[PATCH] Driver for Apple Cinema Display
authorakpm@osdl.org <akpm@osdl.org>
Fri, 26 May 2006 20:17:09 +0000 (13:17 -0700)
committerGreg Kroah-Hartman <gregkh@suse.de>
Wed, 21 Jun 2006 22:04:14 +0000 (15:04 -0700)
This is a driver to control the brightness of an Apple Cinema Display over
USB.  It updates the local brightness value if the user presses a button on
the display.

Signed-off-by: Michael Hanselmann <linux-kernel@hansmi.ch>
Cc: Oliver Neukum <oliver@neukum.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
drivers/usb/Makefile
drivers/usb/misc/Kconfig
drivers/usb/misc/Makefile
drivers/usb/misc/appledisplay.c [new file with mode: 0644]

index 9b7d9769fdcc7179d8e95786b11f0a6f27d40ab4..b299965619042c9b3a5d227dbd127fe83ce20fae 100644 (file)
@@ -61,6 +61,7 @@ obj-$(CONFIG_USB_TEST)                += misc/
 obj-$(CONFIG_USB_USS720)       += misc/
 obj-$(CONFIG_USB_PHIDGETSERVO) += misc/
 obj-$(CONFIG_USB_SISUSBVGA)    += misc/
+obj-$(CONFIG_USB_APPLEDISPLAY) += misc/
 
 obj-$(CONFIG_USB_ATM)          += atm/
 obj-$(CONFIG_USB_SPEEDTOUCH)   += atm/
index 8ba6a701e9c144afcb42473fa166e08ca959c3b8..af79d0447bbd143f285436b84ad25a01732ddebe 100644 (file)
@@ -137,6 +137,15 @@ config USB_IDMOUSE
 
          See also <http://www.fs.tum.de/~echtler/idmouse/>.
 
+config USB_APPLEDISPLAY
+       tristate "Apple Cinema Display support"
+       depends on USB
+       select BACKLIGHT_LCD_SUPPORT
+       select BACKLIGHT_CLASS_DEVICE
+       help
+         Say Y here if you want to control the backlight of Apple Cinema
+         Displays over USB. This driver provides a sysfs interface.
+
 source "drivers/usb/misc/sisusbvga/Kconfig"
 
 config USB_LD
index 6c693bc68e2e8f2ce71df7fe793c988ed3db0c17..946537d31d913cb27071a30a2731b04da8270eee 100644 (file)
@@ -17,6 +17,7 @@ obj-$(CONFIG_USB_PHIDGETSERVO)        += phidgetservo.o
 obj-$(CONFIG_USB_RIO500)       += rio500.o
 obj-$(CONFIG_USB_TEST)         += usbtest.o
 obj-$(CONFIG_USB_USS720)       += uss720.o
+obj-$(CONFIG_USB_APPLEDISPLAY) += appledisplay.o
 
 obj-$(CONFIG_USB_SISUSBVGA)    += sisusbvga/
 
diff --git a/drivers/usb/misc/appledisplay.c b/drivers/usb/misc/appledisplay.c
new file mode 100644 (file)
index 0000000..bfde82f
--- /dev/null
@@ -0,0 +1,383 @@
+/*
+ * Apple Cinema Display driver
+ *
+ * Copyright (C) 2006  Michael Hanselmann (linux-kernel@hansmi.ch)
+ *
+ * Thanks to Caskey L. Dickson for his work with acdctl.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/usb.h>
+#include <linux/backlight.h>
+#include <linux/timer.h>
+#include <linux/workqueue.h>
+#include <asm/atomic.h>
+#include <asm/semaphore.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 struct usb_device_id appledisplay_table [] = {
+       { APPLEDISPLAY_DEVICE(0x9218) },
+       { APPLEDISPLAY_DEVICE(0x9219) },
+       { APPLEDISPLAY_DEVICE(0x921d) },
+
+       /* 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 */
+       char *urbdata;                  /* interrupt URB data buffer */
+       char *msgdata;                  /* control message data buffer */
+
+       struct work_struct work;
+       int button_pressed;
+       spinlock_t lock;
+};
+
+static atomic_t count_displays = ATOMIC_INIT(0);
+static struct workqueue_struct *wq;
+
+static void appledisplay_complete(struct urb *urb, struct pt_regs *regs)
+{
+       struct appledisplay *pdata = urb->context;
+       unsigned long flags;
+       int retval;
+
+       switch (urb->status) {
+       case 0:
+               /* success */
+               break;
+       case -EOVERFLOW:
+               printk(KERN_ERR "appletouch: OVERFLOW with data "
+                       "length %d, actual length is %d\n",
+                       ACD_URB_BUFFER_LEN, pdata->urb->actual_length);
+       case -ECONNRESET:
+       case -ENOENT:
+       case -ESHUTDOWN:
+               /* This urb is terminated, clean up */
+               dbg("%s - urb shutting down with status: %d",
+                       __FUNCTION__, urb->status);
+               return;
+       default:
+               dbg("%s - nonzero urb status received: %d",
+                       __FUNCTION__, urb->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;
+               queue_work(wq, &pdata->work);
+               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) {
+               err("%s - usb_submit_urb failed with result %d",
+                       __FUNCTION__, retval);
+       }
+}
+
+static int appledisplay_bl_update_status(struct backlight_device *bd)
+{
+       struct appledisplay *pdata = class_get_devdata(&bd->class_dev);
+       int retval;
+
+       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);
+
+       return retval;
+}
+
+static int appledisplay_bl_get_brightness(struct backlight_device *bd)
+{
+       struct appledisplay *pdata = class_get_devdata(&bd->class_dev);
+       int retval;
+
+       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);
+
+       if (retval < 0)
+               return retval;
+       else
+               return pdata->msgdata[1];
+}
+
+static struct backlight_properties appledisplay_bl_data = {
+       .owner          = THIS_MODULE,
+       .get_brightness = appledisplay_bl_get_brightness,
+       .update_status  = appledisplay_bl_update_status,
+       .max_brightness = 0xFF
+};
+
+static void appledisplay_work(void *private)
+{
+       struct appledisplay *pdata = private;
+       int retval;
+
+       up(&pdata->bd->sem);
+       retval = appledisplay_bl_get_brightness(pdata->bd);
+       if (retval >= 0)
+               pdata->bd->props->brightness = retval;
+       down(&pdata->bd->sem);
+
+       /* 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 appledisplay *pdata;
+       struct usb_device *udev = interface_to_usbdev(iface);
+       struct usb_host_interface *iface_desc;
+       struct usb_endpoint_descriptor *endpoint;
+       int int_in_endpointAddr = 0;
+       int i, retval = -ENOMEM, brightness;
+       char bl_name[20];
+
+       /* set up the endpoint information */
+       /* use only the first interrupt-in endpoint */
+       iface_desc = iface->cur_altsetting;
+       for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
+               endpoint = &iface_desc->endpoint[i].desc;
+               if (!int_in_endpointAddr &&
+                   (endpoint->bEndpointAddress & USB_DIR_IN) &&
+                   ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
+                    USB_ENDPOINT_XFER_INT)) {
+                       /* we found an interrupt in endpoint */
+                       int_in_endpointAddr = endpoint->bEndpointAddress;
+                       break;
+               }
+       }
+       if (!int_in_endpointAddr) {
+               err("Could not find int-in endpoint");
+               return -EIO;
+       }
+
+       /* allocate memory for our device state and initialize it */
+       pdata = kzalloc(sizeof(struct appledisplay), GFP_KERNEL);
+       if (!pdata) {
+               retval = -ENOMEM;
+               err("Out of memory");
+               goto error;
+       }
+
+       pdata->udev = udev;
+
+       spin_lock_init(&pdata->lock);
+       INIT_WORK(&pdata->work, appledisplay_work, pdata);
+
+       /* Allocate buffer for control messages */
+       pdata->msgdata = kmalloc(ACD_MSG_BUFFER_LEN, GFP_KERNEL);
+       if (!pdata->msgdata) {
+               retval = -ENOMEM;
+               err("appledisplay: Allocating buffer for control messages "
+                       "failed");
+               goto error;
+       }
+
+       /* Allocate interrupt URB */
+       pdata->urb = usb_alloc_urb(0, GFP_KERNEL);
+       if (!pdata->urb) {
+               retval = -ENOMEM;
+               err("appledisplay: Allocating URB failed");
+               goto error;
+       }
+
+       /* Allocate buffer for interrupt data */
+       pdata->urbdata = usb_buffer_alloc(pdata->udev, ACD_URB_BUFFER_LEN,
+               GFP_KERNEL, &pdata->urb->transfer_dma);
+       if (!pdata->urbdata) {
+               retval = -ENOMEM;
+               err("appledisplay: Allocating URB buffer failed");
+               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;
+               err("appledisplay: Submitting URB failed");
+               goto error;
+       }
+
+       /* Register backlight device */
+       snprintf(bl_name, sizeof(bl_name), "appledisplay%d",
+               atomic_inc_return(&count_displays) - 1);
+       pdata->bd = backlight_device_register(bl_name, pdata,
+                                               &appledisplay_bl_data);
+       if (IS_ERR(pdata->bd)) {
+               err("appledisplay: Backlight registration failed");
+               goto error;
+       }
+
+       /* Try to get brightness */
+       up(&pdata->bd->sem);
+       brightness = appledisplay_bl_get_brightness(pdata->bd);
+       down(&pdata->bd->sem);
+
+       if (brightness < 0) {
+               retval = brightness;
+               err("appledisplay: Error while getting initial brightness: %d", retval);
+               goto error;
+       }
+
+       /* Set brightness in backlight device */
+       up(&pdata->bd->sem);
+       pdata->bd->props->brightness = brightness;
+       down(&pdata->bd->sem);
+
+       /* 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_buffer_free(pdata->udev, ACD_URB_BUFFER_LEN,
+                                       pdata->urbdata, pdata->urb->transfer_dma);
+                       usb_free_urb(pdata->urb);
+               }
+               if (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(&pdata->work);
+               backlight_device_unregister(pdata->bd);
+               usb_buffer_free(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)
+{
+       wq = create_singlethread_workqueue("appledisplay");
+       if (!wq) {
+               err("Could not create work queue\n");
+               return -ENOMEM;
+       }
+
+       return usb_register(&appledisplay_driver);
+}
+
+static void __exit appledisplay_exit(void)
+{
+       flush_workqueue(wq);
+       destroy_workqueue(wq);
+       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);