1 // SPDX-License-Identifier: GPL-2.0
2 //
3 // reset-uniphier-glue.c - Glue layer 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 #include <linux/reset/reset-simple.h>
13 
14 #define MAX_CLKS	2
15 #define MAX_RSTS	2
16 
17 struct uniphier_glue_reset_soc_data {
18 	int nclks;
19 	const char * const *clock_names;
20 	int nrsts;
21 	const char * const *reset_names;
22 };
23 
24 struct uniphier_glue_reset_priv {
25 	struct clk_bulk_data clk[MAX_CLKS];
26 	struct reset_control *rst[MAX_RSTS];
27 	struct reset_simple_data rdata;
28 	const struct uniphier_glue_reset_soc_data *data;
29 };
30 
31 static int uniphier_glue_reset_probe(struct platform_device *pdev)
32 {
33 	struct device *dev = &pdev->dev;
34 	struct uniphier_glue_reset_priv *priv;
35 	struct resource *res;
36 	resource_size_t size;
37 	const char *name;
38 	int i, ret, nr;
39 
40 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
41 	if (!priv)
42 		return -ENOMEM;
43 
44 	priv->data = of_device_get_match_data(dev);
45 	if (WARN_ON(!priv->data || priv->data->nclks > MAX_CLKS ||
46 		    priv->data->nrsts > MAX_RSTS))
47 		return -EINVAL;
48 
49 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
50 	size = resource_size(res);
51 	priv->rdata.membase = devm_ioremap_resource(dev, res);
52 	if (IS_ERR(priv->rdata.membase))
53 		return PTR_ERR(priv->rdata.membase);
54 
55 	for (i = 0; i < priv->data->nclks; i++)
56 		priv->clk[i].id = priv->data->clock_names[i];
57 	ret = devm_clk_bulk_get(dev, priv->data->nclks, priv->clk);
58 	if (ret)
59 		return ret;
60 
61 	for (i = 0; i < priv->data->nrsts; i++) {
62 		name = priv->data->reset_names[i];
63 		priv->rst[i] = devm_reset_control_get_shared(dev, name);
64 		if (IS_ERR(priv->rst[i]))
65 			return PTR_ERR(priv->rst[i]);
66 	}
67 
68 	ret = clk_bulk_prepare_enable(priv->data->nclks, priv->clk);
69 	if (ret)
70 		return ret;
71 
72 	for (nr = 0; nr < priv->data->nrsts; nr++) {
73 		ret = reset_control_deassert(priv->rst[nr]);
74 		if (ret)
75 			goto out_rst_assert;
76 	}
77 
78 	spin_lock_init(&priv->rdata.lock);
79 	priv->rdata.rcdev.owner = THIS_MODULE;
80 	priv->rdata.rcdev.nr_resets = size * BITS_PER_BYTE;
81 	priv->rdata.rcdev.ops = &reset_simple_ops;
82 	priv->rdata.rcdev.of_node = dev->of_node;
83 	priv->rdata.active_low = true;
84 
85 	platform_set_drvdata(pdev, priv);
86 
87 	ret = devm_reset_controller_register(dev, &priv->rdata.rcdev);
88 	if (ret)
89 		goto out_rst_assert;
90 
91 	return 0;
92 
93 out_rst_assert:
94 	while (nr--)
95 		reset_control_assert(priv->rst[nr]);
96 
97 	clk_bulk_disable_unprepare(priv->data->nclks, priv->clk);
98 
99 	return ret;
100 }
101 
102 static int uniphier_glue_reset_remove(struct platform_device *pdev)
103 {
104 	struct uniphier_glue_reset_priv *priv = platform_get_drvdata(pdev);
105 	int i;
106 
107 	for (i = 0; i < priv->data->nrsts; i++)
108 		reset_control_assert(priv->rst[i]);
109 
110 	clk_bulk_disable_unprepare(priv->data->nclks, priv->clk);
111 
112 	return 0;
113 }
114 
115 static const char * const uniphier_pro4_clock_reset_names[] = {
116 	"gio", "link",
117 };
118 
119 static const struct uniphier_glue_reset_soc_data uniphier_pro4_data = {
120 	.nclks = ARRAY_SIZE(uniphier_pro4_clock_reset_names),
121 	.clock_names = uniphier_pro4_clock_reset_names,
122 	.nrsts = ARRAY_SIZE(uniphier_pro4_clock_reset_names),
123 	.reset_names = uniphier_pro4_clock_reset_names,
124 };
125 
126 static const char * const uniphier_pxs2_clock_reset_names[] = {
127 	"link",
128 };
129 
130 static const struct uniphier_glue_reset_soc_data uniphier_pxs2_data = {
131 	.nclks = ARRAY_SIZE(uniphier_pxs2_clock_reset_names),
132 	.clock_names = uniphier_pxs2_clock_reset_names,
133 	.nrsts = ARRAY_SIZE(uniphier_pxs2_clock_reset_names),
134 	.reset_names = uniphier_pxs2_clock_reset_names,
135 };
136 
137 static const struct of_device_id uniphier_glue_reset_match[] = {
138 	{
139 		.compatible = "socionext,uniphier-pro4-usb3-reset",
140 		.data = &uniphier_pro4_data,
141 	},
142 	{
143 		.compatible = "socionext,uniphier-pro5-usb3-reset",
144 		.data = &uniphier_pro4_data,
145 	},
146 	{
147 		.compatible = "socionext,uniphier-pxs2-usb3-reset",
148 		.data = &uniphier_pxs2_data,
149 	},
150 	{
151 		.compatible = "socionext,uniphier-ld20-usb3-reset",
152 		.data = &uniphier_pxs2_data,
153 	},
154 	{
155 		.compatible = "socionext,uniphier-pxs3-usb3-reset",
156 		.data = &uniphier_pxs2_data,
157 	},
158 	{
159 		.compatible = "socionext,uniphier-pro4-ahci-reset",
160 		.data = &uniphier_pro4_data,
161 	},
162 	{
163 		.compatible = "socionext,uniphier-pxs2-ahci-reset",
164 		.data = &uniphier_pxs2_data,
165 	},
166 	{
167 		.compatible = "socionext,uniphier-pxs3-ahci-reset",
168 		.data = &uniphier_pxs2_data,
169 	},
170 	{ /* Sentinel */ }
171 };
172 MODULE_DEVICE_TABLE(of, uniphier_glue_reset_match);
173 
174 static struct platform_driver uniphier_glue_reset_driver = {
175 	.probe = uniphier_glue_reset_probe,
176 	.remove = uniphier_glue_reset_remove,
177 	.driver = {
178 		.name = "uniphier-glue-reset",
179 		.of_match_table = uniphier_glue_reset_match,
180 	},
181 };
182 module_platform_driver(uniphier_glue_reset_driver);
183 
184 MODULE_AUTHOR("Kunihiko Hayashi <hayashi.kunihiko@socionext.com>");
185 MODULE_DESCRIPTION("UniPhier Glue layer reset driver");
186 MODULE_LICENSE("GPL");
187