drivers/gpu/drm/udl/udl_main.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2012 Red Hat
  *
  * based in parts on udlfb.c:
  * Copyright (C) 2009 Roberto De Ioris <roberto@unbit.it>
  * Copyright (C) 2009 Jaya Kumar <jayakumar.lkml@gmail.com>
  * Copyright (C) 2009 Bernie Thompson <bernie@plugable.com>
  */

 #include <drm/drm.h>
 #include <drm/drm_print.h>
 #include <drm/drm_probe_helper.h>

 #include "udl_drv.h"

 /* -BULK_SIZE as per usb-skeleton. Can we get full page and avoid overhead? */
 #define BULK_SIZE 512

 #define NR_USB_REQUEST_CHANNEL 0x12

 #define MAX_TRANSFER (PAGE_SIZE*16 - BULK_SIZE)
 #define WRITES_IN_FLIGHT (4)
 #define MAX_VENDOR_DESCRIPTOR_SIZE 256

 #define GET_URB_TIMEOUT	HZ
 #define FREE_URB_TIMEOUT (HZ*2)

 static int udl_parse_vendor_descriptor(struct udl_device *udl)
 {
 	struct usb_device *udev = udl_to_usb_device(udl);
 	char *desc;
 	char *buf;
 	char *desc_end;

 	u8 total_len = 0;

 	buf = kzalloc(MAX_VENDOR_DESCRIPTOR_SIZE, GFP_KERNEL);
 	if (!buf)
 		return false;
 	desc = buf;

 	total_len = usb_get_descriptor(udev, 0x5f, /* vendor specific */
 				    0, desc, MAX_VENDOR_DESCRIPTOR_SIZE);
 	if (total_len > 5) {
 		DRM_INFO("vendor descriptor length:%x data:%11ph\n",
 			total_len, desc);

 		if ((desc[0] != total_len) || /* descriptor length */
 		    (desc[1] != 0x5f) ||   /* vendor descriptor type */
 		    (desc[2] != 0x01) ||   /* version (2 bytes) */
 		    (desc[3] != 0x00) ||
 		    (desc[4] != total_len - 2)) /* length after type */
 			goto unrecognized;

 		desc_end = desc + total_len;
 		desc += 5; /* the fixed header we've already parsed */

 		while (desc < desc_end) {
 			u8 length;
 			u16 key;

 			key = le16_to_cpu(*((u16 *) desc));
 			desc += sizeof(u16);
 			length = *desc;
 			desc++;

 			switch (key) {
 			case 0x0200: { /* max_area */
 				u32 max_area;
 				max_area = le32_to_cpu(*((u32 *)desc));
 				DRM_DEBUG("DL chip limited to %d pixel modes\n",
 					max_area);
 				udl->sku_pixel_limit = max_area;
 				break;
 			}
 			default:
 				break;
 			}
 			desc += length;
 		}
 	}

 	goto success;

 unrecognized:
 	/* allow udlfb to load for now even if firmware unrecognized */
 	DRM_ERROR("Unrecognized vendor firmware descriptor\n");

 success:
 	kfree(buf);
 	return true;
 }

 /*
  * Need to ensure a channel is selected before submitting URBs
  */
 static int udl_select_std_channel(struct udl_device *udl)
 {
 	static const u8 set_def_chn[] = {0x57, 0xCD, 0xDC, 0xA7,
 					 0x1C, 0x88, 0x5E, 0x15,
 					 0x60, 0xFE, 0xC6, 0x97,
 					 0x16, 0x3D, 0x47, 0xF2};

 	void *sendbuf;
 	int ret;
 	struct usb_device *udev = udl_to_usb_device(udl);

 	sendbuf = kmemdup(set_def_chn, sizeof(set_def_chn), GFP_KERNEL);
 	if (!sendbuf)
 		return -ENOMEM;

 	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
 			      NR_USB_REQUEST_CHANNEL,
 			      (USB_DIR_OUT | USB_TYPE_VENDOR), 0, 0,
 			      sendbuf, sizeof(set_def_chn),
 			      USB_CTRL_SET_TIMEOUT);
 	kfree(sendbuf);
 	return ret < 0 ? ret : 0;
 }

 static void udl_release_urb_work(struct work_struct *work)
 {
 	struct urb_node *unode = container_of(work, struct urb_node,
 					      release_urb_work.work);

 	up(&unode->dev->urbs.limit_sem);
 }

 void udl_urb_completion(struct urb *urb)
 {
 	struct urb_node *unode = urb->context;
 	struct udl_device *udl = unode->dev;
 	unsigned long flags;

 	/* sync/async unlink faults aren't errors */
 	if (urb->status) {
 		if (!(urb->status == -ENOENT ||
 		    urb->status == -ECONNRESET ||
 		    urb->status == -ESHUTDOWN)) {
 			DRM_ERROR("%s - nonzero write bulk status received: %d\n",
 				__func__, urb->status);
 		}
 	}

 	urb->transfer_buffer_length = udl->urbs.size; /* reset to actual */

 	spin_lock_irqsave(&udl->urbs.lock, flags);
 	list_add_tail(&unode->entry, &udl->urbs.list);
 	udl->urbs.available++;
 	spin_unlock_irqrestore(&udl->urbs.lock, flags);

 #if 0
 	/*
 	 * When using fb_defio, we deadlock if up() is called
 	 * while another is waiting. So queue to another process.
 	 */
 	if (fb_defio)
 		schedule_delayed_work(&unode->release_urb_work, 0);
 	else
 #endif
 		up(&udl->urbs.limit_sem);
 }

 static void udl_free_urb_list(struct drm_device *dev)
 {
 	struct udl_device *udl = to_udl(dev);
 	int count = udl->urbs.count;
 	struct list_head *node;
 	struct urb_node *unode;
 	struct urb *urb;

 	DRM_DEBUG("Waiting for completes and freeing all render urbs\n");

 	/* keep waiting and freeing, until we've got 'em all */
 	while (count--) {
 		down(&udl->urbs.limit_sem);

 		spin_lock_irq(&udl->urbs.lock);

 		node = udl->urbs.list.next; /* have reserved one with sem */
 		list_del_init(node);

 		spin_unlock_irq(&udl->urbs.lock);

 		unode = list_entry(node, struct urb_node, entry);
 		urb = unode->urb;

 		/* Free each separately allocated piece */
 		usb_free_coherent(urb->dev, udl->urbs.size,
 				  urb->transfer_buffer, urb->transfer_dma);
 		usb_free_urb(urb);
 		kfree(node);
 	}
 	udl->urbs.count = 0;
 }

 static int udl_alloc_urb_list(struct drm_device *dev, int count, size_t size)
 {
 	struct udl_device *udl = to_udl(dev);
 	struct urb *urb;
 	struct urb_node *unode;
 	char *buf;
 	size_t wanted_size = count * size;
 	struct usb_device *udev = udl_to_usb_device(udl);

 	spin_lock_init(&udl->urbs.lock);

 retry:
 	udl->urbs.size = size;
 	INIT_LIST_HEAD(&udl->urbs.list);

 	sema_init(&udl->urbs.limit_sem, 0);
 	udl->urbs.count = 0;
 	udl->urbs.available = 0;

 	while (udl->urbs.count * size < wanted_size) {
 		unode = kzalloc(sizeof(struct urb_node), GFP_KERNEL);
 		if (!unode)
 			break;
 		unode->dev = udl;

 		INIT_DELAYED_WORK(&unode->release_urb_work,
 			  udl_release_urb_work);

 		urb = usb_alloc_urb(0, GFP_KERNEL);
 		if (!urb) {
 			kfree(unode);
 			break;
 		}
 		unode->urb = urb;

 		buf = usb_alloc_coherent(udev, size, GFP_KERNEL,
 					 &urb->transfer_dma);
 		if (!buf) {
 			kfree(unode);
 			usb_free_urb(urb);
 			if (size > PAGE_SIZE) {
 				size /= 2;
 				udl_free_urb_list(dev);
 				goto retry;
 			}
 			break;
 		}

 		/* urb->transfer_buffer_length set to actual before submit */
 		usb_fill_bulk_urb(urb, udev, usb_sndbulkpipe(udev, 1),
 				  buf, size, udl_urb_completion, unode);
 		urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;

 		list_add_tail(&unode->entry, &udl->urbs.list);

 		up(&udl->urbs.limit_sem);
 		udl->urbs.count++;
 		udl->urbs.available++;
 	}

 	DRM_DEBUG("allocated %d %d byte urbs\n", udl->urbs.count, (int) size);

 	return udl->urbs.count;
 }

 struct urb *udl_get_urb(struct drm_device *dev)
 {
 	struct udl_device *udl = to_udl(dev);
 	int ret = 0;
 	struct list_head *entry;
 	struct urb_node *unode;
 	struct urb *urb = NULL;

 	/* Wait for an in-flight buffer to complete and get re-queued */
 	ret = down_timeout(&udl->urbs.limit_sem, GET_URB_TIMEOUT);
 	if (ret) {
 		DRM_INFO("wait for urb interrupted: %x available: %d\n",
 		       ret, udl->urbs.available);
 		goto error;
 	}

 	spin_lock_irq(&udl->urbs.lock);

 	BUG_ON(list_empty(&udl->urbs.list)); /* reserved one with limit_sem */
 	entry = udl->urbs.list.next;
 	list_del_init(entry);
 	udl->urbs.available--;

 	spin_unlock_irq(&udl->urbs.lock);

 	unode = list_entry(entry, struct urb_node, entry);
 	urb = unode->urb;

 error:
 	return urb;
 }

 int udl_submit_urb(struct drm_device *dev, struct urb *urb, size_t len)
 {
 	struct udl_device *udl = to_udl(dev);
 	int ret;

 	BUG_ON(len > udl->urbs.size);

 	urb->transfer_buffer_length = len; /* set to actual payload len */
 	ret = usb_submit_urb(urb, GFP_ATOMIC);
 	if (ret) {
 		udl_urb_completion(urb); /* because no one else will */
 		DRM_ERROR("usb_submit_urb error %x\n", ret);
 	}
 	return ret;
 }

 int udl_init(struct udl_device *udl)
 {
 	struct drm_device *dev = &udl->drm;
 	int ret = -ENOMEM;

 	DRM_DEBUG("\n");

 	udl->dmadev = usb_intf_get_dma_device(to_usb_interface(dev->dev));
 	if (!udl->dmadev)
 		drm_warn(dev, "buffer sharing not supported"); /* not an error */

 	mutex_init(&udl->gem_lock);

 	if (!udl_parse_vendor_descriptor(udl)) {
 		ret = -ENODEV;
 		DRM_ERROR("firmware not recognized. Assume incompatible device\n");
 		goto err;
 	}

 	if (udl_select_std_channel(udl))
 		DRM_ERROR("Selecting channel failed\n");

 	if (!udl_alloc_urb_list(dev, WRITES_IN_FLIGHT, MAX_TRANSFER)) {
 		DRM_ERROR("udl_alloc_urb_list failed\n");
 		goto err;
 	}

 	DRM_DEBUG("\n");
 	ret = udl_modeset_init(dev);
 	if (ret)
 		goto err;

 	drm_kms_helper_poll_init(dev);

 	return 0;

 err:
 	if (udl->urbs.count)
 		udl_free_urb_list(dev);
 	put_device(udl->dmadev);
 	DRM_ERROR("%d\n", ret);
 	return ret;
 }

 int udl_drop_usb(struct drm_device *dev)
 {
 	struct udl_device *udl = to_udl(dev);

 	udl_free_urb_list(dev);
 	put_device(udl->dmadev);
 	udl->dmadev = NULL;

 	return 0;
 }
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Copyright (C) 2012 Red Hat
	*
	* based in parts on udlfb.c:
	* Copyright (C) 2009 Roberto De Ioris <roberto@unbit.it>
	* Copyright (C) 2009 Jaya Kumar <jayakumar.lkml@gmail.com>
	* Copyright (C) 2009 Bernie Thompson <bernie@plugable.com>
	*/

	#include <drm/drm.h>
	#include <drm/drm_print.h>
	#include <drm/drm_probe_helper.h>

	#include "udl_drv.h"

	/* -BULK_SIZE as per usb-skeleton. Can we get full page and avoid overhead? */
	#define BULK_SIZE 512

	#define NR_USB_REQUEST_CHANNEL 0x12

	#define MAX_TRANSFER (PAGE_SIZE*16 - BULK_SIZE)
	#define WRITES_IN_FLIGHT (4)
	#define MAX_VENDOR_DESCRIPTOR_SIZE 256

	#define GET_URB_TIMEOUT HZ
	#define FREE_URB_TIMEOUT (HZ*2)

	static int udl_parse_vendor_descriptor(struct udl_device *udl)
	{
	struct usb_device *udev = udl_to_usb_device(udl);
	char *desc;
	char *buf;
	char *desc_end;

	u8 total_len = 0;

	buf = kzalloc(MAX_VENDOR_DESCRIPTOR_SIZE, GFP_KERNEL);
	if (!buf)
	return false;
	desc = buf;

	total_len = usb_get_descriptor(udev, 0x5f, /* vendor specific */
	0, desc, MAX_VENDOR_DESCRIPTOR_SIZE);
	if (total_len > 5) {
	DRM_INFO("vendor descriptor length:%x data:%11ph\n",
	total_len, desc);

	if ((desc[0] != total_len) \|\| /* descriptor length */
	(desc[1] != 0x5f) \|\| /* vendor descriptor type */
	(desc[2] != 0x01) \|\| /* version (2 bytes) */
	(desc[3] != 0x00) \|\|
	(desc[4] != total_len - 2)) /* length after type */
	goto unrecognized;

	desc_end = desc + total_len;
	desc += 5; /* the fixed header we've already parsed */

	while (desc < desc_end) {
	u8 length;
	u16 key;

	key = le16_to_cpu(((u16 ) desc));
	desc += sizeof(u16);
	length = *desc;
	desc++;

	switch (key) {
	case 0x0200: { /* max_area */
	u32 max_area;
	max_area = le32_to_cpu(((u32 )desc));
	DRM_DEBUG("DL chip limited to %d pixel modes\n",
	max_area);
	udl->sku_pixel_limit = max_area;
	break;
	}
	default:
	break;
	}
	desc += length;
	}
	}

	goto success;

	unrecognized:
	/* allow udlfb to load for now even if firmware unrecognized */
	DRM_ERROR("Unrecognized vendor firmware descriptor\n");

	success:
	kfree(buf);
	return true;
	}

	/*
	* Need to ensure a channel is selected before submitting URBs
	*/
	static int udl_select_std_channel(struct udl_device *udl)
	{
	static const u8 set_def_chn[] = {0x57, 0xCD, 0xDC, 0xA7,
	0x1C, 0x88, 0x5E, 0x15,
	0x60, 0xFE, 0xC6, 0x97,
	0x16, 0x3D, 0x47, 0xF2};

	void *sendbuf;
	int ret;
	struct usb_device *udev = udl_to_usb_device(udl);

	sendbuf = kmemdup(set_def_chn, sizeof(set_def_chn), GFP_KERNEL);
	if (!sendbuf)
	return -ENOMEM;

	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
	NR_USB_REQUEST_CHANNEL,
	(USB_DIR_OUT \| USB_TYPE_VENDOR), 0, 0,
	sendbuf, sizeof(set_def_chn),
	USB_CTRL_SET_TIMEOUT);
	kfree(sendbuf);
	return ret < 0 ? ret : 0;
	}

	static void udl_release_urb_work(struct work_struct *work)
	{
	struct urb_node *unode = container_of(work, struct urb_node,
	release_urb_work.work);

	up(&unode->dev->urbs.limit_sem);
	}

	void udl_urb_completion(struct urb *urb)
	{
	struct urb_node *unode = urb->context;
	struct udl_device *udl = unode->dev;
	unsigned long flags;

	/* sync/async unlink faults aren't errors */
	if (urb->status) {
	if (!(urb->status == -ENOENT \|\|
	urb->status == -ECONNRESET \|\|
	urb->status == -ESHUTDOWN)) {
	DRM_ERROR("%s - nonzero write bulk status received: %d\n",
	__func__, urb->status);
	}
	}

	urb->transfer_buffer_length = udl->urbs.size; /* reset to actual */

	spin_lock_irqsave(&udl->urbs.lock, flags);
	list_add_tail(&unode->entry, &udl->urbs.list);
	udl->urbs.available++;
	spin_unlock_irqrestore(&udl->urbs.lock, flags);

	#if 0
	/*
	* When using fb_defio, we deadlock if up() is called
	* while another is waiting. So queue to another process.
	*/
	if (fb_defio)
	schedule_delayed_work(&unode->release_urb_work, 0);
	else
	#endif
	up(&udl->urbs.limit_sem);
	}

	static void udl_free_urb_list(struct drm_device *dev)
	{
	struct udl_device *udl = to_udl(dev);
	int count = udl->urbs.count;
	struct list_head *node;
	struct urb_node *unode;
	struct urb *urb;

	DRM_DEBUG("Waiting for completes and freeing all render urbs\n");

	/* keep waiting and freeing, until we've got 'em all */
	while (count--) {
	down(&udl->urbs.limit_sem);

	spin_lock_irq(&udl->urbs.lock);

	node = udl->urbs.list.next; /* have reserved one with sem */
	list_del_init(node);

	spin_unlock_irq(&udl->urbs.lock);

	unode = list_entry(node, struct urb_node, entry);
	urb = unode->urb;

	/* Free each separately allocated piece */
	usb_free_coherent(urb->dev, udl->urbs.size,
	urb->transfer_buffer, urb->transfer_dma);
	usb_free_urb(urb);
	kfree(node);
	}
	udl->urbs.count = 0;
	}

	static int udl_alloc_urb_list(struct drm_device *dev, int count, size_t size)
	{
	struct udl_device *udl = to_udl(dev);
	struct urb *urb;
	struct urb_node *unode;
	char *buf;
	size_t wanted_size = count * size;
	struct usb_device *udev = udl_to_usb_device(udl);

	spin_lock_init(&udl->urbs.lock);

	retry:
	udl->urbs.size = size;
	INIT_LIST_HEAD(&udl->urbs.list);

	sema_init(&udl->urbs.limit_sem, 0);
	udl->urbs.count = 0;
	udl->urbs.available = 0;

	while (udl->urbs.count * size < wanted_size) {
	unode = kzalloc(sizeof(struct urb_node), GFP_KERNEL);
	if (!unode)
	break;
	unode->dev = udl;

	INIT_DELAYED_WORK(&unode->release_urb_work,
	udl_release_urb_work);

	urb = usb_alloc_urb(0, GFP_KERNEL);
	if (!urb) {
	kfree(unode);
	break;
	}
	unode->urb = urb;

	buf = usb_alloc_coherent(udev, size, GFP_KERNEL,
	&urb->transfer_dma);
	if (!buf) {
	kfree(unode);
	usb_free_urb(urb);
	if (size > PAGE_SIZE) {
	size /= 2;
	udl_free_urb_list(dev);
	goto retry;
	}
	break;
	}

	/* urb->transfer_buffer_length set to actual before submit */
	usb_fill_bulk_urb(urb, udev, usb_sndbulkpipe(udev, 1),
	buf, size, udl_urb_completion, unode);
	urb->transfer_flags \|= URB_NO_TRANSFER_DMA_MAP;

	list_add_tail(&unode->entry, &udl->urbs.list);

	up(&udl->urbs.limit_sem);
	udl->urbs.count++;
	udl->urbs.available++;
	}

	DRM_DEBUG("allocated %d %d byte urbs\n", udl->urbs.count, (int) size);

	return udl->urbs.count;
	}

	struct urb udl_get_urb(struct drm_device dev)
	{
	struct udl_device *udl = to_udl(dev);
	int ret = 0;
	struct list_head *entry;
	struct urb_node *unode;
	struct urb *urb = NULL;

	/* Wait for an in-flight buffer to complete and get re-queued */
	ret = down_timeout(&udl->urbs.limit_sem, GET_URB_TIMEOUT);
	if (ret) {
	DRM_INFO("wait for urb interrupted: %x available: %d\n",
	ret, udl->urbs.available);
	goto error;
	}

	spin_lock_irq(&udl->urbs.lock);

	BUG_ON(list_empty(&udl->urbs.list)); /* reserved one with limit_sem */
	entry = udl->urbs.list.next;
	list_del_init(entry);
	udl->urbs.available--;

	spin_unlock_irq(&udl->urbs.lock);

	unode = list_entry(entry, struct urb_node, entry);
	urb = unode->urb;

	error:
	return urb;
	}

	int udl_submit_urb(struct drm_device dev, struct urb urb, size_t len)
	{
	struct udl_device *udl = to_udl(dev);
	int ret;

	BUG_ON(len > udl->urbs.size);

	urb->transfer_buffer_length = len; /* set to actual payload len */
	ret = usb_submit_urb(urb, GFP_ATOMIC);
	if (ret) {
	udl_urb_completion(urb); /* because no one else will */
	DRM_ERROR("usb_submit_urb error %x\n", ret);
	}
	return ret;
	}

	int udl_init(struct udl_device *udl)
	{
	struct drm_device *dev = &udl->drm;
	int ret = -ENOMEM;

	DRM_DEBUG("\n");

	udl->dmadev = usb_intf_get_dma_device(to_usb_interface(dev->dev));
	if (!udl->dmadev)
	drm_warn(dev, "buffer sharing not supported"); /* not an error */

	mutex_init(&udl->gem_lock);

	if (!udl_parse_vendor_descriptor(udl)) {
	ret = -ENODEV;
	DRM_ERROR("firmware not recognized. Assume incompatible device\n");
	goto err;
	}

	if (udl_select_std_channel(udl))
	DRM_ERROR("Selecting channel failed\n");

	if (!udl_alloc_urb_list(dev, WRITES_IN_FLIGHT, MAX_TRANSFER)) {
	DRM_ERROR("udl_alloc_urb_list failed\n");
	goto err;
	}

	DRM_DEBUG("\n");
	ret = udl_modeset_init(dev);
	if (ret)
	goto err;

	drm_kms_helper_poll_init(dev);

	return 0;

	err:
	if (udl->urbs.count)
	udl_free_urb_list(dev);
	put_device(udl->dmadev);
	DRM_ERROR("%d\n", ret);
	return ret;
	}

	int udl_drop_usb(struct drm_device *dev)
	{
	struct udl_device *udl = to_udl(dev);

	udl_free_urb_list(dev);
	put_device(udl->dmadev);
	udl->dmadev = NULL;

	return 0;
	}