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