drm/udl: initial UDL driver (v4)

This is an initial drm/kms driver for the displaylink devices.

Supports fb_defio,
supports KMS dumb interface
supports 24bpp via conversion to 16bpp, hw can do this better.
supports hot unplug using new drm core features.

On an unplug, it disables connector polling, unplugs connectors
from sysfs, unplugs fbdev layer (using Kay's API), drops all the
USB device URBs, and call the drm core to unplug the device.

This driver is based in large parts on udlfb.c so I've licensed
it under GPLv2.

Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 338 insertions, 0 deletions

diff --git a/drivers/gpu/drm/udl/udl_main.c b/drivers/gpu/drm/udl/udl_main.c
new file mode 100644
index 000000000000..a8d5f09428c7
--- /dev/null
+++ b/drivers/gpu/drm/udl/udl_main.c
@@ -0,0 +1,338 @@
+/*
+ * 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>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License v2. See the file COPYING in the main directory of this archive for
+ * more details.
+ */
+#include "drmP.h"
+#include "udl_drv.h"
+
+/* -BULK_SIZE as per usb-skeleton. Can we get full page and avoid overhead? */
+#define BULK_SIZE 512
+
+#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 drm_device *dev,
+                                       struct usb_device *usbdev)
+{
+        struct udl_device *udl = dev->dev_private;
+        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(usbdev, 0x5f, /* vendor specific */
+                                    0, desc, MAX_VENDOR_DESCRIPTOR_SIZE);
+        if (total_len > 5) {
+                DRM_INFO("vendor descriptor length:%x data:%02x %02x %02x %02x" \
+                        "%02x %02x %02x %02x %02x %02x %02x\n",
+                        total_len, desc[0],
+                        desc[1], desc[2], desc[3], desc[4], desc[5], desc[6],
+                        desc[7], desc[8], desc[9], desc[10]);
+
+                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 = *((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;
+}
+
+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);
+                        atomic_set(&udl->lost_pixels, 1);
+                }
+        }
+
+        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 = dev->dev_private;
+        int count = udl->urbs.count;
+        struct list_head *node;
+        struct urb_node *unode;
+        struct urb *urb;
+        int ret;
+        unsigned long flags;
+
+        DRM_DEBUG("Waiting for completes and freeing all render urbs\n");
+
+        /* keep waiting and freeing, until we've got 'em all */
+        while (count--) {
+
+                /* Getting interrupted means a leak, but ok at shutdown*/
+                ret = down_interruptible(&udl->urbs.limit_sem);
+                if (ret)
+                        break;
+
+                spin_lock_irqsave(&udl->urbs.lock, flags);
+
+                node = udl->urbs.list.next; /* have reserved one with sem */
+                list_del_init(node);
+
+                spin_unlock_irqrestore(&udl->urbs.lock, flags);
+
+                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 = dev->dev_private;
+        int i = 0;
+        struct urb *urb;
+        struct urb_node *unode;
+        char *buf;
+
+        spin_lock_init(&udl->urbs.lock);
+
+        udl->urbs.size = size;
+        INIT_LIST_HEAD(&udl->urbs.list);
+
+        while (i < count) {
+                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(udl->ddev->usbdev, MAX_TRANSFER, GFP_KERNEL,
+                                         &urb->transfer_dma);
+                if (!buf) {
+                        kfree(unode);
+                        usb_free_urb(urb);
+                        break;
+                }
+
+                /* urb->transfer_buffer_length set to actual before submit */
+                usb_fill_bulk_urb(urb, udl->ddev->usbdev, usb_sndbulkpipe(udl->ddev->usbdev, 1),
+                        buf, size, udl_urb_completion, unode);
+                urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
+
+                list_add_tail(&unode->entry, &udl->urbs.list);
+
+                i++;
+        }
+
+        sema_init(&udl->urbs.limit_sem, i);
+        udl->urbs.count = i;
+        udl->urbs.available = i;
+
+        DRM_DEBUG("allocated %d %d byte urbs\n", i, (int) size);
+
+        return i;
+}
+
+struct urb *udl_get_urb(struct drm_device *dev)
+{
+        struct udl_device *udl = dev->dev_private;
+        int ret = 0;
+        struct list_head *entry;
+        struct urb_node *unode;
+        struct urb *urb = NULL;
+        unsigned long flags;
+
+        /* Wait for an in-flight buffer to complete and get re-queued */
+        ret = down_timeout(&udl->urbs.limit_sem, GET_URB_TIMEOUT);
+        if (ret) {
+                atomic_set(&udl->lost_pixels, 1);
+                DRM_INFO("wait for urb interrupted: %x available: %d\n",
+                       ret, udl->urbs.available);
+                goto error;
+        }
+
+        spin_lock_irqsave(&udl->urbs.lock, flags);
+
+        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_irqrestore(&udl->urbs.lock, flags);
+
+        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 = dev->dev_private;
+        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 */
+                atomic_set(&udl->lost_pixels, 1);
+                DRM_ERROR("usb_submit_urb error %x\n", ret);
+        }
+        return ret;
+}
+
+int udl_driver_load(struct drm_device *dev, unsigned long flags)
+{
+        struct udl_device *udl;
+        int ret;
+
+        DRM_DEBUG("\n");
+        udl = kzalloc(sizeof(struct udl_device), GFP_KERNEL);
+        if (!udl)
+                return -ENOMEM;
+
+        udl->ddev = dev;
+        dev->dev_private = udl;
+
+        if (!udl_parse_vendor_descriptor(dev, dev->usbdev)) {
+                DRM_ERROR("firmware not recognized. Assume incompatible device\n");
+                goto err;
+        }
+
+        if (!udl_alloc_urb_list(dev, WRITES_IN_FLIGHT, MAX_TRANSFER)) {
+                ret = -ENOMEM;
+                DRM_ERROR("udl_alloc_urb_list failed\n");
+                goto err;
+        }
+
+        DRM_DEBUG("\n");
+        ret = udl_modeset_init(dev);
+
+        ret = udl_fbdev_init(dev);
+        return 0;
+err:
+        kfree(udl);
+        DRM_ERROR("%d\n", ret);
+        return ret;
+}
+
+int udl_drop_usb(struct drm_device *dev)
+{
+        udl_free_urb_list(dev);
+        return 0;
+}
+
+int udl_driver_unload(struct drm_device *dev)
+{
+        struct udl_device *udl = dev->dev_private;
+
+        if (udl->urbs.count)
+                udl_free_urb_list(dev);
+
+        udl_fbdev_cleanup(dev);
+        udl_modeset_cleanup(dev);
+        kfree(udl);
+        return 0;
+}