xref: /openbmc/linux/drivers/usb/host/ehci-exynos.c (revision 547840bd)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Samsung Exynos USB HOST EHCI Controller
4  *
5  * Copyright (C) 2011 Samsung Electronics Co.Ltd
6  * Author: Jingoo Han <jg1.han@samsung.com>
7  * Author: Joonyoung Shim <jy0922.shim@samsung.com>
8  */
9 
10 #include <linux/clk.h>
11 #include <linux/dma-mapping.h>
12 #include <linux/io.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/of.h>
16 #include <linux/of_gpio.h>
17 #include <linux/phy/phy.h>
18 #include <linux/platform_device.h>
19 #include <linux/usb.h>
20 #include <linux/usb/hcd.h>
21 
22 #include "ehci.h"
23 
24 #define DRIVER_DESC "EHCI Exynos driver"
25 
26 #define EHCI_INSNREG00(base)			(base + 0x90)
27 #define EHCI_INSNREG00_ENA_INCR16		(0x1 << 25)
28 #define EHCI_INSNREG00_ENA_INCR8		(0x1 << 24)
29 #define EHCI_INSNREG00_ENA_INCR4		(0x1 << 23)
30 #define EHCI_INSNREG00_ENA_INCRX_ALIGN		(0x1 << 22)
31 #define EHCI_INSNREG00_ENABLE_DMA_BURST	\
32 	(EHCI_INSNREG00_ENA_INCR16 | EHCI_INSNREG00_ENA_INCR8 |	\
33 	 EHCI_INSNREG00_ENA_INCR4 | EHCI_INSNREG00_ENA_INCRX_ALIGN)
34 
35 static const char hcd_name[] = "ehci-exynos";
36 static struct hc_driver __read_mostly exynos_ehci_hc_driver;
37 
38 #define PHY_NUMBER 3
39 
40 struct exynos_ehci_hcd {
41 	struct clk *clk;
42 	struct device_node *of_node;
43 	struct phy *phy[PHY_NUMBER];
44 	bool legacy_phy;
45 };
46 
47 #define to_exynos_ehci(hcd) (struct exynos_ehci_hcd *)(hcd_to_ehci(hcd)->priv)
48 
49 static int exynos_ehci_get_phy(struct device *dev,
50 				struct exynos_ehci_hcd *exynos_ehci)
51 {
52 	struct device_node *child;
53 	struct phy *phy;
54 	int phy_number, num_phys;
55 	int ret;
56 
57 	/* Get PHYs for the controller */
58 	num_phys = of_count_phandle_with_args(dev->of_node, "phys",
59 					      "#phy-cells");
60 	for (phy_number = 0; phy_number < num_phys; phy_number++) {
61 		phy = devm_of_phy_get_by_index(dev, dev->of_node, phy_number);
62 		if (IS_ERR(phy))
63 			return PTR_ERR(phy);
64 		exynos_ehci->phy[phy_number] = phy;
65 	}
66 	if (num_phys > 0)
67 		return 0;
68 
69 	/* Get PHYs using legacy bindings */
70 	for_each_available_child_of_node(dev->of_node, child) {
71 		ret = of_property_read_u32(child, "reg", &phy_number);
72 		if (ret) {
73 			dev_err(dev, "Failed to parse device tree\n");
74 			of_node_put(child);
75 			return ret;
76 		}
77 
78 		if (phy_number >= PHY_NUMBER) {
79 			dev_err(dev, "Invalid number of PHYs\n");
80 			of_node_put(child);
81 			return -EINVAL;
82 		}
83 
84 		phy = devm_of_phy_get(dev, child, NULL);
85 		exynos_ehci->phy[phy_number] = phy;
86 		if (IS_ERR(phy)) {
87 			ret = PTR_ERR(phy);
88 			if (ret == -EPROBE_DEFER) {
89 				of_node_put(child);
90 				return ret;
91 			} else if (ret != -ENOSYS && ret != -ENODEV) {
92 				dev_err(dev,
93 					"Error retrieving usb2 phy: %d\n", ret);
94 				of_node_put(child);
95 				return ret;
96 			}
97 		}
98 	}
99 
100 	exynos_ehci->legacy_phy = true;
101 	return 0;
102 }
103 
104 static int exynos_ehci_phy_enable(struct device *dev)
105 {
106 	struct usb_hcd *hcd = dev_get_drvdata(dev);
107 	struct exynos_ehci_hcd *exynos_ehci = to_exynos_ehci(hcd);
108 	int i;
109 	int ret = 0;
110 
111 	for (i = 0; ret == 0 && i < PHY_NUMBER; i++)
112 		if (!IS_ERR(exynos_ehci->phy[i]))
113 			ret = phy_power_on(exynos_ehci->phy[i]);
114 	if (ret)
115 		for (i--; i >= 0; i--)
116 			if (!IS_ERR(exynos_ehci->phy[i]))
117 				phy_power_off(exynos_ehci->phy[i]);
118 
119 	return ret;
120 }
121 
122 static void exynos_ehci_phy_disable(struct device *dev)
123 {
124 	struct usb_hcd *hcd = dev_get_drvdata(dev);
125 	struct exynos_ehci_hcd *exynos_ehci = to_exynos_ehci(hcd);
126 	int i;
127 
128 	for (i = 0; i < PHY_NUMBER; i++)
129 		if (!IS_ERR(exynos_ehci->phy[i]))
130 			phy_power_off(exynos_ehci->phy[i]);
131 }
132 
133 static void exynos_setup_vbus_gpio(struct device *dev)
134 {
135 	int err;
136 	int gpio;
137 
138 	if (!dev->of_node)
139 		return;
140 
141 	gpio = of_get_named_gpio(dev->of_node, "samsung,vbus-gpio", 0);
142 	if (!gpio_is_valid(gpio))
143 		return;
144 
145 	err = devm_gpio_request_one(dev, gpio, GPIOF_OUT_INIT_HIGH,
146 				    "ehci_vbus_gpio");
147 	if (err)
148 		dev_err(dev, "can't request ehci vbus gpio %d", gpio);
149 }
150 
151 static int exynos_ehci_probe(struct platform_device *pdev)
152 {
153 	struct exynos_ehci_hcd *exynos_ehci;
154 	struct usb_hcd *hcd;
155 	struct ehci_hcd *ehci;
156 	struct resource *res;
157 	int irq;
158 	int err;
159 
160 	/*
161 	 * Right now device-tree probed devices don't get dma_mask set.
162 	 * Since shared usb code relies on it, set it here for now.
163 	 * Once we move to full device tree support this will vanish off.
164 	 */
165 	err = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
166 	if (err)
167 		return err;
168 
169 	exynos_setup_vbus_gpio(&pdev->dev);
170 
171 	hcd = usb_create_hcd(&exynos_ehci_hc_driver,
172 			     &pdev->dev, dev_name(&pdev->dev));
173 	if (!hcd) {
174 		dev_err(&pdev->dev, "Unable to create HCD\n");
175 		return -ENOMEM;
176 	}
177 	exynos_ehci = to_exynos_ehci(hcd);
178 
179 	err = exynos_ehci_get_phy(&pdev->dev, exynos_ehci);
180 	if (err)
181 		goto fail_clk;
182 
183 	exynos_ehci->clk = devm_clk_get(&pdev->dev, "usbhost");
184 
185 	if (IS_ERR(exynos_ehci->clk)) {
186 		dev_err(&pdev->dev, "Failed to get usbhost clock\n");
187 		err = PTR_ERR(exynos_ehci->clk);
188 		goto fail_clk;
189 	}
190 
191 	err = clk_prepare_enable(exynos_ehci->clk);
192 	if (err)
193 		goto fail_clk;
194 
195 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
196 	hcd->regs = devm_ioremap_resource(&pdev->dev, res);
197 	if (IS_ERR(hcd->regs)) {
198 		err = PTR_ERR(hcd->regs);
199 		goto fail_io;
200 	}
201 
202 	hcd->rsrc_start = res->start;
203 	hcd->rsrc_len = resource_size(res);
204 
205 	irq = platform_get_irq(pdev, 0);
206 	if (!irq) {
207 		dev_err(&pdev->dev, "Failed to get IRQ\n");
208 		err = -ENODEV;
209 		goto fail_io;
210 	}
211 
212 	err = exynos_ehci_phy_enable(&pdev->dev);
213 	if (err) {
214 		dev_err(&pdev->dev, "Failed to enable USB phy\n");
215 		goto fail_io;
216 	}
217 
218 	ehci = hcd_to_ehci(hcd);
219 	ehci->caps = hcd->regs;
220 
221 	/*
222 	 * Workaround: reset of_node pointer to avoid conflict between legacy
223 	 * Exynos EHCI port subnodes and generic USB device bindings
224 	 */
225 	exynos_ehci->of_node = pdev->dev.of_node;
226 	if (exynos_ehci->legacy_phy)
227 		pdev->dev.of_node = NULL;
228 
229 	/* DMA burst Enable */
230 	writel(EHCI_INSNREG00_ENABLE_DMA_BURST, EHCI_INSNREG00(hcd->regs));
231 
232 	err = usb_add_hcd(hcd, irq, IRQF_SHARED);
233 	if (err) {
234 		dev_err(&pdev->dev, "Failed to add USB HCD\n");
235 		goto fail_add_hcd;
236 	}
237 	device_wakeup_enable(hcd->self.controller);
238 
239 	platform_set_drvdata(pdev, hcd);
240 
241 	return 0;
242 
243 fail_add_hcd:
244 	exynos_ehci_phy_disable(&pdev->dev);
245 	pdev->dev.of_node = exynos_ehci->of_node;
246 fail_io:
247 	clk_disable_unprepare(exynos_ehci->clk);
248 fail_clk:
249 	usb_put_hcd(hcd);
250 	return err;
251 }
252 
253 static int exynos_ehci_remove(struct platform_device *pdev)
254 {
255 	struct usb_hcd *hcd = platform_get_drvdata(pdev);
256 	struct exynos_ehci_hcd *exynos_ehci = to_exynos_ehci(hcd);
257 
258 	pdev->dev.of_node = exynos_ehci->of_node;
259 
260 	usb_remove_hcd(hcd);
261 
262 	exynos_ehci_phy_disable(&pdev->dev);
263 
264 	clk_disable_unprepare(exynos_ehci->clk);
265 
266 	usb_put_hcd(hcd);
267 
268 	return 0;
269 }
270 
271 #ifdef CONFIG_PM
272 static int exynos_ehci_suspend(struct device *dev)
273 {
274 	struct usb_hcd *hcd = dev_get_drvdata(dev);
275 	struct exynos_ehci_hcd *exynos_ehci = to_exynos_ehci(hcd);
276 
277 	bool do_wakeup = device_may_wakeup(dev);
278 	int rc;
279 
280 	rc = ehci_suspend(hcd, do_wakeup);
281 	if (rc)
282 		return rc;
283 
284 	exynos_ehci_phy_disable(dev);
285 
286 	clk_disable_unprepare(exynos_ehci->clk);
287 
288 	return rc;
289 }
290 
291 static int exynos_ehci_resume(struct device *dev)
292 {
293 	struct usb_hcd *hcd = dev_get_drvdata(dev);
294 	struct exynos_ehci_hcd *exynos_ehci = to_exynos_ehci(hcd);
295 	int ret;
296 
297 	ret = clk_prepare_enable(exynos_ehci->clk);
298 	if (ret)
299 		return ret;
300 
301 	ret = exynos_ehci_phy_enable(dev);
302 	if (ret) {
303 		dev_err(dev, "Failed to enable USB phy\n");
304 		clk_disable_unprepare(exynos_ehci->clk);
305 		return ret;
306 	}
307 
308 	/* DMA burst Enable */
309 	writel(EHCI_INSNREG00_ENABLE_DMA_BURST, EHCI_INSNREG00(hcd->regs));
310 
311 	ehci_resume(hcd, false);
312 	return 0;
313 }
314 #else
315 #define exynos_ehci_suspend	NULL
316 #define exynos_ehci_resume	NULL
317 #endif
318 
319 static const struct dev_pm_ops exynos_ehci_pm_ops = {
320 	.suspend	= exynos_ehci_suspend,
321 	.resume		= exynos_ehci_resume,
322 };
323 
324 #ifdef CONFIG_OF
325 static const struct of_device_id exynos_ehci_match[] = {
326 	{ .compatible = "samsung,exynos4210-ehci" },
327 	{},
328 };
329 MODULE_DEVICE_TABLE(of, exynos_ehci_match);
330 #endif
331 
332 static struct platform_driver exynos_ehci_driver = {
333 	.probe		= exynos_ehci_probe,
334 	.remove		= exynos_ehci_remove,
335 	.shutdown	= usb_hcd_platform_shutdown,
336 	.driver = {
337 		.name	= "exynos-ehci",
338 		.pm	= &exynos_ehci_pm_ops,
339 		.of_match_table = of_match_ptr(exynos_ehci_match),
340 	}
341 };
342 static const struct ehci_driver_overrides exynos_overrides __initconst = {
343 	.extra_priv_size = sizeof(struct exynos_ehci_hcd),
344 };
345 
346 static int __init ehci_exynos_init(void)
347 {
348 	if (usb_disabled())
349 		return -ENODEV;
350 
351 	pr_info("%s: " DRIVER_DESC "\n", hcd_name);
352 	ehci_init_driver(&exynos_ehci_hc_driver, &exynos_overrides);
353 	return platform_driver_register(&exynos_ehci_driver);
354 }
355 module_init(ehci_exynos_init);
356 
357 static void __exit ehci_exynos_cleanup(void)
358 {
359 	platform_driver_unregister(&exynos_ehci_driver);
360 }
361 module_exit(ehci_exynos_cleanup);
362 
363 MODULE_DESCRIPTION(DRIVER_DESC);
364 MODULE_ALIAS("platform:exynos-ehci");
365 MODULE_AUTHOR("Jingoo Han");
366 MODULE_AUTHOR("Joonyoung Shim");
367 MODULE_LICENSE("GPL v2");
368