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