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8e8e69d6 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
fedf42b5 MF |
2 | /* |
3 | * Copyright (c) 2015, National Instruments Corp. | |
4 | * | |
5 | * Xilinx Zynq Reset controller driver | |
6 | * | |
fadb03cd | 7 | * Author: Moritz Fischer <moritz.fischer@ettus.com> |
fedf42b5 MF |
8 | */ |
9 | ||
10 | #include <linux/err.h> | |
11 | #include <linux/io.h> | |
fadb03cd | 12 | #include <linux/init.h> |
fedf42b5 MF |
13 | #include <linux/mfd/syscon.h> |
14 | #include <linux/of.h> | |
15 | #include <linux/platform_device.h> | |
16 | #include <linux/reset-controller.h> | |
17 | #include <linux/regmap.h> | |
18 | #include <linux/types.h> | |
19 | ||
20 | struct zynq_reset_data { | |
21 | struct regmap *slcr; | |
22 | struct reset_controller_dev rcdev; | |
23 | u32 offset; | |
24 | }; | |
25 | ||
26 | #define to_zynq_reset_data(p) \ | |
27 | container_of((p), struct zynq_reset_data, rcdev) | |
28 | ||
29 | static int zynq_reset_assert(struct reset_controller_dev *rcdev, | |
30 | unsigned long id) | |
31 | { | |
32 | struct zynq_reset_data *priv = to_zynq_reset_data(rcdev); | |
33 | ||
34 | int bank = id / BITS_PER_LONG; | |
35 | int offset = id % BITS_PER_LONG; | |
36 | ||
37 | pr_debug("%s: %s reset bank %u offset %u\n", KBUILD_MODNAME, __func__, | |
38 | bank, offset); | |
39 | ||
40 | return regmap_update_bits(priv->slcr, | |
41 | priv->offset + (bank * 4), | |
42 | BIT(offset), | |
43 | BIT(offset)); | |
44 | } | |
45 | ||
46 | static int zynq_reset_deassert(struct reset_controller_dev *rcdev, | |
47 | unsigned long id) | |
48 | { | |
49 | struct zynq_reset_data *priv = to_zynq_reset_data(rcdev); | |
50 | ||
51 | int bank = id / BITS_PER_LONG; | |
52 | int offset = id % BITS_PER_LONG; | |
53 | ||
54 | pr_debug("%s: %s reset bank %u offset %u\n", KBUILD_MODNAME, __func__, | |
55 | bank, offset); | |
56 | ||
57 | return regmap_update_bits(priv->slcr, | |
58 | priv->offset + (bank * 4), | |
59 | BIT(offset), | |
60 | ~BIT(offset)); | |
61 | } | |
62 | ||
63 | static int zynq_reset_status(struct reset_controller_dev *rcdev, | |
64 | unsigned long id) | |
65 | { | |
66 | struct zynq_reset_data *priv = to_zynq_reset_data(rcdev); | |
67 | ||
68 | int bank = id / BITS_PER_LONG; | |
69 | int offset = id % BITS_PER_LONG; | |
70 | int ret; | |
71 | u32 reg; | |
72 | ||
73 | pr_debug("%s: %s reset bank %u offset %u\n", KBUILD_MODNAME, __func__, | |
74 | bank, offset); | |
75 | ||
76 | ret = regmap_read(priv->slcr, priv->offset + (bank * 4), ®); | |
77 | if (ret) | |
78 | return ret; | |
79 | ||
80 | return !!(reg & BIT(offset)); | |
81 | } | |
82 | ||
356d108f | 83 | static const struct reset_control_ops zynq_reset_ops = { |
fedf42b5 MF |
84 | .assert = zynq_reset_assert, |
85 | .deassert = zynq_reset_deassert, | |
86 | .status = zynq_reset_status, | |
87 | }; | |
88 | ||
89 | static int zynq_reset_probe(struct platform_device *pdev) | |
90 | { | |
91 | struct resource *res; | |
92 | struct zynq_reset_data *priv; | |
93 | ||
94 | priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); | |
95 | if (!priv) | |
96 | return -ENOMEM; | |
97 | platform_set_drvdata(pdev, priv); | |
98 | ||
99 | priv->slcr = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, | |
100 | "syscon"); | |
101 | if (IS_ERR(priv->slcr)) { | |
102 | dev_err(&pdev->dev, "unable to get zynq-slcr regmap"); | |
103 | return PTR_ERR(priv->slcr); | |
104 | } | |
105 | ||
106 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
107 | if (!res) { | |
108 | dev_err(&pdev->dev, "missing IO resource\n"); | |
109 | return -ENODEV; | |
110 | } | |
111 | ||
112 | priv->offset = res->start; | |
113 | ||
114 | priv->rcdev.owner = THIS_MODULE; | |
115 | priv->rcdev.nr_resets = resource_size(res) / 4 * BITS_PER_LONG; | |
116 | priv->rcdev.ops = &zynq_reset_ops; | |
117 | priv->rcdev.of_node = pdev->dev.of_node; | |
fedf42b5 | 118 | |
da1fda2a | 119 | return devm_reset_controller_register(&pdev->dev, &priv->rcdev); |
fedf42b5 MF |
120 | } |
121 | ||
122 | static const struct of_device_id zynq_reset_dt_ids[] = { | |
123 | { .compatible = "xlnx,zynq-reset", }, | |
124 | { /* sentinel */ }, | |
125 | }; | |
126 | ||
127 | static struct platform_driver zynq_reset_driver = { | |
128 | .probe = zynq_reset_probe, | |
fedf42b5 MF |
129 | .driver = { |
130 | .name = KBUILD_MODNAME, | |
131 | .of_match_table = zynq_reset_dt_ids, | |
132 | }, | |
133 | }; | |
fadb03cd | 134 | builtin_platform_driver(zynq_reset_driver); |