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 fallthrough; 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 /* 111 * there is a window during which no device 112 * is registered 113 */ 114 if (pdata->bd ) 115 schedule_delayed_work(&pdata->work, 0); 116 break; 117 case ACD_BTN_NONE: 118 default: 119 pdata->button_pressed = 0; 120 break; 121 } 122 123 exit: 124 retval = usb_submit_urb(pdata->urb, GFP_ATOMIC); 125 if (retval) { 126 dev_err(dev, "%s - usb_submit_urb failed with result %d\n", 127 __func__, retval); 128 } 129 } 130 131 static int appledisplay_bl_update_status(struct backlight_device *bd) 132 { 133 struct appledisplay *pdata = bl_get_data(bd); 134 int retval; 135 136 mutex_lock(&pdata->sysfslock); 137 pdata->msgdata[0] = 0x10; 138 pdata->msgdata[1] = bd->props.brightness; 139 140 retval = usb_control_msg( 141 pdata->udev, 142 usb_sndctrlpipe(pdata->udev, 0), 143 USB_REQ_SET_REPORT, 144 USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE, 145 ACD_USB_BRIGHTNESS, 146 0, 147 pdata->msgdata, 2, 148 ACD_USB_TIMEOUT); 149 mutex_unlock(&pdata->sysfslock); 150 151 if (retval < 0) 152 return retval; 153 else 154 return 0; 155 } 156 157 static int appledisplay_bl_get_brightness(struct backlight_device *bd) 158 { 159 struct appledisplay *pdata = bl_get_data(bd); 160 int retval, brightness; 161 162 mutex_lock(&pdata->sysfslock); 163 retval = usb_control_msg( 164 pdata->udev, 165 usb_rcvctrlpipe(pdata->udev, 0), 166 USB_REQ_GET_REPORT, 167 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE, 168 ACD_USB_BRIGHTNESS, 169 0, 170 pdata->msgdata, 2, 171 ACD_USB_TIMEOUT); 172 if (retval < 2) { 173 if (retval >= 0) 174 retval = -EMSGSIZE; 175 } else { 176 brightness = pdata->msgdata[1]; 177 } 178 mutex_unlock(&pdata->sysfslock); 179 180 if (retval < 0) 181 return retval; 182 else 183 return brightness; 184 } 185 186 static const struct backlight_ops appledisplay_bl_data = { 187 .get_brightness = appledisplay_bl_get_brightness, 188 .update_status = appledisplay_bl_update_status, 189 }; 190 191 static void appledisplay_work(struct work_struct *work) 192 { 193 struct appledisplay *pdata = 194 container_of(work, struct appledisplay, work.work); 195 int retval; 196 197 retval = appledisplay_bl_get_brightness(pdata->bd); 198 if (retval >= 0) 199 pdata->bd->props.brightness = retval; 200 201 /* Poll again in about 125ms if there's still a button pressed */ 202 if (pdata->button_pressed) 203 schedule_delayed_work(&pdata->work, HZ / 8); 204 } 205 206 static int appledisplay_probe(struct usb_interface *iface, 207 const struct usb_device_id *id) 208 { 209 struct backlight_properties props; 210 struct backlight_device *backlight; 211 struct appledisplay *pdata; 212 struct usb_device *udev = interface_to_usbdev(iface); 213 struct usb_endpoint_descriptor *endpoint; 214 int int_in_endpointAddr = 0; 215 int retval, brightness; 216 char bl_name[20]; 217 218 /* set up the endpoint information */ 219 /* use only the first interrupt-in endpoint */ 220 retval = usb_find_int_in_endpoint(iface->cur_altsetting, &endpoint); 221 if (retval) { 222 dev_err(&iface->dev, "Could not find int-in endpoint\n"); 223 return retval; 224 } 225 226 int_in_endpointAddr = endpoint->bEndpointAddress; 227 228 /* allocate memory for our device state and initialize it */ 229 pdata = kzalloc(sizeof(struct appledisplay), GFP_KERNEL); 230 if (!pdata) { 231 retval = -ENOMEM; 232 goto error; 233 } 234 235 pdata->udev = udev; 236 237 INIT_DELAYED_WORK(&pdata->work, appledisplay_work); 238 mutex_init(&pdata->sysfslock); 239 240 /* Allocate buffer for control messages */ 241 pdata->msgdata = kmalloc(ACD_MSG_BUFFER_LEN, GFP_KERNEL); 242 if (!pdata->msgdata) { 243 retval = -ENOMEM; 244 goto error; 245 } 246 247 /* Allocate interrupt URB */ 248 pdata->urb = usb_alloc_urb(0, GFP_KERNEL); 249 if (!pdata->urb) { 250 retval = -ENOMEM; 251 goto error; 252 } 253 254 /* Allocate buffer for interrupt data */ 255 pdata->urbdata = usb_alloc_coherent(pdata->udev, ACD_URB_BUFFER_LEN, 256 GFP_KERNEL, &pdata->urb->transfer_dma); 257 if (!pdata->urbdata) { 258 retval = -ENOMEM; 259 dev_err(&iface->dev, "Allocating URB buffer failed\n"); 260 goto error; 261 } 262 263 /* Configure interrupt URB */ 264 usb_fill_int_urb(pdata->urb, udev, 265 usb_rcvintpipe(udev, int_in_endpointAddr), 266 pdata->urbdata, ACD_URB_BUFFER_LEN, appledisplay_complete, 267 pdata, 1); 268 pdata->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP; 269 if (usb_submit_urb(pdata->urb, GFP_KERNEL)) { 270 retval = -EIO; 271 dev_err(&iface->dev, "Submitting URB failed\n"); 272 goto error; 273 } 274 275 /* Register backlight device */ 276 snprintf(bl_name, sizeof(bl_name), "appledisplay%d", 277 atomic_inc_return(&count_displays) - 1); 278 memset(&props, 0, sizeof(struct backlight_properties)); 279 props.type = BACKLIGHT_RAW; 280 props.max_brightness = 0xff; 281 backlight = backlight_device_register(bl_name, NULL, pdata, 282 &appledisplay_bl_data, &props); 283 if (IS_ERR(backlight)) { 284 dev_err(&iface->dev, "Backlight registration failed\n"); 285 retval = PTR_ERR(backlight); 286 goto error; 287 } 288 pdata->bd = backlight; 289 290 /* Try to get brightness */ 291 brightness = appledisplay_bl_get_brightness(pdata->bd); 292 293 if (brightness < 0) { 294 retval = brightness; 295 dev_err(&iface->dev, 296 "Error while getting initial brightness: %d\n", retval); 297 goto error; 298 } 299 300 /* Set brightness in backlight device */ 301 pdata->bd->props.brightness = brightness; 302 303 /* save our data pointer in the interface device */ 304 usb_set_intfdata(iface, pdata); 305 306 printk(KERN_INFO "appledisplay: Apple Cinema Display connected\n"); 307 308 return 0; 309 310 error: 311 if (pdata) { 312 if (pdata->urb) { 313 usb_kill_urb(pdata->urb); 314 cancel_delayed_work_sync(&pdata->work); 315 usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN, 316 pdata->urbdata, pdata->urb->transfer_dma); 317 usb_free_urb(pdata->urb); 318 } 319 if (!IS_ERR(pdata->bd)) 320 backlight_device_unregister(pdata->bd); 321 kfree(pdata->msgdata); 322 } 323 usb_set_intfdata(iface, NULL); 324 kfree(pdata); 325 return retval; 326 } 327 328 static void appledisplay_disconnect(struct usb_interface *iface) 329 { 330 struct appledisplay *pdata = usb_get_intfdata(iface); 331 332 if (pdata) { 333 usb_kill_urb(pdata->urb); 334 cancel_delayed_work_sync(&pdata->work); 335 backlight_device_unregister(pdata->bd); 336 usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN, 337 pdata->urbdata, pdata->urb->transfer_dma); 338 usb_free_urb(pdata->urb); 339 kfree(pdata->msgdata); 340 kfree(pdata); 341 } 342 343 printk(KERN_INFO "appledisplay: Apple Cinema Display disconnected\n"); 344 } 345 346 static struct usb_driver appledisplay_driver = { 347 .name = "appledisplay", 348 .probe = appledisplay_probe, 349 .disconnect = appledisplay_disconnect, 350 .id_table = appledisplay_table, 351 }; 352 module_usb_driver(appledisplay_driver); 353 354 MODULE_AUTHOR("Michael Hanselmann"); 355 MODULE_DESCRIPTION("Apple Cinema Display driver"); 356 MODULE_LICENSE("GPL"); 357