1 // SPDX-License-Identifier: GPL-2.0
2 //
3 // reset-uniphier-usb3.c - USB3 reset driver for UniPhier
4 // Copyright 2018 Socionext Inc.
5 // Author: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
6
7 #include <linux/clk.h>
8 #include <linux/module.h>
9 #include <linux/of_device.h>
10 #include <linux/platform_device.h>
11 #include <linux/reset.h>
12
13 #include "reset-simple.h"
14
15 #define MAX_CLKS 2
16 #define MAX_RSTS 2
17
18 struct uniphier_usb3_reset_soc_data {
19 int nclks;
20 const char * const *clock_names;
21 int nrsts;
22 const char * const *reset_names;
23 };
24
25 struct uniphier_usb3_reset_priv {
26 struct clk_bulk_data clk[MAX_CLKS];
27 struct reset_control *rst[MAX_RSTS];
28 struct reset_simple_data rdata;
29 const struct uniphier_usb3_reset_soc_data *data;
30 };
31
uniphier_usb3_reset_probe(struct platform_device * pdev)32 static int uniphier_usb3_reset_probe(struct platform_device *pdev)
33 {
34 struct device *dev = &pdev->dev;
35 struct uniphier_usb3_reset_priv *priv;
36 struct resource *res;
37 resource_size_t size;
38 const char *name;
39 int i, ret, nr;
40
41 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
42 if (!priv)
43 return -ENOMEM;
44
45 priv->data = of_device_get_match_data(dev);
46 if (WARN_ON(!priv->data || priv->data->nclks > MAX_CLKS ||
47 priv->data->nrsts > MAX_RSTS))
48 return -EINVAL;
49
50 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
51 size = resource_size(res);
52 priv->rdata.membase = devm_ioremap_resource(dev, res);
53 if (IS_ERR(priv->rdata.membase))
54 return PTR_ERR(priv->rdata.membase);
55
56 for (i = 0; i < priv->data->nclks; i++)
57 priv->clk[i].id = priv->data->clock_names[i];
58 ret = devm_clk_bulk_get(dev, priv->data->nclks, priv->clk);
59 if (ret)
60 return ret;
61
62 for (i = 0; i < priv->data->nrsts; i++) {
63 name = priv->data->reset_names[i];
64 priv->rst[i] = devm_reset_control_get_shared(dev, name);
65 if (IS_ERR(priv->rst[i]))
66 return PTR_ERR(priv->rst[i]);
67 }
68
69 ret = clk_bulk_prepare_enable(priv->data->nclks, priv->clk);
70 if (ret)
71 return ret;
72
73 for (nr = 0; nr < priv->data->nrsts; nr++) {
74 ret = reset_control_deassert(priv->rst[nr]);
75 if (ret)
76 goto out_rst_assert;
77 }
78
79 spin_lock_init(&priv->rdata.lock);
80 priv->rdata.rcdev.owner = THIS_MODULE;
81 priv->rdata.rcdev.nr_resets = size * BITS_PER_BYTE;
82 priv->rdata.rcdev.ops = &reset_simple_ops;
83 priv->rdata.rcdev.of_node = dev->of_node;
84 priv->rdata.active_low = true;
85
86 platform_set_drvdata(pdev, priv);
87
88 ret = devm_reset_controller_register(dev, &priv->rdata.rcdev);
89 if (ret)
90 goto out_rst_assert;
91
92 return 0;
93
94 out_rst_assert:
95 while (nr--)
96 reset_control_assert(priv->rst[nr]);
97
98 clk_bulk_disable_unprepare(priv->data->nclks, priv->clk);
99
100 return ret;
101 }
102
uniphier_usb3_reset_remove(struct platform_device * pdev)103 static int uniphier_usb3_reset_remove(struct platform_device *pdev)
104 {
105 struct uniphier_usb3_reset_priv *priv = platform_get_drvdata(pdev);
106 int i;
107
108 for (i = 0; i < priv->data->nrsts; i++)
109 reset_control_assert(priv->rst[i]);
110
111 clk_bulk_disable_unprepare(priv->data->nclks, priv->clk);
112
113 return 0;
114 }
115
116 static const char * const uniphier_pro4_clock_reset_names[] = {
117 "gio", "link",
118 };
119
120 static const struct uniphier_usb3_reset_soc_data uniphier_pro4_data = {
121 .nclks = ARRAY_SIZE(uniphier_pro4_clock_reset_names),
122 .clock_names = uniphier_pro4_clock_reset_names,
123 .nrsts = ARRAY_SIZE(uniphier_pro4_clock_reset_names),
124 .reset_names = uniphier_pro4_clock_reset_names,
125 };
126
127 static const char * const uniphier_pxs2_clock_reset_names[] = {
128 "link",
129 };
130
131 static const struct uniphier_usb3_reset_soc_data uniphier_pxs2_data = {
132 .nclks = ARRAY_SIZE(uniphier_pxs2_clock_reset_names),
133 .clock_names = uniphier_pxs2_clock_reset_names,
134 .nrsts = ARRAY_SIZE(uniphier_pxs2_clock_reset_names),
135 .reset_names = uniphier_pxs2_clock_reset_names,
136 };
137
138 static const struct of_device_id uniphier_usb3_reset_match[] = {
139 {
140 .compatible = "socionext,uniphier-pro4-usb3-reset",
141 .data = &uniphier_pro4_data,
142 },
143 {
144 .compatible = "socionext,uniphier-pxs2-usb3-reset",
145 .data = &uniphier_pxs2_data,
146 },
147 {
148 .compatible = "socionext,uniphier-ld20-usb3-reset",
149 .data = &uniphier_pxs2_data,
150 },
151 {
152 .compatible = "socionext,uniphier-pxs3-usb3-reset",
153 .data = &uniphier_pxs2_data,
154 },
155 { /* Sentinel */ }
156 };
157 MODULE_DEVICE_TABLE(of, uniphier_usb3_reset_match);
158
159 static struct platform_driver uniphier_usb3_reset_driver = {
160 .probe = uniphier_usb3_reset_probe,
161 .remove = uniphier_usb3_reset_remove,
162 .driver = {
163 .name = "uniphier-usb3-reset",
164 .of_match_table = uniphier_usb3_reset_match,
165 },
166 };
167 module_platform_driver(uniphier_usb3_reset_driver);
168
169 MODULE_AUTHOR("Kunihiko Hayashi <hayashi.kunihiko@socionext.com>");
170 MODULE_DESCRIPTION("UniPhier USB3 Reset Driver");
171 MODULE_LICENSE("GPL");
172