blob: 970b1ad602938b2040cda2294304fe7ebb0f4fab [file] [log] [blame]
Antoine Ténartbd132512014-09-03 09:48:20 +02001/*
2 * Copyright (C) 2014 Marvell Technology Group Ltd.
3 *
4 * Antoine Tenart <antoine.tenart@free-electrons.com>
5 * Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
6 *
7 * This file is licensed under the terms of the GNU General Public
8 * License version 2. This program is licensed "as is" without any
9 * warranty of any kind, whether express or implied.
10 */
11
12#include <linux/delay.h>
13#include <linux/io.h>
Antoine Tenartaed6f3c2015-05-16 00:41:25 +020014#include <linux/mfd/syscon.h>
Antoine Ténartbd132512014-09-03 09:48:20 +020015#include <linux/module.h>
16#include <linux/of.h>
17#include <linux/of_address.h>
18#include <linux/platform_device.h>
Antoine Tenartaed6f3c2015-05-16 00:41:25 +020019#include <linux/regmap.h>
Antoine Ténartbd132512014-09-03 09:48:20 +020020#include <linux/reset-controller.h>
21#include <linux/slab.h>
22#include <linux/types.h>
23
24#define BERLIN_MAX_RESETS 32
25
26#define to_berlin_reset_priv(p) \
27 container_of((p), struct berlin_reset_priv, rcdev)
28
29struct berlin_reset_priv {
Antoine Tenartaed6f3c2015-05-16 00:41:25 +020030 struct regmap *regmap;
Antoine Ténartbd132512014-09-03 09:48:20 +020031 struct reset_controller_dev rcdev;
32};
33
34static int berlin_reset_reset(struct reset_controller_dev *rcdev,
35 unsigned long id)
36{
37 struct berlin_reset_priv *priv = to_berlin_reset_priv(rcdev);
38 int offset = id >> 8;
39 int mask = BIT(id & 0x1f);
40
Antoine Tenartbfff6292015-05-16 00:53:44 +020041 regmap_write(priv->regmap, offset, mask);
Antoine Ténartbd132512014-09-03 09:48:20 +020042
43 /* let the reset be effective */
44 udelay(10);
45
46 return 0;
47}
48
49static struct reset_control_ops berlin_reset_ops = {
50 .reset = berlin_reset_reset,
51};
52
53static int berlin_reset_xlate(struct reset_controller_dev *rcdev,
54 const struct of_phandle_args *reset_spec)
55{
Antoine Ténartbd132512014-09-03 09:48:20 +020056 unsigned offset, bit;
57
58 if (WARN_ON(reset_spec->args_count != rcdev->of_reset_n_cells))
59 return -EINVAL;
60
61 offset = reset_spec->args[0];
62 bit = reset_spec->args[1];
63
Antoine Ténartbd132512014-09-03 09:48:20 +020064 if (bit >= BERLIN_MAX_RESETS)
65 return -EINVAL;
66
67 return (offset << 8) | bit;
68}
69
Antoine Tenartaed6f3c2015-05-16 00:41:25 +020070static int berlin2_reset_probe(struct platform_device *pdev)
71{
72 struct device_node *parent_np = of_get_parent(pdev->dev.of_node);
73 struct berlin_reset_priv *priv;
74
75 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
76 if (!priv)
77 return -ENOMEM;
78
79 priv->regmap = syscon_node_to_regmap(parent_np);
80 of_node_put(parent_np);
81 if (IS_ERR(priv->regmap))
82 return PTR_ERR(priv->regmap);
83
84 priv->rcdev.owner = THIS_MODULE;
85 priv->rcdev.ops = &berlin_reset_ops;
86 priv->rcdev.of_node = pdev->dev.of_node;
87 priv->rcdev.of_reset_n_cells = 2;
88 priv->rcdev.of_xlate = berlin_reset_xlate;
89
Masahiro Yamadad1f15aa2015-11-05 14:54:56 +090090 return reset_controller_register(&priv->rcdev);
Antoine Tenartaed6f3c2015-05-16 00:41:25 +020091}
92
93static const struct of_device_id berlin_reset_dt_match[] = {
94 { .compatible = "marvell,berlin2-reset" },
95 { },
96};
97MODULE_DEVICE_TABLE(of, berlin_reset_dt_match);
98
99static struct platform_driver berlin_reset_driver = {
100 .probe = berlin2_reset_probe,
101 .driver = {
102 .name = "berlin2-reset",
103 .of_match_table = berlin_reset_dt_match,
104 },
105};
106module_platform_driver(berlin_reset_driver);
107
108MODULE_AUTHOR("Antoine Tenart <antoine.tenart@free-electrons.com>");
109MODULE_AUTHOR("Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>");
110MODULE_DESCRIPTION("Marvell Berlin reset driver");
111MODULE_LICENSE("GPL");