1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * A driver for the Griffin Technology, Inc. "PowerMate" USB controller dial. 4 * 5 * v1.1, (c)2002 William R Sowerbutts <will@sowerbutts.com> 6 * 7 * This device is a anodised aluminium knob which connects over USB. It can measure 8 * clockwise and anticlockwise rotation. The dial also acts as a pushbutton with 9 * a spring for automatic release. The base contains a pair of LEDs which illuminate 10 * the translucent base. It rotates without limit and reports its relative rotation 11 * back to the host when polled by the USB controller. 12 * 13 * Testing with the knob I have has shown that it measures approximately 94 "clicks" 14 * for one full rotation. Testing with my High Speed Rotation Actuator (ok, it was 15 * a variable speed cordless electric drill) has shown that the device can measure 16 * speeds of up to 7 clicks either clockwise or anticlockwise between pollings from 17 * the host. If it counts more than 7 clicks before it is polled, it will wrap back 18 * to zero and start counting again. This was at quite high speed, however, almost 19 * certainly faster than the human hand could turn it. Griffin say that it loses a 20 * pulse or two on a direction change; the granularity is so fine that I never 21 * noticed this in practice. 22 * 23 * The device's microcontroller can be programmed to set the LED to either a constant 24 * intensity, or to a rhythmic pulsing. Several patterns and speeds are available. 25 * 26 * Griffin were very happy to provide documentation and free hardware for development. 27 * 28 * Some userspace tools are available on the web: http://sowerbutts.com/powermate/ 29 * 30 */ 31 32 #include <linux/kernel.h> 33 #include <linux/slab.h> 34 #include <linux/module.h> 35 #include <linux/spinlock.h> 36 #include <linux/usb/input.h> 37 38 #define POWERMATE_VENDOR 0x077d /* Griffin Technology, Inc. */ 39 #define POWERMATE_PRODUCT_NEW 0x0410 /* Griffin PowerMate */ 40 #define POWERMATE_PRODUCT_OLD 0x04AA /* Griffin soundKnob */ 41 42 #define CONTOUR_VENDOR 0x05f3 /* Contour Design, Inc. */ 43 #define CONTOUR_JOG 0x0240 /* Jog and Shuttle */ 44 45 /* these are the command codes we send to the device */ 46 #define SET_STATIC_BRIGHTNESS 0x01 47 #define SET_PULSE_ASLEEP 0x02 48 #define SET_PULSE_AWAKE 0x03 49 #define SET_PULSE_MODE 0x04 50 51 /* these refer to bits in the powermate_device's requires_update field. */ 52 #define UPDATE_STATIC_BRIGHTNESS (1<<0) 53 #define UPDATE_PULSE_ASLEEP (1<<1) 54 #define UPDATE_PULSE_AWAKE (1<<2) 55 #define UPDATE_PULSE_MODE (1<<3) 56 57 /* at least two versions of the hardware exist, with differing payload 58 sizes. the first three bytes always contain the "interesting" data in 59 the relevant format. */ 60 #define POWERMATE_PAYLOAD_SIZE_MAX 6 61 #define POWERMATE_PAYLOAD_SIZE_MIN 3 62 struct powermate_device { 63 signed char *data; 64 dma_addr_t data_dma; 65 struct urb *irq, *config; 66 struct usb_ctrlrequest *configcr; 67 struct usb_device *udev; 68 struct usb_interface *intf; 69 struct input_dev *input; 70 spinlock_t lock; 71 int static_brightness; 72 int pulse_speed; 73 int pulse_table; 74 int pulse_asleep; 75 int pulse_awake; 76 int requires_update; // physical settings which are out of sync 77 char phys[64]; 78 }; 79 80 static char pm_name_powermate[] = "Griffin PowerMate"; 81 static char pm_name_soundknob[] = "Griffin SoundKnob"; 82 83 static void powermate_config_complete(struct urb *urb); 84 85 /* Callback for data arriving from the PowerMate over the USB interrupt pipe */ 86 static void powermate_irq(struct urb *urb) 87 { 88 struct powermate_device *pm = urb->context; 89 struct device *dev = &pm->intf->dev; 90 int retval; 91 92 switch (urb->status) { 93 case 0: 94 /* success */ 95 break; 96 case -ECONNRESET: 97 case -ENOENT: 98 case -ESHUTDOWN: 99 /* this urb is terminated, clean up */ 100 dev_dbg(dev, "%s - urb shutting down with status: %d\n", 101 __func__, urb->status); 102 return; 103 default: 104 dev_dbg(dev, "%s - nonzero urb status received: %d\n", 105 __func__, urb->status); 106 goto exit; 107 } 108 109 /* handle updates to device state */ 110 input_report_key(pm->input, BTN_0, pm->data[0] & 0x01); 111 input_report_rel(pm->input, REL_DIAL, pm->data[1]); 112 input_sync(pm->input); 113 114 exit: 115 retval = usb_submit_urb (urb, GFP_ATOMIC); 116 if (retval) 117 dev_err(dev, "%s - usb_submit_urb failed with result: %d\n", 118 __func__, retval); 119 } 120 121 /* Decide if we need to issue a control message and do so. Must be called with pm->lock taken */ 122 static void powermate_sync_state(struct powermate_device *pm) 123 { 124 if (pm->requires_update == 0) 125 return; /* no updates are required */ 126 if (pm->config->status == -EINPROGRESS) 127 return; /* an update is already in progress; it'll issue this update when it completes */ 128 129 if (pm->requires_update & UPDATE_PULSE_ASLEEP){ 130 pm->configcr->wValue = cpu_to_le16( SET_PULSE_ASLEEP ); 131 pm->configcr->wIndex = cpu_to_le16( pm->pulse_asleep ? 1 : 0 ); 132 pm->requires_update &= ~UPDATE_PULSE_ASLEEP; 133 }else if (pm->requires_update & UPDATE_PULSE_AWAKE){ 134 pm->configcr->wValue = cpu_to_le16( SET_PULSE_AWAKE ); 135 pm->configcr->wIndex = cpu_to_le16( pm->pulse_awake ? 1 : 0 ); 136 pm->requires_update &= ~UPDATE_PULSE_AWAKE; 137 }else if (pm->requires_update & UPDATE_PULSE_MODE){ 138 int op, arg; 139 /* the powermate takes an operation and an argument for its pulse algorithm. 140 the operation can be: 141 0: divide the speed 142 1: pulse at normal speed 143 2: multiply the speed 144 the argument only has an effect for operations 0 and 2, and ranges between 145 1 (least effect) to 255 (maximum effect). 146 147 thus, several states are equivalent and are coalesced into one state. 148 149 we map this onto a range from 0 to 510, with: 150 0 -- 254 -- use divide (0 = slowest) 151 255 -- use normal speed 152 256 -- 510 -- use multiple (510 = fastest). 153 154 Only values of 'arg' quite close to 255 are particularly useful/spectacular. 155 */ 156 if (pm->pulse_speed < 255) { 157 op = 0; // divide 158 arg = 255 - pm->pulse_speed; 159 } else if (pm->pulse_speed > 255) { 160 op = 2; // multiply 161 arg = pm->pulse_speed - 255; 162 } else { 163 op = 1; // normal speed 164 arg = 0; // can be any value 165 } 166 pm->configcr->wValue = cpu_to_le16( (pm->pulse_table << 8) | SET_PULSE_MODE ); 167 pm->configcr->wIndex = cpu_to_le16( (arg << 8) | op ); 168 pm->requires_update &= ~UPDATE_PULSE_MODE; 169 } else if (pm->requires_update & UPDATE_STATIC_BRIGHTNESS) { 170 pm->configcr->wValue = cpu_to_le16( SET_STATIC_BRIGHTNESS ); 171 pm->configcr->wIndex = cpu_to_le16( pm->static_brightness ); 172 pm->requires_update &= ~UPDATE_STATIC_BRIGHTNESS; 173 } else { 174 printk(KERN_ERR "powermate: unknown update required"); 175 pm->requires_update = 0; /* fudge the bug */ 176 return; 177 } 178 179 /* printk("powermate: %04x %04x\n", pm->configcr->wValue, pm->configcr->wIndex); */ 180 181 pm->configcr->bRequestType = 0x41; /* vendor request */ 182 pm->configcr->bRequest = 0x01; 183 pm->configcr->wLength = 0; 184 185 usb_fill_control_urb(pm->config, pm->udev, usb_sndctrlpipe(pm->udev, 0), 186 (void *) pm->configcr, NULL, 0, 187 powermate_config_complete, pm); 188 189 if (usb_submit_urb(pm->config, GFP_ATOMIC)) 190 printk(KERN_ERR "powermate: usb_submit_urb(config) failed"); 191 } 192 193 /* Called when our asynchronous control message completes. We may need to issue another immediately */ 194 static void powermate_config_complete(struct urb *urb) 195 { 196 struct powermate_device *pm = urb->context; 197 198 if (urb->status) 199 printk(KERN_ERR "powermate: config urb returned %d\n", urb->status); 200 201 guard(spinlock_irqsave)(&pm->lock); 202 powermate_sync_state(pm); 203 } 204 205 /* Set the LED up as described and begin the sync with the hardware if required */ 206 static void powermate_pulse_led(struct powermate_device *pm, int static_brightness, int pulse_speed, 207 int pulse_table, int pulse_asleep, int pulse_awake) 208 { 209 if (pulse_speed < 0) 210 pulse_speed = 0; 211 if (pulse_table < 0) 212 pulse_table = 0; 213 if (pulse_speed > 510) 214 pulse_speed = 510; 215 if (pulse_table > 2) 216 pulse_table = 2; 217 218 pulse_asleep = !!pulse_asleep; 219 pulse_awake = !!pulse_awake; 220 221 guard(spinlock_irqsave)(&pm->lock); 222 223 /* mark state updates which are required */ 224 if (static_brightness != pm->static_brightness) { 225 pm->static_brightness = static_brightness; 226 pm->requires_update |= UPDATE_STATIC_BRIGHTNESS; 227 } 228 if (pulse_asleep != pm->pulse_asleep) { 229 pm->pulse_asleep = pulse_asleep; 230 pm->requires_update |= (UPDATE_PULSE_ASLEEP | UPDATE_STATIC_BRIGHTNESS); 231 } 232 if (pulse_awake != pm->pulse_awake) { 233 pm->pulse_awake = pulse_awake; 234 pm->requires_update |= (UPDATE_PULSE_AWAKE | UPDATE_STATIC_BRIGHTNESS); 235 } 236 if (pulse_speed != pm->pulse_speed || pulse_table != pm->pulse_table) { 237 pm->pulse_speed = pulse_speed; 238 pm->pulse_table = pulse_table; 239 pm->requires_update |= UPDATE_PULSE_MODE; 240 } 241 242 powermate_sync_state(pm); 243 } 244 245 /* Callback from the Input layer when an event arrives from userspace to configure the LED */ 246 static int powermate_input_event(struct input_dev *dev, unsigned int type, unsigned int code, int _value) 247 { 248 unsigned int command = (unsigned int)_value; 249 struct powermate_device *pm = input_get_drvdata(dev); 250 251 if (type == EV_MSC && code == MSC_PULSELED){ 252 /* 253 bits 0- 7: 8 bits: LED brightness 254 bits 8-16: 9 bits: pulsing speed modifier (0 ... 510); 0-254 = slower, 255 = standard, 256-510 = faster. 255 bits 17-18: 2 bits: pulse table (0, 1, 2 valid) 256 bit 19: 1 bit : pulse whilst asleep? 257 bit 20: 1 bit : pulse constantly? 258 */ 259 int static_brightness = command & 0xFF; // bits 0-7 260 int pulse_speed = (command >> 8) & 0x1FF; // bits 8-16 261 int pulse_table = (command >> 17) & 0x3; // bits 17-18 262 int pulse_asleep = (command >> 19) & 0x1; // bit 19 263 int pulse_awake = (command >> 20) & 0x1; // bit 20 264 265 powermate_pulse_led(pm, static_brightness, pulse_speed, pulse_table, pulse_asleep, pulse_awake); 266 } 267 268 return 0; 269 } 270 271 static int powermate_alloc_buffers(struct usb_device *udev, struct powermate_device *pm) 272 { 273 pm->data = usb_alloc_coherent(udev, POWERMATE_PAYLOAD_SIZE_MAX, 274 GFP_KERNEL, &pm->data_dma); 275 if (!pm->data) 276 return -1; 277 278 pm->configcr = kmalloc(sizeof(*(pm->configcr)), GFP_KERNEL); 279 if (!pm->configcr) 280 return -ENOMEM; 281 282 return 0; 283 } 284 285 static void powermate_free_buffers(struct usb_device *udev, struct powermate_device *pm) 286 { 287 usb_free_coherent(udev, POWERMATE_PAYLOAD_SIZE_MAX, 288 pm->data, pm->data_dma); 289 kfree(pm->configcr); 290 } 291 292 /* Called whenever a USB device matching one in our supported devices table is connected */ 293 static int powermate_probe(struct usb_interface *intf, const struct usb_device_id *id) 294 { 295 struct usb_device *udev = interface_to_usbdev (intf); 296 struct usb_host_interface *interface; 297 struct usb_endpoint_descriptor *endpoint; 298 struct powermate_device *pm; 299 struct input_dev *input_dev; 300 int pipe, maxp; 301 int error = -ENOMEM; 302 303 interface = intf->cur_altsetting; 304 if (interface->desc.bNumEndpoints < 1) 305 return -EINVAL; 306 307 endpoint = &interface->endpoint[0].desc; 308 if (!usb_endpoint_is_int_in(endpoint)) 309 return -EIO; 310 311 usb_control_msg(udev, usb_sndctrlpipe(udev, 0), 312 0x0a, USB_TYPE_CLASS | USB_RECIP_INTERFACE, 313 0, interface->desc.bInterfaceNumber, NULL, 0, 314 USB_CTRL_SET_TIMEOUT); 315 316 pm = kzalloc(sizeof(*pm), GFP_KERNEL); 317 input_dev = input_allocate_device(); 318 if (!pm || !input_dev) 319 goto fail1; 320 321 if (powermate_alloc_buffers(udev, pm)) 322 goto fail2; 323 324 pm->irq = usb_alloc_urb(0, GFP_KERNEL); 325 if (!pm->irq) 326 goto fail2; 327 328 pm->config = usb_alloc_urb(0, GFP_KERNEL); 329 if (!pm->config) 330 goto fail3; 331 332 pm->udev = udev; 333 pm->intf = intf; 334 pm->input = input_dev; 335 336 usb_make_path(udev, pm->phys, sizeof(pm->phys)); 337 strlcat(pm->phys, "/input0", sizeof(pm->phys)); 338 339 spin_lock_init(&pm->lock); 340 341 switch (le16_to_cpu(udev->descriptor.idProduct)) { 342 case POWERMATE_PRODUCT_NEW: 343 input_dev->name = pm_name_powermate; 344 break; 345 case POWERMATE_PRODUCT_OLD: 346 input_dev->name = pm_name_soundknob; 347 break; 348 default: 349 input_dev->name = pm_name_soundknob; 350 printk(KERN_WARNING "powermate: unknown product id %04x\n", 351 le16_to_cpu(udev->descriptor.idProduct)); 352 } 353 354 input_dev->phys = pm->phys; 355 usb_to_input_id(udev, &input_dev->id); 356 input_dev->dev.parent = &intf->dev; 357 358 input_set_drvdata(input_dev, pm); 359 360 input_dev->event = powermate_input_event; 361 362 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REL) | 363 BIT_MASK(EV_MSC); 364 input_dev->keybit[BIT_WORD(BTN_0)] = BIT_MASK(BTN_0); 365 input_dev->relbit[BIT_WORD(REL_DIAL)] = BIT_MASK(REL_DIAL); 366 input_dev->mscbit[BIT_WORD(MSC_PULSELED)] = BIT_MASK(MSC_PULSELED); 367 368 /* get a handle to the interrupt data pipe */ 369 pipe = usb_rcvintpipe(udev, endpoint->bEndpointAddress); 370 maxp = usb_maxpacket(udev, pipe); 371 372 if (maxp < POWERMATE_PAYLOAD_SIZE_MIN || maxp > POWERMATE_PAYLOAD_SIZE_MAX) { 373 printk(KERN_WARNING "powermate: Expected payload of %d--%d bytes, found %d bytes!\n", 374 POWERMATE_PAYLOAD_SIZE_MIN, POWERMATE_PAYLOAD_SIZE_MAX, maxp); 375 maxp = POWERMATE_PAYLOAD_SIZE_MAX; 376 } 377 378 usb_fill_int_urb(pm->irq, udev, pipe, pm->data, 379 maxp, powermate_irq, 380 pm, endpoint->bInterval); 381 pm->irq->transfer_dma = pm->data_dma; 382 pm->irq->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 383 384 /* register our interrupt URB with the USB system */ 385 if (usb_submit_urb(pm->irq, GFP_KERNEL)) { 386 error = -EIO; 387 goto fail4; 388 } 389 390 error = input_register_device(pm->input); 391 if (error) 392 goto fail5; 393 394 395 /* force an update of everything */ 396 pm->requires_update = UPDATE_PULSE_ASLEEP | UPDATE_PULSE_AWAKE | UPDATE_PULSE_MODE | UPDATE_STATIC_BRIGHTNESS; 397 powermate_pulse_led(pm, 0x80, 255, 0, 1, 0); // set default pulse parameters 398 399 usb_set_intfdata(intf, pm); 400 return 0; 401 402 fail5: usb_kill_urb(pm->irq); 403 fail4: usb_free_urb(pm->config); 404 fail3: usb_free_urb(pm->irq); 405 fail2: powermate_free_buffers(udev, pm); 406 fail1: input_free_device(input_dev); 407 kfree(pm); 408 return error; 409 } 410 411 /* Called when a USB device we've accepted ownership of is removed */ 412 static void powermate_disconnect(struct usb_interface *intf) 413 { 414 struct powermate_device *pm = usb_get_intfdata (intf); 415 416 usb_set_intfdata(intf, NULL); 417 if (pm) { 418 pm->requires_update = 0; 419 usb_kill_urb(pm->irq); 420 input_unregister_device(pm->input); 421 usb_kill_urb(pm->config); 422 usb_free_urb(pm->irq); 423 usb_free_urb(pm->config); 424 powermate_free_buffers(interface_to_usbdev(intf), pm); 425 426 kfree(pm); 427 } 428 } 429 430 static const struct usb_device_id powermate_devices[] = { 431 { USB_DEVICE(POWERMATE_VENDOR, POWERMATE_PRODUCT_NEW) }, 432 { USB_DEVICE(POWERMATE_VENDOR, POWERMATE_PRODUCT_OLD) }, 433 { USB_DEVICE(CONTOUR_VENDOR, CONTOUR_JOG) }, 434 { } /* Terminating entry */ 435 }; 436 437 MODULE_DEVICE_TABLE (usb, powermate_devices); 438 439 static struct usb_driver powermate_driver = { 440 .name = "powermate", 441 .probe = powermate_probe, 442 .disconnect = powermate_disconnect, 443 .id_table = powermate_devices, 444 }; 445 446 module_usb_driver(powermate_driver); 447 448 MODULE_AUTHOR( "William R Sowerbutts" ); 449 MODULE_DESCRIPTION( "Griffin Technology, Inc PowerMate driver" ); 450 MODULE_LICENSE("GPL"); 451