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  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Wireless USB Host Controller
  4 * Root Hub operations
  5 *
  6 *
  7 * Copyright (C) 2005-2006 Intel Corporation
  8 * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
  9 *
 10 * We fake a root hub that has fake ports (as many as simultaneous
 11 * devices the Wireless USB Host Controller can deal with). For each
 12 * port we keep an state in @wusbhc->port[index] identical to the one
 13 * specified in the USB2.0[ch11] spec and some extra device
 14 * information that complements the one in 'struct usb_device' (as
 15 * this lacs a hcpriv pointer).
 16 *
 17 * Note this is common to WHCI and HWA host controllers.
 18 *
 19 * Through here we enable most of the state changes that the USB stack
 20 * will use to connect or disconnect devices. We need to do some
 21 * forced adaptation of Wireless USB device states vs. wired:
 22 *
 23 *        USB:                 WUSB:
 24 *
 25 * Port   Powered-off          port slot n/a
 26 *        Powered-on           port slot available
 27 *        Disconnected         port slot available
 28 *        Connected            port slot assigned device
 29 *        		       device sent DN_Connect
 30 *                             device was authenticated
 31 *        Enabled              device is authenticated, transitioned
 32 *                             from unauth -> auth -> default address
 33 *                             -> enabled
 34 *        Reset                disconnect
 35 *        Disable              disconnect
 36 *
 37 * This maps the standard USB port states with the WUSB device states
 38 * so we can fake ports without having to modify the USB stack.
 39 *
 40 * FIXME: this process will change in the future
 41 *
 42 *
 43 * ENTRY POINTS
 44 *
 45 * Our entry points into here are, as in hcd.c, the USB stack root hub
 46 * ops defined in the usb_hcd struct:
 47 *
 48 * wusbhc_rh_status_data()	Provide hub and port status data bitmap
 49 *
 50 * wusbhc_rh_control()          Execution of all the major requests
 51 *                              you can do to a hub (Set|Clear
 52 *                              features, get descriptors, status, etc).
 53 *
 54 * wusbhc_rh_[suspend|resume]() That
 55 *
 56 * wusbhc_rh_start_port_reset() ??? unimplemented
 57 */
 58#include <linux/slab.h>
 59#include <linux/export.h>
 60#include "wusbhc.h"
 61
 62/*
 63 * Reset a fake port
 64 *
 65 * Using a Reset Device IE is too heavyweight as it causes the device
 66 * to enter the UnConnected state and leave the cluster, this can mean
 67 * that when the device reconnects it is connected to a different fake
 68 * port.
 69 *
 70 * Instead, reset authenticated devices with a SetAddress(0), followed
 71 * by a SetAddresss(AuthAddr).
 72 *
 73 * For unauthenticated devices just pretend to reset but do nothing.
 74 * If the device initialization continues to fail it will eventually
 75 * time out after TrustTimeout and enter the UnConnected state.
 76 *
 77 * @wusbhc is assumed referenced and @wusbhc->mutex unlocked.
 78 *
 79 * Supposedly we are the only thread accesing @wusbhc->port; in any
 80 * case, maybe we should move the mutex locking from
 81 * wusbhc_devconnect_auth() to here.
 82 *
 83 * @port_idx refers to the wusbhc's port index, not the USB port number
 84 */
 85static int wusbhc_rh_port_reset(struct wusbhc *wusbhc, u8 port_idx)
 86{
 87	int result = 0;
 88	struct wusb_port *port = wusb_port_by_idx(wusbhc, port_idx);
 89	struct wusb_dev *wusb_dev = port->wusb_dev;
 90
 91	if (wusb_dev == NULL)
 92		return -ENOTCONN;
 93
 94	port->status |= USB_PORT_STAT_RESET;
 95	port->change |= USB_PORT_STAT_C_RESET;
 96
 97	if (wusb_dev->addr & WUSB_DEV_ADDR_UNAUTH)
 98		result = 0;
 99	else
100		result = wusb_dev_update_address(wusbhc, wusb_dev);
101
102	port->status &= ~USB_PORT_STAT_RESET;
103	port->status |= USB_PORT_STAT_ENABLE;
104	port->change |= USB_PORT_STAT_C_RESET | USB_PORT_STAT_C_ENABLE;	
105
106	return result;
107}
108
109/*
110 * Return the hub change status bitmap
111 *
112 * The bits in the change status bitmap are cleared when a
113 * ClearPortFeature request is issued (USB2.0[11.12.3,11.12.4].
114 *
115 * @wusbhc is assumed referenced and @wusbhc->mutex unlocked.
116 *
117 * WARNING!! This gets called from atomic context; we cannot get the
118 *           mutex--the only race condition we can find is some bit
119 *           changing just after we copy it, which shouldn't be too
120 *           big of a problem [and we can't make it an spinlock
121 *           because other parts need to take it and sleep] .
122 *
123 *           @usb_hcd is refcounted, so it won't disappear under us
124 *           and before killing a host, the polling of the root hub
125 *           would be stopped anyway.
126 */
127int wusbhc_rh_status_data(struct usb_hcd *usb_hcd, char *_buf)
128{
129	struct wusbhc *wusbhc = usb_hcd_to_wusbhc(usb_hcd);
130	size_t cnt, size, bits_set = 0;
131
132	/* WE DON'T LOCK, see comment */
133	/* round up to bytes.  Hub bit is bit 0 so add 1. */
134	size = DIV_ROUND_UP(wusbhc->ports_max + 1, 8);
135
136	/* clear the output buffer. */
137	memset(_buf, 0, size);
138	/* set the bit for each changed port. */
139	for (cnt = 0; cnt < wusbhc->ports_max; cnt++) {
140
141		if (wusb_port_by_idx(wusbhc, cnt)->change) {
142			const int bitpos = cnt+1;
143
144			_buf[bitpos/8] |= (1 << (bitpos % 8));
145			bits_set++;
146		}
147	}
148
149	return bits_set ? size : 0;
150}
151EXPORT_SYMBOL_GPL(wusbhc_rh_status_data);
152
153/*
154 * Return the hub's descriptor
155 *
156 * NOTE: almost cut and paste from ehci-hub.c
157 *
158 * @wusbhc is assumed referenced and @wusbhc->mutex unlocked
159 */
160static int wusbhc_rh_get_hub_descr(struct wusbhc *wusbhc, u16 wValue,
161				   u16 wIndex,
162				   struct usb_hub_descriptor *descr,
163				   u16 wLength)
164{
165	u16 temp = 1 + (wusbhc->ports_max / 8);
166	u8 length = 7 + 2 * temp;
167
168	if (wLength < length)
169		return -ENOSPC;
170	descr->bDescLength = 7 + 2 * temp;
171	descr->bDescriptorType = USB_DT_HUB; /* HUB type */
172	descr->bNbrPorts = wusbhc->ports_max;
173	descr->wHubCharacteristics = cpu_to_le16(
174		HUB_CHAR_COMMON_LPSM	/* All ports power at once */
175		| 0x00			/* not part of compound device */
176		| HUB_CHAR_NO_OCPM	/* No overcurrent protection */
177		| 0x00			/* 8 FS think time FIXME ?? */
178		| 0x00);		/* No port indicators */
179	descr->bPwrOn2PwrGood = 0;
180	descr->bHubContrCurrent = 0;
181	/* two bitmaps:  ports removable, and usb 1.0 legacy PortPwrCtrlMask */
182	memset(&descr->u.hs.DeviceRemovable[0], 0, temp);
183	memset(&descr->u.hs.DeviceRemovable[temp], 0xff, temp);
184	return 0;
185}
186
187/*
188 * Clear a hub feature
189 *
190 * @wusbhc is assumed referenced and @wusbhc->mutex unlocked.
191 *
192 * Nothing to do, so no locking needed ;)
193 */
194static int wusbhc_rh_clear_hub_feat(struct wusbhc *wusbhc, u16 feature)
195{
196	int result;
197
198	switch (feature) {
199	case C_HUB_LOCAL_POWER:
200		/* FIXME: maybe plug bit 0 to the power input status,
201		 * if any?
202		 * see wusbhc_rh_get_hub_status() */
203	case C_HUB_OVER_CURRENT:
204		result = 0;
205		break;
206	default:
207		result = -EPIPE;
208	}
209	return result;
210}
211
212/*
213 * Return hub status (it is always zero...)
214 *
215 * @wusbhc is assumed referenced and @wusbhc->mutex unlocked.
216 *
217 * Nothing to do, so no locking needed ;)
218 */
219static int wusbhc_rh_get_hub_status(struct wusbhc *wusbhc, u32 *buf,
220				    u16 wLength)
221{
222	/* FIXME: maybe plug bit 0 to the power input status (if any)? */
223	*buf = 0;
224	return 0;
225}
226
227/*
228 * Set a port feature
229 *
230 * @wusbhc is assumed referenced and @wusbhc->mutex unlocked.
231 */
232static int wusbhc_rh_set_port_feat(struct wusbhc *wusbhc, u16 feature,
233				   u8 selector, u8 port_idx)
234{
235	struct device *dev = wusbhc->dev;
236
237	if (port_idx > wusbhc->ports_max)
238		return -EINVAL;
239
240	switch (feature) {
241		/* According to USB2.0[11.24.2.13]p2, these features
242		 * are not required to be implemented. */
243	case USB_PORT_FEAT_C_OVER_CURRENT:
244	case USB_PORT_FEAT_C_ENABLE:
245	case USB_PORT_FEAT_C_SUSPEND:
246	case USB_PORT_FEAT_C_CONNECTION:
247	case USB_PORT_FEAT_C_RESET:
248		return 0;
249	case USB_PORT_FEAT_POWER:
250		/* No such thing, but we fake it works */
251		mutex_lock(&wusbhc->mutex);
252		wusb_port_by_idx(wusbhc, port_idx)->status |= USB_PORT_STAT_POWER;
253		mutex_unlock(&wusbhc->mutex);
254		return 0;
255	case USB_PORT_FEAT_RESET:
256		return wusbhc_rh_port_reset(wusbhc, port_idx);
257	case USB_PORT_FEAT_ENABLE:
258	case USB_PORT_FEAT_SUSPEND:
259		dev_err(dev, "(port_idx %d) set feat %d/%d UNIMPLEMENTED\n",
260			port_idx, feature, selector);
261		return -ENOSYS;
262	default:
263		dev_err(dev, "(port_idx %d) set feat %d/%d UNKNOWN\n",
264			port_idx, feature, selector);
265		return -EPIPE;
266	}
267
268	return 0;
269}
270
271/*
272 * Clear a port feature...
273 *
274 * @wusbhc is assumed referenced and @wusbhc->mutex unlocked.
275 */
276static int wusbhc_rh_clear_port_feat(struct wusbhc *wusbhc, u16 feature,
277				     u8 selector, u8 port_idx)
278{
279	int result = 0;
280	struct device *dev = wusbhc->dev;
281
282	if (port_idx > wusbhc->ports_max)
283		return -EINVAL;
284
285	mutex_lock(&wusbhc->mutex);
286	switch (feature) {
287	case USB_PORT_FEAT_POWER:	/* fake port always on */
288		/* According to USB2.0[11.24.2.7.1.4], no need to implement? */
289	case USB_PORT_FEAT_C_OVER_CURRENT:
290		break;
291	case USB_PORT_FEAT_C_RESET:
292		wusb_port_by_idx(wusbhc, port_idx)->change &= ~USB_PORT_STAT_C_RESET;
293		break;
294	case USB_PORT_FEAT_C_CONNECTION:
295		wusb_port_by_idx(wusbhc, port_idx)->change &= ~USB_PORT_STAT_C_CONNECTION;
296		break;
297	case USB_PORT_FEAT_ENABLE:
298		__wusbhc_dev_disable(wusbhc, port_idx);
299		break;
300	case USB_PORT_FEAT_C_ENABLE:
301		wusb_port_by_idx(wusbhc, port_idx)->change &= ~USB_PORT_STAT_C_ENABLE;
302		break;
303	case USB_PORT_FEAT_SUSPEND:
304	case USB_PORT_FEAT_C_SUSPEND:
305		dev_err(dev, "(port_idx %d) Clear feat %d/%d UNIMPLEMENTED\n",
306			port_idx, feature, selector);
307		result = -ENOSYS;
308		break;
309	default:
310		dev_err(dev, "(port_idx %d) Clear feat %d/%d UNKNOWN\n",
311			port_idx, feature, selector);
312		result = -EPIPE;
313		break;
314	}
315	mutex_unlock(&wusbhc->mutex);
316
317	return result;
318}
319
320/*
321 * Return the port's status
322 *
323 * @wusbhc is assumed referenced and @wusbhc->mutex unlocked.
324 */
325static int wusbhc_rh_get_port_status(struct wusbhc *wusbhc, u16 port_idx,
326				     u32 *_buf, u16 wLength)
327{
328	__le16 *buf = (__le16 *)_buf;
329
330	if (port_idx > wusbhc->ports_max)
331		return -EINVAL;
332
333	mutex_lock(&wusbhc->mutex);
334	buf[0] = cpu_to_le16(wusb_port_by_idx(wusbhc, port_idx)->status);
335	buf[1] = cpu_to_le16(wusb_port_by_idx(wusbhc, port_idx)->change);
336	mutex_unlock(&wusbhc->mutex);
337
338	return 0;
339}
340
341/*
342 * Entry point for Root Hub operations
343 *
344 * @wusbhc is assumed referenced and @wusbhc->mutex unlocked.
345 */
346int wusbhc_rh_control(struct usb_hcd *usb_hcd, u16 reqntype, u16 wValue,
347		      u16 wIndex, char *buf, u16 wLength)
348{
349	int result = -ENOSYS;
350	struct wusbhc *wusbhc = usb_hcd_to_wusbhc(usb_hcd);
351
352	switch (reqntype) {
353	case GetHubDescriptor:
354		result = wusbhc_rh_get_hub_descr(
355			wusbhc, wValue, wIndex,
356			(struct usb_hub_descriptor *) buf, wLength);
357		break;
358	case ClearHubFeature:
359		result = wusbhc_rh_clear_hub_feat(wusbhc, wValue);
360		break;
361	case GetHubStatus:
362		result = wusbhc_rh_get_hub_status(wusbhc, (u32 *)buf, wLength);
363		break;
364
365	case SetPortFeature:
366		result = wusbhc_rh_set_port_feat(wusbhc, wValue, wIndex >> 8,
367						 (wIndex & 0xff) - 1);
368		break;
369	case ClearPortFeature:
370		result = wusbhc_rh_clear_port_feat(wusbhc, wValue, wIndex >> 8,
371						   (wIndex & 0xff) - 1);
372		break;
373	case GetPortStatus:
374		result = wusbhc_rh_get_port_status(wusbhc, wIndex - 1,
375						   (u32 *)buf, wLength);
376		break;
377
378	case SetHubFeature:
379	default:
380		dev_err(wusbhc->dev, "%s (%p [%p], %x, %x, %x, %p, %x) "
381			"UNIMPLEMENTED\n", __func__, usb_hcd, wusbhc, reqntype,
382			wValue, wIndex, buf, wLength);
383		/* dump_stack(); */
384		result = -ENOSYS;
385	}
386	return result;
387}
388EXPORT_SYMBOL_GPL(wusbhc_rh_control);
389
390int wusbhc_rh_start_port_reset(struct usb_hcd *usb_hcd, unsigned port_idx)
391{
392	struct wusbhc *wusbhc = usb_hcd_to_wusbhc(usb_hcd);
393	dev_err(wusbhc->dev, "%s (%p [%p], port_idx %u) UNIMPLEMENTED\n",
394		__func__, usb_hcd, wusbhc, port_idx);
395	WARN_ON(1);
396	return -ENOSYS;
397}
398EXPORT_SYMBOL_GPL(wusbhc_rh_start_port_reset);
399
400static void wusb_port_init(struct wusb_port *port)
401{
402	port->status |= USB_PORT_STAT_HIGH_SPEED;
403}
404
405/*
406 * Alloc fake port specific fields and status.
407 */
408int wusbhc_rh_create(struct wusbhc *wusbhc)
409{
410	int result = -ENOMEM;
411	size_t port_size, itr;
412	port_size = wusbhc->ports_max * sizeof(wusbhc->port[0]);
413	wusbhc->port = kzalloc(port_size, GFP_KERNEL);
414	if (wusbhc->port == NULL)
415		goto error_port_alloc;
416	for (itr = 0; itr < wusbhc->ports_max; itr++)
417		wusb_port_init(&wusbhc->port[itr]);
418	result = 0;
419error_port_alloc:
420	return result;
421}
422
423void wusbhc_rh_destroy(struct wusbhc *wusbhc)
424{
425	kfree(wusbhc->port);
426}