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 (4)
 24#define MAX_VENDOR_DESCRIPTOR_SIZE 256
 25
 26#define GET_URB_TIMEOUT	HZ
 27#define FREE_URB_TIMEOUT (HZ*2)
 28
 29static int udl_parse_vendor_descriptor(struct drm_device *dev,
 30				       struct usb_device *usbdev)
 31{
 32	struct udl_device *udl = to_udl(dev);
 33	char *desc;
 34	char *buf;
 35	char *desc_end;
 36
 37	u8 total_len = 0;
 38
 39	buf = kzalloc(MAX_VENDOR_DESCRIPTOR_SIZE, GFP_KERNEL);
 40	if (!buf)
 41		return false;
 42	desc = buf;
 43
 44	total_len = usb_get_descriptor(usbdev, 0x5f, /* vendor specific */
 45				    0, desc, MAX_VENDOR_DESCRIPTOR_SIZE);
 46	if (total_len > 5) {
 47		DRM_INFO("vendor descriptor length:%x data:%11ph\n",
 48			total_len, desc);
 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 = le16_to_cpu(*((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
 96/*
 97 * Need to ensure a channel is selected before submitting URBs
 98 */
 99static int udl_select_std_channel(struct udl_device *udl)
100{
101	int ret;
102	static const u8 set_def_chn[] = {0x57, 0xCD, 0xDC, 0xA7,
103					 0x1C, 0x88, 0x5E, 0x15,
104					 0x60, 0xFE, 0xC6, 0x97,
105					 0x16, 0x3D, 0x47, 0xF2};
106	void *sendbuf;
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(udl->udev,
113			      usb_sndctrlpipe(udl->udev, 0),
114			      NR_USB_REQUEST_CHANNEL,
115			      (USB_DIR_OUT | USB_TYPE_VENDOR), 0, 0,
116			      sendbuf, sizeof(set_def_chn),
117			      USB_CTRL_SET_TIMEOUT);
118	kfree(sendbuf);
119	return ret < 0 ? ret : 0;
120}
121
122static void udl_release_urb_work(struct work_struct *work)
123{
124	struct urb_node *unode = container_of(work, struct urb_node,
125					      release_urb_work.work);
126
127	up(&unode->dev->urbs.limit_sem);
128}
129
130void udl_urb_completion(struct urb *urb)
131{
132	struct urb_node *unode = urb->context;
133	struct udl_device *udl = unode->dev;
134	unsigned long flags;
135
136	/* sync/async unlink faults aren't errors */
137	if (urb->status) {
138		if (!(urb->status == -ENOENT ||
139		    urb->status == -ECONNRESET ||
140		    urb->status == -ESHUTDOWN)) {
141			DRM_ERROR("%s - nonzero write bulk status received: %d\n",
142				__func__, urb->status);
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 = to_udl(dev);
168	int count = udl->urbs.count;
169	struct list_head *node;
170	struct urb_node *unode;
171	struct urb *urb;
172
173	DRM_DEBUG("Waiting for completes and freeing all render urbs\n");
174
175	/* keep waiting and freeing, until we've got 'em all */
176	while (count--) {
177		down(&udl->urbs.limit_sem);
178
179		spin_lock_irq(&udl->urbs.lock);
180
181		node = udl->urbs.list.next; /* have reserved one with sem */
182		list_del_init(node);
183
184		spin_unlock_irq(&udl->urbs.lock);
185
186		unode = list_entry(node, struct urb_node, entry);
187		urb = unode->urb;
188
189		/* Free each separately allocated piece */
190		usb_free_coherent(urb->dev, udl->urbs.size,
191				  urb->transfer_buffer, urb->transfer_dma);
192		usb_free_urb(urb);
193		kfree(node);
194	}
195	udl->urbs.count = 0;
196}
197
198static int udl_alloc_urb_list(struct drm_device *dev, int count, size_t size)
199{
200	struct udl_device *udl = to_udl(dev);
201	struct urb *urb;
202	struct urb_node *unode;
203	char *buf;
204	size_t wanted_size = count * size;
205
206	spin_lock_init(&udl->urbs.lock);
207
208retry:
209	udl->urbs.size = size;
210	INIT_LIST_HEAD(&udl->urbs.list);
211
212	sema_init(&udl->urbs.limit_sem, 0);
213	udl->urbs.count = 0;
214	udl->urbs.available = 0;
215
216	while (udl->urbs.count * size < wanted_size) {
217		unode = kzalloc(sizeof(struct urb_node), GFP_KERNEL);
218		if (!unode)
219			break;
220		unode->dev = udl;
221
222		INIT_DELAYED_WORK(&unode->release_urb_work,
223			  udl_release_urb_work);
224
225		urb = usb_alloc_urb(0, GFP_KERNEL);
226		if (!urb) {
227			kfree(unode);
228			break;
229		}
230		unode->urb = urb;
231
232		buf = usb_alloc_coherent(udl->udev, size, GFP_KERNEL,
233					 &urb->transfer_dma);
234		if (!buf) {
235			kfree(unode);
236			usb_free_urb(urb);
237			if (size > PAGE_SIZE) {
238				size /= 2;
239				udl_free_urb_list(dev);
240				goto retry;
241			}
242			break;
243		}
244
245		/* urb->transfer_buffer_length set to actual before submit */
246		usb_fill_bulk_urb(urb, udl->udev, usb_sndbulkpipe(udl->udev, 1),
247			buf, size, udl_urb_completion, unode);
248		urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
249
250		list_add_tail(&unode->entry, &udl->urbs.list);
251
252		up(&udl->urbs.limit_sem);
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
262struct urb *udl_get_urb(struct drm_device *dev)
263{
264	struct udl_device *udl = to_udl(dev);
265	int ret = 0;
266	struct list_head *entry;
267	struct urb_node *unode;
268	struct urb *urb = NULL;
269
270	/* Wait for an in-flight buffer to complete and get re-queued */
271	ret = down_timeout(&udl->urbs.limit_sem, GET_URB_TIMEOUT);
272	if (ret) {
273		DRM_INFO("wait for urb interrupted: %x available: %d\n",
274		       ret, udl->urbs.available);
275		goto error;
276	}
277
278	spin_lock_irq(&udl->urbs.lock);
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_irq(&udl->urbs.lock);
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 = to_udl(dev);
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		DRM_ERROR("usb_submit_urb error %x\n", ret);
306	}
307	return ret;
308}
309
310int udl_init(struct udl_device *udl)
311{
312	struct drm_device *dev = &udl->drm;
313	int ret = -ENOMEM;
314
315	DRM_DEBUG("\n");
316
317	mutex_init(&udl->gem_lock);
318
319	if (!udl_parse_vendor_descriptor(dev, udl->udev)) {
320		ret = -ENODEV;
321		DRM_ERROR("firmware not recognized. Assume incompatible device\n");
322		goto err;
323	}
324
325	if (udl_select_std_channel(udl))
326		DRM_ERROR("Selecting channel failed\n");
327
328	if (!udl_alloc_urb_list(dev, WRITES_IN_FLIGHT, MAX_TRANSFER)) {
329		DRM_ERROR("udl_alloc_urb_list failed\n");
330		goto err;
331	}
332
333	DRM_DEBUG("\n");
334	ret = udl_modeset_init(dev);
335	if (ret)
336		goto err;
337
338	drm_kms_helper_poll_init(dev);
339
340	return 0;
341
342err:
343	if (udl->urbs.count)
344		udl_free_urb_list(dev);
345	DRM_ERROR("%d\n", ret);
346	return ret;
347}
348
349int udl_drop_usb(struct drm_device *dev)
350{
351	udl_free_urb_list(dev);
352	return 0;
353}