Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
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 <linux/unaligned.h>
12
13#include <drm/drm.h>
14#include <drm/drm_print.h>
15#include <drm/drm_probe_helper.h>
16
17#include "udl_drv.h"
18
19/* -BULK_SIZE as per usb-skeleton. Can we get full page and avoid overhead? */
20#define BULK_SIZE 512
21
22#define NR_USB_REQUEST_CHANNEL 0x12
23
24#define MAX_TRANSFER (PAGE_SIZE*16 - BULK_SIZE)
25#define WRITES_IN_FLIGHT (20)
26#define MAX_VENDOR_DESCRIPTOR_SIZE 256
27
28#define UDL_SKU_PIXEL_LIMIT_DEFAULT 2080000
29
30static struct urb *udl_get_urb_locked(struct udl_device *udl, long timeout);
31
32/*
33 * Try to make sense of whatever we parse. Therefore return @end on
34 * errors, but don't fail hard.
35 */
36static const u8 *udl_parse_key_value_pair(struct udl_device *udl, const u8 *pos, const u8 *end)
37{
38 u16 key;
39 u8 len;
40
41 /* read key */
42 if (pos >= end - 2)
43 return end;
44 key = get_unaligned_le16(pos);
45 pos += 2;
46
47 /* read value length */
48 if (pos >= end - 1)
49 return end;
50 len = *pos++;
51
52 /* read value */
53 if (pos >= end - len)
54 return end;
55 switch (key) {
56 case 0x0200: { /* maximum number of pixels */
57 unsigned int sku_pixel_limit;
58
59 if (len < sizeof(__le32))
60 break;
61 sku_pixel_limit = get_unaligned_le32(pos);
62 if (sku_pixel_limit >= 16 * UDL_SKU_PIXEL_LIMIT_DEFAULT)
63 break; /* almost 100 MiB, so probably bogus */
64 udl->sku_pixel_limit = sku_pixel_limit;
65 break;
66 }
67 default:
68 break;
69 }
70 pos += len;
71
72 return pos;
73}
74
75static int udl_parse_vendor_descriptor(struct udl_device *udl)
76{
77 struct drm_device *dev = &udl->drm;
78 struct usb_device *udev = udl_to_usb_device(udl);
79 bool detected = false;
80 void *buf;
81 int ret;
82 unsigned int len;
83 const u8 *desc;
84 const u8 *desc_end;
85
86 buf = kzalloc(MAX_VENDOR_DESCRIPTOR_SIZE, GFP_KERNEL);
87 if (!buf)
88 return -ENOMEM;
89
90 ret = usb_get_descriptor(udev, 0x5f, /* vendor specific */
91 0, buf, MAX_VENDOR_DESCRIPTOR_SIZE);
92 if (ret < 0)
93 goto out;
94 len = ret;
95
96 if (len < 5)
97 goto out;
98
99 desc = buf;
100 desc_end = desc + len;
101
102 if ((desc[0] != len) || /* descriptor length */
103 (desc[1] != 0x5f) || /* vendor descriptor type */
104 (desc[2] != 0x01) || /* version (2 bytes) */
105 (desc[3] != 0x00) ||
106 (desc[4] != len - 2)) /* length after type */
107 goto out;
108 desc += 5;
109
110 detected = true;
111
112 while (desc < desc_end)
113 desc = udl_parse_key_value_pair(udl, desc, desc_end);
114
115out:
116 if (!detected)
117 drm_warn(dev, "Unrecognized vendor firmware descriptor\n");
118 kfree(buf);
119
120 return 0;
121}
122
123/*
124 * Need to ensure a channel is selected before submitting URBs
125 */
126int udl_select_std_channel(struct udl_device *udl)
127{
128 static const u8 set_def_chn[] = {0x57, 0xCD, 0xDC, 0xA7,
129 0x1C, 0x88, 0x5E, 0x15,
130 0x60, 0xFE, 0xC6, 0x97,
131 0x16, 0x3D, 0x47, 0xF2};
132
133 void *sendbuf;
134 int ret;
135 struct usb_device *udev = udl_to_usb_device(udl);
136
137 sendbuf = kmemdup(set_def_chn, sizeof(set_def_chn), GFP_KERNEL);
138 if (!sendbuf)
139 return -ENOMEM;
140
141 ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
142 NR_USB_REQUEST_CHANNEL,
143 (USB_DIR_OUT | USB_TYPE_VENDOR), 0, 0,
144 sendbuf, sizeof(set_def_chn),
145 USB_CTRL_SET_TIMEOUT);
146 kfree(sendbuf);
147 return ret < 0 ? ret : 0;
148}
149
150void udl_urb_completion(struct urb *urb)
151{
152 struct urb_node *unode = urb->context;
153 struct udl_device *udl = unode->dev;
154 unsigned long flags;
155
156 /* sync/async unlink faults aren't errors */
157 if (urb->status) {
158 if (!(urb->status == -ENOENT ||
159 urb->status == -ECONNRESET ||
160 urb->status == -EPROTO ||
161 urb->status == -ESHUTDOWN)) {
162 DRM_ERROR("%s - nonzero write bulk status received: %d\n",
163 __func__, urb->status);
164 }
165 }
166
167 urb->transfer_buffer_length = udl->urbs.size; /* reset to actual */
168
169 spin_lock_irqsave(&udl->urbs.lock, flags);
170 list_add_tail(&unode->entry, &udl->urbs.list);
171 udl->urbs.available++;
172 spin_unlock_irqrestore(&udl->urbs.lock, flags);
173
174 wake_up(&udl->urbs.sleep);
175}
176
177static void udl_free_urb_list(struct udl_device *udl)
178{
179 struct urb_node *unode;
180 struct urb *urb;
181
182 DRM_DEBUG("Waiting for completes and freeing all render urbs\n");
183
184 /* keep waiting and freeing, until we've got 'em all */
185 while (udl->urbs.count) {
186 spin_lock_irq(&udl->urbs.lock);
187 urb = udl_get_urb_locked(udl, MAX_SCHEDULE_TIMEOUT);
188 udl->urbs.count--;
189 spin_unlock_irq(&udl->urbs.lock);
190 if (WARN_ON(!urb))
191 break;
192 unode = urb->context;
193 /* Free each separately allocated piece */
194 usb_free_coherent(urb->dev, udl->urbs.size,
195 urb->transfer_buffer, urb->transfer_dma);
196 usb_free_urb(urb);
197 kfree(unode);
198 }
199
200 wake_up_all(&udl->urbs.sleep);
201}
202
203static int udl_alloc_urb_list(struct udl_device *udl, int count, size_t size)
204{
205 struct urb *urb;
206 struct urb_node *unode;
207 char *buf;
208 size_t wanted_size = count * size;
209 struct usb_device *udev = udl_to_usb_device(udl);
210
211 spin_lock_init(&udl->urbs.lock);
212 INIT_LIST_HEAD(&udl->urbs.list);
213 init_waitqueue_head(&udl->urbs.sleep);
214 udl->urbs.count = 0;
215 udl->urbs.available = 0;
216
217retry:
218 udl->urbs.size = size;
219
220 while (udl->urbs.count * size < wanted_size) {
221 unode = kzalloc_obj(struct urb_node);
222 if (!unode)
223 break;
224 unode->dev = udl;
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(udl);
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 udl->urbs.count++;
254 udl->urbs.available++;
255 }
256
257 DRM_DEBUG("allocated %d %d byte urbs\n", udl->urbs.count, (int) size);
258
259 return udl->urbs.count;
260}
261
262static struct urb *udl_get_urb_locked(struct udl_device *udl, long timeout)
263{
264 struct urb_node *unode;
265
266 assert_spin_locked(&udl->urbs.lock);
267
268 /* Wait for an in-flight buffer to complete and get re-queued */
269 if (!wait_event_lock_irq_timeout(udl->urbs.sleep,
270 !udl->urbs.count ||
271 !list_empty(&udl->urbs.list),
272 udl->urbs.lock, timeout)) {
273 DRM_INFO("wait for urb interrupted: available: %d\n",
274 udl->urbs.available);
275 return NULL;
276 }
277
278 if (!udl->urbs.count)
279 return NULL;
280
281 unode = list_first_entry(&udl->urbs.list, struct urb_node, entry);
282 list_del_init(&unode->entry);
283 udl->urbs.available--;
284
285 return unode->urb;
286}
287
288struct urb *udl_get_urb(struct udl_device *udl)
289{
290 struct urb *urb;
291
292 spin_lock_irq(&udl->urbs.lock);
293 urb = udl_get_urb_locked(udl, HZ * 2);
294 spin_unlock_irq(&udl->urbs.lock);
295 return urb;
296}
297
298int udl_submit_urb(struct udl_device *udl, struct urb *urb, size_t len)
299{
300 int ret;
301
302 if (WARN_ON(len > udl->urbs.size)) {
303 ret = -EINVAL;
304 goto error;
305 }
306 urb->transfer_buffer_length = len; /* set to actual payload len */
307 ret = usb_submit_urb(urb, GFP_ATOMIC);
308 error:
309 if (ret) {
310 udl_urb_completion(urb); /* because no one else will */
311 DRM_ERROR("usb_submit_urb error %x\n", ret);
312 }
313 return ret;
314}
315
316/* wait until all pending URBs have been processed */
317void udl_sync_pending_urbs(struct udl_device *udl)
318{
319 struct drm_device *dev = &udl->drm;
320
321 spin_lock_irq(&udl->urbs.lock);
322 /* 2 seconds as a sane timeout */
323 if (!wait_event_lock_irq_timeout(udl->urbs.sleep,
324 udl->urbs.available == udl->urbs.count,
325 udl->urbs.lock,
326 msecs_to_jiffies(2000)))
327 drm_err(dev, "Timeout for syncing pending URBs\n");
328 spin_unlock_irq(&udl->urbs.lock);
329}
330
331int udl_init(struct udl_device *udl)
332{
333 struct drm_device *dev = &udl->drm;
334 int ret = -ENOMEM;
335 struct device *dma_dev;
336
337 DRM_DEBUG("\n");
338
339 dma_dev = usb_intf_get_dma_device(to_usb_interface(dev->dev));
340 if (dma_dev) {
341 drm_dev_set_dma_dev(dev, dma_dev);
342 put_device(dma_dev);
343 } else {
344 drm_warn(dev, "buffer sharing not supported"); /* not an error */
345 }
346
347 /*
348 * Not all devices provide vendor descriptors with device
349 * information. Initialize to default values of real-world
350 * devices. It is just enough memory for FullHD.
351 */
352 udl->sku_pixel_limit = UDL_SKU_PIXEL_LIMIT_DEFAULT;
353
354 ret = udl_parse_vendor_descriptor(udl);
355 if (ret)
356 goto err;
357
358 if (udl_select_std_channel(udl))
359 DRM_ERROR("Selecting channel failed\n");
360
361 if (!udl_alloc_urb_list(udl, WRITES_IN_FLIGHT, MAX_TRANSFER)) {
362 DRM_ERROR("udl_alloc_urb_list failed\n");
363 ret = -ENOMEM;
364 goto err;
365 }
366
367 DRM_DEBUG("\n");
368 ret = udl_modeset_init(udl);
369 if (ret)
370 goto err;
371
372 return 0;
373
374err:
375 if (udl->urbs.count)
376 udl_free_urb_list(udl);
377 DRM_ERROR("%d\n", ret);
378 return ret;
379}
380
381int udl_drop_usb(struct udl_device *udl)
382{
383 udl_free_urb_list(udl);
384
385 return 0;
386}