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.h>
17#include <linux/of_platform.h>
18#include <linux/platform_device.h>
19#include <linux/suspend.h>
20#include <asm/suspend.h>
21#include <asm/fncpy.h>
22#include "core.h"
23
24/* Pointer to function copied to ocram */
25static u32 (*socfpga_sdram_self_refresh_in_ocram)(u32 sdr_base);
26
27static int socfpga_setup_ocram_self_refresh(void)
28{
29 struct platform_device *pdev;
30 phys_addr_t ocram_pbase;
31 struct device_node *np;
32 struct gen_pool *ocram_pool;
33 unsigned long ocram_base;
34 void __iomem *suspend_ocram_base;
35 int ret = 0;
36
37 np = of_find_compatible_node(NULL, NULL, compat: "mmio-sram");
38 if (!np) {
39 pr_err("%s: Unable to find mmio-sram in dtb\n", __func__);
40 return -ENODEV;
41 }
42
43 pdev = of_find_device_by_node(np);
44 if (!pdev) {
45 pr_warn("%s: failed to find ocram device!\n", __func__);
46 ret = -ENODEV;
47 goto put_node;
48 }
49
50 ocram_pool = gen_pool_get(dev: &pdev->dev, NULL);
51 if (!ocram_pool) {
52 pr_warn("%s: ocram pool unavailable!\n", __func__);
53 ret = -ENODEV;
54 goto put_device;
55 }
56
57 ocram_base = gen_pool_alloc(pool: ocram_pool, size: socfpga_sdram_self_refresh_sz);
58 if (!ocram_base) {
59 pr_warn("%s: unable to alloc ocram!\n", __func__);
60 ret = -ENOMEM;
61 goto put_device;
62 }
63
64 ocram_pbase = gen_pool_virt_to_phys(pool: ocram_pool, ocram_base);
65
66 suspend_ocram_base = __arm_ioremap_exec(ocram_pbase,
67 socfpga_sdram_self_refresh_sz,
68 false);
69 if (!suspend_ocram_base) {
70 pr_warn("%s: __arm_ioremap_exec failed!\n", __func__);
71 ret = -ENOMEM;
72 goto put_device;
73 }
74
75 /* Copy the code that puts DDR in self refresh to ocram */
76 socfpga_sdram_self_refresh_in_ocram =
77 (void *)fncpy(suspend_ocram_base,
78 &socfpga_sdram_self_refresh,
79 socfpga_sdram_self_refresh_sz);
80
81 WARN(!socfpga_sdram_self_refresh_in_ocram,
82 "could not copy function to ocram");
83 if (!socfpga_sdram_self_refresh_in_ocram)
84 ret = -EFAULT;
85
86put_device:
87 put_device(dev: &pdev->dev);
88put_node:
89 of_node_put(node: np);
90
91 return ret;
92}
93
94static int socfpga_pm_suspend(unsigned long arg)
95{
96 u32 ret;
97
98 if (!sdr_ctl_base_addr)
99 return -EFAULT;
100
101 ret = socfpga_sdram_self_refresh_in_ocram((u32)sdr_ctl_base_addr);
102
103 pr_debug("%s self-refresh loops request=%d exit=%d\n", __func__,
104 ret & 0xffff, (ret >> 16) & 0xffff);
105
106 return 0;
107}
108
109static int socfpga_pm_enter(suspend_state_t state)
110{
111 switch (state) {
112 case PM_SUSPEND_MEM:
113 outer_disable();
114 cpu_suspend(0, socfpga_pm_suspend);
115 outer_resume();
116 break;
117 default:
118 return -EINVAL;
119 }
120 return 0;
121}
122
123static const struct platform_suspend_ops socfpga_pm_ops = {
124 .valid = suspend_valid_only_mem,
125 .enter = socfpga_pm_enter,
126};
127
128static int __init socfpga_pm_init(void)
129{
130 int ret;
131
132 ret = socfpga_setup_ocram_self_refresh();
133 if (ret)
134 return ret;
135
136 suspend_set_ops(ops: &socfpga_pm_ops);
137 pr_info("SoCFPGA initialized for DDR self-refresh during suspend.\n");
138
139 return 0;
140}
141arch_initcall(socfpga_pm_init);
142

source code of linux/arch/arm/mach-socfpga/pm.c