1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * SAMSUNG EXYNOS USB HOST OHCI Controller
4  *
5  * Copyright (C) 2011 Samsung Electronics Co.Ltd
6  * Author: Jingoo Han <jg1.han@samsung.com>
7  */
8 
9 #include <linux/clk.h>
10 #include <linux/dma-mapping.h>
11 #include <linux/io.h>
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/of.h>
15 #include <linux/platform_device.h>
16 #include <linux/phy/phy.h>
17 #include <linux/usb.h>
18 #include <linux/usb/hcd.h>
19 
20 #include "ohci.h"
21 
22 #define DRIVER_DESC "OHCI Exynos driver"
23 
24 static const char hcd_name[] = "ohci-exynos";
25 static struct hc_driver __read_mostly exynos_ohci_hc_driver;
26 
27 #define to_exynos_ohci(hcd) (struct exynos_ohci_hcd *)(hcd_to_ohci(hcd)->priv)
28 
29 #define PHY_NUMBER 3
30 
31 struct exynos_ohci_hcd {
32 	struct clk *clk;
33 	struct device_node *of_node;
34 	struct phy *phy[PHY_NUMBER];
35 	bool legacy_phy;
36 };
37 
exynos_ohci_get_phy(struct device * dev,struct exynos_ohci_hcd * exynos_ohci)38 static int exynos_ohci_get_phy(struct device *dev,
39 				struct exynos_ohci_hcd *exynos_ohci)
40 {
41 	struct device_node *child;
42 	struct phy *phy;
43 	int phy_number, num_phys;
44 	int ret;
45 
46 	/* Get PHYs for the controller */
47 	num_phys = of_count_phandle_with_args(dev->of_node, "phys",
48 					      "#phy-cells");
49 	for (phy_number = 0; phy_number < num_phys; phy_number++) {
50 		phy = devm_of_phy_get_by_index(dev, dev->of_node, phy_number);
51 		if (IS_ERR(phy))
52 			return PTR_ERR(phy);
53 		exynos_ohci->phy[phy_number] = phy;
54 	}
55 	if (num_phys > 0)
56 		return 0;
57 
58 	/* Get PHYs using legacy bindings */
59 	for_each_available_child_of_node(dev->of_node, child) {
60 		ret = of_property_read_u32(child, "reg", &phy_number);
61 		if (ret) {
62 			dev_err(dev, "Failed to parse device tree\n");
63 			of_node_put(child);
64 			return ret;
65 		}
66 
67 		if (phy_number >= PHY_NUMBER) {
68 			dev_err(dev, "Invalid number of PHYs\n");
69 			of_node_put(child);
70 			return -EINVAL;
71 		}
72 
73 		phy = devm_of_phy_get(dev, child, NULL);
74 		exynos_ohci->phy[phy_number] = phy;
75 		if (IS_ERR(phy)) {
76 			ret = PTR_ERR(phy);
77 			if (ret == -EPROBE_DEFER) {
78 				of_node_put(child);
79 				return ret;
80 			} else if (ret != -ENOSYS && ret != -ENODEV) {
81 				dev_err(dev,
82 					"Error retrieving usb2 phy: %d\n", ret);
83 				of_node_put(child);
84 				return ret;
85 			}
86 		}
87 	}
88 
89 	exynos_ohci->legacy_phy = true;
90 	return 0;
91 }
92 
exynos_ohci_phy_enable(struct device * dev)93 static int exynos_ohci_phy_enable(struct device *dev)
94 {
95 	struct usb_hcd *hcd = dev_get_drvdata(dev);
96 	struct exynos_ohci_hcd *exynos_ohci = to_exynos_ohci(hcd);
97 	int i;
98 	int ret = 0;
99 
100 	for (i = 0; ret == 0 && i < PHY_NUMBER; i++)
101 		if (!IS_ERR(exynos_ohci->phy[i]))
102 			ret = phy_power_on(exynos_ohci->phy[i]);
103 	if (ret)
104 		for (i--; i >= 0; i--)
105 			if (!IS_ERR(exynos_ohci->phy[i]))
106 				phy_power_off(exynos_ohci->phy[i]);
107 
108 	return ret;
109 }
110 
exynos_ohci_phy_disable(struct device * dev)111 static void exynos_ohci_phy_disable(struct device *dev)
112 {
113 	struct usb_hcd *hcd = dev_get_drvdata(dev);
114 	struct exynos_ohci_hcd *exynos_ohci = to_exynos_ohci(hcd);
115 	int i;
116 
117 	for (i = 0; i < PHY_NUMBER; i++)
118 		if (!IS_ERR(exynos_ohci->phy[i]))
119 			phy_power_off(exynos_ohci->phy[i]);
120 }
121 
exynos_ohci_probe(struct platform_device * pdev)122 static int exynos_ohci_probe(struct platform_device *pdev)
123 {
124 	struct exynos_ohci_hcd *exynos_ohci;
125 	struct usb_hcd *hcd;
126 	struct resource *res;
127 	int irq;
128 	int err;
129 
130 	/*
131 	 * Right now device-tree probed devices don't get dma_mask set.
132 	 * Since shared usb code relies on it, set it here for now.
133 	 * Once we move to full device tree support this will vanish off.
134 	 */
135 	err = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
136 	if (err)
137 		return err;
138 
139 	hcd = usb_create_hcd(&exynos_ohci_hc_driver,
140 				&pdev->dev, dev_name(&pdev->dev));
141 	if (!hcd) {
142 		dev_err(&pdev->dev, "Unable to create HCD\n");
143 		return -ENOMEM;
144 	}
145 
146 	exynos_ohci = to_exynos_ohci(hcd);
147 
148 	err = exynos_ohci_get_phy(&pdev->dev, exynos_ohci);
149 	if (err)
150 		goto fail_clk;
151 
152 	exynos_ohci->clk = devm_clk_get(&pdev->dev, "usbhost");
153 
154 	if (IS_ERR(exynos_ohci->clk)) {
155 		dev_err(&pdev->dev, "Failed to get usbhost clock\n");
156 		err = PTR_ERR(exynos_ohci->clk);
157 		goto fail_clk;
158 	}
159 
160 	err = clk_prepare_enable(exynos_ohci->clk);
161 	if (err)
162 		goto fail_clk;
163 
164 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
165 	hcd->regs = devm_ioremap_resource(&pdev->dev, res);
166 	if (IS_ERR(hcd->regs)) {
167 		err = PTR_ERR(hcd->regs);
168 		goto fail_io;
169 	}
170 	hcd->rsrc_start = res->start;
171 	hcd->rsrc_len = resource_size(res);
172 
173 	irq = platform_get_irq(pdev, 0);
174 	if (irq < 0) {
175 		err = irq;
176 		goto fail_io;
177 	}
178 
179 	platform_set_drvdata(pdev, hcd);
180 
181 	err = exynos_ohci_phy_enable(&pdev->dev);
182 	if (err) {
183 		dev_err(&pdev->dev, "Failed to enable USB phy\n");
184 		goto fail_io;
185 	}
186 
187 	/*
188 	 * Workaround: reset of_node pointer to avoid conflict between legacy
189 	 * Exynos OHCI port subnodes and generic USB device bindings
190 	 */
191 	exynos_ohci->of_node = pdev->dev.of_node;
192 	if (exynos_ohci->legacy_phy)
193 		pdev->dev.of_node = NULL;
194 
195 	err = usb_add_hcd(hcd, irq, IRQF_SHARED);
196 	if (err) {
197 		dev_err(&pdev->dev, "Failed to add USB HCD\n");
198 		goto fail_add_hcd;
199 	}
200 	device_wakeup_enable(hcd->self.controller);
201 	return 0;
202 
203 fail_add_hcd:
204 	exynos_ohci_phy_disable(&pdev->dev);
205 	pdev->dev.of_node = exynos_ohci->of_node;
206 fail_io:
207 	clk_disable_unprepare(exynos_ohci->clk);
208 fail_clk:
209 	usb_put_hcd(hcd);
210 	return err;
211 }
212 
exynos_ohci_remove(struct platform_device * pdev)213 static int exynos_ohci_remove(struct platform_device *pdev)
214 {
215 	struct usb_hcd *hcd = platform_get_drvdata(pdev);
216 	struct exynos_ohci_hcd *exynos_ohci = to_exynos_ohci(hcd);
217 
218 	pdev->dev.of_node = exynos_ohci->of_node;
219 
220 	usb_remove_hcd(hcd);
221 
222 	exynos_ohci_phy_disable(&pdev->dev);
223 
224 	clk_disable_unprepare(exynos_ohci->clk);
225 
226 	usb_put_hcd(hcd);
227 
228 	return 0;
229 }
230 
exynos_ohci_shutdown(struct platform_device * pdev)231 static void exynos_ohci_shutdown(struct platform_device *pdev)
232 {
233 	struct usb_hcd *hcd = platform_get_drvdata(pdev);
234 
235 	if (hcd->driver->shutdown)
236 		hcd->driver->shutdown(hcd);
237 }
238 
239 #ifdef CONFIG_PM
exynos_ohci_suspend(struct device * dev)240 static int exynos_ohci_suspend(struct device *dev)
241 {
242 	struct usb_hcd *hcd = dev_get_drvdata(dev);
243 	struct exynos_ohci_hcd *exynos_ohci = to_exynos_ohci(hcd);
244 	bool do_wakeup = device_may_wakeup(dev);
245 	int rc = ohci_suspend(hcd, do_wakeup);
246 
247 	if (rc)
248 		return rc;
249 
250 	exynos_ohci_phy_disable(dev);
251 
252 	clk_disable_unprepare(exynos_ohci->clk);
253 
254 	return 0;
255 }
256 
exynos_ohci_resume(struct device * dev)257 static int exynos_ohci_resume(struct device *dev)
258 {
259 	struct usb_hcd *hcd			= dev_get_drvdata(dev);
260 	struct exynos_ohci_hcd *exynos_ohci	= to_exynos_ohci(hcd);
261 	int ret;
262 
263 	clk_prepare_enable(exynos_ohci->clk);
264 
265 	ret = exynos_ohci_phy_enable(dev);
266 	if (ret) {
267 		dev_err(dev, "Failed to enable USB phy\n");
268 		clk_disable_unprepare(exynos_ohci->clk);
269 		return ret;
270 	}
271 
272 	ohci_resume(hcd, false);
273 
274 	return 0;
275 }
276 #else
277 #define exynos_ohci_suspend	NULL
278 #define exynos_ohci_resume	NULL
279 #endif
280 
281 static const struct ohci_driver_overrides exynos_overrides __initconst = {
282 	.extra_priv_size =	sizeof(struct exynos_ohci_hcd),
283 };
284 
285 static const struct dev_pm_ops exynos_ohci_pm_ops = {
286 	.suspend	= exynos_ohci_suspend,
287 	.resume		= exynos_ohci_resume,
288 };
289 
290 #ifdef CONFIG_OF
291 static const struct of_device_id exynos_ohci_match[] = {
292 	{ .compatible = "samsung,exynos4210-ohci" },
293 	{},
294 };
295 MODULE_DEVICE_TABLE(of, exynos_ohci_match);
296 #endif
297 
298 static struct platform_driver exynos_ohci_driver = {
299 	.probe		= exynos_ohci_probe,
300 	.remove		= exynos_ohci_remove,
301 	.shutdown	= exynos_ohci_shutdown,
302 	.driver = {
303 		.name	= "exynos-ohci",
304 		.pm	= &exynos_ohci_pm_ops,
305 		.of_match_table	= of_match_ptr(exynos_ohci_match),
306 	}
307 };
ohci_exynos_init(void)308 static int __init ohci_exynos_init(void)
309 {
310 	if (usb_disabled())
311 		return -ENODEV;
312 
313 	pr_info("%s: " DRIVER_DESC "\n", hcd_name);
314 	ohci_init_driver(&exynos_ohci_hc_driver, &exynos_overrides);
315 	return platform_driver_register(&exynos_ohci_driver);
316 }
317 module_init(ohci_exynos_init);
318 
ohci_exynos_cleanup(void)319 static void __exit ohci_exynos_cleanup(void)
320 {
321 	platform_driver_unregister(&exynos_ohci_driver);
322 }
323 module_exit(ohci_exynos_cleanup);
324 
325 MODULE_ALIAS("platform:exynos-ohci");
326 MODULE_AUTHOR("Jingoo Han <jg1.han@samsung.com>");
327 MODULE_LICENSE("GPL v2");
328