// SPDX-License-Identifier: GPL-2.0+
/*
* Apple Cinema Display driver
*
* Copyright (C) 2006 Michael Hanselmann ([email protected])
*
* 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;
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;
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);
fallthrough;
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;
}
switch(pdata->urbdata[1]) {
case ACD_BTN_BRIGHT_UP:
case ACD_BTN_BRIGHT_DOWN:
pdata->button_pressed = 1;
/*
* there is a window during which no device
* is registered
*/
if (pdata->bd )
schedule_delayed_work(&pdata->work, 0);
break;
case ACD_BTN_NONE:
default:
pdata->button_pressed = 0;
break;
}
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);
if (retval < 0)
return retval;
else
return 0;
}
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);
if (retval < 2) {
if (retval >= 0)
retval = -EMSGSIZE;
} else {
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 backlight_device *backlight;
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;
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);
pdata->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
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;
backlight = backlight_device_register(bl_name, NULL, pdata,
&appledisplay_bl_data, &props);
if (IS_ERR(backlight)) {
dev_err(&iface->dev, "Backlight registration failed\n");
retval = PTR_ERR(backlight);
goto error;
}
pdata->bd = backlight;
/* 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);
cancel_delayed_work_sync(&pdata->work);
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,
};
module_usb_driver(appledisplay_driver);
MODULE_AUTHOR("Michael Hanselmann");
MODULE_DESCRIPTION("Apple Cinema Display driver");
MODULE_LICENSE("GPL");
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