1/*
2 * Copyright (C) 2012 Red Hat
3 *
4 * based in parts on udlfb.c:
5 * Copyright (C) 2009 Roberto De Ioris <roberto@unbit.it>
6 * Copyright (C) 2009 Jaya Kumar <jayakumar.lkml@gmail.com>
7 * Copyright (C) 2009 Bernie Thompson <bernie@plugable.com>
8 *
9 * This file is subject to the terms and conditions of the GNU General Public
10 * License v2. See the file COPYING in the main directory of this archive for
11 * more details.
12 */
13#include <drm/drmP.h>
14#include "udl_drv.h"
15
16/* -BULK_SIZE as per usb-skeleton. Can we get full page and avoid overhead? */
17#define BULK_SIZE 512
18
19#define MAX_TRANSFER (PAGE_SIZE*16 - BULK_SIZE)
20#define WRITES_IN_FLIGHT (4)
21#define MAX_VENDOR_DESCRIPTOR_SIZE 256
22
23#define GET_URB_TIMEOUT	HZ
24#define FREE_URB_TIMEOUT (HZ*2)
25
26static int udl_parse_vendor_descriptor(struct drm_device *dev,
27				       struct usb_device *usbdev)
28{
29	struct udl_device *udl = dev->dev_private;
30	char *desc;
31	char *buf;
32	char *desc_end;
33
34	u8 total_len = 0;
35
36	buf = kzalloc(MAX_VENDOR_DESCRIPTOR_SIZE, GFP_KERNEL);
37	if (!buf)
38		return false;
39	desc = buf;
40
41	total_len = usb_get_descriptor(usbdev, 0x5f, /* vendor specific */
42				    0, desc, MAX_VENDOR_DESCRIPTOR_SIZE);
43	if (total_len > 5) {
44		DRM_INFO("vendor descriptor length:%x data:%11ph\n",
45			total_len, desc);
46
47		if ((desc[0] != total_len) || /* descriptor length */
48		    (desc[1] != 0x5f) ||   /* vendor descriptor type */
49		    (desc[2] != 0x01) ||   /* version (2 bytes) */
50		    (desc[3] != 0x00) ||
51		    (desc[4] != total_len - 2)) /* length after type */
52			goto unrecognized;
53
54		desc_end = desc + total_len;
55		desc += 5; /* the fixed header we've already parsed */
56
57		while (desc < desc_end) {
58			u8 length;
59			u16 key;
60
61			key = le16_to_cpu(*((u16 *) desc));
62			desc += sizeof(u16);
63			length = *desc;
64			desc++;
65
66			switch (key) {
67			case 0x0200: { /* max_area */
68				u32 max_area;
69				max_area = le32_to_cpu(*((u32 *)desc));
70				DRM_DEBUG("DL chip limited to %d pixel modes\n",
71					max_area);
72				udl->sku_pixel_limit = max_area;
73				break;
74			}
75			default:
76				break;
77			}
78			desc += length;
79		}
80	}
81
82	goto success;
83
84unrecognized:
85	/* allow udlfb to load for now even if firmware unrecognized */
86	DRM_ERROR("Unrecognized vendor firmware descriptor\n");
87
88success:
89	kfree(buf);
90	return true;
91}
92
93static void udl_release_urb_work(struct work_struct *work)
94{
95	struct urb_node *unode = container_of(work, struct urb_node,
96					      release_urb_work.work);
97
98	up(&unode->dev->urbs.limit_sem);
99}
100
101void udl_urb_completion(struct urb *urb)
102{
103	struct urb_node *unode = urb->context;
104	struct udl_device *udl = unode->dev;
105	unsigned long flags;
106
107	/* sync/async unlink faults aren't errors */
108	if (urb->status) {
109		if (!(urb->status == -ENOENT ||
110		    urb->status == -ECONNRESET ||
111		    urb->status == -ESHUTDOWN)) {
112			DRM_ERROR("%s - nonzero write bulk status received: %d\n",
113				__func__, urb->status);
114			atomic_set(&udl->lost_pixels, 1);
115		}
116	}
117
118	urb->transfer_buffer_length = udl->urbs.size; /* reset to actual */
119
120	spin_lock_irqsave(&udl->urbs.lock, flags);
121	list_add_tail(&unode->entry, &udl->urbs.list);
122	udl->urbs.available++;
123	spin_unlock_irqrestore(&udl->urbs.lock, flags);
124
125#if 0
126	/*
127	 * When using fb_defio, we deadlock if up() is called
128	 * while another is waiting. So queue to another process.
129	 */
130	if (fb_defio)
131		schedule_delayed_work(&unode->release_urb_work, 0);
132	else
133#endif
134		up(&udl->urbs.limit_sem);
135}
136
137static void udl_free_urb_list(struct drm_device *dev)
138{
139	struct udl_device *udl = dev->dev_private;
140	int count = udl->urbs.count;
141	struct list_head *node;
142	struct urb_node *unode;
143	struct urb *urb;
144	int ret;
145	unsigned long flags;
146
147	DRM_DEBUG("Waiting for completes and freeing all render urbs\n");
148
149	/* keep waiting and freeing, until we've got 'em all */
150	while (count--) {
151
152		/* Getting interrupted means a leak, but ok at shutdown*/
153		ret = down_interruptible(&udl->urbs.limit_sem);
154		if (ret)
155			break;
156
157		spin_lock_irqsave(&udl->urbs.lock, flags);
158
159		node = udl->urbs.list.next; /* have reserved one with sem */
160		list_del_init(node);
161
162		spin_unlock_irqrestore(&udl->urbs.lock, flags);
163
164		unode = list_entry(node, struct urb_node, entry);
165		urb = unode->urb;
166
167		/* Free each separately allocated piece */
168		usb_free_coherent(urb->dev, udl->urbs.size,
169				  urb->transfer_buffer, urb->transfer_dma);
170		usb_free_urb(urb);
171		kfree(node);
172	}
173	udl->urbs.count = 0;
174}
175
176static int udl_alloc_urb_list(struct drm_device *dev, int count, size_t size)
177{
178	struct udl_device *udl = dev->dev_private;
179	int i = 0;
180	struct urb *urb;
181	struct urb_node *unode;
182	char *buf;
183
184	spin_lock_init(&udl->urbs.lock);
185
186	udl->urbs.size = size;
187	INIT_LIST_HEAD(&udl->urbs.list);
188
189	while (i < count) {
190		unode = kzalloc(sizeof(struct urb_node), GFP_KERNEL);
191		if (!unode)
192			break;
193		unode->dev = udl;
194
195		INIT_DELAYED_WORK(&unode->release_urb_work,
196			  udl_release_urb_work);
197
198		urb = usb_alloc_urb(0, GFP_KERNEL);
199		if (!urb) {
200			kfree(unode);
201			break;
202		}
203		unode->urb = urb;
204
205		buf = usb_alloc_coherent(udl->udev, MAX_TRANSFER, GFP_KERNEL,
206					 &urb->transfer_dma);
207		if (!buf) {
208			kfree(unode);
209			usb_free_urb(urb);
210			break;
211		}
212
213		/* urb->transfer_buffer_length set to actual before submit */
214		usb_fill_bulk_urb(urb, udl->udev, usb_sndbulkpipe(udl->udev, 1),
215			buf, size, udl_urb_completion, unode);
216		urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
217
218		list_add_tail(&unode->entry, &udl->urbs.list);
219
220		i++;
221	}
222
223	sema_init(&udl->urbs.limit_sem, i);
224	udl->urbs.count = i;
225	udl->urbs.available = i;
226
227	DRM_DEBUG("allocated %d %d byte urbs\n", i, (int) size);
228
229	return i;
230}
231
232struct urb *udl_get_urb(struct drm_device *dev)
233{
234	struct udl_device *udl = dev->dev_private;
235	int ret = 0;
236	struct list_head *entry;
237	struct urb_node *unode;
238	struct urb *urb = NULL;
239	unsigned long flags;
240
241	/* Wait for an in-flight buffer to complete and get re-queued */
242	ret = down_timeout(&udl->urbs.limit_sem, GET_URB_TIMEOUT);
243	if (ret) {
244		atomic_set(&udl->lost_pixels, 1);
245		DRM_INFO("wait for urb interrupted: %x available: %d\n",
246		       ret, udl->urbs.available);
247		goto error;
248	}
249
250	spin_lock_irqsave(&udl->urbs.lock, flags);
251
252	BUG_ON(list_empty(&udl->urbs.list)); /* reserved one with limit_sem */
253	entry = udl->urbs.list.next;
254	list_del_init(entry);
255	udl->urbs.available--;
256
257	spin_unlock_irqrestore(&udl->urbs.lock, flags);
258
259	unode = list_entry(entry, struct urb_node, entry);
260	urb = unode->urb;
261
262error:
263	return urb;
264}
265
266int udl_submit_urb(struct drm_device *dev, struct urb *urb, size_t len)
267{
268	struct udl_device *udl = dev->dev_private;
269	int ret;
270
271	BUG_ON(len > udl->urbs.size);
272
273	urb->transfer_buffer_length = len; /* set to actual payload len */
274	ret = usb_submit_urb(urb, GFP_ATOMIC);
275	if (ret) {
276		udl_urb_completion(urb); /* because no one else will */
277		atomic_set(&udl->lost_pixels, 1);
278		DRM_ERROR("usb_submit_urb error %x\n", ret);
279	}
280	return ret;
281}
282
283int udl_driver_load(struct drm_device *dev, unsigned long flags)
284{
285	struct usb_device *udev = (void*)flags;
286	struct udl_device *udl;
287	int ret = -ENOMEM;
288
289	DRM_DEBUG("\n");
290	udl = kzalloc(sizeof(struct udl_device), GFP_KERNEL);
291	if (!udl)
292		return -ENOMEM;
293
294	udl->udev = udev;
295	udl->ddev = dev;
296	dev->dev_private = udl;
297
298	if (!udl_parse_vendor_descriptor(dev, udl->udev)) {
299		ret = -ENODEV;
300		DRM_ERROR("firmware not recognized. Assume incompatible device\n");
301		goto err;
302	}
303
304	if (!udl_alloc_urb_list(dev, WRITES_IN_FLIGHT, MAX_TRANSFER)) {
305		DRM_ERROR("udl_alloc_urb_list failed\n");
306		goto err;
307	}
308
309	DRM_DEBUG("\n");
310	ret = udl_modeset_init(dev);
311	if (ret)
312		goto err;
313
314	ret = udl_fbdev_init(dev);
315	if (ret)
316		goto err;
317
318	ret = drm_vblank_init(dev, 1);
319	if (ret)
320		goto err_fb;
321
322	return 0;
323err_fb:
324	udl_fbdev_cleanup(dev);
325err:
326	if (udl->urbs.count)
327		udl_free_urb_list(dev);
328	kfree(udl);
329	DRM_ERROR("%d\n", ret);
330	return ret;
331}
332
333int udl_drop_usb(struct drm_device *dev)
334{
335	udl_free_urb_list(dev);
336	return 0;
337}
338
339int udl_driver_unload(struct drm_device *dev)
340{
341	struct udl_device *udl = dev->dev_private;
342
343	drm_vblank_cleanup(dev);
344
345	if (udl->urbs.count)
346		udl_free_urb_list(dev);
347
348	udl_fbdev_cleanup(dev);
349	udl_modeset_cleanup(dev);
350	kfree(udl);
351	return 0;
352}
353