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
62struct 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
80static char pm_name_powermate[] = "Griffin PowerMate";
81static char pm_name_soundknob[] = "Griffin SoundKnob";
82
83static void powermate_config_complete(struct urb *urb);
84
85/* Callback for data arriving from the PowerMate over the USB interrupt pipe */
86static 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(dev: pm->input, BTN_0, value: pm->data[0] & 0x01);
111 input_report_rel(dev: pm->input, REL_DIAL, value: pm->data[1]);
112 input_sync(dev: pm->input);
113
114exit:
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 */
122static 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(urb: pm->config, dev: pm->udev, usb_sndctrlpipe(pm->udev, 0),
186 setup_packet: (void *) pm->configcr, NULL, buffer_length: 0,
187 complete_fn: powermate_config_complete, context: pm);
188
189 if (usb_submit_urb(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 */
194static 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(lock: &pm->lock, flags);
205}
206
207/* Set the LED up as described and begin the sync with the hardware if required */
208static 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) {
230 pm->static_brightness = static_brightness;
231 pm->requires_update |= UPDATE_STATIC_BRIGHTNESS;
232 }
233 if (pulse_asleep != pm->pulse_asleep) {
234 pm->pulse_asleep = pulse_asleep;
235 pm->requires_update |= (UPDATE_PULSE_ASLEEP | UPDATE_STATIC_BRIGHTNESS);
236 }
237 if (pulse_awake != pm->pulse_awake) {
238 pm->pulse_awake = pulse_awake;
239 pm->requires_update |= (UPDATE_PULSE_AWAKE | UPDATE_STATIC_BRIGHTNESS);
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;
244 pm->requires_update |= UPDATE_PULSE_MODE;
245 }
246
247 powermate_sync_state(pm);
248
249 spin_unlock_irqrestore(lock: &pm->lock, flags);
250}
251
252/* Callback from the Input layer when an event arrives from userspace to configure the LED */
253static 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
278static int powermate_alloc_buffers(struct usb_device *udev, struct powermate_device *pm)
279{
280 pm->data = usb_alloc_coherent(dev: udev, POWERMATE_PAYLOAD_SIZE_MAX,
281 GFP_KERNEL, dma: &pm->data_dma);
282 if (!pm->data)
283 return -1;
284
285 pm->configcr = kmalloc(size: sizeof(*(pm->configcr)), GFP_KERNEL);
286 if (!pm->configcr)
287 return -ENOMEM;
288
289 return 0;
290}
291
292static void powermate_free_buffers(struct usb_device *udev, struct powermate_device *pm)
293{
294 usb_free_coherent(dev: udev, POWERMATE_PAYLOAD_SIZE_MAX,
295 addr: pm->data, dma: pm->data_dma);
296 kfree(objp: pm->configcr);
297}
298
299/* Called whenever a USB device matching one in our supported devices table is connected */
300static 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;
304 struct usb_endpoint_descriptor *endpoint;
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 if (interface->desc.bNumEndpoints < 1)
312 return -EINVAL;
313
314 endpoint = &interface->endpoint[0].desc;
315 if (!usb_endpoint_is_int_in(epd: endpoint))
316 return -EIO;
317
318 usb_control_msg(dev: udev, usb_sndctrlpipe(udev, 0),
319 request: 0x0a, USB_TYPE_CLASS | USB_RECIP_INTERFACE,
320 value: 0, index: interface->desc.bInterfaceNumber, NULL, size: 0,
321 USB_CTRL_SET_TIMEOUT);
322
323 pm = kzalloc(size: sizeof(struct powermate_device), GFP_KERNEL);
324 input_dev = input_allocate_device();
325 if (!pm || !input_dev)
326 goto fail1;
327
328 if (powermate_alloc_buffers(udev, pm))
329 goto fail2;
330
331 pm->irq = usb_alloc_urb(iso_packets: 0, GFP_KERNEL);
332 if (!pm->irq)
333 goto fail2;
334
335 pm->config = usb_alloc_urb(iso_packets: 0, GFP_KERNEL);
336 if (!pm->config)
337 goto fail3;
338
339 pm->udev = udev;
340 pm->intf = intf;
341 pm->input = input_dev;
342
343 usb_make_path(dev: udev, buf: pm->phys, size: sizeof(pm->phys));
344 strlcat(p: pm->phys, q: "/input0", avail: sizeof(pm->phys));
345
346 spin_lock_init(&pm->lock);
347
348 switch (le16_to_cpu(udev->descriptor.idProduct)) {
349 case POWERMATE_PRODUCT_NEW:
350 input_dev->name = pm_name_powermate;
351 break;
352 case POWERMATE_PRODUCT_OLD:
353 input_dev->name = pm_name_soundknob;
354 break;
355 default:
356 input_dev->name = pm_name_soundknob;
357 printk(KERN_WARNING "powermate: unknown product id %04x\n",
358 le16_to_cpu(udev->descriptor.idProduct));
359 }
360
361 input_dev->phys = pm->phys;
362 usb_to_input_id(dev: udev, id: &input_dev->id);
363 input_dev->dev.parent = &intf->dev;
364
365 input_set_drvdata(dev: input_dev, data: pm);
366
367 input_dev->event = powermate_input_event;
368
369 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REL) |
370 BIT_MASK(EV_MSC);
371 input_dev->keybit[BIT_WORD(BTN_0)] = BIT_MASK(BTN_0);
372 input_dev->relbit[BIT_WORD(REL_DIAL)] = BIT_MASK(REL_DIAL);
373 input_dev->mscbit[BIT_WORD(MSC_PULSELED)] = BIT_MASK(MSC_PULSELED);
374
375 /* get a handle to the interrupt data pipe */
376 pipe = usb_rcvintpipe(udev, endpoint->bEndpointAddress);
377 maxp = usb_maxpacket(udev, pipe);
378
379 if (maxp < POWERMATE_PAYLOAD_SIZE_MIN || maxp > POWERMATE_PAYLOAD_SIZE_MAX) {
380 printk(KERN_WARNING "powermate: Expected payload of %d--%d bytes, found %d bytes!\n",
381 POWERMATE_PAYLOAD_SIZE_MIN, POWERMATE_PAYLOAD_SIZE_MAX, maxp);
382 maxp = POWERMATE_PAYLOAD_SIZE_MAX;
383 }
384
385 usb_fill_int_urb(urb: pm->irq, dev: udev, pipe, transfer_buffer: pm->data,
386 buffer_length: maxp, complete_fn: powermate_irq,
387 context: pm, interval: endpoint->bInterval);
388 pm->irq->transfer_dma = pm->data_dma;
389 pm->irq->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
390
391 /* register our interrupt URB with the USB system */
392 if (usb_submit_urb(urb: pm->irq, GFP_KERNEL)) {
393 error = -EIO;
394 goto fail4;
395 }
396
397 error = input_register_device(pm->input);
398 if (error)
399 goto fail5;
400
401
402 /* force an update of everything */
403 pm->requires_update = UPDATE_PULSE_ASLEEP | UPDATE_PULSE_AWAKE | UPDATE_PULSE_MODE | UPDATE_STATIC_BRIGHTNESS;
404 powermate_pulse_led(pm, static_brightness: 0x80, pulse_speed: 255, pulse_table: 0, pulse_asleep: 1, pulse_awake: 0); // set default pulse parameters
405
406 usb_set_intfdata(intf, data: pm);
407 return 0;
408
409 fail5: usb_kill_urb(urb: pm->irq);
410 fail4: usb_free_urb(urb: pm->config);
411 fail3: usb_free_urb(urb: pm->irq);
412 fail2: powermate_free_buffers(udev, pm);
413 fail1: input_free_device(dev: input_dev);
414 kfree(objp: pm);
415 return error;
416}
417
418/* Called when a USB device we've accepted ownership of is removed */
419static void powermate_disconnect(struct usb_interface *intf)
420{
421 struct powermate_device *pm = usb_get_intfdata (intf);
422
423 usb_set_intfdata(intf, NULL);
424 if (pm) {
425 pm->requires_update = 0;
426 usb_kill_urb(urb: pm->irq);
427 input_unregister_device(pm->input);
428 usb_kill_urb(urb: pm->config);
429 usb_free_urb(urb: pm->irq);
430 usb_free_urb(urb: pm->config);
431 powermate_free_buffers(interface_to_usbdev(intf), pm);
432
433 kfree(objp: pm);
434 }
435}
436
437static const struct usb_device_id powermate_devices[] = {
438 { USB_DEVICE(POWERMATE_VENDOR, POWERMATE_PRODUCT_NEW) },
439 { USB_DEVICE(POWERMATE_VENDOR, POWERMATE_PRODUCT_OLD) },
440 { USB_DEVICE(CONTOUR_VENDOR, CONTOUR_JOG) },
441 { } /* Terminating entry */
442};
443
444MODULE_DEVICE_TABLE (usb, powermate_devices);
445
446static struct usb_driver powermate_driver = {
447 .name = "powermate",
448 .probe = powermate_probe,
449 .disconnect = powermate_disconnect,
450 .id_table = powermate_devices,
451};
452
453module_usb_driver(powermate_driver);
454
455MODULE_AUTHOR( "William R Sowerbutts" );
456MODULE_DESCRIPTION( "Griffin Technology, Inc PowerMate driver" );
457MODULE_LICENSE("GPL");
458

source code of linux/drivers/input/misc/powermate.c