1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Apple Cinema Display driver 4 * 5 * Copyright (C) 2006 Michael Hanselmann (linux-kernel@hansmi.ch) 6 * 7 * Thanks to Caskey L. Dickson for his work with acdctl. 8 */ 9 10 #include <linux/kernel.h> 11 #include <linux/errno.h> 12 #include <linux/init.h> 13 #include <linux/module.h> 14 #include <linux/slab.h> 15 #include <linux/usb.h> 16 #include <linux/backlight.h> 17 #include <linux/timer.h> 18 #include <linux/workqueue.h> 19 #include <linux/atomic.h> 20 21 #define APPLE_VENDOR_ID 0x05AC 22 23 #define USB_REQ_GET_REPORT 0x01 24 #define USB_REQ_SET_REPORT 0x09 25 26 #define ACD_USB_TIMEOUT 250 27 28 #define ACD_USB_EDID 0x0302 29 #define ACD_USB_BRIGHTNESS 0x0310 30 31 #define ACD_BTN_NONE 0 32 #define ACD_BTN_BRIGHT_UP 3 33 #define ACD_BTN_BRIGHT_DOWN 4 34 35 #define ACD_URB_BUFFER_LEN 2 36 #define ACD_MSG_BUFFER_LEN 2 37 38 #define APPLEDISPLAY_DEVICE(prod) \ 39 .match_flags = USB_DEVICE_ID_MATCH_DEVICE | \ 40 USB_DEVICE_ID_MATCH_INT_CLASS | \ 41 USB_DEVICE_ID_MATCH_INT_PROTOCOL, \ 42 .idVendor = APPLE_VENDOR_ID, \ 43 .idProduct = (prod), \ 44 .bInterfaceClass = USB_CLASS_HID, \ 45 .bInterfaceProtocol = 0x00 46 47 /* table of devices that work with this driver */ 48 static const struct usb_device_id appledisplay_table[] = { 49 { APPLEDISPLAY_DEVICE(0x9218) }, 50 { APPLEDISPLAY_DEVICE(0x9219) }, 51 { APPLEDISPLAY_DEVICE(0x921c) }, 52 { APPLEDISPLAY_DEVICE(0x921d) }, 53 { APPLEDISPLAY_DEVICE(0x9222) }, 54 { APPLEDISPLAY_DEVICE(0x9226) }, 55 { APPLEDISPLAY_DEVICE(0x9236) }, 56 57 /* Terminating entry */ 58 { } 59 }; 60 MODULE_DEVICE_TABLE(usb, appledisplay_table); 61 62 /* Structure to hold all of our device specific stuff */ 63 struct appledisplay { 64 struct usb_device *udev; /* usb device */ 65 struct urb *urb; /* usb request block */ 66 struct backlight_device *bd; /* backlight device */ 67 u8 *urbdata; /* interrupt URB data buffer */ 68 u8 *msgdata; /* control message data buffer */ 69 70 struct delayed_work work; 71 int button_pressed; 72 struct mutex sysfslock; /* concurrent read and write */ 73 }; 74 75 static atomic_t count_displays = ATOMIC_INIT(0); 76 77 static void appledisplay_complete(struct urb *urb) 78 { 79 struct appledisplay *pdata = urb->context; 80 struct device *dev = &pdata->udev->dev; 81 int status = urb->status; 82 int retval; 83 84 switch (status) { 85 case 0: 86 /* success */ 87 break; 88 case -EOVERFLOW: 89 dev_err(dev, 90 "OVERFLOW with data length %d, actual length is %d\n", 91 ACD_URB_BUFFER_LEN, pdata->urb->actual_length); 92 /* fall through */ 93 case -ECONNRESET: 94 case -ENOENT: 95 case -ESHUTDOWN: 96 /* This urb is terminated, clean up */ 97 dev_dbg(dev, "%s - urb shuttingdown with status: %d\n", 98 __func__, status); 99 return; 100 default: 101 dev_dbg(dev, "%s - nonzero urb status received: %d\n", 102 __func__, status); 103 goto exit; 104 } 105 106 switch(pdata->urbdata[1]) { 107 case ACD_BTN_BRIGHT_UP: 108 case ACD_BTN_BRIGHT_DOWN: 109 pdata->button_pressed = 1; 110 schedule_delayed_work(&pdata->work, 0); 111 break; 112 case ACD_BTN_NONE: 113 default: 114 pdata->button_pressed = 0; 115 break; 116 } 117 118 exit: 119 retval = usb_submit_urb(pdata->urb, GFP_ATOMIC); 120 if (retval) { 121 dev_err(dev, "%s - usb_submit_urb failed with result %d\n", 122 __func__, retval); 123 } 124 } 125 126 static int appledisplay_bl_update_status(struct backlight_device *bd) 127 { 128 struct appledisplay *pdata = bl_get_data(bd); 129 int retval; 130 131 mutex_lock(&pdata->sysfslock); 132 pdata->msgdata[0] = 0x10; 133 pdata->msgdata[1] = bd->props.brightness; 134 135 retval = usb_control_msg( 136 pdata->udev, 137 usb_sndctrlpipe(pdata->udev, 0), 138 USB_REQ_SET_REPORT, 139 USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE, 140 ACD_USB_BRIGHTNESS, 141 0, 142 pdata->msgdata, 2, 143 ACD_USB_TIMEOUT); 144 mutex_unlock(&pdata->sysfslock); 145 146 if (retval < 0) 147 return retval; 148 else 149 return 0; 150 } 151 152 static int appledisplay_bl_get_brightness(struct backlight_device *bd) 153 { 154 struct appledisplay *pdata = bl_get_data(bd); 155 int retval, brightness; 156 157 mutex_lock(&pdata->sysfslock); 158 retval = usb_control_msg( 159 pdata->udev, 160 usb_rcvctrlpipe(pdata->udev, 0), 161 USB_REQ_GET_REPORT, 162 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE, 163 ACD_USB_BRIGHTNESS, 164 0, 165 pdata->msgdata, 2, 166 ACD_USB_TIMEOUT); 167 if (retval < 2) { 168 if (retval >= 0) 169 retval = -EMSGSIZE; 170 } else { 171 brightness = pdata->msgdata[1]; 172 } 173 mutex_unlock(&pdata->sysfslock); 174 175 if (retval < 0) 176 return retval; 177 else 178 return brightness; 179 } 180 181 static const struct backlight_ops appledisplay_bl_data = { 182 .get_brightness = appledisplay_bl_get_brightness, 183 .update_status = appledisplay_bl_update_status, 184 }; 185 186 static void appledisplay_work(struct work_struct *work) 187 { 188 struct appledisplay *pdata = 189 container_of(work, struct appledisplay, work.work); 190 int retval; 191 192 retval = appledisplay_bl_get_brightness(pdata->bd); 193 if (retval >= 0) 194 pdata->bd->props.brightness = retval; 195 196 /* Poll again in about 125ms if there's still a button pressed */ 197 if (pdata->button_pressed) 198 schedule_delayed_work(&pdata->work, HZ / 8); 199 } 200 201 static int appledisplay_probe(struct usb_interface *iface, 202 const struct usb_device_id *id) 203 { 204 struct backlight_properties props; 205 struct appledisplay *pdata; 206 struct usb_device *udev = interface_to_usbdev(iface); 207 struct usb_endpoint_descriptor *endpoint; 208 int int_in_endpointAddr = 0; 209 int retval, brightness; 210 char bl_name[20]; 211 212 /* set up the endpoint information */ 213 /* use only the first interrupt-in endpoint */ 214 retval = usb_find_int_in_endpoint(iface->cur_altsetting, &endpoint); 215 if (retval) { 216 dev_err(&iface->dev, "Could not find int-in endpoint\n"); 217 return retval; 218 } 219 220 int_in_endpointAddr = endpoint->bEndpointAddress; 221 222 /* allocate memory for our device state and initialize it */ 223 pdata = kzalloc(sizeof(struct appledisplay), GFP_KERNEL); 224 if (!pdata) { 225 retval = -ENOMEM; 226 goto error; 227 } 228 229 pdata->udev = udev; 230 231 INIT_DELAYED_WORK(&pdata->work, appledisplay_work); 232 mutex_init(&pdata->sysfslock); 233 234 /* Allocate buffer for control messages */ 235 pdata->msgdata = kmalloc(ACD_MSG_BUFFER_LEN, GFP_KERNEL); 236 if (!pdata->msgdata) { 237 retval = -ENOMEM; 238 goto error; 239 } 240 241 /* Allocate interrupt URB */ 242 pdata->urb = usb_alloc_urb(0, GFP_KERNEL); 243 if (!pdata->urb) { 244 retval = -ENOMEM; 245 goto error; 246 } 247 248 /* Allocate buffer for interrupt data */ 249 pdata->urbdata = usb_alloc_coherent(pdata->udev, ACD_URB_BUFFER_LEN, 250 GFP_KERNEL, &pdata->urb->transfer_dma); 251 if (!pdata->urbdata) { 252 retval = -ENOMEM; 253 dev_err(&iface->dev, "Allocating URB buffer failed\n"); 254 goto error; 255 } 256 257 /* Configure interrupt URB */ 258 usb_fill_int_urb(pdata->urb, udev, 259 usb_rcvintpipe(udev, int_in_endpointAddr), 260 pdata->urbdata, ACD_URB_BUFFER_LEN, appledisplay_complete, 261 pdata, 1); 262 pdata->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP; 263 if (usb_submit_urb(pdata->urb, GFP_KERNEL)) { 264 retval = -EIO; 265 dev_err(&iface->dev, "Submitting URB failed\n"); 266 goto error; 267 } 268 269 /* Register backlight device */ 270 snprintf(bl_name, sizeof(bl_name), "appledisplay%d", 271 atomic_inc_return(&count_displays) - 1); 272 memset(&props, 0, sizeof(struct backlight_properties)); 273 props.type = BACKLIGHT_RAW; 274 props.max_brightness = 0xff; 275 pdata->bd = backlight_device_register(bl_name, NULL, pdata, 276 &appledisplay_bl_data, &props); 277 if (IS_ERR(pdata->bd)) { 278 dev_err(&iface->dev, "Backlight registration failed\n"); 279 retval = PTR_ERR(pdata->bd); 280 goto error; 281 } 282 283 /* Try to get brightness */ 284 brightness = appledisplay_bl_get_brightness(pdata->bd); 285 286 if (brightness < 0) { 287 retval = brightness; 288 dev_err(&iface->dev, 289 "Error while getting initial brightness: %d\n", retval); 290 goto error; 291 } 292 293 /* Set brightness in backlight device */ 294 pdata->bd->props.brightness = brightness; 295 296 /* save our data pointer in the interface device */ 297 usb_set_intfdata(iface, pdata); 298 299 printk(KERN_INFO "appledisplay: Apple Cinema Display connected\n"); 300 301 return 0; 302 303 error: 304 if (pdata) { 305 if (pdata->urb) { 306 usb_kill_urb(pdata->urb); 307 cancel_delayed_work_sync(&pdata->work); 308 if (pdata->urbdata) 309 usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN, 310 pdata->urbdata, pdata->urb->transfer_dma); 311 usb_free_urb(pdata->urb); 312 } 313 if (!IS_ERR(pdata->bd)) 314 backlight_device_unregister(pdata->bd); 315 kfree(pdata->msgdata); 316 } 317 usb_set_intfdata(iface, NULL); 318 kfree(pdata); 319 return retval; 320 } 321 322 static void appledisplay_disconnect(struct usb_interface *iface) 323 { 324 struct appledisplay *pdata = usb_get_intfdata(iface); 325 326 if (pdata) { 327 usb_kill_urb(pdata->urb); 328 cancel_delayed_work_sync(&pdata->work); 329 backlight_device_unregister(pdata->bd); 330 usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN, 331 pdata->urbdata, pdata->urb->transfer_dma); 332 usb_free_urb(pdata->urb); 333 kfree(pdata->msgdata); 334 kfree(pdata); 335 } 336 337 printk(KERN_INFO "appledisplay: Apple Cinema Display disconnected\n"); 338 } 339 340 static struct usb_driver appledisplay_driver = { 341 .name = "appledisplay", 342 .probe = appledisplay_probe, 343 .disconnect = appledisplay_disconnect, 344 .id_table = appledisplay_table, 345 }; 346 347 static int __init appledisplay_init(void) 348 { 349 return usb_register(&appledisplay_driver); 350 } 351 352 static void __exit appledisplay_exit(void) 353 { 354 usb_deregister(&appledisplay_driver); 355 } 356 357 MODULE_AUTHOR("Michael Hanselmann"); 358 MODULE_DESCRIPTION("Apple Cinema Display driver"); 359 MODULE_LICENSE("GPL"); 360 361 module_init(appledisplay_init); 362 module_exit(appledisplay_exit); 363