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 
26 static struct urb *udl_get_urb_locked(struct udl_device *udl, long timeout);
27 
udl_parse_vendor_descriptor(struct udl_device * udl)28 static 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 
85 unrecognized:
86 	/* allow udlfb to load for now even if firmware unrecognized */
87 	DRM_ERROR("Unrecognized vendor firmware descriptor\n");
88 
89 success:
90 	kfree(buf);
91 	return true;
92 }
93 
94 /*
95  * Need to ensure a channel is selected before submitting URBs
96  */
udl_select_std_channel(struct udl_device * udl)97 int 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 
udl_urb_completion(struct urb * urb)121 void 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 
udl_free_urb_list(struct drm_device * dev)148 static 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 
udl_alloc_urb_list(struct drm_device * dev,int count,size_t size)175 static 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 
190 retry:
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 
udl_get_urb_locked(struct udl_device * udl,long timeout)235 static 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 ? unode->urb : NULL;
259 }
260 
261 #define GET_URB_TIMEOUT	HZ
udl_get_urb(struct drm_device * dev)262 struct 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 
udl_submit_urb(struct drm_device * dev,struct urb * urb,size_t len)273 int 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 */
udl_sync_pending_urbs(struct drm_device * dev)293 void 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 
udl_init(struct udl_device * udl)307 int 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 
343 err:
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 
udl_drop_usb(struct drm_device * dev)351 int 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