1/*
2 * Power Management driver for Marvell Kirkwood SoCs
3 *
4 * Copyright (C) 2013 Ezequiel Garcia <ezequiel@free-electrons.com>
5 * Copyright (C) 2010 Simon Guinot <sguinot@lacie.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License,
9 * version 2 of the License.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 * GNU General Public License for more details.
15 */
16
17#include <linux/kernel.h>
18#include <linux/suspend.h>
19#include <linux/io.h>
20#include "kirkwood.h"
21
22static void __iomem *ddr_operation_base;
23static void __iomem *memory_pm_ctrl;
24
25static void kirkwood_low_power(void)
26{
27	u32 mem_pm_ctrl;
28
29	mem_pm_ctrl = readl(memory_pm_ctrl);
30
31	/* Set peripherals to low-power mode */
32	writel_relaxed(~0, memory_pm_ctrl);
33
34	/* Set DDR in self-refresh */
35	writel_relaxed(0x7, ddr_operation_base);
36
37	/*
38	 * Set CPU in wait-for-interrupt state.
39	 * This disables the CPU core clocks,
40	 * the array clocks, and also the L2 controller.
41	 */
42	cpu_do_idle();
43
44	writel_relaxed(mem_pm_ctrl, memory_pm_ctrl);
45}
46
47static int kirkwood_suspend_enter(suspend_state_t state)
48{
49	switch (state) {
50	case PM_SUSPEND_STANDBY:
51		kirkwood_low_power();
52		break;
53	default:
54		return -EINVAL;
55	}
56	return 0;
57}
58
59static int kirkwood_pm_valid_standby(suspend_state_t state)
60{
61	return state == PM_SUSPEND_STANDBY;
62}
63
64static const struct platform_suspend_ops kirkwood_suspend_ops = {
65	.enter = kirkwood_suspend_enter,
66	.valid = kirkwood_pm_valid_standby,
67};
68
69int __init kirkwood_pm_init(void)
70{
71	ddr_operation_base = ioremap(DDR_OPERATION_BASE, 4);
72	memory_pm_ctrl = ioremap(MEMORY_PM_CTRL_PHYS, 4);
73
74	suspend_set_ops(&kirkwood_suspend_ops);
75	return 0;
76}
77