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powermate.c
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1 /*
2  * A driver for the Griffin Technology, Inc. "PowerMate" USB controller dial.
3  *
4  * v1.1, (c)2002 William R Sowerbutts <[email protected]>
5  *
6  * This device is a anodised aluminium knob which connects over USB. It can measure
7  * clockwise and anticlockwise rotation. The dial also acts as a pushbutton with
8  * a spring for automatic release. The base contains a pair of LEDs which illuminate
9  * the translucent base. It rotates without limit and reports its relative rotation
10  * back to the host when polled by the USB controller.
11  *
12  * Testing with the knob I have has shown that it measures approximately 94 "clicks"
13  * for one full rotation. Testing with my High Speed Rotation Actuator (ok, it was
14  * a variable speed cordless electric drill) has shown that the device can measure
15  * speeds of up to 7 clicks either clockwise or anticlockwise between pollings from
16  * the host. If it counts more than 7 clicks before it is polled, it will wrap back
17  * to zero and start counting again. This was at quite high speed, however, almost
18  * certainly faster than the human hand could turn it. Griffin say that it loses a
19  * pulse or two on a direction change; the granularity is so fine that I never
20  * noticed this in practice.
21  *
22  * The device's microcontroller can be programmed to set the LED to either a constant
23  * intensity, or to a rhythmic pulsing. Several patterns and speeds are available.
24  *
25  * Griffin were very happy to provide documentation and free hardware for development.
26  *
27  * Some userspace tools are available on the web: http://sowerbutts.com/powermate/
28  *
29  */
30 
31 #include <linux/kernel.h>
32 #include <linux/slab.h>
33 #include <linux/module.h>
34 #include <linux/init.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
63  signed char *data;
65  struct urb *irq, *config;
67  struct usb_device *udev;
69  struct input_dev *input;
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 
130  pm->configcr->wValue = cpu_to_le16( SET_PULSE_ASLEEP );
131  pm->configcr->wIndex = cpu_to_le16( pm->pulse_asleep ? 1 : 0 );
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 );
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 );
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 );
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  unsigned long flags;
198 
199  if (urb->status)
200  printk(KERN_ERR "powermate: config urb returned %d\n", urb->status);
201 
202  spin_lock_irqsave(&pm->lock, flags);
203  powermate_sync_state(pm);
204  spin_unlock_irqrestore(&pm->lock, flags);
205 }
206 
207 /* Set the LED up as described and begin the sync with the hardware if required */
208 static void powermate_pulse_led(struct powermate_device *pm, int static_brightness, int pulse_speed,
209  int pulse_table, int pulse_asleep, int pulse_awake)
210 {
211  unsigned long flags;
212 
213  if (pulse_speed < 0)
214  pulse_speed = 0;
215  if (pulse_table < 0)
216  pulse_table = 0;
217  if (pulse_speed > 510)
218  pulse_speed = 510;
219  if (pulse_table > 2)
220  pulse_table = 2;
221 
222  pulse_asleep = !!pulse_asleep;
223  pulse_awake = !!pulse_awake;
224 
225 
226  spin_lock_irqsave(&pm->lock, flags);
227 
228  /* mark state updates which are required */
229  if (static_brightness != pm->static_brightness) {
232  }
233  if (pulse_asleep != pm->pulse_asleep) {
236  }
237  if (pulse_awake != pm->pulse_awake) {
238  pm->pulse_awake = pulse_awake;
240  }
241  if (pulse_speed != pm->pulse_speed || pulse_table != pm->pulse_table) {
242  pm->pulse_speed = pulse_speed;
243  pm->pulse_table = pulse_table;
245  }
246 
247  powermate_sync_state(pm);
248 
249  spin_unlock_irqrestore(&pm->lock, flags);
250 }
251 
252 /* Callback from the Input layer when an event arrives from userspace to configure the LED */
253 static int powermate_input_event(struct input_dev *dev, unsigned int type, unsigned int code, int _value)
254 {
255  unsigned int command = (unsigned int)_value;
256  struct powermate_device *pm = input_get_drvdata(dev);
257 
258  if (type == EV_MSC && code == MSC_PULSELED){
259  /*
260  bits 0- 7: 8 bits: LED brightness
261  bits 8-16: 9 bits: pulsing speed modifier (0 ... 510); 0-254 = slower, 255 = standard, 256-510 = faster.
262  bits 17-18: 2 bits: pulse table (0, 1, 2 valid)
263  bit 19: 1 bit : pulse whilst asleep?
264  bit 20: 1 bit : pulse constantly?
265  */
266  int static_brightness = command & 0xFF; // bits 0-7
267  int pulse_speed = (command >> 8) & 0x1FF; // bits 8-16
268  int pulse_table = (command >> 17) & 0x3; // bits 17-18
269  int pulse_asleep = (command >> 19) & 0x1; // bit 19
270  int pulse_awake = (command >> 20) & 0x1; // bit 20
271 
272  powermate_pulse_led(pm, static_brightness, pulse_speed, pulse_table, pulse_asleep, pulse_awake);
273  }
274 
275  return 0;
276 }
277 
278 static int powermate_alloc_buffers(struct usb_device *udev, struct powermate_device *pm)
279 {
281  GFP_ATOMIC, &pm->data_dma);
282  if (!pm->data)
283  return -1;
284 
285  pm->configcr = kmalloc(sizeof(*(pm->configcr)), GFP_KERNEL);
286  if (!pm->configcr)
287  return -ENOMEM;
288 
289  return 0;
290 }
291 
292 static void powermate_free_buffers(struct usb_device *udev, struct powermate_device *pm)
293 {
295  pm->data, pm->data_dma);
296  kfree(pm->configcr);
297 }
298 
299 /* Called whenever a USB device matching one in our supported devices table is connected */
300 static int powermate_probe(struct usb_interface *intf, const struct usb_device_id *id)
301 {
302  struct usb_device *udev = interface_to_usbdev (intf);
303  struct usb_host_interface *interface;
305  struct powermate_device *pm;
306  struct input_dev *input_dev;
307  int pipe, maxp;
308  int error = -ENOMEM;
309 
310  interface = intf->cur_altsetting;
311  endpoint = &interface->endpoint[0].desc;
312  if (!usb_endpoint_is_int_in(endpoint))
313  return -EIO;
314 
315  usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
317  0, interface->desc.bInterfaceNumber, NULL, 0,
318  USB_CTRL_SET_TIMEOUT);
319 
320  pm = kzalloc(sizeof(struct powermate_device), GFP_KERNEL);
321  input_dev = input_allocate_device();
322  if (!pm || !input_dev)
323  goto fail1;
324 
325  if (powermate_alloc_buffers(udev, pm))
326  goto fail2;
327 
328  pm->irq = usb_alloc_urb(0, GFP_KERNEL);
329  if (!pm->irq)
330  goto fail2;
331 
332  pm->config = usb_alloc_urb(0, GFP_KERNEL);
333  if (!pm->config)
334  goto fail3;
335 
336  pm->udev = udev;
337  pm->intf = intf;
338  pm->input = input_dev;
339 
340  usb_make_path(udev, pm->phys, sizeof(pm->phys));
341  strlcat(pm->phys, "/input0", sizeof(pm->phys));
342 
343  spin_lock_init(&pm->lock);
344 
345  switch (le16_to_cpu(udev->descriptor.idProduct)) {
347  input_dev->name = pm_name_powermate;
348  break;
350  input_dev->name = pm_name_soundknob;
351  break;
352  default:
353  input_dev->name = pm_name_soundknob;
354  printk(KERN_WARNING "powermate: unknown product id %04x\n",
355  le16_to_cpu(udev->descriptor.idProduct));
356  }
357 
358  input_dev->phys = pm->phys;
359  usb_to_input_id(udev, &input_dev->id);
360  input_dev->dev.parent = &intf->dev;
361 
362  input_set_drvdata(input_dev, pm);
363 
364  input_dev->event = powermate_input_event;
365 
366  input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REL) |
367  BIT_MASK(EV_MSC);
368  input_dev->keybit[BIT_WORD(BTN_0)] = BIT_MASK(BTN_0);
369  input_dev->relbit[BIT_WORD(REL_DIAL)] = BIT_MASK(REL_DIAL);
370  input_dev->mscbit[BIT_WORD(MSC_PULSELED)] = BIT_MASK(MSC_PULSELED);
371 
372  /* get a handle to the interrupt data pipe */
373  pipe = usb_rcvintpipe(udev, endpoint->bEndpointAddress);
374  maxp = usb_maxpacket(udev, pipe, usb_pipeout(pipe));
375 
376  if (maxp < POWERMATE_PAYLOAD_SIZE_MIN || maxp > POWERMATE_PAYLOAD_SIZE_MAX) {
377  printk(KERN_WARNING "powermate: Expected payload of %d--%d bytes, found %d bytes!\n",
378  POWERMATE_PAYLOAD_SIZE_MIN, POWERMATE_PAYLOAD_SIZE_MAX, maxp);
380  }
381 
382  usb_fill_int_urb(pm->irq, udev, pipe, pm->data,
383  maxp, powermate_irq,
384  pm, endpoint->bInterval);
385  pm->irq->transfer_dma = pm->data_dma;
386  pm->irq->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
387 
388  /* register our interrupt URB with the USB system */
389  if (usb_submit_urb(pm->irq, GFP_KERNEL)) {
390  error = -EIO;
391  goto fail4;
392  }
393 
394  error = input_register_device(pm->input);
395  if (error)
396  goto fail5;
397 
398 
399  /* force an update of everything */
401  powermate_pulse_led(pm, 0x80, 255, 0, 1, 0); // set default pulse parameters
402 
403  usb_set_intfdata(intf, pm);
404  return 0;
405 
406  fail5: usb_kill_urb(pm->irq);
407  fail4: usb_free_urb(pm->config);
408  fail3: usb_free_urb(pm->irq);
409  fail2: powermate_free_buffers(udev, pm);
410  fail1: input_free_device(input_dev);
411  kfree(pm);
412  return error;
413 }
414 
415 /* Called when a USB device we've accepted ownership of is removed */
416 static void powermate_disconnect(struct usb_interface *intf)
417 {
418  struct powermate_device *pm = usb_get_intfdata (intf);
419 
420  usb_set_intfdata(intf, NULL);
421  if (pm) {
422  pm->requires_update = 0;
423  usb_kill_urb(pm->irq);
424  input_unregister_device(pm->input);
425  usb_free_urb(pm->irq);
426  usb_free_urb(pm->config);
427  powermate_free_buffers(interface_to_usbdev(intf), pm);
428 
429  kfree(pm);
430  }
431 }
432 
433 static struct usb_device_id powermate_devices [] = {
434  { USB_DEVICE(POWERMATE_VENDOR, POWERMATE_PRODUCT_NEW) },
435  { USB_DEVICE(POWERMATE_VENDOR, POWERMATE_PRODUCT_OLD) },
436  { USB_DEVICE(CONTOUR_VENDOR, CONTOUR_JOG) },
437  { } /* Terminating entry */
438 };
439 
440 MODULE_DEVICE_TABLE (usb, powermate_devices);
441 
442 static struct usb_driver powermate_driver = {
443  .name = "powermate",
444  .probe = powermate_probe,
445  .disconnect = powermate_disconnect,
446  .id_table = powermate_devices,
447 };
448 
449 module_usb_driver(powermate_driver);
450 
451 MODULE_AUTHOR( "William R Sowerbutts" );
452 MODULE_DESCRIPTION( "Griffin Technology, Inc PowerMate driver" );
453 MODULE_LICENSE("GPL");