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bd13251f AT |
1 | /* |
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> | |
aed6f3ca | 14 | #include <linux/mfd/syscon.h> |
bd13251f AT |
15 | #include <linux/module.h> |
16 | #include <linux/of.h> | |
17 | #include <linux/of_address.h> | |
18 | #include <linux/platform_device.h> | |
aed6f3ca | 19 | #include <linux/regmap.h> |
bd13251f AT |
20 | #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 | ||
29 | struct berlin_reset_priv { | |
aed6f3ca | 30 | struct regmap *regmap; |
bd13251f AT |
31 | struct reset_controller_dev rcdev; |
32 | }; | |
33 | ||
34 | static 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 | ||
bfff6296 | 41 | regmap_write(priv->regmap, offset, mask); |
bd13251f AT |
42 | |
43 | /* let the reset be effective */ | |
44 | udelay(10); | |
45 | ||
46 | return 0; | |
47 | } | |
48 | ||
49 | static struct reset_control_ops berlin_reset_ops = { | |
50 | .reset = berlin_reset_reset, | |
51 | }; | |
52 | ||
53 | static int berlin_reset_xlate(struct reset_controller_dev *rcdev, | |
54 | const struct of_phandle_args *reset_spec) | |
55 | { | |
bd13251f AT |
56 | 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 | ||
bd13251f AT |
64 | if (bit >= BERLIN_MAX_RESETS) |
65 | return -EINVAL; | |
66 | ||
67 | return (offset << 8) | bit; | |
68 | } | |
69 | ||
aed6f3ca AT |
70 | static 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 | ||
d1f15aa0 | 90 | return reset_controller_register(&priv->rcdev); |
aed6f3ca AT |
91 | } |
92 | ||
93 | static const struct of_device_id berlin_reset_dt_match[] = { | |
94 | { .compatible = "marvell,berlin2-reset" }, | |
95 | { }, | |
96 | }; | |
97 | MODULE_DEVICE_TABLE(of, berlin_reset_dt_match); | |
98 | ||
99 | static 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 | }; | |
106 | module_platform_driver(berlin_reset_driver); | |
107 | ||
108 | MODULE_AUTHOR("Antoine Tenart <antoine.tenart@free-electrons.com>"); | |
109 | MODULE_AUTHOR("Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>"); | |
110 | MODULE_DESCRIPTION("Marvell Berlin reset driver"); | |
111 | MODULE_LICENSE("GPL"); |