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_get(dev, child, NULL);
 84		exynos_ehci->phy[phy_number] = phy;
 85		if (IS_ERR(phy)) {
 86			ret = PTR_ERR(phy);
 87			if (ret == -EPROBE_DEFER) {
 88				of_node_put(child);
 89				return ret;
 90			} else if (ret != -ENOSYS && ret != -ENODEV) {
 91				dev_err(dev,
 92					"Error retrieving usb2 phy: %d\n", ret);
 93				of_node_put(child);
 94				return ret;
 95			}
 96		}
 97	}
 98
 99	exynos_ehci->legacy_phy = true;
100	return 0;
101}
102
103static int exynos_ehci_phy_enable(struct device *dev)
104{
105	struct usb_hcd *hcd = dev_get_drvdata(dev);
106	struct exynos_ehci_hcd *exynos_ehci = to_exynos_ehci(hcd);
107	int i;
108	int ret = 0;
109
110	for (i = 0; ret == 0 && i < PHY_NUMBER; i++)
111		if (!IS_ERR(exynos_ehci->phy[i]))
112			ret = phy_power_on(exynos_ehci->phy[i]);
113	if (ret)
114		for (i--; i >= 0; i--)
115			if (!IS_ERR(exynos_ehci->phy[i]))
116				phy_power_off(exynos_ehci->phy[i]);
117
118	return ret;
119}
120
121static void exynos_ehci_phy_disable(struct device *dev)
122{
123	struct usb_hcd *hcd = dev_get_drvdata(dev);
124	struct exynos_ehci_hcd *exynos_ehci = to_exynos_ehci(hcd);
125	int i;
126
127	for (i = 0; i < PHY_NUMBER; i++)
128		if (!IS_ERR(exynos_ehci->phy[i]))
129			phy_power_off(exynos_ehci->phy[i]);
130}
131
132static void exynos_setup_vbus_gpio(struct device *dev)
133{
134	struct gpio_desc *gpio;
135	int err;
136
137	gpio = devm_gpiod_get_optional(dev, "samsung,vbus", GPIOD_OUT_HIGH);
138	err = PTR_ERR_OR_ZERO(gpio);
139	if (err)
140		dev_err(dev, "can't request ehci vbus gpio: %d\n", err);
141}
142
143static int exynos_ehci_probe(struct platform_device *pdev)
144{
145	struct exynos_ehci_hcd *exynos_ehci;
146	struct usb_hcd *hcd;
147	struct ehci_hcd *ehci;
148	struct resource *res;
149	int irq;
150	int err;
151
152	/*
153	 * Right now device-tree probed devices don't get dma_mask set.
154	 * Since shared usb code relies on it, set it here for now.
155	 * Once we move to full device tree support this will vanish off.
156	 */
157	err = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
158	if (err)
159		return err;
160
161	exynos_setup_vbus_gpio(&pdev->dev);
162
163	hcd = usb_create_hcd(&exynos_ehci_hc_driver,
164			     &pdev->dev, dev_name(&pdev->dev));
165	if (!hcd) {
166		dev_err(&pdev->dev, "Unable to create HCD\n");
167		return -ENOMEM;
168	}
169	exynos_ehci = to_exynos_ehci(hcd);
170
171	err = exynos_ehci_get_phy(&pdev->dev, exynos_ehci);
172	if (err)
173		goto fail_clk;
174
175	exynos_ehci->clk = devm_clk_get(&pdev->dev, "usbhost");
176
177	if (IS_ERR(exynos_ehci->clk)) {
178		dev_err(&pdev->dev, "Failed to get usbhost clock\n");
179		err = PTR_ERR(exynos_ehci->clk);
180		goto fail_clk;
181	}
182
183	err = clk_prepare_enable(exynos_ehci->clk);
184	if (err)
185		goto fail_clk;
186
187	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
188	hcd->regs = devm_ioremap_resource(&pdev->dev, res);
189	if (IS_ERR(hcd->regs)) {
190		err = PTR_ERR(hcd->regs);
191		goto fail_io;
192	}
193
194	hcd->rsrc_start = res->start;
195	hcd->rsrc_len = resource_size(res);
196
197	irq = platform_get_irq(pdev, 0);
198	if (irq < 0) {
199		err = irq;
200		goto fail_io;
201	}
202
203	err = exynos_ehci_phy_enable(&pdev->dev);
204	if (err) {
205		dev_err(&pdev->dev, "Failed to enable USB phy\n");
206		goto fail_io;
207	}
208
209	ehci = hcd_to_ehci(hcd);
210	ehci->caps = hcd->regs;
211
212	/*
213	 * Workaround: reset of_node pointer to avoid conflict between legacy
214	 * Exynos EHCI port subnodes and generic USB device bindings
215	 */
216	exynos_ehci->of_node = pdev->dev.of_node;
217	if (exynos_ehci->legacy_phy)
218		pdev->dev.of_node = NULL;
219
220	/* DMA burst Enable */
221	writel(EHCI_INSNREG00_ENABLE_DMA_BURST, EHCI_INSNREG00(hcd->regs));
222
223	err = usb_add_hcd(hcd, irq, IRQF_SHARED);
224	if (err) {
225		dev_err(&pdev->dev, "Failed to add USB HCD\n");
226		goto fail_add_hcd;
227	}
228	device_wakeup_enable(hcd->self.controller);
229
230	platform_set_drvdata(pdev, hcd);
231
232	return 0;
233
234fail_add_hcd:
235	exynos_ehci_phy_disable(&pdev->dev);
236	pdev->dev.of_node = exynos_ehci->of_node;
237fail_io:
238	clk_disable_unprepare(exynos_ehci->clk);
239fail_clk:
240	usb_put_hcd(hcd);
241	return err;
242}
243
244static int exynos_ehci_remove(struct platform_device *pdev)
245{
246	struct usb_hcd *hcd = platform_get_drvdata(pdev);
247	struct exynos_ehci_hcd *exynos_ehci = to_exynos_ehci(hcd);
248
249	pdev->dev.of_node = exynos_ehci->of_node;
250
251	usb_remove_hcd(hcd);
252
253	exynos_ehci_phy_disable(&pdev->dev);
254
255	clk_disable_unprepare(exynos_ehci->clk);
256
257	usb_put_hcd(hcd);
258
259	return 0;
260}
261
262#ifdef CONFIG_PM
263static int exynos_ehci_suspend(struct device *dev)
264{
265	struct usb_hcd *hcd = dev_get_drvdata(dev);
266	struct exynos_ehci_hcd *exynos_ehci = to_exynos_ehci(hcd);
267
268	bool do_wakeup = device_may_wakeup(dev);
269	int rc;
270
271	rc = ehci_suspend(hcd, do_wakeup);
272	if (rc)
273		return rc;
274
275	exynos_ehci_phy_disable(dev);
276
277	clk_disable_unprepare(exynos_ehci->clk);
278
279	return rc;
280}
281
282static int exynos_ehci_resume(struct device *dev)
283{
284	struct usb_hcd *hcd = dev_get_drvdata(dev);
285	struct exynos_ehci_hcd *exynos_ehci = to_exynos_ehci(hcd);
286	int ret;
287
288	ret = clk_prepare_enable(exynos_ehci->clk);
289	if (ret)
290		return ret;
291
292	ret = exynos_ehci_phy_enable(dev);
293	if (ret) {
294		dev_err(dev, "Failed to enable USB phy\n");
295		clk_disable_unprepare(exynos_ehci->clk);
296		return ret;
297	}
298
299	/* DMA burst Enable */
300	writel(EHCI_INSNREG00_ENABLE_DMA_BURST, EHCI_INSNREG00(hcd->regs));
301
302	ehci_resume(hcd, false);
303	return 0;
304}
305#else
306#define exynos_ehci_suspend	NULL
307#define exynos_ehci_resume	NULL
308#endif
309
310static const struct dev_pm_ops exynos_ehci_pm_ops = {
311	.suspend	= exynos_ehci_suspend,
312	.resume		= exynos_ehci_resume,
313};
314
315#ifdef CONFIG_OF
316static const struct of_device_id exynos_ehci_match[] = {
317	{ .compatible = "samsung,exynos4210-ehci" },
318	{},
319};
320MODULE_DEVICE_TABLE(of, exynos_ehci_match);
321#endif
322
323static struct platform_driver exynos_ehci_driver = {
324	.probe		= exynos_ehci_probe,
325	.remove		= exynos_ehci_remove,
326	.shutdown	= usb_hcd_platform_shutdown,
327	.driver = {
328		.name	= "exynos-ehci",
329		.pm	= &exynos_ehci_pm_ops,
330		.of_match_table = of_match_ptr(exynos_ehci_match),
331	}
332};
333static const struct ehci_driver_overrides exynos_overrides __initconst = {
334	.extra_priv_size = sizeof(struct exynos_ehci_hcd),
335};
336
337static int __init ehci_exynos_init(void)
338{
339	if (usb_disabled())
340		return -ENODEV;
341
342	ehci_init_driver(&exynos_ehci_hc_driver, &exynos_overrides);
343	return platform_driver_register(&exynos_ehci_driver);
344}
345module_init(ehci_exynos_init);
346
347static void __exit ehci_exynos_cleanup(void)
348{
349	platform_driver_unregister(&exynos_ehci_driver);
350}
351module_exit(ehci_exynos_cleanup);
352
353MODULE_DESCRIPTION(DRIVER_DESC);
354MODULE_ALIAS("platform:exynos-ehci");
355MODULE_AUTHOR("Jingoo Han");
356MODULE_AUTHOR("Joonyoung Shim");
357MODULE_LICENSE("GPL v2");