blob: 79c32ca84ef161a9205fc9bb061d187188889035 [file] [log] [blame]
Steffen Trumtrara39a4932014-04-15 17:06:44 -05001/*
2 * Copyright 2014 Steffen Trumtrar <s.trumtrar@pengutronix.de>
3 *
4 * based on
5 * Allwinner SoCs Reset Controller driver
6 *
7 * Copyright 2013 Maxime Ripard
8 *
9 * Maxime Ripard <maxime.ripard@free-electrons.com>
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
15 */
16
17#include <linux/err.h>
18#include <linux/io.h>
19#include <linux/module.h>
20#include <linux/of.h>
21#include <linux/platform_device.h>
22#include <linux/reset-controller.h>
23#include <linux/spinlock.h>
24#include <linux/types.h>
25
26#define NR_BANKS 4
27#define OFFSET_MODRST 0x10
28
29struct socfpga_reset_data {
30 spinlock_t lock;
31 void __iomem *membase;
32 struct reset_controller_dev rcdev;
33};
34
35static int socfpga_reset_assert(struct reset_controller_dev *rcdev,
36 unsigned long id)
37{
38 struct socfpga_reset_data *data = container_of(rcdev,
39 struct socfpga_reset_data,
40 rcdev);
41 int bank = id / BITS_PER_LONG;
42 int offset = id % BITS_PER_LONG;
43 unsigned long flags;
44 u32 reg;
45
46 spin_lock_irqsave(&data->lock, flags);
47
48 reg = readl(data->membase + OFFSET_MODRST + (bank * NR_BANKS));
49 writel(reg | BIT(offset), data->membase + OFFSET_MODRST +
50 (bank * NR_BANKS));
51 spin_unlock_irqrestore(&data->lock, flags);
52
53 return 0;
54}
55
56static int socfpga_reset_deassert(struct reset_controller_dev *rcdev,
57 unsigned long id)
58{
59 struct socfpga_reset_data *data = container_of(rcdev,
60 struct socfpga_reset_data,
61 rcdev);
62
63 int bank = id / BITS_PER_LONG;
64 int offset = id % BITS_PER_LONG;
65 unsigned long flags;
66 u32 reg;
67
68 spin_lock_irqsave(&data->lock, flags);
69
70 reg = readl(data->membase + OFFSET_MODRST + (bank * NR_BANKS));
71 writel(reg & ~BIT(offset), data->membase + OFFSET_MODRST +
72 (bank * NR_BANKS));
73
74 spin_unlock_irqrestore(&data->lock, flags);
75
76 return 0;
77}
78
79static struct reset_control_ops socfpga_reset_ops = {
80 .assert = socfpga_reset_assert,
81 .deassert = socfpga_reset_deassert,
82};
83
84static int socfpga_reset_probe(struct platform_device *pdev)
85{
86 struct socfpga_reset_data *data;
87 struct resource *res;
88
89 /*
90 * The binding was mainlined without the required property.
91 * Do not continue, when we encounter an old DT.
92 */
93 if (!of_find_property(pdev->dev.of_node, "#reset-cells", NULL)) {
94 dev_err(&pdev->dev, "%s missing #reset-cells property\n",
95 pdev->dev.of_node->full_name);
96 return -EINVAL;
97 }
98
99 data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
100 if (!data)
101 return -ENOMEM;
102
103 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
104 data->membase = devm_ioremap_resource(&pdev->dev, res);
105 if (IS_ERR(data->membase))
106 return PTR_ERR(data->membase);
107
108 spin_lock_init(&data->lock);
109
110 data->rcdev.owner = THIS_MODULE;
111 data->rcdev.nr_resets = NR_BANKS * BITS_PER_LONG;
112 data->rcdev.ops = &socfpga_reset_ops;
113 data->rcdev.of_node = pdev->dev.of_node;
114 reset_controller_register(&data->rcdev);
115
116 return 0;
117}
118
119static int socfpga_reset_remove(struct platform_device *pdev)
120{
121 struct socfpga_reset_data *data = platform_get_drvdata(pdev);
122
123 reset_controller_unregister(&data->rcdev);
124
125 return 0;
126}
127
128static const struct of_device_id socfpga_reset_dt_ids[] = {
129 { .compatible = "altr,rst-mgr", },
130 { /* sentinel */ },
131};
132
133static struct platform_driver socfpga_reset_driver = {
134 .probe = socfpga_reset_probe,
135 .remove = socfpga_reset_remove,
136 .driver = {
137 .name = "socfpga-reset",
138 .owner = THIS_MODULE,
139 .of_match_table = socfpga_reset_dt_ids,
140 },
141};
142module_platform_driver(socfpga_reset_driver);
143
144MODULE_AUTHOR("Steffen Trumtrar <s.trumtrar@pengutronix.de");
145MODULE_DESCRIPTION("Socfpga Reset Controller Driver");
146MODULE_LICENSE("GPL");