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_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
exynos_ehci_phy_enable(struct device * dev)103 static 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
exynos_ehci_phy_disable(struct device * dev)121 static 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
exynos_setup_vbus_gpio(struct device * dev)132 static 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
exynos_ehci_probe(struct platform_device * pdev)143 static 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
234 fail_add_hcd:
235 exynos_ehci_phy_disable(&pdev->dev);
236 pdev->dev.of_node = exynos_ehci->of_node;
237 fail_io:
238 clk_disable_unprepare(exynos_ehci->clk);
239 fail_clk:
240 usb_put_hcd(hcd);
241 return err;
242 }
243
exynos_ehci_remove(struct platform_device * pdev)244 static 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
exynos_ehci_suspend(struct device * dev)263 static 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
exynos_ehci_resume(struct device * dev)282 static 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
310 static 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
316 static const struct of_device_id exynos_ehci_match[] = {
317 { .compatible = "samsung,exynos4210-ehci" },
318 {},
319 };
320 MODULE_DEVICE_TABLE(of, exynos_ehci_match);
321 #endif
322
323 static 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 };
333 static const struct ehci_driver_overrides exynos_overrides __initconst = {
334 .extra_priv_size = sizeof(struct exynos_ehci_hcd),
335 };
336
ehci_exynos_init(void)337 static 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 }
345 module_init(ehci_exynos_init);
346
ehci_exynos_cleanup(void)347 static void __exit ehci_exynos_cleanup(void)
348 {
349 platform_driver_unregister(&exynos_ehci_driver);
350 }
351 module_exit(ehci_exynos_cleanup);
352
353 MODULE_DESCRIPTION(DRIVER_DESC);
354 MODULE_ALIAS("platform:exynos-ehci");
355 MODULE_AUTHOR("Jingoo Han");
356 MODULE_AUTHOR("Joonyoung Shim");
357 MODULE_LICENSE("GPL v2");
358
