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 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
exynos_ehci_phy_enable(struct device * dev)90 static 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
exynos_ehci_phy_disable(struct device * dev)106 static 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
exynos_setup_vbus_gpio(struct device * dev)116 static 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
exynos_ehci_probe(struct platform_device * pdev)127 static 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
213 fail_add_hcd:
214 exynos_ehci_phy_disable(&pdev->dev);
215 pdev->dev.of_node = exynos_ehci->of_node;
216 fail_io:
217 usb_put_hcd(hcd);
218 return err;
219 }
220
exynos_ehci_remove(struct platform_device * pdev)221 static 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
exynos_ehci_suspend(struct device * dev)235 static 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
exynos_ehci_resume(struct device * dev)254 static 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
278 static DEFINE_SIMPLE_DEV_PM_OPS(exynos_ehci_pm_ops,
279 exynos_ehci_suspend, exynos_ehci_resume);
280
281 #ifdef CONFIG_OF
282 static const struct of_device_id exynos_ehci_match[] = {
283 { .compatible = "samsung,exynos4210-ehci" },
284 {},
285 };
286 MODULE_DEVICE_TABLE(of, exynos_ehci_match);
287 #endif
288
289 static struct platform_driver exynos_ehci_driver = {
290 .probe = exynos_ehci_probe,
291 .remove_new = 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 };
299 static const struct ehci_driver_overrides exynos_overrides __initconst = {
300 .extra_priv_size = sizeof(struct exynos_ehci_hcd),
301 };
302
ehci_exynos_init(void)303 static 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 }
311 module_init(ehci_exynos_init);
312
ehci_exynos_cleanup(void)313 static void __exit ehci_exynos_cleanup(void)
314 {
315 platform_driver_unregister(&exynos_ehci_driver);
316 }
317 module_exit(ehci_exynos_cleanup);
318
319 MODULE_DESCRIPTION(DRIVER_DESC);
320 MODULE_ALIAS("platform:exynos-ehci");
321 MODULE_AUTHOR("Jingoo Han");
322 MODULE_AUTHOR("Joonyoung Shim");
323 MODULE_LICENSE("GPL v2");
324