/*
* 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);
