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 (20)
24#define MAX_VENDOR_DESCRIPTOR_SIZE 256
25
26static struct urb *udl_get_urb_locked(struct udl_device *udl, long timeout);
27
28static int udl_parse_vendor_descriptor(struct udl_device *udl)
29{
30	struct usb_device *udev = udl_to_usb_device(udl);
31	char *desc;
32	char *buf;
33	char *desc_end;
34
35	u8 total_len = 0;
36
37	buf = kzalloc(MAX_VENDOR_DESCRIPTOR_SIZE, GFP_KERNEL);
38	if (!buf)
39		return false;
40	desc = buf;
41
42	total_len = usb_get_descriptor(udev, 0x5f, /* vendor specific */
43				    0, desc, MAX_VENDOR_DESCRIPTOR_SIZE);
44	if (total_len > 5) {
45		DRM_INFO("vendor descriptor length:%x data:%11ph\n",
46			total_len, desc);
47
48		if ((desc[0] != total_len) || /* descriptor length */
49		    (desc[1] != 0x5f) ||   /* vendor descriptor type */
50		    (desc[2] != 0x01) ||   /* version (2 bytes) */
51		    (desc[3] != 0x00) ||
52		    (desc[4] != total_len - 2)) /* length after type */
53			goto unrecognized;
54
55		desc_end = desc + total_len;
56		desc += 5; /* the fixed header we've already parsed */
57
58		while (desc < desc_end) {
59			u8 length;
60			u16 key;
61
62			key = le16_to_cpu(*((u16 *) desc));
63			desc += sizeof(u16);
64			length = *desc;
65			desc++;
66
67			switch (key) {
68			case 0x0200: { /* max_area */
69				u32 max_area;
70				max_area = le32_to_cpu(*((u32 *)desc));
71				DRM_DEBUG("DL chip limited to %d pixel modes\n",
72					max_area);
73				udl->sku_pixel_limit = max_area;
74				break;
75			}
76			default:
77				break;
78			}
79			desc += length;
80		}
81	}
82
83	goto success;
84
85unrecognized:
86	/* allow udlfb to load for now even if firmware unrecognized */
87	DRM_ERROR("Unrecognized vendor firmware descriptor\n");
88
89success:
90	kfree(buf);
91	return true;
92}
93
94/*
95 * Need to ensure a channel is selected before submitting URBs
96 */
97int udl_select_std_channel(struct udl_device *udl)
98{
99	static const u8 set_def_chn[] = {0x57, 0xCD, 0xDC, 0xA7,
100					 0x1C, 0x88, 0x5E, 0x15,
101					 0x60, 0xFE, 0xC6, 0x97,
102					 0x16, 0x3D, 0x47, 0xF2};
103
104	void *sendbuf;
105	int ret;
106	struct usb_device *udev = udl_to_usb_device(udl);
107
108	sendbuf = kmemdup(set_def_chn, sizeof(set_def_chn), GFP_KERNEL);
109	if (!sendbuf)
110		return -ENOMEM;
111
112	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
113			      NR_USB_REQUEST_CHANNEL,
114			      (USB_DIR_OUT | USB_TYPE_VENDOR), 0, 0,
115			      sendbuf, sizeof(set_def_chn),
116			      USB_CTRL_SET_TIMEOUT);
117	kfree(sendbuf);
118	return ret < 0 ? ret : 0;
119}
120
121void udl_urb_completion(struct urb *urb)
122{
123	struct urb_node *unode = urb->context;
124	struct udl_device *udl = unode->dev;
125	unsigned long flags;
126
127	/* sync/async unlink faults aren't errors */
128	if (urb->status) {
129		if (!(urb->status == -ENOENT ||
130		    urb->status == -ECONNRESET ||
131		    urb->status == -EPROTO ||
132		    urb->status == -ESHUTDOWN)) {
133			DRM_ERROR("%s - nonzero write bulk status received: %d\n",
134				__func__, urb->status);
135		}
136	}
137
138	urb->transfer_buffer_length = udl->urbs.size; /* reset to actual */
139
140	spin_lock_irqsave(&udl->urbs.lock, flags);
141	list_add_tail(&unode->entry, &udl->urbs.list);
142	udl->urbs.available++;
143	spin_unlock_irqrestore(&udl->urbs.lock, flags);
144
145	wake_up(&udl->urbs.sleep);
146}
147
148static void udl_free_urb_list(struct drm_device *dev)
149{
150	struct udl_device *udl = to_udl(dev);
151	struct urb_node *unode;
152	struct urb *urb;
153
154	DRM_DEBUG("Waiting for completes and freeing all render urbs\n");
155
156	/* keep waiting and freeing, until we've got 'em all */
157	while (udl->urbs.count) {
158		spin_lock_irq(&udl->urbs.lock);
159		urb = udl_get_urb_locked(udl, MAX_SCHEDULE_TIMEOUT);
160		udl->urbs.count--;
161		spin_unlock_irq(&udl->urbs.lock);
162		if (WARN_ON(!urb))
163			break;
164		unode = urb->context;
165		/* Free each separately allocated piece */
166		usb_free_coherent(urb->dev, udl->urbs.size,
167				  urb->transfer_buffer, urb->transfer_dma);
168		usb_free_urb(urb);
169		kfree(unode);
170	}
171
172	wake_up_all(&udl->urbs.sleep);
173}
174
175static int udl_alloc_urb_list(struct drm_device *dev, int count, size_t size)
176{
177	struct udl_device *udl = to_udl(dev);
178	struct urb *urb;
179	struct urb_node *unode;
180	char *buf;
181	size_t wanted_size = count * size;
182	struct usb_device *udev = udl_to_usb_device(udl);
183
184	spin_lock_init(&udl->urbs.lock);
185	INIT_LIST_HEAD(&udl->urbs.list);
186	init_waitqueue_head(&udl->urbs.sleep);
187	udl->urbs.count = 0;
188	udl->urbs.available = 0;
189
190retry:
191	udl->urbs.size = size;
192
193	while (udl->urbs.count * size < wanted_size) {
194		unode = kzalloc(sizeof(struct urb_node), GFP_KERNEL);
195		if (!unode)
196			break;
197		unode->dev = udl;
198
199		urb = usb_alloc_urb(0, GFP_KERNEL);
200		if (!urb) {
201			kfree(unode);
202			break;
203		}
204		unode->urb = urb;
205
206		buf = usb_alloc_coherent(udev, size, GFP_KERNEL,
207					 &urb->transfer_dma);
208		if (!buf) {
209			kfree(unode);
210			usb_free_urb(urb);
211			if (size > PAGE_SIZE) {
212				size /= 2;
213				udl_free_urb_list(dev);
214				goto retry;
215			}
216			break;
217		}
218
219		/* urb->transfer_buffer_length set to actual before submit */
220		usb_fill_bulk_urb(urb, udev, usb_sndbulkpipe(udev, 1),
221				  buf, size, udl_urb_completion, unode);
222		urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
223
224		list_add_tail(&unode->entry, &udl->urbs.list);
225
226		udl->urbs.count++;
227		udl->urbs.available++;
228	}
229
230	DRM_DEBUG("allocated %d %d byte urbs\n", udl->urbs.count, (int) size);
231
232	return udl->urbs.count;
233}
234
235static struct urb *udl_get_urb_locked(struct udl_device *udl, long timeout)
236{
237	struct urb_node *unode;
238
239	assert_spin_locked(&udl->urbs.lock);
240
241	/* Wait for an in-flight buffer to complete and get re-queued */
242	if (!wait_event_lock_irq_timeout(udl->urbs.sleep,
243					 !udl->urbs.count ||
244					 !list_empty(&udl->urbs.list),
245					 udl->urbs.lock, timeout)) {
246		DRM_INFO("wait for urb interrupted: available: %d\n",
247			 udl->urbs.available);
248		return NULL;
249	}
250
251	if (!udl->urbs.count)
252		return NULL;
253
254	unode = list_first_entry(&udl->urbs.list, struct urb_node, entry);
255	list_del_init(&unode->entry);
256	udl->urbs.available--;
257
258	return unode->urb;
259}
260
261#define GET_URB_TIMEOUT	HZ
262struct urb *udl_get_urb(struct drm_device *dev)
263{
264	struct udl_device *udl = to_udl(dev);
265	struct urb *urb;
266
267	spin_lock_irq(&udl->urbs.lock);
268	urb = udl_get_urb_locked(udl, GET_URB_TIMEOUT);
269	spin_unlock_irq(&udl->urbs.lock);
270	return urb;
271}
272
273int udl_submit_urb(struct drm_device *dev, struct urb *urb, size_t len)
274{
275	struct udl_device *udl = to_udl(dev);
276	int ret;
277
278	if (WARN_ON(len > udl->urbs.size)) {
279		ret = -EINVAL;
280		goto error;
281	}
282	urb->transfer_buffer_length = len; /* set to actual payload len */
283	ret = usb_submit_urb(urb, GFP_ATOMIC);
284 error:
285	if (ret) {
286		udl_urb_completion(urb); /* because no one else will */
287		DRM_ERROR("usb_submit_urb error %x\n", ret);
288	}
289	return ret;
290}
291
292/* wait until all pending URBs have been processed */
293void udl_sync_pending_urbs(struct drm_device *dev)
294{
295	struct udl_device *udl = to_udl(dev);
296
297	spin_lock_irq(&udl->urbs.lock);
298	/* 2 seconds as a sane timeout */
299	if (!wait_event_lock_irq_timeout(udl->urbs.sleep,
300					 udl->urbs.available == udl->urbs.count,
301					 udl->urbs.lock,
302					 msecs_to_jiffies(2000)))
303		drm_err(dev, "Timeout for syncing pending URBs\n");
304	spin_unlock_irq(&udl->urbs.lock);
305}
306
307int udl_init(struct udl_device *udl)
308{
309	struct drm_device *dev = &udl->drm;
310	int ret = -ENOMEM;
311
312	DRM_DEBUG("\n");
313
314	udl->dmadev = usb_intf_get_dma_device(to_usb_interface(dev->dev));
315	if (!udl->dmadev)
316		drm_warn(dev, "buffer sharing not supported"); /* not an error */
317
318	mutex_init(&udl->gem_lock);
319
320	if (!udl_parse_vendor_descriptor(udl)) {
321		ret = -ENODEV;
322		DRM_ERROR("firmware not recognized. Assume incompatible device\n");
323		goto err;
324	}
325
326	if (udl_select_std_channel(udl))
327		DRM_ERROR("Selecting channel failed\n");
328
329	if (!udl_alloc_urb_list(dev, WRITES_IN_FLIGHT, MAX_TRANSFER)) {
330		DRM_ERROR("udl_alloc_urb_list failed\n");
331		goto err;
332	}
333
334	DRM_DEBUG("\n");
335	ret = udl_modeset_init(dev);
336	if (ret)
337		goto err;
338
339	drm_kms_helper_poll_init(dev);
340
341	return 0;
342
343err:
344	if (udl->urbs.count)
345		udl_free_urb_list(dev);
346	put_device(udl->dmadev);
347	DRM_ERROR("%d\n", ret);
348	return ret;
349}
350
351int udl_drop_usb(struct drm_device *dev)
352{
353	struct udl_device *udl = to_udl(dev);
354
355	udl_free_urb_list(dev);
356	put_device(udl->dmadev);
357	udl->dmadev = NULL;
358
359	return 0;
360}
361