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
35 static struct hc_driver __read_mostly exynos_ehci_hc_driver;
36
37 #define PHY_NUMBER 3
38
39 struct 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
exynos_ehci_get_phy(struct device * dev,struct exynos_ehci_hcd * exynos_ehci)48 static 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
exynos_ehci_phy_enable(struct device * dev)95 static 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
exynos_ehci_phy_disable(struct device * dev)111 static 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
exynos_setup_vbus_gpio(struct device * dev)121 static 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
exynos_ehci_probe(struct platform_device * pdev)132 static 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
222 fail_add_hcd:
223 exynos_ehci_phy_disable(&pdev->dev);
224 pdev->dev.of_node = exynos_ehci->of_node;
225 fail_io:
226 clk_disable_unprepare(exynos_ehci->clk);
227 fail_clk:
228 usb_put_hcd(hcd);
229 return err;
230 }
231
exynos_ehci_remove(struct platform_device * pdev)232 static 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
exynos_ehci_suspend(struct device * dev)249 static 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
exynos_ehci_resume(struct device * dev)268 static 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
296 static 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
302 static const struct of_device_id exynos_ehci_match[] = {
303 { .compatible = "samsung,exynos4210-ehci" },
304 {},
305 };
306 MODULE_DEVICE_TABLE(of, exynos_ehci_match);
307 #endif
308
309 static 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 };
319 static const struct ehci_driver_overrides exynos_overrides __initconst = {
320 .extra_priv_size = sizeof(struct exynos_ehci_hcd),
321 };
322
ehci_exynos_init(void)323 static 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 }
331 module_init(ehci_exynos_init);
332
ehci_exynos_cleanup(void)333 static void __exit ehci_exynos_cleanup(void)
334 {
335 platform_driver_unregister(&exynos_ehci_driver);
336 }
337 module_exit(ehci_exynos_cleanup);
338
339 MODULE_DESCRIPTION(DRIVER_DESC);
340 MODULE_ALIAS("platform:exynos-ehci");
341 MODULE_AUTHOR("Jingoo Han");
342 MODULE_AUTHOR("Joonyoung Shim");
343 MODULE_LICENSE("GPL v2");
344