1/*
2 *  arch/arm/mach-socfpga/pm.c
3 *
4 * Copyright (C) 2014-2015 Altera Corporation. All rights reserved.
5 *
6 * with code from pm-imx6.c
7 * Copyright 2011-2014 Freescale Semiconductor, Inc.
8 * Copyright 2011 Linaro Ltd.
9 *
10 * This program is free software; you can redistribute it and/or modify it
11 * under the terms and conditions of the GNU General Public License,
12 * version 2, as published by the Free Software Foundation.
13 *
14 * This program is distributed in the hope it will be useful, but WITHOUT
15 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
16 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
17 * more details.
18 *
19 * You should have received a copy of the GNU General Public License along with
20 * this program.  If not, see <http://www.gnu.org/licenses/>.
21 */
22
23#include <linux/bitops.h>
24#include <linux/genalloc.h>
25#include <linux/init.h>
26#include <linux/io.h>
27#include <linux/of_platform.h>
28#include <linux/suspend.h>
29#include <asm/suspend.h>
30#include <asm/fncpy.h>
31#include "core.h"
32
33/* Pointer to function copied to ocram */
34static u32 (*socfpga_sdram_self_refresh_in_ocram)(u32 sdr_base);
35
36static int socfpga_setup_ocram_self_refresh(void)
37{
38	struct platform_device *pdev;
39	phys_addr_t ocram_pbase;
40	struct device_node *np;
41	struct gen_pool *ocram_pool;
42	unsigned long ocram_base;
43	void __iomem *suspend_ocram_base;
44	int ret = 0;
45
46	np = of_find_compatible_node(NULL, NULL, "mmio-sram");
47	if (!np) {
48		pr_err("%s: Unable to find mmio-sram in dtb\n", __func__);
49		return -ENODEV;
50	}
51
52	pdev = of_find_device_by_node(np);
53	if (!pdev) {
54		pr_warn("%s: failed to find ocram device!\n", __func__);
55		ret = -ENODEV;
56		goto put_node;
57	}
58
59	ocram_pool = gen_pool_get(&pdev->dev, NULL);
60	if (!ocram_pool) {
61		pr_warn("%s: ocram pool unavailable!\n", __func__);
62		ret = -ENODEV;
63		goto put_node;
64	}
65
66	ocram_base = gen_pool_alloc(ocram_pool, socfpga_sdram_self_refresh_sz);
67	if (!ocram_base) {
68		pr_warn("%s: unable to alloc ocram!\n", __func__);
69		ret = -ENOMEM;
70		goto put_node;
71	}
72
73	ocram_pbase = gen_pool_virt_to_phys(ocram_pool, ocram_base);
74
75	suspend_ocram_base = __arm_ioremap_exec(ocram_pbase,
76						socfpga_sdram_self_refresh_sz,
77						false);
78	if (!suspend_ocram_base) {
79		pr_warn("%s: __arm_ioremap_exec failed!\n", __func__);
80		ret = -ENOMEM;
81		goto put_node;
82	}
83
84	/* Copy the code that puts DDR in self refresh to ocram */
85	socfpga_sdram_self_refresh_in_ocram =
86		(void *)fncpy(suspend_ocram_base,
87			      &socfpga_sdram_self_refresh,
88			      socfpga_sdram_self_refresh_sz);
89
90	WARN(!socfpga_sdram_self_refresh_in_ocram,
91	     "could not copy function to ocram");
92	if (!socfpga_sdram_self_refresh_in_ocram)
93		ret = -EFAULT;
94
95put_node:
96	of_node_put(np);
97
98	return ret;
99}
100
101static int socfpga_pm_suspend(unsigned long arg)
102{
103	u32 ret;
104
105	if (!sdr_ctl_base_addr)
106		return -EFAULT;
107
108	ret = socfpga_sdram_self_refresh_in_ocram((u32)sdr_ctl_base_addr);
109
110	pr_debug("%s self-refresh loops request=%d exit=%d\n", __func__,
111		 ret & 0xffff, (ret >> 16) & 0xffff);
112
113	return 0;
114}
115
116static int socfpga_pm_enter(suspend_state_t state)
117{
118	switch (state) {
119	case PM_SUSPEND_STANDBY:
120	case PM_SUSPEND_MEM:
121		outer_disable();
122		cpu_suspend(0, socfpga_pm_suspend);
123		outer_resume();
124		break;
125	default:
126		return -EINVAL;
127	}
128	return 0;
129}
130
131static const struct platform_suspend_ops socfpga_pm_ops = {
132	.valid	= suspend_valid_only_mem,
133	.enter	= socfpga_pm_enter,
134};
135
136static int __init socfpga_pm_init(void)
137{
138	int ret;
139
140	ret = socfpga_setup_ocram_self_refresh();
141	if (ret)
142		return ret;
143
144	suspend_set_ops(&socfpga_pm_ops);
145	pr_info("SoCFPGA initialized for DDR self-refresh during suspend.\n");
146
147	return 0;
148}
149arch_initcall(socfpga_pm_init);
150