diff options
Diffstat (limited to 'drivers/usb/misc/appledisplay.c')
| -rw-r--r-- | drivers/usb/misc/appledisplay.c | 349 |
1 files changed, 349 insertions, 0 deletions
diff --git a/drivers/usb/misc/appledisplay.c b/drivers/usb/misc/appledisplay.c new file mode 100644 index 0000000000..c8098e9b43 --- /dev/null +++ b/drivers/usb/misc/appledisplay.c @@ -0,0 +1,349 @@ +// 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; + 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; + 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 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; + 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); + 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"); |