a593Smuzhiyun 	 */
35*4882a593Smuzhiyun 	cpu_do_idle();
36*4882a593Smuzhiyun 
37*4882a593Smuzhiyun 	writel_relaxed(mem_pm_ctrl, memory_pm_ctrl);
38*4882a593Smuzhiyun }
39*4882a593Smuzhiyun 
kirkwood_suspend_enter(suspend_state_t state)40*4882a593Smuzhiyun static int kirkwood_suspend_enter(suspend_state_t state)
41*4882a593Smuzhiyun {
42*4882a593Smuzhiyun 	switch (state) {
43*4882a593Smuzhiyun 	case PM_SUSPEND_STANDBY:
44*4882a593Smuzhiyun 		kirkwood_low_power();
45*4882a593Smuzhiyun 		break;
46*4882a593Smuzhiyun 	default:
47*4882a593Smuzhiyun 		return -EINVAL;
48*4882a593Smuzhiyun 	}
49*4882a593Smuzhiyun 	return 0;
50*4882a593Smuzhiyun }
51*4882a593Smuzhiyun 
kirkwood_pm_valid_standby(suspend_state_t state)52*4882a593Smuzhiyun static int kirkwood_pm_valid_standby(suspend_state_t state)
53*4882a593Smuzhiyun {
54*4882a593Smuzhiyun 	return state == PM_SUSPEND_STANDBY;
55*4882a593Smuzhiyun }
56*4882a593Smuzhiyun 
57*4882a593Smuzhiyun static const struct platform_suspend_ops kirkwood_suspend_ops = {
58*4882a593Smuzhiyun 	.enter = kirkwood_suspend_enter,
59*4882a593Smuzhiyun 	.valid = kirkwood_pm_valid_standby,
60*4882a593Smuzhiyun };
61*4882a593Smuzhiyun 
kirkwood_pm_init(void)62*4882a593Smuzhiyun void __init kirkwood_pm_init(void)
63*4882a593Smuzhiyun {
64*4882a593Smuzhiyun 	ddr_operation_base = ioremap(DDR_OPERATION_BASE, 4);
65*4882a593Smuzhiyun 	memory_pm_ctrl = ioremap(MEMORY_PM_CTRL_PHYS, 4);
66*4882a593Smuzhiyun 
67*4882a593Smuzhiyun 	suspend_set_ops(&kirkwood_suspend_ops);
68*4882a593Smuzhiyun }
69