xref: /openbmc/linux/drivers/usb/dwc2/platform.c (revision 174cd4b1)
1 /*
2  * platform.c - DesignWare HS OTG Controller platform driver
3  *
4  * Copyright (C) Matthijs Kooijman <matthijs@stdin.nl>
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions, and the following disclaimer,
11  *    without modification.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. The names of the above-listed copyright holders may not be used
16  *    to endorse or promote products derived from this software without
17  *    specific prior written permission.
18  *
19  * ALTERNATIVELY, this software may be distributed under the terms of the
20  * GNU General Public License ("GPL") as published by the Free Software
21  * Foundation; either version 2 of the License, or (at your option) any
22  * later version.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
25  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
26  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
27  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
28  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
29  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
30  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
31  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
32  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
33  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
34  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35  */
36 
37 #include <linux/kernel.h>
38 #include <linux/module.h>
39 #include <linux/slab.h>
40 #include <linux/clk.h>
41 #include <linux/device.h>
42 #include <linux/dma-mapping.h>
43 #include <linux/of_device.h>
44 #include <linux/mutex.h>
45 #include <linux/platform_device.h>
46 #include <linux/phy/phy.h>
47 #include <linux/platform_data/s3c-hsotg.h>
48 #include <linux/reset.h>
49 
50 #include <linux/usb/of.h>
51 
52 #include "core.h"
53 #include "hcd.h"
54 #include "debug.h"
55 
56 static const char dwc2_driver_name[] = "dwc2";
57 
58 /*
59  * Check the dr_mode against the module configuration and hardware
60  * capabilities.
61  *
62  * The hardware, module, and dr_mode, can each be set to host, device,
63  * or otg. Check that all these values are compatible and adjust the
64  * value of dr_mode if possible.
65  *
66  *                      actual
67  *    HW  MOD dr_mode   dr_mode
68  *  ------------------------------
69  *   HST  HST  any    :  HST
70  *   HST  DEV  any    :  ---
71  *   HST  OTG  any    :  HST
72  *
73  *   DEV  HST  any    :  ---
74  *   DEV  DEV  any    :  DEV
75  *   DEV  OTG  any    :  DEV
76  *
77  *   OTG  HST  any    :  HST
78  *   OTG  DEV  any    :  DEV
79  *   OTG  OTG  any    :  dr_mode
80  */
81 static int dwc2_get_dr_mode(struct dwc2_hsotg *hsotg)
82 {
83 	enum usb_dr_mode mode;
84 
85 	hsotg->dr_mode = usb_get_dr_mode(hsotg->dev);
86 	if (hsotg->dr_mode == USB_DR_MODE_UNKNOWN)
87 		hsotg->dr_mode = USB_DR_MODE_OTG;
88 
89 	mode = hsotg->dr_mode;
90 
91 	if (dwc2_hw_is_device(hsotg)) {
92 		if (IS_ENABLED(CONFIG_USB_DWC2_HOST)) {
93 			dev_err(hsotg->dev,
94 				"Controller does not support host mode.\n");
95 			return -EINVAL;
96 		}
97 		mode = USB_DR_MODE_PERIPHERAL;
98 	} else if (dwc2_hw_is_host(hsotg)) {
99 		if (IS_ENABLED(CONFIG_USB_DWC2_PERIPHERAL)) {
100 			dev_err(hsotg->dev,
101 				"Controller does not support device mode.\n");
102 			return -EINVAL;
103 		}
104 		mode = USB_DR_MODE_HOST;
105 	} else {
106 		if (IS_ENABLED(CONFIG_USB_DWC2_HOST))
107 			mode = USB_DR_MODE_HOST;
108 		else if (IS_ENABLED(CONFIG_USB_DWC2_PERIPHERAL))
109 			mode = USB_DR_MODE_PERIPHERAL;
110 	}
111 
112 	if (mode != hsotg->dr_mode) {
113 		dev_warn(hsotg->dev,
114 			 "Configuration mismatch. dr_mode forced to %s\n",
115 			mode == USB_DR_MODE_HOST ? "host" : "device");
116 
117 		hsotg->dr_mode = mode;
118 	}
119 
120 	return 0;
121 }
122 
123 static int __dwc2_lowlevel_hw_enable(struct dwc2_hsotg *hsotg)
124 {
125 	struct platform_device *pdev = to_platform_device(hsotg->dev);
126 	int ret;
127 
128 	ret = regulator_bulk_enable(ARRAY_SIZE(hsotg->supplies),
129 				    hsotg->supplies);
130 	if (ret)
131 		return ret;
132 
133 	if (hsotg->clk) {
134 		ret = clk_prepare_enable(hsotg->clk);
135 		if (ret)
136 			return ret;
137 	}
138 
139 	if (hsotg->uphy) {
140 		ret = usb_phy_init(hsotg->uphy);
141 	} else if (hsotg->plat && hsotg->plat->phy_init) {
142 		ret = hsotg->plat->phy_init(pdev, hsotg->plat->phy_type);
143 	} else {
144 		ret = phy_power_on(hsotg->phy);
145 		if (ret == 0)
146 			ret = phy_init(hsotg->phy);
147 	}
148 
149 	return ret;
150 }
151 
152 /**
153  * dwc2_lowlevel_hw_enable - enable platform lowlevel hw resources
154  * @hsotg: The driver state
155  *
156  * A wrapper for platform code responsible for controlling
157  * low-level USB platform resources (phy, clock, regulators)
158  */
159 int dwc2_lowlevel_hw_enable(struct dwc2_hsotg *hsotg)
160 {
161 	int ret = __dwc2_lowlevel_hw_enable(hsotg);
162 
163 	if (ret == 0)
164 		hsotg->ll_hw_enabled = true;
165 	return ret;
166 }
167 
168 static int __dwc2_lowlevel_hw_disable(struct dwc2_hsotg *hsotg)
169 {
170 	struct platform_device *pdev = to_platform_device(hsotg->dev);
171 	int ret = 0;
172 
173 	if (hsotg->uphy) {
174 		usb_phy_shutdown(hsotg->uphy);
175 	} else if (hsotg->plat && hsotg->plat->phy_exit) {
176 		ret = hsotg->plat->phy_exit(pdev, hsotg->plat->phy_type);
177 	} else {
178 		ret = phy_exit(hsotg->phy);
179 		if (ret == 0)
180 			ret = phy_power_off(hsotg->phy);
181 	}
182 	if (ret)
183 		return ret;
184 
185 	if (hsotg->clk)
186 		clk_disable_unprepare(hsotg->clk);
187 
188 	ret = regulator_bulk_disable(ARRAY_SIZE(hsotg->supplies),
189 				     hsotg->supplies);
190 
191 	return ret;
192 }
193 
194 /**
195  * dwc2_lowlevel_hw_disable - disable platform lowlevel hw resources
196  * @hsotg: The driver state
197  *
198  * A wrapper for platform code responsible for controlling
199  * low-level USB platform resources (phy, clock, regulators)
200  */
201 int dwc2_lowlevel_hw_disable(struct dwc2_hsotg *hsotg)
202 {
203 	int ret = __dwc2_lowlevel_hw_disable(hsotg);
204 
205 	if (ret == 0)
206 		hsotg->ll_hw_enabled = false;
207 	return ret;
208 }
209 
210 static int dwc2_lowlevel_hw_init(struct dwc2_hsotg *hsotg)
211 {
212 	int i, ret;
213 
214 	hsotg->reset = devm_reset_control_get_optional(hsotg->dev, "dwc2");
215 	if (IS_ERR(hsotg->reset)) {
216 		ret = PTR_ERR(hsotg->reset);
217 		switch (ret) {
218 		case -ENOENT:
219 		case -ENOTSUPP:
220 			hsotg->reset = NULL;
221 			break;
222 		default:
223 			dev_err(hsotg->dev, "error getting reset control %d\n",
224 				ret);
225 			return ret;
226 		}
227 	}
228 
229 	if (hsotg->reset)
230 		reset_control_deassert(hsotg->reset);
231 
232 	/* Set default UTMI width */
233 	hsotg->phyif = GUSBCFG_PHYIF16;
234 
235 	/*
236 	 * Attempt to find a generic PHY, then look for an old style
237 	 * USB PHY and then fall back to pdata
238 	 */
239 	hsotg->phy = devm_phy_get(hsotg->dev, "usb2-phy");
240 	if (IS_ERR(hsotg->phy)) {
241 		ret = PTR_ERR(hsotg->phy);
242 		switch (ret) {
243 		case -ENODEV:
244 		case -ENOSYS:
245 			hsotg->phy = NULL;
246 			break;
247 		case -EPROBE_DEFER:
248 			return ret;
249 		default:
250 			dev_err(hsotg->dev, "error getting phy %d\n", ret);
251 			return ret;
252 		}
253 	}
254 
255 	if (!hsotg->phy) {
256 		hsotg->uphy = devm_usb_get_phy(hsotg->dev, USB_PHY_TYPE_USB2);
257 		if (IS_ERR(hsotg->uphy)) {
258 			ret = PTR_ERR(hsotg->uphy);
259 			switch (ret) {
260 			case -ENODEV:
261 			case -ENXIO:
262 				hsotg->uphy = NULL;
263 				break;
264 			case -EPROBE_DEFER:
265 				return ret;
266 			default:
267 				dev_err(hsotg->dev, "error getting usb phy %d\n",
268 					ret);
269 				return ret;
270 			}
271 		}
272 	}
273 
274 	hsotg->plat = dev_get_platdata(hsotg->dev);
275 
276 	if (hsotg->phy) {
277 		/*
278 		 * If using the generic PHY framework, check if the PHY bus
279 		 * width is 8-bit and set the phyif appropriately.
280 		 */
281 		if (phy_get_bus_width(hsotg->phy) == 8)
282 			hsotg->phyif = GUSBCFG_PHYIF8;
283 	}
284 
285 	/* Clock */
286 	hsotg->clk = devm_clk_get(hsotg->dev, "otg");
287 	if (IS_ERR(hsotg->clk)) {
288 		hsotg->clk = NULL;
289 		dev_dbg(hsotg->dev, "cannot get otg clock\n");
290 	}
291 
292 	/* Regulators */
293 	for (i = 0; i < ARRAY_SIZE(hsotg->supplies); i++)
294 		hsotg->supplies[i].supply = dwc2_hsotg_supply_names[i];
295 
296 	ret = devm_regulator_bulk_get(hsotg->dev, ARRAY_SIZE(hsotg->supplies),
297 				      hsotg->supplies);
298 	if (ret) {
299 		dev_err(hsotg->dev, "failed to request supplies: %d\n", ret);
300 		return ret;
301 	}
302 	return 0;
303 }
304 
305 /**
306  * dwc2_driver_remove() - Called when the DWC_otg core is unregistered with the
307  * DWC_otg driver
308  *
309  * @dev: Platform device
310  *
311  * This routine is called, for example, when the rmmod command is executed. The
312  * device may or may not be electrically present. If it is present, the driver
313  * stops device processing. Any resources used on behalf of this device are
314  * freed.
315  */
316 static int dwc2_driver_remove(struct platform_device *dev)
317 {
318 	struct dwc2_hsotg *hsotg = platform_get_drvdata(dev);
319 
320 	dwc2_debugfs_exit(hsotg);
321 	if (hsotg->hcd_enabled)
322 		dwc2_hcd_remove(hsotg);
323 	if (hsotg->gadget_enabled)
324 		dwc2_hsotg_remove(hsotg);
325 
326 	if (hsotg->ll_hw_enabled)
327 		dwc2_lowlevel_hw_disable(hsotg);
328 
329 	if (hsotg->reset)
330 		reset_control_assert(hsotg->reset);
331 
332 	return 0;
333 }
334 
335 /**
336  * dwc2_driver_shutdown() - Called on device shutdown
337  *
338  * @dev: Platform device
339  *
340  * In specific conditions (involving usb hubs) dwc2 devices can create a
341  * lot of interrupts, even to the point of overwhelming devices running
342  * at low frequencies. Some devices need to do special clock handling
343  * at shutdown-time which may bring the system clock below the threshold
344  * of being able to handle the dwc2 interrupts. Disabling dwc2-irqs
345  * prevents reboots/poweroffs from getting stuck in such cases.
346  */
347 static void dwc2_driver_shutdown(struct platform_device *dev)
348 {
349 	struct dwc2_hsotg *hsotg = platform_get_drvdata(dev);
350 
351 	disable_irq(hsotg->irq);
352 }
353 
354 /**
355  * dwc2_driver_probe() - Called when the DWC_otg core is bound to the DWC_otg
356  * driver
357  *
358  * @dev: Platform device
359  *
360  * This routine creates the driver components required to control the device
361  * (core, HCD, and PCD) and initializes the device. The driver components are
362  * stored in a dwc2_hsotg structure. A reference to the dwc2_hsotg is saved
363  * in the device private data. This allows the driver to access the dwc2_hsotg
364  * structure on subsequent calls to driver methods for this device.
365  */
366 static int dwc2_driver_probe(struct platform_device *dev)
367 {
368 	struct dwc2_hsotg *hsotg;
369 	struct resource *res;
370 	int retval;
371 
372 	hsotg = devm_kzalloc(&dev->dev, sizeof(*hsotg), GFP_KERNEL);
373 	if (!hsotg)
374 		return -ENOMEM;
375 
376 	hsotg->dev = &dev->dev;
377 
378 	/*
379 	 * Use reasonable defaults so platforms don't have to provide these.
380 	 */
381 	if (!dev->dev.dma_mask)
382 		dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
383 	retval = dma_set_coherent_mask(&dev->dev, DMA_BIT_MASK(32));
384 	if (retval)
385 		return retval;
386 
387 	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
388 	hsotg->regs = devm_ioremap_resource(&dev->dev, res);
389 	if (IS_ERR(hsotg->regs))
390 		return PTR_ERR(hsotg->regs);
391 
392 	dev_dbg(&dev->dev, "mapped PA %08lx to VA %p\n",
393 		(unsigned long)res->start, hsotg->regs);
394 
395 	retval = dwc2_lowlevel_hw_init(hsotg);
396 	if (retval)
397 		return retval;
398 
399 	spin_lock_init(&hsotg->lock);
400 
401 	hsotg->irq = platform_get_irq(dev, 0);
402 	if (hsotg->irq < 0) {
403 		dev_err(&dev->dev, "missing IRQ resource\n");
404 		return hsotg->irq;
405 	}
406 
407 	dev_dbg(hsotg->dev, "registering common handler for irq%d\n",
408 		hsotg->irq);
409 	retval = devm_request_irq(hsotg->dev, hsotg->irq,
410 				  dwc2_handle_common_intr, IRQF_SHARED,
411 				  dev_name(hsotg->dev), hsotg);
412 	if (retval)
413 		return retval;
414 
415 	retval = dwc2_lowlevel_hw_enable(hsotg);
416 	if (retval)
417 		return retval;
418 
419 	retval = dwc2_get_dr_mode(hsotg);
420 	if (retval)
421 		goto error;
422 
423 	/*
424 	 * Reset before dwc2_get_hwparams() then it could get power-on real
425 	 * reset value form registers.
426 	 */
427 	dwc2_core_reset_and_force_dr_mode(hsotg);
428 
429 	/* Detect config values from hardware */
430 	retval = dwc2_get_hwparams(hsotg);
431 	if (retval)
432 		goto error;
433 
434 	dwc2_force_dr_mode(hsotg);
435 
436 	retval = dwc2_init_params(hsotg);
437 	if (retval)
438 		goto error;
439 
440 	if (hsotg->dr_mode != USB_DR_MODE_HOST) {
441 		retval = dwc2_gadget_init(hsotg, hsotg->irq);
442 		if (retval)
443 			goto error;
444 		hsotg->gadget_enabled = 1;
445 	}
446 
447 	if (hsotg->dr_mode != USB_DR_MODE_PERIPHERAL) {
448 		retval = dwc2_hcd_init(hsotg);
449 		if (retval) {
450 			if (hsotg->gadget_enabled)
451 				dwc2_hsotg_remove(hsotg);
452 			goto error;
453 		}
454 		hsotg->hcd_enabled = 1;
455 	}
456 
457 	platform_set_drvdata(dev, hsotg);
458 
459 	dwc2_debugfs_init(hsotg);
460 
461 	/* Gadget code manages lowlevel hw on its own */
462 	if (hsotg->dr_mode == USB_DR_MODE_PERIPHERAL)
463 		dwc2_lowlevel_hw_disable(hsotg);
464 
465 	return 0;
466 
467 error:
468 	dwc2_lowlevel_hw_disable(hsotg);
469 	return retval;
470 }
471 
472 static int __maybe_unused dwc2_suspend(struct device *dev)
473 {
474 	struct dwc2_hsotg *dwc2 = dev_get_drvdata(dev);
475 	int ret = 0;
476 
477 	if (dwc2_is_device_mode(dwc2))
478 		dwc2_hsotg_suspend(dwc2);
479 
480 	if (dwc2->ll_hw_enabled)
481 		ret = __dwc2_lowlevel_hw_disable(dwc2);
482 
483 	return ret;
484 }
485 
486 static int __maybe_unused dwc2_resume(struct device *dev)
487 {
488 	struct dwc2_hsotg *dwc2 = dev_get_drvdata(dev);
489 	int ret = 0;
490 
491 	if (dwc2->ll_hw_enabled) {
492 		ret = __dwc2_lowlevel_hw_enable(dwc2);
493 		if (ret)
494 			return ret;
495 	}
496 
497 	if (dwc2_is_device_mode(dwc2))
498 		ret = dwc2_hsotg_resume(dwc2);
499 
500 	return ret;
501 }
502 
503 static const struct dev_pm_ops dwc2_dev_pm_ops = {
504 	SET_SYSTEM_SLEEP_PM_OPS(dwc2_suspend, dwc2_resume)
505 };
506 
507 static struct platform_driver dwc2_platform_driver = {
508 	.driver = {
509 		.name = dwc2_driver_name,
510 		.of_match_table = dwc2_of_match_table,
511 		.pm = &dwc2_dev_pm_ops,
512 	},
513 	.probe = dwc2_driver_probe,
514 	.remove = dwc2_driver_remove,
515 	.shutdown = dwc2_driver_shutdown,
516 };
517 
518 module_platform_driver(dwc2_platform_driver);
519 
520 MODULE_DESCRIPTION("DESIGNWARE HS OTG Platform Glue");
521 MODULE_AUTHOR("Matthijs Kooijman <matthijs@stdin.nl>");
522 MODULE_LICENSE("Dual BSD/GPL");
523