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 "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:%02x %02x %02x %02x" \
45			"%02x %02x %02x %02x %02x %02x %02x\n",
46			total_len, desc[0],
47			desc[1], desc[2], desc[3], desc[4], desc[5], desc[6],
48			desc[7], desc[8], desc[9], desc[10]);
49
50		if ((desc[0] != total_len) || /* descriptor length */
51		    (desc[1] != 0x5f) ||   /* vendor descriptor type */
52		    (desc[2] != 0x01) ||   /* version (2 bytes) */
53		    (desc[3] != 0x00) ||
54		    (desc[4] != total_len - 2)) /* length after type */
55			goto unrecognized;
56
57		desc_end = desc + total_len;
58		desc += 5; /* the fixed header we've already parsed */
59
60		while (desc < desc_end) {
61			u8 length;
62			u16 key;
63
64			key = *((u16 *) desc);
65			desc += sizeof(u16);
66			length = *desc;
67			desc++;
68
69			switch (key) {
70			case 0x0200: { /* max_area */
71				u32 max_area;
72				max_area = le32_to_cpu(*((u32 *)desc));
73				DRM_DEBUG("DL chip limited to %d pixel modes\n",
74					max_area);
75				udl->sku_pixel_limit = max_area;
76				break;
77			}
78			default:
79				break;
80			}
81			desc += length;
82		}
83	}
84
85	goto success;
86
87unrecognized:
88	/* allow udlfb to load for now even if firmware unrecognized */
89	DRM_ERROR("Unrecognized vendor firmware descriptor\n");
90
91success:
92	kfree(buf);
93	return true;
94}
95
96static void udl_release_urb_work(struct work_struct *work)
97{
98	struct urb_node *unode = container_of(work, struct urb_node,
99					      release_urb_work.work);
100
101	up(&unode->dev->urbs.limit_sem);
102}
103
104void udl_urb_completion(struct urb *urb)
105{
106	struct urb_node *unode = urb->context;
107	struct udl_device *udl = unode->dev;
108	unsigned long flags;
109
110	/* sync/async unlink faults aren't errors */
111	if (urb->status) {
112		if (!(urb->status == -ENOENT ||
113		    urb->status == -ECONNRESET ||
114		    urb->status == -ESHUTDOWN)) {
115			DRM_ERROR("%s - nonzero write bulk status received: %d\n",
116				__func__, urb->status);
117			atomic_set(&udl->lost_pixels, 1);
118		}
119	}
120
121	urb->transfer_buffer_length = udl->urbs.size; /* reset to actual */
122
123	spin_lock_irqsave(&udl->urbs.lock, flags);
124	list_add_tail(&unode->entry, &udl->urbs.list);
125	udl->urbs.available++;
126	spin_unlock_irqrestore(&udl->urbs.lock, flags);
127
128#if 0
129	/*
130	 * When using fb_defio, we deadlock if up() is called
131	 * while another is waiting. So queue to another process.
132	 */
133	if (fb_defio)
134		schedule_delayed_work(&unode->release_urb_work, 0);
135	else
136#endif
137		up(&udl->urbs.limit_sem);
138}
139
140static void udl_free_urb_list(struct drm_device *dev)
141{
142	struct udl_device *udl = dev->dev_private;
143	int count = udl->urbs.count;
144	struct list_head *node;
145	struct urb_node *unode;
146	struct urb *urb;
147	int ret;
148	unsigned long flags;
149
150	DRM_DEBUG("Waiting for completes and freeing all render urbs\n");
151
152	/* keep waiting and freeing, until we've got 'em all */
153	while (count--) {
154
155		/* Getting interrupted means a leak, but ok at shutdown*/
156		ret = down_interruptible(&udl->urbs.limit_sem);
157		if (ret)
158			break;
159
160		spin_lock_irqsave(&udl->urbs.lock, flags);
161
162		node = udl->urbs.list.next; /* have reserved one with sem */
163		list_del_init(node);
164
165		spin_unlock_irqrestore(&udl->urbs.lock, flags);
166
167		unode = list_entry(node, struct urb_node, entry);
168		urb = unode->urb;
169
170		/* Free each separately allocated piece */
171		usb_free_coherent(urb->dev, udl->urbs.size,
172				  urb->transfer_buffer, urb->transfer_dma);
173		usb_free_urb(urb);
174		kfree(node);
175	}
176	udl->urbs.count = 0;
177}
178
179static int udl_alloc_urb_list(struct drm_device *dev, int count, size_t size)
180{
181	struct udl_device *udl = dev->dev_private;
182	int i = 0;
183	struct urb *urb;
184	struct urb_node *unode;
185	char *buf;
186
187	spin_lock_init(&udl->urbs.lock);
188
189	udl->urbs.size = size;
190	INIT_LIST_HEAD(&udl->urbs.list);
191
192	while (i < count) {
193		unode = kzalloc(sizeof(struct urb_node), GFP_KERNEL);
194		if (!unode)
195			break;
196		unode->dev = udl;
197
198		INIT_DELAYED_WORK(&unode->release_urb_work,
199			  udl_release_urb_work);
200
201		urb = usb_alloc_urb(0, GFP_KERNEL);
202		if (!urb) {
203			kfree(unode);
204			break;
205		}
206		unode->urb = urb;
207
208		buf = usb_alloc_coherent(udl->ddev->usbdev, MAX_TRANSFER, GFP_KERNEL,
209					 &urb->transfer_dma);
210		if (!buf) {
211			kfree(unode);
212			usb_free_urb(urb);
213			break;
214		}
215
216		/* urb->transfer_buffer_length set to actual before submit */
217		usb_fill_bulk_urb(urb, udl->ddev->usbdev, usb_sndbulkpipe(udl->ddev->usbdev, 1),
218			buf, size, udl_urb_completion, unode);
219		urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
220
221		list_add_tail(&unode->entry, &udl->urbs.list);
222
223		i++;
224	}
225
226	sema_init(&udl->urbs.limit_sem, i);
227	udl->urbs.count = i;
228	udl->urbs.available = i;
229
230	DRM_DEBUG("allocated %d %d byte urbs\n", i, (int) size);
231
232	return i;
233}
234
235struct urb *udl_get_urb(struct drm_device *dev)
236{
237	struct udl_device *udl = dev->dev_private;
238	int ret = 0;
239	struct list_head *entry;
240	struct urb_node *unode;
241	struct urb *urb = NULL;
242	unsigned long flags;
243
244	/* Wait for an in-flight buffer to complete and get re-queued */
245	ret = down_timeout(&udl->urbs.limit_sem, GET_URB_TIMEOUT);
246	if (ret) {
247		atomic_set(&udl->lost_pixels, 1);
248		DRM_INFO("wait for urb interrupted: %x available: %d\n",
249		       ret, udl->urbs.available);
250		goto error;
251	}
252
253	spin_lock_irqsave(&udl->urbs.lock, flags);
254
255	BUG_ON(list_empty(&udl->urbs.list)); /* reserved one with limit_sem */
256	entry = udl->urbs.list.next;
257	list_del_init(entry);
258	udl->urbs.available--;
259
260	spin_unlock_irqrestore(&udl->urbs.lock, flags);
261
262	unode = list_entry(entry, struct urb_node, entry);
263	urb = unode->urb;
264
265error:
266	return urb;
267}
268
269int udl_submit_urb(struct drm_device *dev, struct urb *urb, size_t len)
270{
271	struct udl_device *udl = dev->dev_private;
272	int ret;
273
274	BUG_ON(len > udl->urbs.size);
275
276	urb->transfer_buffer_length = len; /* set to actual payload len */
277	ret = usb_submit_urb(urb, GFP_ATOMIC);
278	if (ret) {
279		udl_urb_completion(urb); /* because no one else will */
280		atomic_set(&udl->lost_pixels, 1);
281		DRM_ERROR("usb_submit_urb error %x\n", ret);
282	}
283	return ret;
284}
285
286int udl_driver_load(struct drm_device *dev, unsigned long flags)
287{
288	struct udl_device *udl;
289	int ret;
290
291	DRM_DEBUG("\n");
292	udl = kzalloc(sizeof(struct udl_device), GFP_KERNEL);
293	if (!udl)
294		return -ENOMEM;
295
296	udl->ddev = dev;
297	dev->dev_private = udl;
298
299	if (!udl_parse_vendor_descriptor(dev, dev->usbdev)) {
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		ret = -ENOMEM;
306		DRM_ERROR("udl_alloc_urb_list failed\n");
307		goto err;
308	}
309
310	DRM_DEBUG("\n");
311	ret = udl_modeset_init(dev);
312
313	ret = udl_fbdev_init(dev);
314	return 0;
315err:
316	kfree(udl);
317	DRM_ERROR("%d\n", ret);
318	return ret;
319}
320
321int udl_drop_usb(struct drm_device *dev)
322{
323	udl_free_urb_list(dev);
324	return 0;
325}
326
327int udl_driver_unload(struct drm_device *dev)
328{
329	struct udl_device *udl = dev->dev_private;
330
331	if (udl->urbs.count)
332		udl_free_urb_list(dev);
333
334	udl_fbdev_cleanup(dev);
335	udl_modeset_cleanup(dev);
336	kfree(udl);
337	return 0;
338}
339