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