1/*
 2 * Zynq power management
 3 *
 4 *  Copyright (C) 2012 - 2014 Xilinx
 5 *
 6 *  Sören Brinkmann <soren.brinkmann@xilinx.com>
 7 *
 8 * This program is free software: you can redistribute it and/or modify
 9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation, either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
20 */
21
22#include <linux/io.h>
23#include <linux/of_address.h>
24#include <linux/of_device.h>
25#include "common.h"
26
27/* register offsets */
28#define DDRC_CTRL_REG1_OFFS		0x60
29#define DDRC_DRAM_PARAM_REG3_OFFS	0x20
30
31/* bitfields */
32#define DDRC_CLOCKSTOP_MASK	BIT(23)
33#define DDRC_SELFREFRESH_MASK	BIT(12)
34
35static void __iomem *ddrc_base;
36
37/**
38 * zynq_pm_ioremap() - Create IO mappings
39 * @comp:	DT compatible string
40 * Return: Pointer to the mapped memory or NULL.
41 *
42 * Remap the memory region for a compatible DT node.
43 */
44static void __iomem *zynq_pm_ioremap(const char *comp)
45{
46	struct device_node *np;
47	void __iomem *base = NULL;
48
49	np = of_find_compatible_node(NULL, NULL, comp);
50	if (np) {
51		base = of_iomap(np, 0);
52		of_node_put(np);
53	} else {
54		pr_warn("%s: no compatible node found for '%s'\n", __func__,
55				comp);
56	}
57
58	return base;
59}
60
61/**
62 * zynq_pm_late_init() - Power management init
63 *
64 * Initialization of power management related features and infrastructure.
65 */
66void __init zynq_pm_late_init(void)
67{
68	u32 reg;
69
70	ddrc_base = zynq_pm_ioremap("xlnx,zynq-ddrc-a05");
71	if (!ddrc_base) {
72		pr_warn("%s: Unable to map DDRC IO memory.\n", __func__);
73	} else {
74		/*
75		 * Enable DDRC clock stop feature. The HW takes care of
76		 * entering/exiting the correct mode depending
77		 * on activity state.
78		 */
79		reg = readl(ddrc_base + DDRC_DRAM_PARAM_REG3_OFFS);
80		reg |= DDRC_CLOCKSTOP_MASK;
81		writel(reg, ddrc_base + DDRC_DRAM_PARAM_REG3_OFFS);
82	}
83}

 1// SPDX-License-Identifier: GPL-2.0-or-later
 2/*
 3 * Zynq power management
 4 *
 5 *  Copyright (C) 2012 - 2014 Xilinx
 6 *
 7 *  Sören Brinkmann <soren.brinkmann@xilinx.com>
 
 
 
 
 
 
 
 
 
 
 
 
 
 8 */
 9
10#include <linux/io.h>
11#include <linux/of_address.h>
12#include <linux/of_device.h>
13#include "common.h"
14
15/* register offsets */
16#define DDRC_CTRL_REG1_OFFS		0x60
17#define DDRC_DRAM_PARAM_REG3_OFFS	0x20
18
19/* bitfields */
20#define DDRC_CLOCKSTOP_MASK	BIT(23)
21#define DDRC_SELFREFRESH_MASK	BIT(12)
22
23static void __iomem *ddrc_base;
24
25/**
26 * zynq_pm_ioremap() - Create IO mappings
27 * @comp:	DT compatible string
28 * Return: Pointer to the mapped memory or NULL.
29 *
30 * Remap the memory region for a compatible DT node.
31 */
32static void __iomem *zynq_pm_ioremap(const char *comp)
33{
34	struct device_node *np;
35	void __iomem *base = NULL;
36
37	np = of_find_compatible_node(NULL, NULL, comp);
38	if (np) {
39		base = of_iomap(np, 0);
40		of_node_put(np);
41	} else {
42		pr_warn("%s: no compatible node found for '%s'\n", __func__,
43				comp);
44	}
45
46	return base;
47}
48
49/**
50 * zynq_pm_late_init() - Power management init
51 *
52 * Initialization of power management related features and infrastructure.
53 */
54void __init zynq_pm_late_init(void)
55{
56	u32 reg;
57
58	ddrc_base = zynq_pm_ioremap("xlnx,zynq-ddrc-a05");
59	if (!ddrc_base) {
60		pr_warn("%s: Unable to map DDRC IO memory.\n", __func__);
61	} else {
62		/*
63		 * Enable DDRC clock stop feature. The HW takes care of
64		 * entering/exiting the correct mode depending
65		 * on activity state.
66		 */
67		reg = readl(ddrc_base + DDRC_DRAM_PARAM_REG3_OFFS);
68		reg |= DDRC_CLOCKSTOP_MASK;
69		writel(reg, ddrc_base + DDRC_DRAM_PARAM_REG3_OFFS);
70	}
71}