1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright (C) 2012 Red Hat
  4 *
  5 * based in parts on udlfb.c:
  6 * Copyright (C) 2009 Roberto De Ioris <roberto@unbit.it>
  7 * Copyright (C) 2009 Jaya Kumar <jayakumar.lkml@gmail.com>
  8 * Copyright (C) 2009 Bernie Thompson <bernie@plugable.com>
  9 */
 10
 11#include <drm/drm.h>
 12#include <drm/drm_print.h>
 13#include <drm/drm_probe_helper.h>
 14
 15#include "udl_drv.h"
 16
 17/* -BULK_SIZE as per usb-skeleton. Can we get full page and avoid overhead? */
 18#define BULK_SIZE 512
 19
 20#define NR_USB_REQUEST_CHANNEL 0x12
 21
 22#define MAX_TRANSFER (PAGE_SIZE*16 - BULK_SIZE)
 23#define WRITES_IN_FLIGHT (4)
 24#define MAX_VENDOR_DESCRIPTOR_SIZE 256
 25
 26#define GET_URB_TIMEOUT	HZ
 27#define FREE_URB_TIMEOUT (HZ*2)
 28
 29static int udl_parse_vendor_descriptor(struct udl_device *udl)
 30{
 31	struct usb_device *udev = udl_to_usb_device(udl);
 32	char *desc;
 33	char *buf;
 34	char *desc_end;
 35
 36	u8 total_len = 0;
 37
 38	buf = kzalloc(MAX_VENDOR_DESCRIPTOR_SIZE, GFP_KERNEL);
 39	if (!buf)
 40		return false;
 41	desc = buf;
 42
 43	total_len = usb_get_descriptor(udev, 0x5f, /* vendor specific */
 44				    0, desc, MAX_VENDOR_DESCRIPTOR_SIZE);
 45	if (total_len > 5) {
 46		DRM_INFO("vendor descriptor length:%x data:%11ph\n",
 47			total_len, desc);
 48
 49		if ((desc[0] != total_len) || /* descriptor length */
 50		    (desc[1] != 0x5f) ||   /* vendor descriptor type */
 51		    (desc[2] != 0x01) ||   /* version (2 bytes) */
 52		    (desc[3] != 0x00) ||
 53		    (desc[4] != total_len - 2)) /* length after type */
 54			goto unrecognized;
 55
 56		desc_end = desc + total_len;
 57		desc += 5; /* the fixed header we've already parsed */
 58
 59		while (desc < desc_end) {
 60			u8 length;
 61			u16 key;
 62
 63			key = le16_to_cpu(*((u16 *) desc));
 64			desc += sizeof(u16);
 65			length = *desc;
 66			desc++;
 67
 68			switch (key) {
 69			case 0x0200: { /* max_area */
 70				u32 max_area;
 71				max_area = le32_to_cpu(*((u32 *)desc));
 72				DRM_DEBUG("DL chip limited to %d pixel modes\n",
 73					max_area);
 74				udl->sku_pixel_limit = max_area;
 75				break;
 76			}
 77			default:
 78				break;
 79			}
 80			desc += length;
 81		}
 82	}
 83
 84	goto success;
 85
 86unrecognized:
 87	/* allow udlfb to load for now even if firmware unrecognized */
 88	DRM_ERROR("Unrecognized vendor firmware descriptor\n");
 89
 90success:
 91	kfree(buf);
 92	return true;
 93}
 94
 95/*
 96 * Need to ensure a channel is selected before submitting URBs
 97 */
 98static int udl_select_std_channel(struct udl_device *udl)
 99{
100	static const u8 set_def_chn[] = {0x57, 0xCD, 0xDC, 0xA7,
101					 0x1C, 0x88, 0x5E, 0x15,
102					 0x60, 0xFE, 0xC6, 0x97,
103					 0x16, 0x3D, 0x47, 0xF2};
104
105	void *sendbuf;
106	int ret;
107	struct usb_device *udev = udl_to_usb_device(udl);
108
109	sendbuf = kmemdup(set_def_chn, sizeof(set_def_chn), GFP_KERNEL);
110	if (!sendbuf)
111		return -ENOMEM;
112
113	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
114			      NR_USB_REQUEST_CHANNEL,
115			      (USB_DIR_OUT | USB_TYPE_VENDOR), 0, 0,
116			      sendbuf, sizeof(set_def_chn),
117			      USB_CTRL_SET_TIMEOUT);
118	kfree(sendbuf);
119	return ret < 0 ? ret : 0;
120}
121
122static void udl_release_urb_work(struct work_struct *work)
123{
124	struct urb_node *unode = container_of(work, struct urb_node,
125					      release_urb_work.work);
126
127	up(&unode->dev->urbs.limit_sem);
128}
129
130void udl_urb_completion(struct urb *urb)
131{
132	struct urb_node *unode = urb->context;
133	struct udl_device *udl = unode->dev;
134	unsigned long flags;
135
136	/* sync/async unlink faults aren't errors */
137	if (urb->status) {
138		if (!(urb->status == -ENOENT ||
139		    urb->status == -ECONNRESET ||
140		    urb->status == -ESHUTDOWN)) {
141			DRM_ERROR("%s - nonzero write bulk status received: %d\n",
142				__func__, urb->status);
143		}
144	}
145
146	urb->transfer_buffer_length = udl->urbs.size; /* reset to actual */
147
148	spin_lock_irqsave(&udl->urbs.lock, flags);
149	list_add_tail(&unode->entry, &udl->urbs.list);
150	udl->urbs.available++;
151	spin_unlock_irqrestore(&udl->urbs.lock, flags);
152
153#if 0
154	/*
155	 * When using fb_defio, we deadlock if up() is called
156	 * while another is waiting. So queue to another process.
157	 */
158	if (fb_defio)
159		schedule_delayed_work(&unode->release_urb_work, 0);
160	else
161#endif
162		up(&udl->urbs.limit_sem);
163}
164
165static void udl_free_urb_list(struct drm_device *dev)
166{
167	struct udl_device *udl = to_udl(dev);
168	int count = udl->urbs.count;
169	struct list_head *node;
170	struct urb_node *unode;
171	struct urb *urb;
172
173	DRM_DEBUG("Waiting for completes and freeing all render urbs\n");
174
175	/* keep waiting and freeing, until we've got 'em all */
176	while (count--) {
177		down(&udl->urbs.limit_sem);
178
179		spin_lock_irq(&udl->urbs.lock);
180
181		node = udl->urbs.list.next; /* have reserved one with sem */
182		list_del_init(node);
183
184		spin_unlock_irq(&udl->urbs.lock);
185
186		unode = list_entry(node, struct urb_node, entry);
187		urb = unode->urb;
188
189		/* Free each separately allocated piece */
190		usb_free_coherent(urb->dev, udl->urbs.size,
191				  urb->transfer_buffer, urb->transfer_dma);
192		usb_free_urb(urb);
193		kfree(node);
194	}
195	udl->urbs.count = 0;
196}
197
198static int udl_alloc_urb_list(struct drm_device *dev, int count, size_t size)
199{
200	struct udl_device *udl = to_udl(dev);
201	struct urb *urb;
202	struct urb_node *unode;
203	char *buf;
204	size_t wanted_size = count * size;
205	struct usb_device *udev = udl_to_usb_device(udl);
206
207	spin_lock_init(&udl->urbs.lock);
208
209retry:
210	udl->urbs.size = size;
211	INIT_LIST_HEAD(&udl->urbs.list);
212
213	sema_init(&udl->urbs.limit_sem, 0);
214	udl->urbs.count = 0;
215	udl->urbs.available = 0;
216
217	while (udl->urbs.count * size < wanted_size) {
218		unode = kzalloc(sizeof(struct urb_node), GFP_KERNEL);
219		if (!unode)
220			break;
221		unode->dev = udl;
222
223		INIT_DELAYED_WORK(&unode->release_urb_work,
224			  udl_release_urb_work);
225
226		urb = usb_alloc_urb(0, GFP_KERNEL);
227		if (!urb) {
228			kfree(unode);
229			break;
230		}
231		unode->urb = urb;
232
233		buf = usb_alloc_coherent(udev, size, GFP_KERNEL,
234					 &urb->transfer_dma);
235		if (!buf) {
236			kfree(unode);
237			usb_free_urb(urb);
238			if (size > PAGE_SIZE) {
239				size /= 2;
240				udl_free_urb_list(dev);
241				goto retry;
242			}
243			break;
244		}
245
246		/* urb->transfer_buffer_length set to actual before submit */
247		usb_fill_bulk_urb(urb, udev, usb_sndbulkpipe(udev, 1),
248				  buf, size, udl_urb_completion, unode);
249		urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
250
251		list_add_tail(&unode->entry, &udl->urbs.list);
252
253		up(&udl->urbs.limit_sem);
254		udl->urbs.count++;
255		udl->urbs.available++;
256	}
257
258	DRM_DEBUG("allocated %d %d byte urbs\n", udl->urbs.count, (int) size);
259
260	return udl->urbs.count;
261}
262
263struct urb *udl_get_urb(struct drm_device *dev)
264{
265	struct udl_device *udl = to_udl(dev);
266	int ret = 0;
267	struct list_head *entry;
268	struct urb_node *unode;
269	struct urb *urb = NULL;
270
271	/* Wait for an in-flight buffer to complete and get re-queued */
272	ret = down_timeout(&udl->urbs.limit_sem, GET_URB_TIMEOUT);
273	if (ret) {
274		DRM_INFO("wait for urb interrupted: %x available: %d\n",
275		       ret, udl->urbs.available);
276		goto error;
277	}
278
279	spin_lock_irq(&udl->urbs.lock);
280
281	BUG_ON(list_empty(&udl->urbs.list)); /* reserved one with limit_sem */
282	entry = udl->urbs.list.next;
283	list_del_init(entry);
284	udl->urbs.available--;
285
286	spin_unlock_irq(&udl->urbs.lock);
287
288	unode = list_entry(entry, struct urb_node, entry);
289	urb = unode->urb;
290
291error:
292	return urb;
293}
294
295int udl_submit_urb(struct drm_device *dev, struct urb *urb, size_t len)
296{
297	struct udl_device *udl = to_udl(dev);
298	int ret;
299
300	BUG_ON(len > udl->urbs.size);
301
302	urb->transfer_buffer_length = len; /* set to actual payload len */
303	ret = usb_submit_urb(urb, GFP_ATOMIC);
304	if (ret) {
305		udl_urb_completion(urb); /* because no one else will */
306		DRM_ERROR("usb_submit_urb error %x\n", ret);
307	}
308	return ret;
309}
310
311int udl_init(struct udl_device *udl)
312{
313	struct drm_device *dev = &udl->drm;
314	int ret = -ENOMEM;
315
316	DRM_DEBUG("\n");
317
318	udl->dmadev = usb_intf_get_dma_device(to_usb_interface(dev->dev));
319	if (!udl->dmadev)
320		drm_warn(dev, "buffer sharing not supported"); /* not an error */
321
322	mutex_init(&udl->gem_lock);
323
324	if (!udl_parse_vendor_descriptor(udl)) {
325		ret = -ENODEV;
326		DRM_ERROR("firmware not recognized. Assume incompatible device\n");
327		goto err;
328	}
329
330	if (udl_select_std_channel(udl))
331		DRM_ERROR("Selecting channel failed\n");
332
333	if (!udl_alloc_urb_list(dev, WRITES_IN_FLIGHT, MAX_TRANSFER)) {
334		DRM_ERROR("udl_alloc_urb_list failed\n");
335		goto err;
336	}
337
338	DRM_DEBUG("\n");
339	ret = udl_modeset_init(dev);
340	if (ret)
341		goto err;
342
343	drm_kms_helper_poll_init(dev);
344
345	return 0;
346
347err:
348	if (udl->urbs.count)
349		udl_free_urb_list(dev);
350	put_device(udl->dmadev);
351	DRM_ERROR("%d\n", ret);
352	return ret;
353}
354
355int udl_drop_usb(struct drm_device *dev)
356{
357	struct udl_device *udl = to_udl(dev);
358
359	udl_free_urb_list(dev);
360	put_device(udl->dmadev);
361	udl->dmadev = NULL;
362
363	return 0;
364}