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 NR_USB_REQUEST_CHANNEL 0x12
 20
 21#define MAX_TRANSFER (PAGE_SIZE*16 - BULK_SIZE)
 22#define WRITES_IN_FLIGHT (4)
 23#define MAX_VENDOR_DESCRIPTOR_SIZE 256
 24
 25#define GET_URB_TIMEOUT	HZ
 26#define FREE_URB_TIMEOUT (HZ*2)
 27
 28static int udl_parse_vendor_descriptor(struct drm_device *dev,
 29				       struct usb_device *usbdev)
 30{
 31	struct udl_device *udl = dev->dev_private;
 32	char *desc;
 33	char *buf;
 34	char *desc_end;
 35
 36	u8 total_len = 0;
 37
 38	buf = kzalloc(MAX_VENDOR_DESCRIPTOR_SIZE, GFP_KERNEL);
 39	if (!buf)
 40		return false;
 41	desc = buf;
 42
 43	total_len = usb_get_descriptor(usbdev, 0x5f, /* vendor specific */
 44				    0, desc, MAX_VENDOR_DESCRIPTOR_SIZE);
 45	if (total_len > 5) {
 46		DRM_INFO("vendor descriptor length:%x data:%11ph\n",
 47			total_len, desc);
 48
 49		if ((desc[0] != total_len) || /* descriptor length */
 50		    (desc[1] != 0x5f) ||   /* vendor descriptor type */
 51		    (desc[2] != 0x01) ||   /* version (2 bytes) */
 52		    (desc[3] != 0x00) ||
 53		    (desc[4] != total_len - 2)) /* length after type */
 54			goto unrecognized;
 55
 56		desc_end = desc + total_len;
 57		desc += 5; /* the fixed header we've already parsed */
 58
 59		while (desc < desc_end) {
 60			u8 length;
 61			u16 key;
 62
 63			key = le16_to_cpu(*((u16 *) desc));
 64			desc += sizeof(u16);
 65			length = *desc;
 66			desc++;
 67
 68			switch (key) {
 69			case 0x0200: { /* max_area */
 70				u32 max_area;
 71				max_area = le32_to_cpu(*((u32 *)desc));
 72				DRM_DEBUG("DL chip limited to %d pixel modes\n",
 73					max_area);
 74				udl->sku_pixel_limit = max_area;
 75				break;
 76			}
 77			default:
 78				break;
 79			}
 80			desc += length;
 81		}
 82	}
 83
 84	goto success;
 85
 86unrecognized:
 87	/* allow udlfb to load for now even if firmware unrecognized */
 88	DRM_ERROR("Unrecognized vendor firmware descriptor\n");
 89
 90success:
 91	kfree(buf);
 92	return true;
 93}
 94
 95/*
 96 * Need to ensure a channel is selected before submitting URBs
 97 */
 98static int udl_select_std_channel(struct udl_device *udl)
 99{
100	int ret;
101	static const u8 set_def_chn[] = {0x57, 0xCD, 0xDC, 0xA7,
102					 0x1C, 0x88, 0x5E, 0x15,
103					 0x60, 0xFE, 0xC6, 0x97,
104					 0x16, 0x3D, 0x47, 0xF2};
105	void *sendbuf;
106
107	sendbuf = kmemdup(set_def_chn, sizeof(set_def_chn), GFP_KERNEL);
108	if (!sendbuf)
109		return -ENOMEM;
110
111	ret = usb_control_msg(udl->udev,
112			      usb_sndctrlpipe(udl->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
121static void udl_release_urb_work(struct work_struct *work)
122{
123	struct urb_node *unode = container_of(work, struct urb_node,
124					      release_urb_work.work);
125
126	up(&unode->dev->urbs.limit_sem);
127}
128
129void udl_urb_completion(struct urb *urb)
130{
131	struct urb_node *unode = urb->context;
132	struct udl_device *udl = unode->dev;
133	unsigned long flags;
134
135	/* sync/async unlink faults aren't errors */
136	if (urb->status) {
137		if (!(urb->status == -ENOENT ||
138		    urb->status == -ECONNRESET ||
139		    urb->status == -ESHUTDOWN)) {
140			DRM_ERROR("%s - nonzero write bulk status received: %d\n",
141				__func__, urb->status);
142			atomic_set(&udl->lost_pixels, 1);
143		}
144	}
145
146	urb->transfer_buffer_length = udl->urbs.size; /* reset to actual */
147
148	spin_lock_irqsave(&udl->urbs.lock, flags);
149	list_add_tail(&unode->entry, &udl->urbs.list);
150	udl->urbs.available++;
151	spin_unlock_irqrestore(&udl->urbs.lock, flags);
152
153#if 0
154	/*
155	 * When using fb_defio, we deadlock if up() is called
156	 * while another is waiting. So queue to another process.
157	 */
158	if (fb_defio)
159		schedule_delayed_work(&unode->release_urb_work, 0);
160	else
161#endif
162		up(&udl->urbs.limit_sem);
163}
164
165static void udl_free_urb_list(struct drm_device *dev)
166{
167	struct udl_device *udl = dev->dev_private;
168	int count = udl->urbs.count;
169	struct list_head *node;
170	struct urb_node *unode;
171	struct urb *urb;
172	int ret;
173	unsigned long flags;
174
175	DRM_DEBUG("Waiting for completes and freeing all render urbs\n");
176
177	/* keep waiting and freeing, until we've got 'em all */
178	while (count--) {
179
180		/* Getting interrupted means a leak, but ok at shutdown*/
181		ret = down_interruptible(&udl->urbs.limit_sem);
182		if (ret)
183			break;
184
185		spin_lock_irqsave(&udl->urbs.lock, flags);
186
187		node = udl->urbs.list.next; /* have reserved one with sem */
188		list_del_init(node);
189
190		spin_unlock_irqrestore(&udl->urbs.lock, flags);
191
192		unode = list_entry(node, struct urb_node, entry);
193		urb = unode->urb;
194
195		/* Free each separately allocated piece */
196		usb_free_coherent(urb->dev, udl->urbs.size,
197				  urb->transfer_buffer, urb->transfer_dma);
198		usb_free_urb(urb);
199		kfree(node);
200	}
201	udl->urbs.count = 0;
202}
203
204static int udl_alloc_urb_list(struct drm_device *dev, int count, size_t size)
205{
206	struct udl_device *udl = dev->dev_private;
207	int i = 0;
208	struct urb *urb;
209	struct urb_node *unode;
210	char *buf;
211
212	spin_lock_init(&udl->urbs.lock);
213
214	udl->urbs.size = size;
215	INIT_LIST_HEAD(&udl->urbs.list);
216
217	while (i < count) {
218		unode = kzalloc(sizeof(struct urb_node), GFP_KERNEL);
219		if (!unode)
220			break;
221		unode->dev = udl;
222
223		INIT_DELAYED_WORK(&unode->release_urb_work,
224			  udl_release_urb_work);
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(udl->udev, MAX_TRANSFER, GFP_KERNEL,
234					 &urb->transfer_dma);
235		if (!buf) {
236			kfree(unode);
237			usb_free_urb(urb);
238			break;
239		}
240
241		/* urb->transfer_buffer_length set to actual before submit */
242		usb_fill_bulk_urb(urb, udl->udev, usb_sndbulkpipe(udl->udev, 1),
243			buf, size, udl_urb_completion, unode);
244		urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
245
246		list_add_tail(&unode->entry, &udl->urbs.list);
247
248		i++;
249	}
250
251	sema_init(&udl->urbs.limit_sem, i);
252	udl->urbs.count = i;
253	udl->urbs.available = i;
254
255	DRM_DEBUG("allocated %d %d byte urbs\n", i, (int) size);
256
257	return i;
258}
259
260struct urb *udl_get_urb(struct drm_device *dev)
261{
262	struct udl_device *udl = dev->dev_private;
263	int ret = 0;
264	struct list_head *entry;
265	struct urb_node *unode;
266	struct urb *urb = NULL;
267	unsigned long flags;
268
269	/* Wait for an in-flight buffer to complete and get re-queued */
270	ret = down_timeout(&udl->urbs.limit_sem, GET_URB_TIMEOUT);
271	if (ret) {
272		atomic_set(&udl->lost_pixels, 1);
273		DRM_INFO("wait for urb interrupted: %x available: %d\n",
274		       ret, udl->urbs.available);
275		goto error;
276	}
277
278	spin_lock_irqsave(&udl->urbs.lock, flags);
279
280	BUG_ON(list_empty(&udl->urbs.list)); /* reserved one with limit_sem */
281	entry = udl->urbs.list.next;
282	list_del_init(entry);
283	udl->urbs.available--;
284
285	spin_unlock_irqrestore(&udl->urbs.lock, flags);
286
287	unode = list_entry(entry, struct urb_node, entry);
288	urb = unode->urb;
289
290error:
291	return urb;
292}
293
294int udl_submit_urb(struct drm_device *dev, struct urb *urb, size_t len)
295{
296	struct udl_device *udl = dev->dev_private;
297	int ret;
298
299	BUG_ON(len > udl->urbs.size);
300
301	urb->transfer_buffer_length = len; /* set to actual payload len */
302	ret = usb_submit_urb(urb, GFP_ATOMIC);
303	if (ret) {
304		udl_urb_completion(urb); /* because no one else will */
305		atomic_set(&udl->lost_pixels, 1);
306		DRM_ERROR("usb_submit_urb error %x\n", ret);
307	}
308	return ret;
309}
310
311int udl_driver_load(struct drm_device *dev, unsigned long flags)
312{
313	struct usb_device *udev = (void*)flags;
314	struct udl_device *udl;
315	int ret = -ENOMEM;
316
317	DRM_DEBUG("\n");
318	udl = kzalloc(sizeof(struct udl_device), GFP_KERNEL);
319	if (!udl)
320		return -ENOMEM;
321
322	udl->udev = udev;
323	udl->ddev = dev;
324	dev->dev_private = udl;
325
326	if (!udl_parse_vendor_descriptor(dev, udl->udev)) {
327		ret = -ENODEV;
328		DRM_ERROR("firmware not recognized. Assume incompatible device\n");
329		goto err;
330	}
331
332	if (udl_select_std_channel(udl))
333		DRM_ERROR("Selecting channel failed\n");
334
335	if (!udl_alloc_urb_list(dev, WRITES_IN_FLIGHT, MAX_TRANSFER)) {
336		DRM_ERROR("udl_alloc_urb_list failed\n");
337		goto err;
338	}
339
340	DRM_DEBUG("\n");
341	ret = udl_modeset_init(dev);
342	if (ret)
343		goto err;
344
345	ret = udl_fbdev_init(dev);
346	if (ret)
347		goto err;
348
349	ret = drm_vblank_init(dev, 1);
350	if (ret)
351		goto err_fb;
352
353	return 0;
354err_fb:
355	udl_fbdev_cleanup(dev);
356err:
357	if (udl->urbs.count)
358		udl_free_urb_list(dev);
359	kfree(udl);
360	DRM_ERROR("%d\n", ret);
361	return ret;
362}
363
364int udl_drop_usb(struct drm_device *dev)
365{
366	udl_free_urb_list(dev);
367	return 0;
368}
369
370int udl_driver_unload(struct drm_device *dev)
371{
372	struct udl_device *udl = dev->dev_private;
373
374	drm_vblank_cleanup(dev);
375
376	if (udl->urbs.count)
377		udl_free_urb_list(dev);
378
379	udl_fbdev_cleanup(dev);
380	udl_modeset_cleanup(dev);
381	kfree(udl);
382	return 0;
383}