v4.19.13 snapshot.
diff --git a/drivers/usb/misc/appledisplay.c b/drivers/usb/misc/appledisplay.c
new file mode 100644
index 0000000..1c6da8d
--- /dev/null
+++ b/drivers/usb/misc/appledisplay.c
@@ -0,0 +1,359 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Apple Cinema Display driver
+ *
+ * Copyright (C) 2006 Michael Hanselmann (linux-kernel@hansmi.ch)
+ *
+ * Thanks to Caskey L. Dickson for his work with acdctl.
+ */
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/usb.h>
+#include <linux/backlight.h>
+#include <linux/timer.h>
+#include <linux/workqueue.h>
+#include <linux/atomic.h>
+
+#define APPLE_VENDOR_ID 0x05AC
+
+#define USB_REQ_GET_REPORT 0x01
+#define USB_REQ_SET_REPORT 0x09
+
+#define ACD_USB_TIMEOUT 250
+
+#define ACD_USB_EDID 0x0302
+#define ACD_USB_BRIGHTNESS 0x0310
+
+#define ACD_BTN_NONE 0
+#define ACD_BTN_BRIGHT_UP 3
+#define ACD_BTN_BRIGHT_DOWN 4
+
+#define ACD_URB_BUFFER_LEN 2
+#define ACD_MSG_BUFFER_LEN 2
+
+#define APPLEDISPLAY_DEVICE(prod) \
+ .match_flags = USB_DEVICE_ID_MATCH_DEVICE | \
+ USB_DEVICE_ID_MATCH_INT_CLASS | \
+ USB_DEVICE_ID_MATCH_INT_PROTOCOL, \
+ .idVendor = APPLE_VENDOR_ID, \
+ .idProduct = (prod), \
+ .bInterfaceClass = USB_CLASS_HID, \
+ .bInterfaceProtocol = 0x00
+
+/* table of devices that work with this driver */
+static const struct usb_device_id appledisplay_table[] = {
+ { APPLEDISPLAY_DEVICE(0x9218) },
+ { APPLEDISPLAY_DEVICE(0x9219) },
+ { APPLEDISPLAY_DEVICE(0x921c) },
+ { APPLEDISPLAY_DEVICE(0x921d) },
+ { APPLEDISPLAY_DEVICE(0x9222) },
+ { APPLEDISPLAY_DEVICE(0x9226) },
+ { APPLEDISPLAY_DEVICE(0x9236) },
+
+ /* Terminating entry */
+ { }
+};
+MODULE_DEVICE_TABLE(usb, appledisplay_table);
+
+/* Structure to hold all of our device specific stuff */
+struct appledisplay {
+ struct usb_device *udev; /* usb device */
+ struct urb *urb; /* usb request block */
+ struct backlight_device *bd; /* backlight device */
+ u8 *urbdata; /* interrupt URB data buffer */
+ u8 *msgdata; /* control message data buffer */
+
+ struct delayed_work work;
+ int button_pressed;
+ spinlock_t lock;
+ struct mutex sysfslock; /* concurrent read and write */
+};
+
+static atomic_t count_displays = ATOMIC_INIT(0);
+
+static void appledisplay_complete(struct urb *urb)
+{
+ struct appledisplay *pdata = urb->context;
+ struct device *dev = &pdata->udev->dev;
+ unsigned long flags;
+ int status = urb->status;
+ int retval;
+
+ switch (status) {
+ case 0:
+ /* success */
+ break;
+ case -EOVERFLOW:
+ dev_err(dev,
+ "OVERFLOW with data length %d, actual length is %d\n",
+ ACD_URB_BUFFER_LEN, pdata->urb->actual_length);
+ /* fall through */
+ case -ECONNRESET:
+ case -ENOENT:
+ case -ESHUTDOWN:
+ /* This urb is terminated, clean up */
+ dev_dbg(dev, "%s - urb shuttingdown with status: %d\n",
+ __func__, status);
+ return;
+ default:
+ dev_dbg(dev, "%s - nonzero urb status received: %d\n",
+ __func__, status);
+ goto exit;
+ }
+
+ spin_lock_irqsave(&pdata->lock, flags);
+
+ switch(pdata->urbdata[1]) {
+ case ACD_BTN_BRIGHT_UP:
+ case ACD_BTN_BRIGHT_DOWN:
+ pdata->button_pressed = 1;
+ schedule_delayed_work(&pdata->work, 0);
+ break;
+ case ACD_BTN_NONE:
+ default:
+ pdata->button_pressed = 0;
+ break;
+ }
+
+ spin_unlock_irqrestore(&pdata->lock, flags);
+
+exit:
+ retval = usb_submit_urb(pdata->urb, GFP_ATOMIC);
+ if (retval) {
+ dev_err(dev, "%s - usb_submit_urb failed with result %d\n",
+ __func__, retval);
+ }
+}
+
+static int appledisplay_bl_update_status(struct backlight_device *bd)
+{
+ struct appledisplay *pdata = bl_get_data(bd);
+ int retval;
+
+ mutex_lock(&pdata->sysfslock);
+ pdata->msgdata[0] = 0x10;
+ pdata->msgdata[1] = bd->props.brightness;
+
+ retval = usb_control_msg(
+ pdata->udev,
+ usb_sndctrlpipe(pdata->udev, 0),
+ USB_REQ_SET_REPORT,
+ USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
+ ACD_USB_BRIGHTNESS,
+ 0,
+ pdata->msgdata, 2,
+ ACD_USB_TIMEOUT);
+ mutex_unlock(&pdata->sysfslock);
+
+ return retval;
+}
+
+static int appledisplay_bl_get_brightness(struct backlight_device *bd)
+{
+ struct appledisplay *pdata = bl_get_data(bd);
+ int retval, brightness;
+
+ mutex_lock(&pdata->sysfslock);
+ retval = usb_control_msg(
+ pdata->udev,
+ usb_rcvctrlpipe(pdata->udev, 0),
+ USB_REQ_GET_REPORT,
+ USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
+ ACD_USB_BRIGHTNESS,
+ 0,
+ pdata->msgdata, 2,
+ ACD_USB_TIMEOUT);
+ brightness = pdata->msgdata[1];
+ mutex_unlock(&pdata->sysfslock);
+
+ if (retval < 0)
+ return retval;
+ else
+ return brightness;
+}
+
+static const struct backlight_ops appledisplay_bl_data = {
+ .get_brightness = appledisplay_bl_get_brightness,
+ .update_status = appledisplay_bl_update_status,
+};
+
+static void appledisplay_work(struct work_struct *work)
+{
+ struct appledisplay *pdata =
+ container_of(work, struct appledisplay, work.work);
+ int retval;
+
+ retval = appledisplay_bl_get_brightness(pdata->bd);
+ if (retval >= 0)
+ pdata->bd->props.brightness = retval;
+
+ /* Poll again in about 125ms if there's still a button pressed */
+ if (pdata->button_pressed)
+ schedule_delayed_work(&pdata->work, HZ / 8);
+}
+
+static int appledisplay_probe(struct usb_interface *iface,
+ const struct usb_device_id *id)
+{
+ struct backlight_properties props;
+ struct appledisplay *pdata;
+ struct usb_device *udev = interface_to_usbdev(iface);
+ struct usb_endpoint_descriptor *endpoint;
+ int int_in_endpointAddr = 0;
+ int retval, brightness;
+ char bl_name[20];
+
+ /* set up the endpoint information */
+ /* use only the first interrupt-in endpoint */
+ retval = usb_find_int_in_endpoint(iface->cur_altsetting, &endpoint);
+ if (retval) {
+ dev_err(&iface->dev, "Could not find int-in endpoint\n");
+ return retval;
+ }
+
+ int_in_endpointAddr = endpoint->bEndpointAddress;
+
+ /* allocate memory for our device state and initialize it */
+ pdata = kzalloc(sizeof(struct appledisplay), GFP_KERNEL);
+ if (!pdata) {
+ retval = -ENOMEM;
+ goto error;
+ }
+
+ pdata->udev = udev;
+
+ spin_lock_init(&pdata->lock);
+ INIT_DELAYED_WORK(&pdata->work, appledisplay_work);
+ mutex_init(&pdata->sysfslock);
+
+ /* Allocate buffer for control messages */
+ pdata->msgdata = kmalloc(ACD_MSG_BUFFER_LEN, GFP_KERNEL);
+ if (!pdata->msgdata) {
+ retval = -ENOMEM;
+ goto error;
+ }
+
+ /* Allocate interrupt URB */
+ pdata->urb = usb_alloc_urb(0, GFP_KERNEL);
+ if (!pdata->urb) {
+ retval = -ENOMEM;
+ goto error;
+ }
+
+ /* Allocate buffer for interrupt data */
+ pdata->urbdata = usb_alloc_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
+ GFP_KERNEL, &pdata->urb->transfer_dma);
+ if (!pdata->urbdata) {
+ retval = -ENOMEM;
+ dev_err(&iface->dev, "Allocating URB buffer failed\n");
+ goto error;
+ }
+
+ /* Configure interrupt URB */
+ usb_fill_int_urb(pdata->urb, udev,
+ usb_rcvintpipe(udev, int_in_endpointAddr),
+ pdata->urbdata, ACD_URB_BUFFER_LEN, appledisplay_complete,
+ pdata, 1);
+ if (usb_submit_urb(pdata->urb, GFP_KERNEL)) {
+ retval = -EIO;
+ dev_err(&iface->dev, "Submitting URB failed\n");
+ goto error;
+ }
+
+ /* Register backlight device */
+ snprintf(bl_name, sizeof(bl_name), "appledisplay%d",
+ atomic_inc_return(&count_displays) - 1);
+ memset(&props, 0, sizeof(struct backlight_properties));
+ props.type = BACKLIGHT_RAW;
+ props.max_brightness = 0xff;
+ pdata->bd = backlight_device_register(bl_name, NULL, pdata,
+ &appledisplay_bl_data, &props);
+ if (IS_ERR(pdata->bd)) {
+ dev_err(&iface->dev, "Backlight registration failed\n");
+ retval = PTR_ERR(pdata->bd);
+ goto error;
+ }
+
+ /* Try to get brightness */
+ brightness = appledisplay_bl_get_brightness(pdata->bd);
+
+ if (brightness < 0) {
+ retval = brightness;
+ dev_err(&iface->dev,
+ "Error while getting initial brightness: %d\n", retval);
+ goto error;
+ }
+
+ /* Set brightness in backlight device */
+ pdata->bd->props.brightness = brightness;
+
+ /* save our data pointer in the interface device */
+ usb_set_intfdata(iface, pdata);
+
+ printk(KERN_INFO "appledisplay: Apple Cinema Display connected\n");
+
+ return 0;
+
+error:
+ if (pdata) {
+ if (pdata->urb) {
+ usb_kill_urb(pdata->urb);
+ if (pdata->urbdata)
+ usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
+ pdata->urbdata, pdata->urb->transfer_dma);
+ usb_free_urb(pdata->urb);
+ }
+ if (!IS_ERR(pdata->bd))
+ backlight_device_unregister(pdata->bd);
+ kfree(pdata->msgdata);
+ }
+ usb_set_intfdata(iface, NULL);
+ kfree(pdata);
+ return retval;
+}
+
+static void appledisplay_disconnect(struct usb_interface *iface)
+{
+ struct appledisplay *pdata = usb_get_intfdata(iface);
+
+ if (pdata) {
+ usb_kill_urb(pdata->urb);
+ cancel_delayed_work_sync(&pdata->work);
+ backlight_device_unregister(pdata->bd);
+ usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
+ pdata->urbdata, pdata->urb->transfer_dma);
+ usb_free_urb(pdata->urb);
+ kfree(pdata->msgdata);
+ kfree(pdata);
+ }
+
+ printk(KERN_INFO "appledisplay: Apple Cinema Display disconnected\n");
+}
+
+static struct usb_driver appledisplay_driver = {
+ .name = "appledisplay",
+ .probe = appledisplay_probe,
+ .disconnect = appledisplay_disconnect,
+ .id_table = appledisplay_table,
+};
+
+static int __init appledisplay_init(void)
+{
+ return usb_register(&appledisplay_driver);
+}
+
+static void __exit appledisplay_exit(void)
+{
+ usb_deregister(&appledisplay_driver);
+}
+
+MODULE_AUTHOR("Michael Hanselmann");
+MODULE_DESCRIPTION("Apple Cinema Display driver");
+MODULE_LICENSE("GPL");
+
+module_init(appledisplay_init);
+module_exit(appledisplay_exit);