1 // SPDX-License-Identifier: GPL-2.0
2 /**
3  * dwc3-of-simple.c - OF glue layer for simple integrations
4  *
5  * Copyright (c) 2015 Texas Instruments Incorporated - http://www.ti.com
6  *
7  * Author: Felipe Balbi <balbi@ti.com>
8  *
9  * This is a combination of the old dwc3-qcom.c by Ivan T. Ivanov
10  * <iivanov@mm-sol.com> and the original patch adding support for Xilinx' SoC
11  * by Subbaraya Sundeep Bhatta <subbaraya.sundeep.bhatta@xilinx.com>
12  */
13 
14 #include <linux/module.h>
15 #include <linux/kernel.h>
16 #include <linux/slab.h>
17 #include <linux/platform_device.h>
18 #include <linux/dma-mapping.h>
19 #include <linux/clk.h>
20 #include <linux/of.h>
21 #include <linux/of_platform.h>
22 #include <linux/pm_runtime.h>
23 #include <linux/reset.h>
24 
25 struct dwc3_of_simple {
26 	struct device		*dev;
27 	struct clk		**clks;
28 	int			num_clocks;
29 	struct reset_control	*resets;
30 	bool			pulse_resets;
31 	bool			need_reset;
32 };
33 
34 static int dwc3_of_simple_clk_init(struct dwc3_of_simple *simple, int count)
35 {
36 	struct device		*dev = simple->dev;
37 	struct device_node	*np = dev->of_node;
38 	int			i;
39 
40 	simple->num_clocks = count;
41 
42 	if (!count)
43 		return 0;
44 
45 	simple->clks = devm_kcalloc(dev, simple->num_clocks,
46 			sizeof(struct clk *), GFP_KERNEL);
47 	if (!simple->clks)
48 		return -ENOMEM;
49 
50 	for (i = 0; i < simple->num_clocks; i++) {
51 		struct clk	*clk;
52 		int		ret;
53 
54 		clk = of_clk_get(np, i);
55 		if (IS_ERR(clk)) {
56 			while (--i >= 0) {
57 				clk_disable_unprepare(simple->clks[i]);
58 				clk_put(simple->clks[i]);
59 			}
60 			return PTR_ERR(clk);
61 		}
62 
63 		ret = clk_prepare_enable(clk);
64 		if (ret < 0) {
65 			while (--i >= 0) {
66 				clk_disable_unprepare(simple->clks[i]);
67 				clk_put(simple->clks[i]);
68 			}
69 			clk_put(clk);
70 
71 			return ret;
72 		}
73 
74 		simple->clks[i] = clk;
75 	}
76 
77 	return 0;
78 }
79 
80 static int dwc3_of_simple_probe(struct platform_device *pdev)
81 {
82 	struct dwc3_of_simple	*simple;
83 	struct device		*dev = &pdev->dev;
84 	struct device_node	*np = dev->of_node;
85 
86 	int			ret;
87 	int			i;
88 	bool			shared_resets = false;
89 
90 	simple = devm_kzalloc(dev, sizeof(*simple), GFP_KERNEL);
91 	if (!simple)
92 		return -ENOMEM;
93 
94 	platform_set_drvdata(pdev, simple);
95 	simple->dev = dev;
96 
97 	/*
98 	 * Some controllers need to toggle the usb3-otg reset before trying to
99 	 * initialize the PHY, otherwise the PHY times out.
100 	 */
101 	if (of_device_is_compatible(np, "rockchip,rk3399-dwc3"))
102 		simple->need_reset = true;
103 
104 	if (of_device_is_compatible(np, "amlogic,meson-axg-dwc3") ||
105 	    of_device_is_compatible(np, "amlogic,meson-gxl-dwc3")) {
106 		shared_resets = true;
107 		simple->pulse_resets = true;
108 	}
109 
110 	simple->resets = of_reset_control_array_get(np, shared_resets, true);
111 	if (IS_ERR(simple->resets)) {
112 		ret = PTR_ERR(simple->resets);
113 		dev_err(dev, "failed to get device resets, err=%d\n", ret);
114 		return ret;
115 	}
116 
117 	if (simple->pulse_resets) {
118 		ret = reset_control_reset(simple->resets);
119 		if (ret)
120 			goto err_resetc_put;
121 	} else {
122 		ret = reset_control_deassert(simple->resets);
123 		if (ret)
124 			goto err_resetc_put;
125 	}
126 
127 	ret = dwc3_of_simple_clk_init(simple, of_count_phandle_with_args(np,
128 						"clocks", "#clock-cells"));
129 	if (ret)
130 		goto err_resetc_assert;
131 
132 	ret = of_platform_populate(np, NULL, NULL, dev);
133 	if (ret) {
134 		for (i = 0; i < simple->num_clocks; i++) {
135 			clk_disable_unprepare(simple->clks[i]);
136 			clk_put(simple->clks[i]);
137 		}
138 
139 		goto err_resetc_assert;
140 	}
141 
142 	pm_runtime_set_active(dev);
143 	pm_runtime_enable(dev);
144 	pm_runtime_get_sync(dev);
145 
146 	return 0;
147 
148 err_resetc_assert:
149 	if (!simple->pulse_resets)
150 		reset_control_assert(simple->resets);
151 
152 err_resetc_put:
153 	reset_control_put(simple->resets);
154 	return ret;
155 }
156 
157 static int dwc3_of_simple_remove(struct platform_device *pdev)
158 {
159 	struct dwc3_of_simple	*simple = platform_get_drvdata(pdev);
160 	struct device		*dev = &pdev->dev;
161 	int			i;
162 
163 	of_platform_depopulate(dev);
164 
165 	for (i = 0; i < simple->num_clocks; i++) {
166 		clk_disable_unprepare(simple->clks[i]);
167 		clk_put(simple->clks[i]);
168 	}
169 	simple->num_clocks = 0;
170 
171 	if (!simple->pulse_resets)
172 		reset_control_assert(simple->resets);
173 
174 	reset_control_put(simple->resets);
175 
176 	pm_runtime_disable(dev);
177 	pm_runtime_put_noidle(dev);
178 	pm_runtime_set_suspended(dev);
179 
180 	return 0;
181 }
182 
183 #ifdef CONFIG_PM
184 static int dwc3_of_simple_runtime_suspend(struct device *dev)
185 {
186 	struct dwc3_of_simple	*simple = dev_get_drvdata(dev);
187 	int			i;
188 
189 	for (i = 0; i < simple->num_clocks; i++)
190 		clk_disable(simple->clks[i]);
191 
192 	return 0;
193 }
194 
195 static int dwc3_of_simple_runtime_resume(struct device *dev)
196 {
197 	struct dwc3_of_simple	*simple = dev_get_drvdata(dev);
198 	int			ret;
199 	int			i;
200 
201 	for (i = 0; i < simple->num_clocks; i++) {
202 		ret = clk_enable(simple->clks[i]);
203 		if (ret < 0) {
204 			while (--i >= 0)
205 				clk_disable(simple->clks[i]);
206 			return ret;
207 		}
208 	}
209 
210 	return 0;
211 }
212 
213 static int dwc3_of_simple_suspend(struct device *dev)
214 {
215 	struct dwc3_of_simple *simple = dev_get_drvdata(dev);
216 
217 	if (simple->need_reset)
218 		reset_control_assert(simple->resets);
219 
220 	return 0;
221 }
222 
223 static int dwc3_of_simple_resume(struct device *dev)
224 {
225 	struct dwc3_of_simple *simple = dev_get_drvdata(dev);
226 
227 	if (simple->need_reset)
228 		reset_control_deassert(simple->resets);
229 
230 	return 0;
231 }
232 #endif
233 
234 static const struct dev_pm_ops dwc3_of_simple_dev_pm_ops = {
235 	SET_SYSTEM_SLEEP_PM_OPS(dwc3_of_simple_suspend, dwc3_of_simple_resume)
236 	SET_RUNTIME_PM_OPS(dwc3_of_simple_runtime_suspend,
237 			dwc3_of_simple_runtime_resume, NULL)
238 };
239 
240 static const struct of_device_id of_dwc3_simple_match[] = {
241 	{ .compatible = "rockchip,rk3399-dwc3" },
242 	{ .compatible = "xlnx,zynqmp-dwc3" },
243 	{ .compatible = "cavium,octeon-7130-usb-uctl" },
244 	{ .compatible = "sprd,sc9860-dwc3" },
245 	{ .compatible = "amlogic,meson-axg-dwc3" },
246 	{ .compatible = "amlogic,meson-gxl-dwc3" },
247 	{ .compatible = "allwinner,sun50i-h6-dwc3" },
248 	{ /* Sentinel */ }
249 };
250 MODULE_DEVICE_TABLE(of, of_dwc3_simple_match);
251 
252 static struct platform_driver dwc3_of_simple_driver = {
253 	.probe		= dwc3_of_simple_probe,
254 	.remove		= dwc3_of_simple_remove,
255 	.driver		= {
256 		.name	= "dwc3-of-simple",
257 		.of_match_table = of_dwc3_simple_match,
258 		.pm	= &dwc3_of_simple_dev_pm_ops,
259 	},
260 };
261 
262 module_platform_driver(dwc3_of_simple_driver);
263 MODULE_LICENSE("GPL v2");
264 MODULE_DESCRIPTION("DesignWare USB3 OF Simple Glue Layer");
265 MODULE_AUTHOR("Felipe Balbi <balbi@ti.com>");
266