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a39a4939 ST |
1 | /* |
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 | |
a39a4939 ST |
27 | |
28 | struct socfpga_reset_data { | |
29 | spinlock_t lock; | |
30 | void __iomem *membase; | |
27e44646 | 31 | u32 modrst_offset; |
a39a4939 ST |
32 | struct reset_controller_dev rcdev; |
33 | }; | |
34 | ||
35 | static 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 | ||
27e44646 DN |
48 | reg = readl(data->membase + data->modrst_offset + (bank * NR_BANKS)); |
49 | writel(reg | BIT(offset), data->membase + data->modrst_offset + | |
a39a4939 ST |
50 | (bank * NR_BANKS)); |
51 | spin_unlock_irqrestore(&data->lock, flags); | |
52 | ||
53 | return 0; | |
54 | } | |
55 | ||
56 | static 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 | ||
27e44646 DN |
70 | reg = readl(data->membase + data->modrst_offset + (bank * NR_BANKS)); |
71 | writel(reg & ~BIT(offset), data->membase + data->modrst_offset + | |
a39a4939 ST |
72 | (bank * NR_BANKS)); |
73 | ||
74 | spin_unlock_irqrestore(&data->lock, flags); | |
75 | ||
76 | return 0; | |
77 | } | |
78 | ||
f200890f DN |
79 | static int socfpga_reset_status(struct reset_controller_dev *rcdev, |
80 | unsigned long id) | |
81 | { | |
82 | struct socfpga_reset_data *data = container_of(rcdev, | |
83 | struct socfpga_reset_data, rcdev); | |
84 | int bank = id / BITS_PER_LONG; | |
85 | int offset = id % BITS_PER_LONG; | |
86 | u32 reg; | |
87 | ||
27e44646 | 88 | reg = readl(data->membase + data->modrst_offset + (bank * NR_BANKS)); |
f200890f DN |
89 | |
90 | return !(reg & BIT(offset)); | |
91 | } | |
92 | ||
387eb3f3 | 93 | static const struct reset_control_ops socfpga_reset_ops = { |
a39a4939 ST |
94 | .assert = socfpga_reset_assert, |
95 | .deassert = socfpga_reset_deassert, | |
f200890f | 96 | .status = socfpga_reset_status, |
a39a4939 ST |
97 | }; |
98 | ||
99 | static int socfpga_reset_probe(struct platform_device *pdev) | |
100 | { | |
101 | struct socfpga_reset_data *data; | |
102 | struct resource *res; | |
27e44646 DN |
103 | struct device *dev = &pdev->dev; |
104 | struct device_node *np = dev->of_node; | |
a39a4939 ST |
105 | |
106 | /* | |
107 | * The binding was mainlined without the required property. | |
108 | * Do not continue, when we encounter an old DT. | |
109 | */ | |
110 | if (!of_find_property(pdev->dev.of_node, "#reset-cells", NULL)) { | |
111 | dev_err(&pdev->dev, "%s missing #reset-cells property\n", | |
112 | pdev->dev.of_node->full_name); | |
113 | return -EINVAL; | |
114 | } | |
115 | ||
116 | data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); | |
117 | if (!data) | |
118 | return -ENOMEM; | |
119 | ||
120 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
121 | data->membase = devm_ioremap_resource(&pdev->dev, res); | |
122 | if (IS_ERR(data->membase)) | |
123 | return PTR_ERR(data->membase); | |
124 | ||
27e44646 DN |
125 | if (of_property_read_u32(np, "altr,modrst-offset", &data->modrst_offset)) { |
126 | dev_warn(dev, "missing altr,modrst-offset property, assuming 0x10!\n"); | |
127 | data->modrst_offset = 0x10; | |
128 | } | |
129 | ||
a39a4939 ST |
130 | spin_lock_init(&data->lock); |
131 | ||
132 | data->rcdev.owner = THIS_MODULE; | |
133 | data->rcdev.nr_resets = NR_BANKS * BITS_PER_LONG; | |
134 | data->rcdev.ops = &socfpga_reset_ops; | |
135 | data->rcdev.of_node = pdev->dev.of_node; | |
a39a4939 | 136 | |
dc22e08e | 137 | return devm_reset_controller_register(dev, &data->rcdev); |
a39a4939 ST |
138 | } |
139 | ||
140 | static const struct of_device_id socfpga_reset_dt_ids[] = { | |
141 | { .compatible = "altr,rst-mgr", }, | |
142 | { /* sentinel */ }, | |
143 | }; | |
144 | ||
145 | static struct platform_driver socfpga_reset_driver = { | |
146 | .probe = socfpga_reset_probe, | |
a39a4939 ST |
147 | .driver = { |
148 | .name = "socfpga-reset", | |
a39a4939 ST |
149 | .of_match_table = socfpga_reset_dt_ids, |
150 | }, | |
151 | }; | |
152 | module_platform_driver(socfpga_reset_driver); | |
153 | ||
154 | MODULE_AUTHOR("Steffen Trumtrar <s.trumtrar@pengutronix.de"); | |
155 | MODULE_DESCRIPTION("Socfpga Reset Controller Driver"); | |
156 | MODULE_LICENSE("GPL"); |