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  1// SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
  2/*
  3 * platform.c - DesignWare HS OTG Controller platform driver
  4 *
  5 * Copyright (C) Matthijs Kooijman <matthijs@stdin.nl>
  6 *
  7 * Redistribution and use in source and binary forms, with or without
  8 * modification, are permitted provided that the following conditions
  9 * are met:
 10 * 1. Redistributions of source code must retain the above copyright
 11 *    notice, this list of conditions, and the following disclaimer,
 12 *    without modification.
 13 * 2. Redistributions in binary form must reproduce the above copyright
 14 *    notice, this list of conditions and the following disclaimer in the
 15 *    documentation and/or other materials provided with the distribution.
 16 * 3. The names of the above-listed copyright holders may not be used
 17 *    to endorse or promote products derived from this software without
 18 *    specific prior written permission.
 19 *
 20 * ALTERNATIVELY, this software may be distributed under the terms of the
 21 * GNU General Public License ("GPL") as published by the Free Software
 22 * Foundation; either version 2 of the License, or (at your option) any
 23 * later version.
 24 *
 25 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 26 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 27 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 28 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 29 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 30 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 31 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 32 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 33 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 34 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 35 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 36 */
 37
 38#include <linux/kernel.h>
 39#include <linux/module.h>
 40#include <linux/slab.h>
 41#include <linux/clk.h>
 42#include <linux/device.h>
 43#include <linux/dma-mapping.h>
 44#include <linux/of_device.h>
 45#include <linux/mutex.h>
 46#include <linux/platform_device.h>
 47#include <linux/phy/phy.h>
 48#include <linux/platform_data/s3c-hsotg.h>
 49#include <linux/reset.h>
 50
 51#include <linux/usb/of.h>
 52
 53#include "core.h"
 54#include "hcd.h"
 55#include "debug.h"
 56
 57static const char dwc2_driver_name[] = "dwc2";
 58
 59/*
 60 * Check the dr_mode against the module configuration and hardware
 61 * capabilities.
 62 *
 63 * The hardware, module, and dr_mode, can each be set to host, device,
 64 * or otg. Check that all these values are compatible and adjust the
 65 * value of dr_mode if possible.
 66 *
 67 *                      actual
 68 *    HW  MOD dr_mode   dr_mode
 69 *  ------------------------------
 70 *   HST  HST  any    :  HST
 71 *   HST  DEV  any    :  ---
 72 *   HST  OTG  any    :  HST
 73 *
 74 *   DEV  HST  any    :  ---
 75 *   DEV  DEV  any    :  DEV
 76 *   DEV  OTG  any    :  DEV
 77 *
 78 *   OTG  HST  any    :  HST
 79 *   OTG  DEV  any    :  DEV
 80 *   OTG  OTG  any    :  dr_mode
 81 */
 82static int dwc2_get_dr_mode(struct dwc2_hsotg *hsotg)
 83{
 84	enum usb_dr_mode mode;
 85
 86	hsotg->dr_mode = usb_get_dr_mode(hsotg->dev);
 87	if (hsotg->dr_mode == USB_DR_MODE_UNKNOWN)
 88		hsotg->dr_mode = USB_DR_MODE_OTG;
 89
 90	mode = hsotg->dr_mode;
 91
 92	if (dwc2_hw_is_device(hsotg)) {
 93		if (IS_ENABLED(CONFIG_USB_DWC2_HOST)) {
 94			dev_err(hsotg->dev,
 95				"Controller does not support host mode.\n");
 96			return -EINVAL;
 97		}
 98		mode = USB_DR_MODE_PERIPHERAL;
 99	} else if (dwc2_hw_is_host(hsotg)) {
100		if (IS_ENABLED(CONFIG_USB_DWC2_PERIPHERAL)) {
101			dev_err(hsotg->dev,
102				"Controller does not support device mode.\n");
103			return -EINVAL;
104		}
105		mode = USB_DR_MODE_HOST;
106	} else {
107		if (IS_ENABLED(CONFIG_USB_DWC2_HOST))
108			mode = USB_DR_MODE_HOST;
109		else if (IS_ENABLED(CONFIG_USB_DWC2_PERIPHERAL))
110			mode = USB_DR_MODE_PERIPHERAL;
111	}
112
113	if (mode != hsotg->dr_mode) {
114		dev_warn(hsotg->dev,
115			 "Configuration mismatch. dr_mode forced to %s\n",
116			mode == USB_DR_MODE_HOST ? "host" : "device");
117
118		hsotg->dr_mode = mode;
119	}
120
121	return 0;
122}
123
124static int __dwc2_lowlevel_hw_enable(struct dwc2_hsotg *hsotg)
125{
126	struct platform_device *pdev = to_platform_device(hsotg->dev);
127	int ret;
128
129	ret = regulator_bulk_enable(ARRAY_SIZE(hsotg->supplies),
130				    hsotg->supplies);
131	if (ret)
132		return ret;
133
134	if (hsotg->clk) {
135		ret = clk_prepare_enable(hsotg->clk);
136		if (ret)
137			return ret;
138	}
139
140	if (hsotg->uphy) {
141		ret = usb_phy_init(hsotg->uphy);
142	} else if (hsotg->plat && hsotg->plat->phy_init) {
143		ret = hsotg->plat->phy_init(pdev, hsotg->plat->phy_type);
144	} else {
145		ret = phy_power_on(hsotg->phy);
146		if (ret == 0)
147			ret = phy_init(hsotg->phy);
148	}
149
150	return ret;
151}
152
153/**
154 * dwc2_lowlevel_hw_enable - enable platform lowlevel hw resources
155 * @hsotg: The driver state
156 *
157 * A wrapper for platform code responsible for controlling
158 * low-level USB platform resources (phy, clock, regulators)
159 */
160int dwc2_lowlevel_hw_enable(struct dwc2_hsotg *hsotg)
161{
162	int ret = __dwc2_lowlevel_hw_enable(hsotg);
163
164	if (ret == 0)
165		hsotg->ll_hw_enabled = true;
166	return ret;
167}
168
169static int __dwc2_lowlevel_hw_disable(struct dwc2_hsotg *hsotg)
170{
171	struct platform_device *pdev = to_platform_device(hsotg->dev);
172	int ret = 0;
173
174	if (hsotg->uphy) {
175		usb_phy_shutdown(hsotg->uphy);
176	} else if (hsotg->plat && hsotg->plat->phy_exit) {
177		ret = hsotg->plat->phy_exit(pdev, hsotg->plat->phy_type);
178	} else {
179		ret = phy_exit(hsotg->phy);
180		if (ret == 0)
181			ret = phy_power_off(hsotg->phy);
182	}
183	if (ret)
184		return ret;
185
186	if (hsotg->clk)
187		clk_disable_unprepare(hsotg->clk);
188
189	ret = regulator_bulk_disable(ARRAY_SIZE(hsotg->supplies),
190				     hsotg->supplies);
191
192	return ret;
193}
194
195/**
196 * dwc2_lowlevel_hw_disable - disable platform lowlevel hw resources
197 * @hsotg: The driver state
198 *
199 * A wrapper for platform code responsible for controlling
200 * low-level USB platform resources (phy, clock, regulators)
201 */
202int dwc2_lowlevel_hw_disable(struct dwc2_hsotg *hsotg)
203{
204	int ret = __dwc2_lowlevel_hw_disable(hsotg);
205
206	if (ret == 0)
207		hsotg->ll_hw_enabled = false;
208	return ret;
209}
210
211static int dwc2_lowlevel_hw_init(struct dwc2_hsotg *hsotg)
212{
213	int i, ret;
214
215	hsotg->reset = devm_reset_control_get_optional(hsotg->dev, "dwc2");
216	if (IS_ERR(hsotg->reset)) {
217		ret = PTR_ERR(hsotg->reset);
218		dev_err(hsotg->dev, "error getting reset control %d\n", ret);
219		return ret;
220	}
221
222	reset_control_deassert(hsotg->reset);
223
224	hsotg->reset_ecc = devm_reset_control_get_optional(hsotg->dev, "dwc2-ecc");
225	if (IS_ERR(hsotg->reset_ecc)) {
226		ret = PTR_ERR(hsotg->reset_ecc);
227		dev_err(hsotg->dev, "error getting reset control for ecc %d\n", ret);
228		return ret;
229	}
230
231	reset_control_deassert(hsotg->reset_ecc);
232
233	/* Set default UTMI width */
234	hsotg->phyif = GUSBCFG_PHYIF16;
235
236	/*
237	 * Attempt to find a generic PHY, then look for an old style
238	 * USB PHY and then fall back to pdata
239	 */
240	hsotg->phy = devm_phy_get(hsotg->dev, "usb2-phy");
241	if (IS_ERR(hsotg->phy)) {
242		ret = PTR_ERR(hsotg->phy);
243		switch (ret) {
244		case -ENODEV:
245		case -ENOSYS:
246			hsotg->phy = NULL;
247			break;
248		case -EPROBE_DEFER:
249			return ret;
250		default:
251			dev_err(hsotg->dev, "error getting phy %d\n", ret);
252			return ret;
253		}
254	}
255
256	if (!hsotg->phy) {
257		hsotg->uphy = devm_usb_get_phy(hsotg->dev, USB_PHY_TYPE_USB2);
258		if (IS_ERR(hsotg->uphy)) {
259			ret = PTR_ERR(hsotg->uphy);
260			switch (ret) {
261			case -ENODEV:
262			case -ENXIO:
263				hsotg->uphy = NULL;
264				break;
265			case -EPROBE_DEFER:
266				return ret;
267			default:
268				dev_err(hsotg->dev, "error getting usb phy %d\n",
269					ret);
270				return ret;
271			}
272		}
273	}
274
275	hsotg->plat = dev_get_platdata(hsotg->dev);
276
277	if (hsotg->phy) {
278		/*
279		 * If using the generic PHY framework, check if the PHY bus
280		 * width is 8-bit and set the phyif appropriately.
281		 */
282		if (phy_get_bus_width(hsotg->phy) == 8)
283			hsotg->phyif = GUSBCFG_PHYIF8;
284	}
285
286	/* Clock */
287	hsotg->clk = devm_clk_get(hsotg->dev, "otg");
288	if (IS_ERR(hsotg->clk)) {
289		hsotg->clk = NULL;
290		dev_dbg(hsotg->dev, "cannot get otg clock\n");
291	}
292
293	/* Regulators */
294	for (i = 0; i < ARRAY_SIZE(hsotg->supplies); i++)
295		hsotg->supplies[i].supply = dwc2_hsotg_supply_names[i];
296
297	ret = devm_regulator_bulk_get(hsotg->dev, ARRAY_SIZE(hsotg->supplies),
298				      hsotg->supplies);
299	if (ret) {
300		dev_err(hsotg->dev, "failed to request supplies: %d\n", ret);
301		return ret;
302	}
303	return 0;
304}
305
306/**
307 * dwc2_driver_remove() - Called when the DWC_otg core is unregistered with the
308 * DWC_otg driver
309 *
310 * @dev: Platform device
311 *
312 * This routine is called, for example, when the rmmod command is executed. The
313 * device may or may not be electrically present. If it is present, the driver
314 * stops device processing. Any resources used on behalf of this device are
315 * freed.
316 */
317static int dwc2_driver_remove(struct platform_device *dev)
318{
319	struct dwc2_hsotg *hsotg = platform_get_drvdata(dev);
320
321	dwc2_debugfs_exit(hsotg);
322	if (hsotg->hcd_enabled)
323		dwc2_hcd_remove(hsotg);
324	if (hsotg->gadget_enabled)
325		dwc2_hsotg_remove(hsotg);
326
327	if (hsotg->ll_hw_enabled)
328		dwc2_lowlevel_hw_disable(hsotg);
329
330	reset_control_assert(hsotg->reset);
331	reset_control_assert(hsotg->reset_ecc);
332
333	return 0;
334}
335
336/**
337 * dwc2_driver_shutdown() - Called on device shutdown
338 *
339 * @dev: Platform device
340 *
341 * In specific conditions (involving usb hubs) dwc2 devices can create a
342 * lot of interrupts, even to the point of overwhelming devices running
343 * at low frequencies. Some devices need to do special clock handling
344 * at shutdown-time which may bring the system clock below the threshold
345 * of being able to handle the dwc2 interrupts. Disabling dwc2-irqs
346 * prevents reboots/poweroffs from getting stuck in such cases.
347 */
348static void dwc2_driver_shutdown(struct platform_device *dev)
349{
350	struct dwc2_hsotg *hsotg = platform_get_drvdata(dev);
351
352	disable_irq(hsotg->irq);
353}
354
355/**
356 * dwc2_driver_probe() - Called when the DWC_otg core is bound to the DWC_otg
357 * driver
358 *
359 * @dev: Platform device
360 *
361 * This routine creates the driver components required to control the device
362 * (core, HCD, and PCD) and initializes the device. The driver components are
363 * stored in a dwc2_hsotg structure. A reference to the dwc2_hsotg is saved
364 * in the device private data. This allows the driver to access the dwc2_hsotg
365 * structure on subsequent calls to driver methods for this device.
366 */
367static int dwc2_driver_probe(struct platform_device *dev)
368{
369	struct dwc2_hsotg *hsotg;
370	struct resource *res;
371	int retval;
372
373	hsotg = devm_kzalloc(&dev->dev, sizeof(*hsotg), GFP_KERNEL);
374	if (!hsotg)
375		return -ENOMEM;
376
377	hsotg->dev = &dev->dev;
378
379	/*
380	 * Use reasonable defaults so platforms don't have to provide these.
381	 */
382	if (!dev->dev.dma_mask)
383		dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
384	retval = dma_set_coherent_mask(&dev->dev, DMA_BIT_MASK(32));
385	if (retval) {
386		dev_err(&dev->dev, "can't set coherent DMA mask: %d\n", retval);
387		return retval;
388	}
389
390	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
391	hsotg->regs = devm_ioremap_resource(&dev->dev, res);
392	if (IS_ERR(hsotg->regs))
393		return PTR_ERR(hsotg->regs);
394
395	dev_dbg(&dev->dev, "mapped PA %08lx to VA %p\n",
396		(unsigned long)res->start, hsotg->regs);
397
398	retval = dwc2_lowlevel_hw_init(hsotg);
399	if (retval)
400		return retval;
401
402	spin_lock_init(&hsotg->lock);
403
404	hsotg->irq = platform_get_irq(dev, 0);
405	if (hsotg->irq < 0) {
406		dev_err(&dev->dev, "missing IRQ resource\n");
407		return hsotg->irq;
408	}
409
410	dev_dbg(hsotg->dev, "registering common handler for irq%d\n",
411		hsotg->irq);
412	retval = devm_request_irq(hsotg->dev, hsotg->irq,
413				  dwc2_handle_common_intr, IRQF_SHARED,
414				  dev_name(hsotg->dev), hsotg);
415	if (retval)
416		return retval;
417
418	retval = dwc2_lowlevel_hw_enable(hsotg);
419	if (retval)
420		return retval;
421
422	retval = dwc2_get_dr_mode(hsotg);
423	if (retval)
424		goto error;
425
426	/*
427	 * Reset before dwc2_get_hwparams() then it could get power-on real
428	 * reset value form registers.
429	 */
430	retval = dwc2_core_reset(hsotg, false);
431	if (retval)
432		goto error;
433
434	/* Detect config values from hardware */
435	retval = dwc2_get_hwparams(hsotg);
436	if (retval)
437		goto error;
438
439	/*
440	 * For OTG cores, set the force mode bits to reflect the value
441	 * of dr_mode. Force mode bits should not be touched at any
442	 * other time after this.
443	 */
444	dwc2_force_dr_mode(hsotg);
445
446	retval = dwc2_init_params(hsotg);
447	if (retval)
448		goto error;
449
450	if (hsotg->dr_mode != USB_DR_MODE_HOST) {
451		retval = dwc2_gadget_init(hsotg);
452		if (retval)
453			goto error;
454		hsotg->gadget_enabled = 1;
455	}
456
457	if (hsotg->dr_mode != USB_DR_MODE_PERIPHERAL) {
458		retval = dwc2_hcd_init(hsotg);
459		if (retval) {
460			if (hsotg->gadget_enabled)
461				dwc2_hsotg_remove(hsotg);
462			goto error;
463		}
464		hsotg->hcd_enabled = 1;
465	}
466
467	platform_set_drvdata(dev, hsotg);
468	hsotg->hibernated = 0;
469
470	dwc2_debugfs_init(hsotg);
471
472	/* Gadget code manages lowlevel hw on its own */
473	if (hsotg->dr_mode == USB_DR_MODE_PERIPHERAL)
474		dwc2_lowlevel_hw_disable(hsotg);
475
476	return 0;
477
478error:
479	dwc2_lowlevel_hw_disable(hsotg);
480	return retval;
481}
482
483static int __maybe_unused dwc2_suspend(struct device *dev)
484{
485	struct dwc2_hsotg *dwc2 = dev_get_drvdata(dev);
486	int ret = 0;
487
488	if (dwc2_is_device_mode(dwc2))
489		dwc2_hsotg_suspend(dwc2);
490
491	if (dwc2->ll_hw_enabled)
492		ret = __dwc2_lowlevel_hw_disable(dwc2);
493
494	return ret;
495}
496
497static int __maybe_unused dwc2_resume(struct device *dev)
498{
499	struct dwc2_hsotg *dwc2 = dev_get_drvdata(dev);
500	int ret = 0;
501
502	if (dwc2->ll_hw_enabled) {
503		ret = __dwc2_lowlevel_hw_enable(dwc2);
504		if (ret)
505			return ret;
506	}
507
508	if (dwc2_is_device_mode(dwc2))
509		ret = dwc2_hsotg_resume(dwc2);
510
511	return ret;
512}
513
514static const struct dev_pm_ops dwc2_dev_pm_ops = {
515	SET_SYSTEM_SLEEP_PM_OPS(dwc2_suspend, dwc2_resume)
516};
517
518static struct platform_driver dwc2_platform_driver = {
519	.driver = {
520		.name = dwc2_driver_name,
521		.of_match_table = dwc2_of_match_table,
522		.pm = &dwc2_dev_pm_ops,
523	},
524	.probe = dwc2_driver_probe,
525	.remove = dwc2_driver_remove,
526	.shutdown = dwc2_driver_shutdown,
527};
528
529module_platform_driver(dwc2_platform_driver);
530
531MODULE_DESCRIPTION("DESIGNWARE HS OTG Platform Glue");
532MODULE_AUTHOR("Matthijs Kooijman <matthijs@stdin.nl>");
533MODULE_LICENSE("Dual BSD/GPL");