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/spinlock.h>
35#include <linux/usb/input.h>
36
37#define POWERMATE_VENDOR	0x077d	/* Griffin Technology, Inc. */
38#define POWERMATE_PRODUCT_NEW	0x0410	/* Griffin PowerMate */
39#define POWERMATE_PRODUCT_OLD	0x04AA	/* Griffin soundKnob */
40
41#define CONTOUR_VENDOR		0x05f3	/* Contour Design, Inc. */
42#define CONTOUR_JOG		0x0240	/* Jog and Shuttle */
43
44/* these are the command codes we send to the device */
45#define SET_STATIC_BRIGHTNESS  0x01
46#define SET_PULSE_ASLEEP       0x02
47#define SET_PULSE_AWAKE        0x03
48#define SET_PULSE_MODE         0x04
49
50/* these refer to bits in the powermate_device's requires_update field. */
51#define UPDATE_STATIC_BRIGHTNESS (1<<0)
52#define UPDATE_PULSE_ASLEEP      (1<<1)
53#define UPDATE_PULSE_AWAKE       (1<<2)
54#define UPDATE_PULSE_MODE        (1<<3)
55
56/* at least two versions of the hardware exist, with differing payload
57   sizes. the first three bytes always contain the "interesting" data in
58   the relevant format. */
59#define POWERMATE_PAYLOAD_SIZE_MAX 6
60#define POWERMATE_PAYLOAD_SIZE_MIN 3
61struct powermate_device {
62	signed char *data;
63	dma_addr_t data_dma;
64	struct urb *irq, *config;
65	struct usb_ctrlrequest *configcr;
66	struct usb_device *udev;
67	struct usb_interface *intf;
68	struct input_dev *input;
69	spinlock_t lock;
70	int static_brightness;
71	int pulse_speed;
72	int pulse_table;
73	int pulse_asleep;
74	int pulse_awake;
75	int requires_update; // physical settings which are out of sync
76	char phys[64];
77};
78
79static char pm_name_powermate[] = "Griffin PowerMate";
80static char pm_name_soundknob[] = "Griffin SoundKnob";
81
82static void powermate_config_complete(struct urb *urb);
83
84/* Callback for data arriving from the PowerMate over the USB interrupt pipe */
85static void powermate_irq(struct urb *urb)
86{
87	struct powermate_device *pm = urb->context;
88	struct device *dev = &pm->intf->dev;
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		dev_dbg(dev, "%s - urb shutting down with status: %d\n",
100			__func__, urb->status);
101		return;
102	default:
103		dev_dbg(dev, "%s - nonzero urb status received: %d\n",
104			__func__, urb->status);
105		goto exit;
106	}
107
108	/* handle updates to device state */
109	input_report_key(pm->input, BTN_0, pm->data[0] & 0x01);
110	input_report_rel(pm->input, REL_DIAL, pm->data[1]);
111	input_sync(pm->input);
112
113exit:
114	retval = usb_submit_urb (urb, GFP_ATOMIC);
115	if (retval)
116		dev_err(dev, "%s - usb_submit_urb failed with result: %d\n",
117			__func__, retval);
118}
119
120/* Decide if we need to issue a control message and do so. Must be called with pm->lock taken */
121static void powermate_sync_state(struct powermate_device *pm)
122{
123	if (pm->requires_update == 0)
124		return; /* no updates are required */
125	if (pm->config->status == -EINPROGRESS)
126		return; /* an update is already in progress; it'll issue this update when it completes */
127
128	if (pm->requires_update & UPDATE_PULSE_ASLEEP){
129		pm->configcr->wValue = cpu_to_le16( SET_PULSE_ASLEEP );
130		pm->configcr->wIndex = cpu_to_le16( pm->pulse_asleep ? 1 : 0 );
131		pm->requires_update &= ~UPDATE_PULSE_ASLEEP;
132	}else if (pm->requires_update & UPDATE_PULSE_AWAKE){
133		pm->configcr->wValue = cpu_to_le16( SET_PULSE_AWAKE );
134		pm->configcr->wIndex = cpu_to_le16( pm->pulse_awake ? 1 : 0 );
135		pm->requires_update &= ~UPDATE_PULSE_AWAKE;
136	}else if (pm->requires_update & UPDATE_PULSE_MODE){
137		int op, arg;
138		/* the powermate takes an operation and an argument for its pulse algorithm.
139		   the operation can be:
140		   0: divide the speed
141		   1: pulse at normal speed
142		   2: multiply the speed
143		   the argument only has an effect for operations 0 and 2, and ranges between
144		   1 (least effect) to 255 (maximum effect).
145
146		   thus, several states are equivalent and are coalesced into one state.
147
148		   we map this onto a range from 0 to 510, with:
149		   0 -- 254    -- use divide (0 = slowest)
150		   255         -- use normal speed
151		   256 -- 510  -- use multiple (510 = fastest).
152
153		   Only values of 'arg' quite close to 255 are particularly useful/spectacular.
154		*/
155		if (pm->pulse_speed < 255) {
156			op = 0;                   // divide
157			arg = 255 - pm->pulse_speed;
158		} else if (pm->pulse_speed > 255) {
159			op = 2;                   // multiply
160			arg = pm->pulse_speed - 255;
161		} else {
162			op = 1;                   // normal speed
163			arg = 0;                  // can be any value
164		}
165		pm->configcr->wValue = cpu_to_le16( (pm->pulse_table << 8) | SET_PULSE_MODE );
166		pm->configcr->wIndex = cpu_to_le16( (arg << 8) | op );
167		pm->requires_update &= ~UPDATE_PULSE_MODE;
168	} else if (pm->requires_update & UPDATE_STATIC_BRIGHTNESS) {
169		pm->configcr->wValue = cpu_to_le16( SET_STATIC_BRIGHTNESS );
170		pm->configcr->wIndex = cpu_to_le16( pm->static_brightness );
171		pm->requires_update &= ~UPDATE_STATIC_BRIGHTNESS;
172	} else {
173		printk(KERN_ERR "powermate: unknown update required");
174		pm->requires_update = 0; /* fudge the bug */
175		return;
176	}
177
178/*	printk("powermate: %04x %04x\n", pm->configcr->wValue, pm->configcr->wIndex); */
179
180	pm->configcr->bRequestType = 0x41; /* vendor request */
181	pm->configcr->bRequest = 0x01;
182	pm->configcr->wLength = 0;
183
184	usb_fill_control_urb(pm->config, pm->udev, usb_sndctrlpipe(pm->udev, 0),
185			     (void *) pm->configcr, NULL, 0,
186			     powermate_config_complete, pm);
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 */
193static 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 */
207static 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 */
252static 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
277static int powermate_alloc_buffers(struct usb_device *udev, struct powermate_device *pm)
278{
279	pm->data = usb_alloc_coherent(udev, POWERMATE_PAYLOAD_SIZE_MAX,
280				      GFP_ATOMIC, &pm->data_dma);
281	if (!pm->data)
282		return -1;
283
284	pm->configcr = kmalloc(sizeof(*(pm->configcr)), GFP_KERNEL);
285	if (!pm->configcr)
286		return -ENOMEM;
287
288	return 0;
289}
290
291static void powermate_free_buffers(struct usb_device *udev, struct powermate_device *pm)
292{
293	usb_free_coherent(udev, POWERMATE_PAYLOAD_SIZE_MAX,
294			  pm->data, pm->data_dma);
295	kfree(pm->configcr);
296}
297
298/* Called whenever a USB device matching one in our supported devices table is connected */
299static int powermate_probe(struct usb_interface *intf, const struct usb_device_id *id)
300{
301	struct usb_device *udev = interface_to_usbdev (intf);
302	struct usb_host_interface *interface;
303	struct usb_endpoint_descriptor *endpoint;
304	struct powermate_device *pm;
305	struct input_dev *input_dev;
306	int pipe, maxp;
307	int error = -ENOMEM;
308
309	interface = intf->cur_altsetting;
310	if (interface->desc.bNumEndpoints < 1)
311		return -EINVAL;
312
313	endpoint = &interface->endpoint[0].desc;
314	if (!usb_endpoint_is_int_in(endpoint))
315		return -EIO;
316
317	usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
318		0x0a, USB_TYPE_CLASS | USB_RECIP_INTERFACE,
319		0, interface->desc.bInterfaceNumber, NULL, 0,
320		USB_CTRL_SET_TIMEOUT);
321
322	pm = kzalloc(sizeof(struct powermate_device), GFP_KERNEL);
323	input_dev = input_allocate_device();
324	if (!pm || !input_dev)
325		goto fail1;
326
327	if (powermate_alloc_buffers(udev, pm))
328		goto fail2;
329
330	pm->irq = usb_alloc_urb(0, GFP_KERNEL);
331	if (!pm->irq)
332		goto fail2;
333
334	pm->config = usb_alloc_urb(0, GFP_KERNEL);
335	if (!pm->config)
336		goto fail3;
337
338	pm->udev = udev;
339	pm->intf = intf;
340	pm->input = input_dev;
341
342	usb_make_path(udev, pm->phys, sizeof(pm->phys));
343	strlcat(pm->phys, "/input0", sizeof(pm->phys));
344
345	spin_lock_init(&pm->lock);
346
347	switch (le16_to_cpu(udev->descriptor.idProduct)) {
348	case POWERMATE_PRODUCT_NEW:
349		input_dev->name = pm_name_powermate;
350		break;
351	case POWERMATE_PRODUCT_OLD:
352		input_dev->name = pm_name_soundknob;
353		break;
354	default:
355		input_dev->name = pm_name_soundknob;
356		printk(KERN_WARNING "powermate: unknown product id %04x\n",
357		       le16_to_cpu(udev->descriptor.idProduct));
358	}
359
360	input_dev->phys = pm->phys;
361	usb_to_input_id(udev, &input_dev->id);
362	input_dev->dev.parent = &intf->dev;
363
364	input_set_drvdata(input_dev, pm);
365
366	input_dev->event = powermate_input_event;
367
368	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REL) |
369		BIT_MASK(EV_MSC);
370	input_dev->keybit[BIT_WORD(BTN_0)] = BIT_MASK(BTN_0);
371	input_dev->relbit[BIT_WORD(REL_DIAL)] = BIT_MASK(REL_DIAL);
372	input_dev->mscbit[BIT_WORD(MSC_PULSELED)] = BIT_MASK(MSC_PULSELED);
373
374	/* get a handle to the interrupt data pipe */
375	pipe = usb_rcvintpipe(udev, endpoint->bEndpointAddress);
376	maxp = usb_maxpacket(udev, pipe, usb_pipeout(pipe));
377
378	if (maxp < POWERMATE_PAYLOAD_SIZE_MIN || maxp > POWERMATE_PAYLOAD_SIZE_MAX) {
379		printk(KERN_WARNING "powermate: Expected payload of %d--%d bytes, found %d bytes!\n",
380			POWERMATE_PAYLOAD_SIZE_MIN, POWERMATE_PAYLOAD_SIZE_MAX, maxp);
381		maxp = POWERMATE_PAYLOAD_SIZE_MAX;
382	}
383
384	usb_fill_int_urb(pm->irq, udev, pipe, pm->data,
385			 maxp, powermate_irq,
386			 pm, endpoint->bInterval);
387	pm->irq->transfer_dma = pm->data_dma;
388	pm->irq->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
389
390	/* register our interrupt URB with the USB system */
391	if (usb_submit_urb(pm->irq, GFP_KERNEL)) {
392		error = -EIO;
393		goto fail4;
394	}
395
396	error = input_register_device(pm->input);
397	if (error)
398		goto fail5;
399
400
401	/* force an update of everything */
402	pm->requires_update = UPDATE_PULSE_ASLEEP | UPDATE_PULSE_AWAKE | UPDATE_PULSE_MODE | UPDATE_STATIC_BRIGHTNESS;
403	powermate_pulse_led(pm, 0x80, 255, 0, 1, 0); // set default pulse parameters
404
405	usb_set_intfdata(intf, pm);
406	return 0;
407
408 fail5:	usb_kill_urb(pm->irq);
409 fail4:	usb_free_urb(pm->config);
410 fail3:	usb_free_urb(pm->irq);
411 fail2:	powermate_free_buffers(udev, pm);
412 fail1:	input_free_device(input_dev);
413	kfree(pm);
414	return error;
415}
416
417/* Called when a USB device we've accepted ownership of is removed */
418static void powermate_disconnect(struct usb_interface *intf)
419{
420	struct powermate_device *pm = usb_get_intfdata (intf);
421
422	usb_set_intfdata(intf, NULL);
423	if (pm) {
424		pm->requires_update = 0;
425		usb_kill_urb(pm->irq);
426		input_unregister_device(pm->input);
427		usb_free_urb(pm->irq);
428		usb_free_urb(pm->config);
429		powermate_free_buffers(interface_to_usbdev(intf), pm);
430
431		kfree(pm);
432	}
433}
434
435static struct usb_device_id powermate_devices [] = {
436	{ USB_DEVICE(POWERMATE_VENDOR, POWERMATE_PRODUCT_NEW) },
437	{ USB_DEVICE(POWERMATE_VENDOR, POWERMATE_PRODUCT_OLD) },
438	{ USB_DEVICE(CONTOUR_VENDOR, CONTOUR_JOG) },
439	{ } /* Terminating entry */
440};
441
442MODULE_DEVICE_TABLE (usb, powermate_devices);
443
444static struct usb_driver powermate_driver = {
445        .name =         "powermate",
446        .probe =        powermate_probe,
447        .disconnect =   powermate_disconnect,
448        .id_table =     powermate_devices,
449};
450
451module_usb_driver(powermate_driver);
452
453MODULE_AUTHOR( "William R Sowerbutts" );
454MODULE_DESCRIPTION( "Griffin Technology, Inc PowerMate driver" );
455MODULE_LICENSE("GPL");
456