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);