1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 *  arch/arm/mach-socfpga/pm.c
4 *
5 * Copyright (C) 2014-2015 Altera Corporation. All rights reserved.
6 *
7 * with code from pm-imx6.c
8 * Copyright 2011-2014 Freescale Semiconductor, Inc.
9 * Copyright 2011 Linaro Ltd.
10 */
11
12#include <linux/bitops.h>
13#include <linux/genalloc.h>
14#include <linux/init.h>
15#include <linux/io.h>
16#include <linux/of_platform.h>
17#include <linux/suspend.h>
18#include <asm/suspend.h>
19#include <asm/fncpy.h>
20#include "core.h"
21
22/* Pointer to function copied to ocram */
23static u32 (*socfpga_sdram_self_refresh_in_ocram)(u32 sdr_base);
24
25static int socfpga_setup_ocram_self_refresh(void)
26{
27	struct platform_device *pdev;
28	phys_addr_t ocram_pbase;
29	struct device_node *np;
30	struct gen_pool *ocram_pool;
31	unsigned long ocram_base;
32	void __iomem *suspend_ocram_base;
33	int ret = 0;
34
35	np = of_find_compatible_node(NULL, NULL, "mmio-sram");
36	if (!np) {
37		pr_err("%s: Unable to find mmio-sram in dtb\n", __func__);
38		return -ENODEV;
39	}
40
41	pdev = of_find_device_by_node(np);
42	if (!pdev) {
43		pr_warn("%s: failed to find ocram device!\n", __func__);
44		ret = -ENODEV;
45		goto put_node;
46	}
47
48	ocram_pool = gen_pool_get(&pdev->dev, NULL);
49	if (!ocram_pool) {
50		pr_warn("%s: ocram pool unavailable!\n", __func__);
51		ret = -ENODEV;
52		goto put_device;
53	}
54
55	ocram_base = gen_pool_alloc(ocram_pool, socfpga_sdram_self_refresh_sz);
56	if (!ocram_base) {
57		pr_warn("%s: unable to alloc ocram!\n", __func__);
58		ret = -ENOMEM;
59		goto put_device;
60	}
61
62	ocram_pbase = gen_pool_virt_to_phys(ocram_pool, ocram_base);
63
64	suspend_ocram_base = __arm_ioremap_exec(ocram_pbase,
65						socfpga_sdram_self_refresh_sz,
66						false);
67	if (!suspend_ocram_base) {
68		pr_warn("%s: __arm_ioremap_exec failed!\n", __func__);
69		ret = -ENOMEM;
70		goto put_device;
71	}
72
73	/* Copy the code that puts DDR in self refresh to ocram */
74	socfpga_sdram_self_refresh_in_ocram =
75		(void *)fncpy(suspend_ocram_base,
76			      &socfpga_sdram_self_refresh,
77			      socfpga_sdram_self_refresh_sz);
78
79	WARN(!socfpga_sdram_self_refresh_in_ocram,
80	     "could not copy function to ocram");
81	if (!socfpga_sdram_self_refresh_in_ocram)
82		ret = -EFAULT;
83
84put_device:
85	put_device(&pdev->dev);
86put_node:
87	of_node_put(np);
88
89	return ret;
90}
91
92static int socfpga_pm_suspend(unsigned long arg)
93{
94	u32 ret;
95
96	if (!sdr_ctl_base_addr)
97		return -EFAULT;
98
99	ret = socfpga_sdram_self_refresh_in_ocram((u32)sdr_ctl_base_addr);
100
101	pr_debug("%s self-refresh loops request=%d exit=%d\n", __func__,
102		 ret & 0xffff, (ret >> 16) & 0xffff);
103
104	return 0;
105}
106
107static int socfpga_pm_enter(suspend_state_t state)
108{
109	switch (state) {
110	case PM_SUSPEND_MEM:
111		outer_disable();
112		cpu_suspend(0, socfpga_pm_suspend);
113		outer_resume();
114		break;
115	default:
116		return -EINVAL;
117	}
118	return 0;
119}
120
121static const struct platform_suspend_ops socfpga_pm_ops = {
122	.valid	= suspend_valid_only_mem,
123	.enter	= socfpga_pm_enter,
124};
125
126static int __init socfpga_pm_init(void)
127{
128	int ret;
129
130	ret = socfpga_setup_ocram_self_refresh();
131	if (ret)
132		return ret;
133
134	suspend_set_ops(&socfpga_pm_ops);
135	pr_info("SoCFPGA initialized for DDR self-refresh during suspend.\n");
136
137	return 0;
138}
139arch_initcall(socfpga_pm_init);
140