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_bulk_data rst[MAX_RSTS];
27 	struct reset_simple_data rdata;
28 	const struct uniphier_glue_reset_soc_data *data;
29 };
30 
uniphier_clk_disable(void * _priv)31 static void uniphier_clk_disable(void *_priv)
32 {
33 	struct uniphier_glue_reset_priv *priv = _priv;
34 
35 	clk_bulk_disable_unprepare(priv->data->nclks, priv->clk);
36 }
37 
uniphier_rst_assert(void * _priv)38 static void uniphier_rst_assert(void *_priv)
39 {
40 	struct uniphier_glue_reset_priv *priv = _priv;
41 
42 	reset_control_bulk_assert(priv->data->nrsts, priv->rst);
43 }
44 
uniphier_glue_reset_probe(struct platform_device * pdev)45 static int uniphier_glue_reset_probe(struct platform_device *pdev)
46 {
47 	struct device *dev = &pdev->dev;
48 	struct uniphier_glue_reset_priv *priv;
49 	struct resource *res;
50 	int i, ret;
51 
52 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
53 	if (!priv)
54 		return -ENOMEM;
55 
56 	priv->data = of_device_get_match_data(dev);
57 	if (WARN_ON(!priv->data || priv->data->nclks > MAX_CLKS ||
58 		    priv->data->nrsts > MAX_RSTS))
59 		return -EINVAL;
60 
61 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
62 	priv->rdata.membase = devm_ioremap_resource(dev, res);
63 	if (IS_ERR(priv->rdata.membase))
64 		return PTR_ERR(priv->rdata.membase);
65 
66 	for (i = 0; i < priv->data->nclks; i++)
67 		priv->clk[i].id = priv->data->clock_names[i];
68 	ret = devm_clk_bulk_get(dev, priv->data->nclks, priv->clk);
69 	if (ret)
70 		return ret;
71 
72 	for (i = 0; i < priv->data->nrsts; i++)
73 		priv->rst[i].id = priv->data->reset_names[i];
74 	ret = devm_reset_control_bulk_get_shared(dev, priv->data->nrsts,
75 						 priv->rst);
76 	if (ret)
77 		return ret;
78 
79 	ret = clk_bulk_prepare_enable(priv->data->nclks, priv->clk);
80 	if (ret)
81 		return ret;
82 
83 	ret = devm_add_action_or_reset(dev, uniphier_clk_disable, priv);
84 	if (ret)
85 		return ret;
86 
87 	ret = reset_control_bulk_deassert(priv->data->nrsts, priv->rst);
88 	if (ret)
89 		return ret;
90 
91 	ret = devm_add_action_or_reset(dev, uniphier_rst_assert, priv);
92 	if (ret)
93 		return ret;
94 
95 	spin_lock_init(&priv->rdata.lock);
96 	priv->rdata.rcdev.owner = THIS_MODULE;
97 	priv->rdata.rcdev.nr_resets = resource_size(res) * BITS_PER_BYTE;
98 	priv->rdata.rcdev.ops = &reset_simple_ops;
99 	priv->rdata.rcdev.of_node = dev->of_node;
100 	priv->rdata.active_low = true;
101 
102 	platform_set_drvdata(pdev, priv);
103 
104 	return devm_reset_controller_register(dev, &priv->rdata.rcdev);
105 }
106 
107 static const char * const uniphier_pro4_clock_reset_names[] = {
108 	"gio", "link",
109 };
110 
111 static const struct uniphier_glue_reset_soc_data uniphier_pro4_data = {
112 	.nclks = ARRAY_SIZE(uniphier_pro4_clock_reset_names),
113 	.clock_names = uniphier_pro4_clock_reset_names,
114 	.nrsts = ARRAY_SIZE(uniphier_pro4_clock_reset_names),
115 	.reset_names = uniphier_pro4_clock_reset_names,
116 };
117 
118 static const char * const uniphier_pxs2_clock_reset_names[] = {
119 	"link",
120 };
121 
122 static const struct uniphier_glue_reset_soc_data uniphier_pxs2_data = {
123 	.nclks = ARRAY_SIZE(uniphier_pxs2_clock_reset_names),
124 	.clock_names = uniphier_pxs2_clock_reset_names,
125 	.nrsts = ARRAY_SIZE(uniphier_pxs2_clock_reset_names),
126 	.reset_names = uniphier_pxs2_clock_reset_names,
127 };
128 
129 static const struct of_device_id uniphier_glue_reset_match[] = {
130 	{
131 		.compatible = "socionext,uniphier-pro4-usb3-reset",
132 		.data = &uniphier_pro4_data,
133 	},
134 	{
135 		.compatible = "socionext,uniphier-pro5-usb3-reset",
136 		.data = &uniphier_pro4_data,
137 	},
138 	{
139 		.compatible = "socionext,uniphier-pxs2-usb3-reset",
140 		.data = &uniphier_pxs2_data,
141 	},
142 	{
143 		.compatible = "socionext,uniphier-ld20-usb3-reset",
144 		.data = &uniphier_pxs2_data,
145 	},
146 	{
147 		.compatible = "socionext,uniphier-pxs3-usb3-reset",
148 		.data = &uniphier_pxs2_data,
149 	},
150 	{
151 		.compatible = "socionext,uniphier-nx1-usb3-reset",
152 		.data = &uniphier_pxs2_data,
153 	},
154 	{
155 		.compatible = "socionext,uniphier-pro4-ahci-reset",
156 		.data = &uniphier_pro4_data,
157 	},
158 	{
159 		.compatible = "socionext,uniphier-pxs2-ahci-reset",
160 		.data = &uniphier_pxs2_data,
161 	},
162 	{
163 		.compatible = "socionext,uniphier-pxs3-ahci-reset",
164 		.data = &uniphier_pxs2_data,
165 	},
166 	{ /* Sentinel */ }
167 };
168 MODULE_DEVICE_TABLE(of, uniphier_glue_reset_match);
169 
170 static struct platform_driver uniphier_glue_reset_driver = {
171 	.probe = uniphier_glue_reset_probe,
172 	.driver = {
173 		.name = "uniphier-glue-reset",
174 		.of_match_table = uniphier_glue_reset_match,
175 	},
176 };
177 module_platform_driver(uniphier_glue_reset_driver);
178 
179 MODULE_AUTHOR("Kunihiko Hayashi <hayashi.kunihiko@socionext.com>");
180 MODULE_DESCRIPTION("UniPhier Glue layer reset driver");
181 MODULE_LICENSE("GPL");
182