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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 <will@sowerbutts.com>
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
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 	dma_addr_t configcr_dma;
68 	struct usb_device *udev;
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 */
powermate_irq(struct urb * urb)86 static void powermate_irq(struct urb *urb)
87 {
88 	struct powermate_device *pm = urb->context;
89 	int retval;
90 
91 	switch (urb->status) {
92 	case 0:
93 		/* success */
94 		break;
95 	case -ECONNRESET:
96 	case -ENOENT:
97 	case -ESHUTDOWN:
98 		/* this urb is terminated, clean up */
99 		dbg("%s - urb shutting down with status: %d", __func__, urb->status);
100 		return;
101 	default:
102 		dbg("%s - nonzero urb status received: %d", __func__, urb->status);
103 		goto exit;
104 	}
105 
106 	/* handle updates to device state */
107 	input_report_key(pm->input, BTN_0, pm->data[0] & 0x01);
108 	input_report_rel(pm->input, REL_DIAL, pm->data[1]);
109 	input_sync(pm->input);
110 
111 exit:
112 	retval = usb_submit_urb (urb, GFP_ATOMIC);
113 	if (retval)
114 		err ("%s - usb_submit_urb failed with result %d",
115 		     __func__, retval);
116 }
117 
118 /* Decide if we need to issue a control message and do so. Must be called with pm->lock taken */
powermate_sync_state(struct powermate_device * pm)119 static void powermate_sync_state(struct powermate_device *pm)
120 {
121 	if (pm->requires_update == 0)
122 		return; /* no updates are required */
123 	if (pm->config->status == -EINPROGRESS)
124 		return; /* an update is already in progress; it'll issue this update when it completes */
125 
126 	if (pm->requires_update & UPDATE_PULSE_ASLEEP){
127 		pm->configcr->wValue = cpu_to_le16( SET_PULSE_ASLEEP );
128 		pm->configcr->wIndex = cpu_to_le16( pm->pulse_asleep ? 1 : 0 );
129 		pm->requires_update &= ~UPDATE_PULSE_ASLEEP;
130 	}else if (pm->requires_update & UPDATE_PULSE_AWAKE){
131 		pm->configcr->wValue = cpu_to_le16( SET_PULSE_AWAKE );
132 		pm->configcr->wIndex = cpu_to_le16( pm->pulse_awake ? 1 : 0 );
133 		pm->requires_update &= ~UPDATE_PULSE_AWAKE;
134 	}else if (pm->requires_update & UPDATE_PULSE_MODE){
135 		int op, arg;
136 		/* the powermate takes an operation and an argument for its pulse algorithm.
137 		   the operation can be:
138 		   0: divide the speed
139 		   1: pulse at normal speed
140 		   2: multiply the speed
141 		   the argument only has an effect for operations 0 and 2, and ranges between
142 		   1 (least effect) to 255 (maximum effect).
143 
144 		   thus, several states are equivalent and are coalesced into one state.
145 
146 		   we map this onto a range from 0 to 510, with:
147 		   0 -- 254    -- use divide (0 = slowest)
148 		   255         -- use normal speed
149 		   256 -- 510  -- use multiple (510 = fastest).
150 
151 		   Only values of 'arg' quite close to 255 are particularly useful/spectacular.
152 		*/
153 		if (pm->pulse_speed < 255) {
154 			op = 0;                   // divide
155 			arg = 255 - pm->pulse_speed;
156 		} else if (pm->pulse_speed > 255) {
157 			op = 2;                   // multiply
158 			arg = pm->pulse_speed - 255;
159 		} else {
160 			op = 1;                   // normal speed
161 			arg = 0;                  // can be any value
162 		}
163 		pm->configcr->wValue = cpu_to_le16( (pm->pulse_table << 8) | SET_PULSE_MODE );
164 		pm->configcr->wIndex = cpu_to_le16( (arg << 8) | op );
165 		pm->requires_update &= ~UPDATE_PULSE_MODE;
166 	} else if (pm->requires_update & UPDATE_STATIC_BRIGHTNESS) {
167 		pm->configcr->wValue = cpu_to_le16( SET_STATIC_BRIGHTNESS );
168 		pm->configcr->wIndex = cpu_to_le16( pm->static_brightness );
169 		pm->requires_update &= ~UPDATE_STATIC_BRIGHTNESS;
170 	} else {
171 		printk(KERN_ERR "powermate: unknown update required");
172 		pm->requires_update = 0; /* fudge the bug */
173 		return;
174 	}
175 
176 /*	printk("powermate: %04x %04x\n", pm->configcr->wValue, pm->configcr->wIndex); */
177 
178 	pm->configcr->bRequestType = 0x41; /* vendor request */
179 	pm->configcr->bRequest = 0x01;
180 	pm->configcr->wLength = 0;
181 
182 	usb_fill_control_urb(pm->config, pm->udev, usb_sndctrlpipe(pm->udev, 0),
183 			     (void *) pm->configcr, NULL, 0,
184 			     powermate_config_complete, pm);
185 	pm->config->setup_dma = pm->configcr_dma;
186 	pm->config->transfer_flags |= URB_NO_SETUP_DMA_MAP;
187 
188 	if (usb_submit_urb(pm->config, GFP_ATOMIC))
189 		printk(KERN_ERR "powermate: usb_submit_urb(config) failed");
190 }
191 
192 /* Called when our asynchronous control message completes. We may need to issue another immediately */
powermate_config_complete(struct urb * urb)193 static void powermate_config_complete(struct urb *urb)
194 {
195 	struct powermate_device *pm = urb->context;
196 	unsigned long flags;
197 
198 	if (urb->status)
199 		printk(KERN_ERR "powermate: config urb returned %d\n", urb->status);
200 
201 	spin_lock_irqsave(&pm->lock, flags);
202 	powermate_sync_state(pm);
203 	spin_unlock_irqrestore(&pm->lock, flags);
204 }
205 
206 /* Set the LED up as described and begin the sync with the hardware if required */
powermate_pulse_led(struct powermate_device * pm,int static_brightness,int pulse_speed,int pulse_table,int pulse_asleep,int pulse_awake)207 static void powermate_pulse_led(struct powermate_device *pm, int static_brightness, int pulse_speed,
208 				int pulse_table, int pulse_asleep, int pulse_awake)
209 {
210 	unsigned long flags;
211 
212 	if (pulse_speed < 0)
213 		pulse_speed = 0;
214 	if (pulse_table < 0)
215 		pulse_table = 0;
216 	if (pulse_speed > 510)
217 		pulse_speed = 510;
218 	if (pulse_table > 2)
219 		pulse_table = 2;
220 
221 	pulse_asleep = !!pulse_asleep;
222 	pulse_awake = !!pulse_awake;
223 
224 
225 	spin_lock_irqsave(&pm->lock, flags);
226 
227 	/* mark state updates which are required */
228 	if (static_brightness != pm->static_brightness) {
229 		pm->static_brightness = static_brightness;
230 		pm->requires_update |= UPDATE_STATIC_BRIGHTNESS;
231 	}
232 	if (pulse_asleep != pm->pulse_asleep) {
233 		pm->pulse_asleep = pulse_asleep;
234 		pm->requires_update |= (UPDATE_PULSE_ASLEEP | UPDATE_STATIC_BRIGHTNESS);
235 	}
236 	if (pulse_awake != pm->pulse_awake) {
237 		pm->pulse_awake = pulse_awake;
238 		pm->requires_update |= (UPDATE_PULSE_AWAKE | UPDATE_STATIC_BRIGHTNESS);
239 	}
240 	if (pulse_speed != pm->pulse_speed || pulse_table != pm->pulse_table) {
241 		pm->pulse_speed = pulse_speed;
242 		pm->pulse_table = pulse_table;
243 		pm->requires_update |= UPDATE_PULSE_MODE;
244 	}
245 
246 	powermate_sync_state(pm);
247 
248 	spin_unlock_irqrestore(&pm->lock, flags);
249 }
250 
251 /* Callback from the Input layer when an event arrives from userspace to configure the LED */
powermate_input_event(struct input_dev * dev,unsigned int type,unsigned int code,int _value)252 static int powermate_input_event(struct input_dev *dev, unsigned int type, unsigned int code, int _value)
253 {
254 	unsigned int command = (unsigned int)_value;
255 	struct powermate_device *pm = input_get_drvdata(dev);
256 
257 	if (type == EV_MSC && code == MSC_PULSELED){
258 		/*
259 		    bits  0- 7: 8 bits: LED brightness
260 		    bits  8-16: 9 bits: pulsing speed modifier (0 ... 510); 0-254 = slower, 255 = standard, 256-510 = faster.
261 		    bits 17-18: 2 bits: pulse table (0, 1, 2 valid)
262 		    bit     19: 1 bit : pulse whilst asleep?
263 		    bit     20: 1 bit : pulse constantly?
264 		*/
265 		int static_brightness = command & 0xFF;   // bits 0-7
266 		int pulse_speed = (command >> 8) & 0x1FF; // bits 8-16
267 		int pulse_table = (command >> 17) & 0x3;  // bits 17-18
268 		int pulse_asleep = (command >> 19) & 0x1; // bit 19
269 		int pulse_awake  = (command >> 20) & 0x1; // bit 20
270 
271 		powermate_pulse_led(pm, static_brightness, pulse_speed, pulse_table, pulse_asleep, pulse_awake);
272 	}
273 
274 	return 0;
275 }
276 
powermate_alloc_buffers(struct usb_device * udev,struct powermate_device * pm)277 static int powermate_alloc_buffers(struct usb_device *udev, struct powermate_device *pm)
278 {
279 	pm->data = usb_buffer_alloc(udev, POWERMATE_PAYLOAD_SIZE_MAX,
280 				    GFP_ATOMIC, &pm->data_dma);
281 	if (!pm->data)
282 		return -1;
283 
284 	pm->configcr = usb_buffer_alloc(udev, sizeof(*(pm->configcr)),
285 					GFP_ATOMIC, &pm->configcr_dma);
286 	if (!pm->configcr)
287 		return -1;
288 
289 	return 0;
290 }
291 
powermate_free_buffers(struct usb_device * udev,struct powermate_device * pm)292 static void powermate_free_buffers(struct usb_device *udev, struct powermate_device *pm)
293 {
294 	usb_buffer_free(udev, POWERMATE_PAYLOAD_SIZE_MAX,
295 			pm->data, pm->data_dma);
296 	usb_buffer_free(udev, sizeof(*(pm->configcr)),
297 			pm->configcr, pm->configcr_dma);
298 }
299 
300 /* Called whenever a USB device matching one in our supported devices table is connected */
powermate_probe(struct usb_interface * intf,const struct usb_device_id * id)301 static int powermate_probe(struct usb_interface *intf, const struct usb_device_id *id)
302 {
303 	struct usb_device *udev = interface_to_usbdev (intf);
304 	struct usb_host_interface *interface;
305 	struct usb_endpoint_descriptor *endpoint;
306 	struct powermate_device *pm;
307 	struct input_dev *input_dev;
308 	int pipe, maxp;
309 	int error = -ENOMEM;
310 
311 	interface = intf->cur_altsetting;
312 	endpoint = &interface->endpoint[0].desc;
313 	if (!usb_endpoint_is_int_in(endpoint))
314 		return -EIO;
315 
316 	usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
317 		0x0a, USB_TYPE_CLASS | USB_RECIP_INTERFACE,
318 		0, interface->desc.bInterfaceNumber, NULL, 0,
319 		USB_CTRL_SET_TIMEOUT);
320 
321 	pm = kzalloc(sizeof(struct powermate_device), GFP_KERNEL);
322 	input_dev = input_allocate_device();
323 	if (!pm || !input_dev)
324 		goto fail1;
325 
326 	if (powermate_alloc_buffers(udev, pm))
327 		goto fail2;
328 
329 	pm->irq = usb_alloc_urb(0, GFP_KERNEL);
330 	if (!pm->irq)
331 		goto fail2;
332 
333 	pm->config = usb_alloc_urb(0, GFP_KERNEL);
334 	if (!pm->config)
335 		goto fail3;
336 
337 	pm->udev = udev;
338 	pm->input = input_dev;
339 
340 	usb_make_path(udev, pm->phys, sizeof(pm->phys));
341 	strlcpy(pm->phys, "/input0", sizeof(pm->phys));
342 
343 	spin_lock_init(&pm->lock);
344 
345 	switch (le16_to_cpu(udev->descriptor.idProduct)) {
346 	case POWERMATE_PRODUCT_NEW:
347 		input_dev->name = pm_name_powermate;
348 		break;
349 	case POWERMATE_PRODUCT_OLD:
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);
379 		maxp = POWERMATE_PAYLOAD_SIZE_MAX;
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 */
400 	pm->requires_update = UPDATE_PULSE_ASLEEP | UPDATE_PULSE_AWAKE | UPDATE_PULSE_MODE | UPDATE_STATIC_BRIGHTNESS;
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 */
powermate_disconnect(struct usb_interface * intf)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 
powermate_init(void)449 static int __init powermate_init(void)
450 {
451 	return usb_register(&powermate_driver);
452 }
453 
powermate_cleanup(void)454 static void __exit powermate_cleanup(void)
455 {
456 	usb_deregister(&powermate_driver);
457 }
458 
459 module_init(powermate_init);
460 module_exit(powermate_cleanup);
461 
462 MODULE_AUTHOR( "William R Sowerbutts" );
463 MODULE_DESCRIPTION( "Griffin Technology, Inc PowerMate driver" );
464 MODULE_LICENSE("GPL");
465