drivers/input/misc/powermate.c - kernel/msm-4.9 - Gitiles

 /*
  * A driver for the Griffin Technology, Inc. "PowerMate" USB controller dial.
  *
  * v1.1, (c)2002 William R Sowerbutts <will@sowerbutts.com>
  *
  * This device is a anodised aluminium knob which connects over USB. It can measure
  * clockwise and anticlockwise rotation. The dial also acts as a pushbutton with
  * a spring for automatic release. The base contains a pair of LEDs which illuminate
  * the translucent base. It rotates without limit and reports its relative rotation
  * back to the host when polled by the USB controller.
  *
  * Testing with the knob I have has shown that it measures approximately 94 "clicks"
  * for one full rotation. Testing with my High Speed Rotation Actuator (ok, it was
  * a variable speed cordless electric drill) has shown that the device can measure
  * speeds of up to 7 clicks either clockwise or anticlockwise between pollings from
  * the host. If it counts more than 7 clicks before it is polled, it will wrap back
  * to zero and start counting again. This was at quite high speed, however, almost
  * certainly faster than the human hand could turn it. Griffin say that it loses a
  * pulse or two on a direction change; the granularity is so fine that I never
  * noticed this in practice.
  *
  * The device's microcontroller can be programmed to set the LED to either a constant
  * intensity, or to a rhythmic pulsing. Several patterns and speeds are available.
  *
  * Griffin were very happy to provide documentation and free hardware for development.
  *
  * Some userspace tools are available on the web: http://sowerbutts.com/powermate/
  *
  */

 #include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/spinlock.h>
 #include <linux/usb/input.h>

 #define POWERMATE_VENDOR	0x077d	/* Griffin Technology, Inc. */
 #define POWERMATE_PRODUCT_NEW	0x0410	/* Griffin PowerMate */
 #define POWERMATE_PRODUCT_OLD	0x04AA	/* Griffin soundKnob */

 #define CONTOUR_VENDOR		0x05f3	/* Contour Design, Inc. */
 #define CONTOUR_JOG		0x0240	/* Jog and Shuttle */

 /* these are the command codes we send to the device */
 #define SET_STATIC_BRIGHTNESS  0x01
 #define SET_PULSE_ASLEEP       0x02
 #define SET_PULSE_AWAKE        0x03
 #define SET_PULSE_MODE         0x04

 /* these refer to bits in the powermate_device's requires_update field. */
 #define UPDATE_STATIC_BRIGHTNESS (1<<0)
 #define UPDATE_PULSE_ASLEEP      (1<<1)
 #define UPDATE_PULSE_AWAKE       (1<<2)
 #define UPDATE_PULSE_MODE        (1<<3)

 /* at least two versions of the hardware exist, with differing payload
    sizes. the first three bytes always contain the "interesting" data in
    the relevant format. */
 #define POWERMATE_PAYLOAD_SIZE_MAX 6
 #define POWERMATE_PAYLOAD_SIZE_MIN 3
 struct powermate_device {
 	signed char *data;
 	dma_addr_t data_dma;
 	struct urb *irq, *config;
 	struct usb_ctrlrequest *configcr;
 	struct usb_device *udev;
 	struct usb_interface *intf;
 	struct input_dev *input;
 	spinlock_t lock;
 	int static_brightness;
 	int pulse_speed;
 	int pulse_table;
 	int pulse_asleep;
 	int pulse_awake;
 	int requires_update; // physical settings which are out of sync
 	char phys[64];
 };

 static char pm_name_powermate[] = "Griffin PowerMate";
 static char pm_name_soundknob[] = "Griffin SoundKnob";

 static void powermate_config_complete(struct urb *urb);

 /* Callback for data arriving from the PowerMate over the USB interrupt pipe */
 static void powermate_irq(struct urb *urb)
 {
 	struct powermate_device *pm = urb->context;
 	struct device *dev = &pm->intf->dev;
 	int retval;

 	switch (urb->status) {
 	case 0:
 		/* success */
 		break;
 	case -ECONNRESET:
 	case -ENOENT:
 	case -ESHUTDOWN:
 		/* this urb is terminated, clean up */
 		dev_dbg(dev, "%s - urb shutting down with status: %d\n",
 			__func__, urb->status);
 		return;
 	default:
 		dev_dbg(dev, "%s - nonzero urb status received: %d\n",
 			__func__, urb->status);
 		goto exit;
 	}

 	/* handle updates to device state */
 	input_report_key(pm->input, BTN_0, pm->data[0] & 0x01);
 	input_report_rel(pm->input, REL_DIAL, pm->data[1]);
 	input_sync(pm->input);

 exit:
 	retval = usb_submit_urb (urb, GFP_ATOMIC);
 	if (retval)
 		dev_err(dev, "%s - usb_submit_urb failed with result: %d\n",
 			__func__, retval);
 }

 /* Decide if we need to issue a control message and do so. Must be called with pm->lock taken */
 static void powermate_sync_state(struct powermate_device *pm)
 {
 	if (pm->requires_update == 0)
 		return; /* no updates are required */
 	if (pm->config->status == -EINPROGRESS)
 		return; /* an update is already in progress; it'll issue this update when it completes */

 	if (pm->requires_update & UPDATE_PULSE_ASLEEP){
 		pm->configcr->wValue = cpu_to_le16( SET_PULSE_ASLEEP );
 		pm->configcr->wIndex = cpu_to_le16( pm->pulse_asleep ? 1 : 0 );
 		pm->requires_update &= ~UPDATE_PULSE_ASLEEP;
 	}else if (pm->requires_update & UPDATE_PULSE_AWAKE){
 		pm->configcr->wValue = cpu_to_le16( SET_PULSE_AWAKE );
 		pm->configcr->wIndex = cpu_to_le16( pm->pulse_awake ? 1 : 0 );
 		pm->requires_update &= ~UPDATE_PULSE_AWAKE;
 	}else if (pm->requires_update & UPDATE_PULSE_MODE){
 		int op, arg;
 		/* the powermate takes an operation and an argument for its pulse algorithm.
 		   the operation can be:
 		   0: divide the speed
 		   1: pulse at normal speed
 		   2: multiply the speed
 		   the argument only has an effect for operations 0 and 2, and ranges between
 		   1 (least effect) to 255 (maximum effect).

 		   thus, several states are equivalent and are coalesced into one state.

 		   we map this onto a range from 0 to 510, with:
 		   0 -- 254    -- use divide (0 = slowest)
 		   255         -- use normal speed
 		   256 -- 510  -- use multiple (510 = fastest).

 		   Only values of 'arg' quite close to 255 are particularly useful/spectacular.
 		*/
 		if (pm->pulse_speed < 255) {
 			op = 0;                   // divide
 			arg = 255 - pm->pulse_speed;
 		} else if (pm->pulse_speed > 255) {
 			op = 2;                   // multiply
 			arg = pm->pulse_speed - 255;
 		} else {
 			op = 1;                   // normal speed
 			arg = 0;                  // can be any value
 		}
 		pm->configcr->wValue = cpu_to_le16( (pm->pulse_table << 8) | SET_PULSE_MODE );
 		pm->configcr->wIndex = cpu_to_le16( (arg << 8) | op );
 		pm->requires_update &= ~UPDATE_PULSE_MODE;
 	} else if (pm->requires_update & UPDATE_STATIC_BRIGHTNESS) {
 		pm->configcr->wValue = cpu_to_le16( SET_STATIC_BRIGHTNESS );
 		pm->configcr->wIndex = cpu_to_le16( pm->static_brightness );
 		pm->requires_update &= ~UPDATE_STATIC_BRIGHTNESS;
 	} else {
 		printk(KERN_ERR "powermate: unknown update required");
 		pm->requires_update = 0; /* fudge the bug */
 		return;
 	}

 /*	printk("powermate: %04x %04x\n", pm->configcr->wValue, pm->configcr->wIndex); */

 	pm->configcr->bRequestType = 0x41; /* vendor request */
 	pm->configcr->bRequest = 0x01;
 	pm->configcr->wLength = 0;

 	usb_fill_control_urb(pm->config, pm->udev, usb_sndctrlpipe(pm->udev, 0),
 			     (void *) pm->configcr, NULL, 0,
 			     powermate_config_complete, pm);

 	if (usb_submit_urb(pm->config, GFP_ATOMIC))
 		printk(KERN_ERR "powermate: usb_submit_urb(config) failed");
 }

 /* Called when our asynchronous control message completes. We may need to issue another immediately */
 static void powermate_config_complete(struct urb *urb)
 {
 	struct powermate_device *pm = urb->context;
 	unsigned long flags;

 	if (urb->status)
 		printk(KERN_ERR "powermate: config urb returned %d\n", urb->status);

 	spin_lock_irqsave(&pm->lock, flags);
 	powermate_sync_state(pm);
 	spin_unlock_irqrestore(&pm->lock, flags);
 }

 /* Set the LED up as described and begin the sync with the hardware if required */
 static void powermate_pulse_led(struct powermate_device *pm, int static_brightness, int pulse_speed,
 				int pulse_table, int pulse_asleep, int pulse_awake)
 {
 	unsigned long flags;

 	if (pulse_speed < 0)
 		pulse_speed = 0;
 	if (pulse_table < 0)
 		pulse_table = 0;
 	if (pulse_speed > 510)
 		pulse_speed = 510;
 	if (pulse_table > 2)
 		pulse_table = 2;

 	pulse_asleep = !!pulse_asleep;
 	pulse_awake = !!pulse_awake;


 	spin_lock_irqsave(&pm->lock, flags);

 	/* mark state updates which are required */
 	if (static_brightness != pm->static_brightness) {
 		pm->static_brightness = static_brightness;
 		pm->requires_update |= UPDATE_STATIC_BRIGHTNESS;
 	}
 	if (pulse_asleep != pm->pulse_asleep) {
 		pm->pulse_asleep = pulse_asleep;
 		pm->requires_update |= (UPDATE_PULSE_ASLEEP | UPDATE_STATIC_BRIGHTNESS);
 	}
 	if (pulse_awake != pm->pulse_awake) {
 		pm->pulse_awake = pulse_awake;
 		pm->requires_update |= (UPDATE_PULSE_AWAKE | UPDATE_STATIC_BRIGHTNESS);
 	}
 	if (pulse_speed != pm->pulse_speed || pulse_table != pm->pulse_table) {
 		pm->pulse_speed = pulse_speed;
 		pm->pulse_table = pulse_table;
 		pm->requires_update |= UPDATE_PULSE_MODE;
 	}

 	powermate_sync_state(pm);

 	spin_unlock_irqrestore(&pm->lock, flags);
 }

 /* Callback from the Input layer when an event arrives from userspace to configure the LED */
 static int powermate_input_event(struct input_dev *dev, unsigned int type, unsigned int code, int _value)
 {
 	unsigned int command = (unsigned int)_value;
 	struct powermate_device *pm = input_get_drvdata(dev);

 	if (type == EV_MSC && code == MSC_PULSELED){
 		/*
 		    bits  0- 7: 8 bits: LED brightness
 		    bits  8-16: 9 bits: pulsing speed modifier (0 ... 510); 0-254 = slower, 255 = standard, 256-510 = faster.
 		    bits 17-18: 2 bits: pulse table (0, 1, 2 valid)
 		    bit     19: 1 bit : pulse whilst asleep?
 		    bit     20: 1 bit : pulse constantly?
 		*/
 		int static_brightness = command & 0xFF;   // bits 0-7
 		int pulse_speed = (command >> 8) & 0x1FF; // bits 8-16
 		int pulse_table = (command >> 17) & 0x3;  // bits 17-18
 		int pulse_asleep = (command >> 19) & 0x1; // bit 19
 		int pulse_awake  = (command >> 20) & 0x1; // bit 20

 		powermate_pulse_led(pm, static_brightness, pulse_speed, pulse_table, pulse_asleep, pulse_awake);
 	}

 	return 0;
 }

 static int powermate_alloc_buffers(struct usb_device *udev, struct powermate_device *pm)
 {
 	pm->data = usb_alloc_coherent(udev, POWERMATE_PAYLOAD_SIZE_MAX,
 				      GFP_ATOMIC, &pm->data_dma);
 	if (!pm->data)
 		return -1;

 	pm->configcr = kmalloc(sizeof(*(pm->configcr)), GFP_KERNEL);
 	if (!pm->configcr)
 		return -ENOMEM;

 	return 0;
 }

 static void powermate_free_buffers(struct usb_device *udev, struct powermate_device *pm)
 {
 	usb_free_coherent(udev, POWERMATE_PAYLOAD_SIZE_MAX,
 			  pm->data, pm->data_dma);
 	kfree(pm->configcr);
 }

 /* Called whenever a USB device matching one in our supported devices table is connected */
 static int powermate_probe(struct usb_interface *intf, const struct usb_device_id *id)
 {
 	struct usb_device *udev = interface_to_usbdev (intf);
 	struct usb_host_interface *interface;
 	struct usb_endpoint_descriptor *endpoint;
 	struct powermate_device *pm;
 	struct input_dev *input_dev;
 	int pipe, maxp;
 	int error = -ENOMEM;

 	interface = intf->cur_altsetting;
 	endpoint = &interface->endpoint[0].desc;
 	if (!usb_endpoint_is_int_in(endpoint))
 		return -EIO;

 	usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
 		0x0a, USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 		0, interface->desc.bInterfaceNumber, NULL, 0,
 		USB_CTRL_SET_TIMEOUT);

 	pm = kzalloc(sizeof(struct powermate_device), GFP_KERNEL);
 	input_dev = input_allocate_device();
 	if (!pm || !input_dev)
 		goto fail1;

 	if (powermate_alloc_buffers(udev, pm))
 		goto fail2;

 	pm->irq = usb_alloc_urb(0, GFP_KERNEL);
 	if (!pm->irq)
 		goto fail2;

 	pm->config = usb_alloc_urb(0, GFP_KERNEL);
 	if (!pm->config)
 		goto fail3;

 	pm->udev = udev;
 	pm->intf = intf;
 	pm->input = input_dev;

 	usb_make_path(udev, pm->phys, sizeof(pm->phys));
 	strlcat(pm->phys, "/input0", sizeof(pm->phys));

 	spin_lock_init(&pm->lock);

 	switch (le16_to_cpu(udev->descriptor.idProduct)) {
 	case POWERMATE_PRODUCT_NEW:
 		input_dev->name = pm_name_powermate;
 		break;
 	case POWERMATE_PRODUCT_OLD:
 		input_dev->name = pm_name_soundknob;
 		break;
 	default:
 		input_dev->name = pm_name_soundknob;
 		printk(KERN_WARNING "powermate: unknown product id %04x\n",
 		       le16_to_cpu(udev->descriptor.idProduct));
 	}

 	input_dev->phys = pm->phys;
 	usb_to_input_id(udev, &input_dev->id);
 	input_dev->dev.parent = &intf->dev;

 	input_set_drvdata(input_dev, pm);

 	input_dev->event = powermate_input_event;

 	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REL) |
 		BIT_MASK(EV_MSC);
 	input_dev->keybit[BIT_WORD(BTN_0)] = BIT_MASK(BTN_0);
 	input_dev->relbit[BIT_WORD(REL_DIAL)] = BIT_MASK(REL_DIAL);
 	input_dev->mscbit[BIT_WORD(MSC_PULSELED)] = BIT_MASK(MSC_PULSELED);

 	/* get a handle to the interrupt data pipe */
 	pipe = usb_rcvintpipe(udev, endpoint->bEndpointAddress);
 	maxp = usb_maxpacket(udev, pipe, usb_pipeout(pipe));

 	if (maxp < POWERMATE_PAYLOAD_SIZE_MIN || maxp > POWERMATE_PAYLOAD_SIZE_MAX) {
 		printk(KERN_WARNING "powermate: Expected payload of %d--%d bytes, found %d bytes!\n",
 			POWERMATE_PAYLOAD_SIZE_MIN, POWERMATE_PAYLOAD_SIZE_MAX, maxp);
 		maxp = POWERMATE_PAYLOAD_SIZE_MAX;
 	}

 	usb_fill_int_urb(pm->irq, udev, pipe, pm->data,
 			 maxp, powermate_irq,
 			 pm, endpoint->bInterval);
 	pm->irq->transfer_dma = pm->data_dma;
 	pm->irq->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;

 	/* register our interrupt URB with the USB system */
 	if (usb_submit_urb(pm->irq, GFP_KERNEL)) {
 		error = -EIO;
 		goto fail4;
 	}

 	error = input_register_device(pm->input);
 	if (error)
 		goto fail5;


 	/* force an update of everything */
 	pm->requires_update = UPDATE_PULSE_ASLEEP | UPDATE_PULSE_AWAKE | UPDATE_PULSE_MODE | UPDATE_STATIC_BRIGHTNESS;
 	powermate_pulse_led(pm, 0x80, 255, 0, 1, 0); // set default pulse parameters

 	usb_set_intfdata(intf, pm);
 	return 0;

  fail5:	usb_kill_urb(pm->irq);
  fail4:	usb_free_urb(pm->config);
  fail3:	usb_free_urb(pm->irq);
  fail2:	powermate_free_buffers(udev, pm);
  fail1:	input_free_device(input_dev);
 	kfree(pm);
 	return error;
 }

 /* Called when a USB device we've accepted ownership of is removed */
 static void powermate_disconnect(struct usb_interface *intf)
 {
 	struct powermate_device *pm = usb_get_intfdata (intf);

 	usb_set_intfdata(intf, NULL);
 	if (pm) {
 		pm->requires_update = 0;
 		usb_kill_urb(pm->irq);
 		input_unregister_device(pm->input);
 		usb_free_urb(pm->irq);
 		usb_free_urb(pm->config);
 		powermate_free_buffers(interface_to_usbdev(intf), pm);

 		kfree(pm);
 	}
 }

 static struct usb_device_id powermate_devices [] = {
 	{ USB_DEVICE(POWERMATE_VENDOR, POWERMATE_PRODUCT_NEW) },
 	{ USB_DEVICE(POWERMATE_VENDOR, POWERMATE_PRODUCT_OLD) },
 	{ USB_DEVICE(CONTOUR_VENDOR, CONTOUR_JOG) },
 	{ } /* Terminating entry */
 };

 MODULE_DEVICE_TABLE (usb, powermate_devices);

 static struct usb_driver powermate_driver = {
         .name =         "powermate",
         .probe =        powermate_probe,
         .disconnect =   powermate_disconnect,
         .id_table =     powermate_devices,
 };

 module_usb_driver(powermate_driver);

 MODULE_AUTHOR( "William R Sowerbutts" );
 MODULE_DESCRIPTION( "Griffin Technology, Inc PowerMate driver" );
 MODULE_LICENSE("GPL");
	/*
	* A driver for the Griffin Technology, Inc. "PowerMate" USB controller dial.
	*
	* v1.1, (c)2002 William R Sowerbutts <will@sowerbutts.com>
	*
	* This device is a anodised aluminium knob which connects over USB. It can measure
	* clockwise and anticlockwise rotation. The dial also acts as a pushbutton with
	* a spring for automatic release. The base contains a pair of LEDs which illuminate
	* the translucent base. It rotates without limit and reports its relative rotation
	* back to the host when polled by the USB controller.
	*
	* Testing with the knob I have has shown that it measures approximately 94 "clicks"
	* for one full rotation. Testing with my High Speed Rotation Actuator (ok, it was
	* a variable speed cordless electric drill) has shown that the device can measure
	* speeds of up to 7 clicks either clockwise or anticlockwise between pollings from
	* the host. If it counts more than 7 clicks before it is polled, it will wrap back
	* to zero and start counting again. This was at quite high speed, however, almost
	* certainly faster than the human hand could turn it. Griffin say that it loses a
	* pulse or two on a direction change; the granularity is so fine that I never
	* noticed this in practice.
	*
	* The device's microcontroller can be programmed to set the LED to either a constant
	* intensity, or to a rhythmic pulsing. Several patterns and speeds are available.
	*
	* Griffin were very happy to provide documentation and free hardware for development.
	*
	* Some userspace tools are available on the web: http://sowerbutts.com/powermate/
	*
	*/

	#include <linux/kernel.h>
	#include <linux/slab.h>
	#include <linux/module.h>
	#include <linux/spinlock.h>
	#include <linux/usb/input.h>

	#define POWERMATE_VENDOR 0x077d /* Griffin Technology, Inc. */
	#define POWERMATE_PRODUCT_NEW 0x0410 /* Griffin PowerMate */
	#define POWERMATE_PRODUCT_OLD 0x04AA /* Griffin soundKnob */

	#define CONTOUR_VENDOR 0x05f3 /* Contour Design, Inc. */
	#define CONTOUR_JOG 0x0240 /* Jog and Shuttle */

	/* these are the command codes we send to the device */
	#define SET_STATIC_BRIGHTNESS 0x01
	#define SET_PULSE_ASLEEP 0x02
	#define SET_PULSE_AWAKE 0x03
	#define SET_PULSE_MODE 0x04

	/* these refer to bits in the powermate_device's requires_update field. */
	#define UPDATE_STATIC_BRIGHTNESS (1<<0)
	#define UPDATE_PULSE_ASLEEP (1<<1)
	#define UPDATE_PULSE_AWAKE (1<<2)
	#define UPDATE_PULSE_MODE (1<<3)

	/* at least two versions of the hardware exist, with differing payload
	sizes. the first three bytes always contain the "interesting" data in
	the relevant format. */
	#define POWERMATE_PAYLOAD_SIZE_MAX 6
	#define POWERMATE_PAYLOAD_SIZE_MIN 3
	struct powermate_device {
	signed char *data;
	dma_addr_t data_dma;
	struct urb irq, config;
	struct usb_ctrlrequest *configcr;
	struct usb_device *udev;
	struct usb_interface *intf;
	struct input_dev *input;
	spinlock_t lock;
	int static_brightness;
	int pulse_speed;
	int pulse_table;
	int pulse_asleep;
	int pulse_awake;
	int requires_update; // physical settings which are out of sync
	char phys[64];
	};

	static char pm_name_powermate[] = "Griffin PowerMate";
	static char pm_name_soundknob[] = "Griffin SoundKnob";

	static void powermate_config_complete(struct urb *urb);

	/* Callback for data arriving from the PowerMate over the USB interrupt pipe */
	static void powermate_irq(struct urb *urb)
	{
	struct powermate_device *pm = urb->context;
	struct device *dev = &pm->intf->dev;
	int retval;

	switch (urb->status) {
	case 0:
	/* success */
	break;
	case -ECONNRESET:
	case -ENOENT:
	case -ESHUTDOWN:
	/* this urb is terminated, clean up */
	dev_dbg(dev, "%s - urb shutting down with status: %d\n",
	__func__, urb->status);
	return;
	default:
	dev_dbg(dev, "%s - nonzero urb status received: %d\n",
	__func__, urb->status);
	goto exit;
	}

	/* handle updates to device state */
	input_report_key(pm->input, BTN_0, pm->data[0] & 0x01);
	input_report_rel(pm->input, REL_DIAL, pm->data[1]);
	input_sync(pm->input);

	exit:
	retval = usb_submit_urb (urb, GFP_ATOMIC);
	if (retval)
	dev_err(dev, "%s - usb_submit_urb failed with result: %d\n",
	__func__, retval);
	}

	/* Decide if we need to issue a control message and do so. Must be called with pm->lock taken */
	static void powermate_sync_state(struct powermate_device *pm)
	{
	if (pm->requires_update == 0)
	return; /* no updates are required */
	if (pm->config->status == -EINPROGRESS)
	return; /* an update is already in progress; it'll issue this update when it completes */

	if (pm->requires_update & UPDATE_PULSE_ASLEEP){
	pm->configcr->wValue = cpu_to_le16( SET_PULSE_ASLEEP );
	pm->configcr->wIndex = cpu_to_le16( pm->pulse_asleep ? 1 : 0 );
	pm->requires_update &= ~UPDATE_PULSE_ASLEEP;
	}else if (pm->requires_update & UPDATE_PULSE_AWAKE){
	pm->configcr->wValue = cpu_to_le16( SET_PULSE_AWAKE );
	pm->configcr->wIndex = cpu_to_le16( pm->pulse_awake ? 1 : 0 );
	pm->requires_update &= ~UPDATE_PULSE_AWAKE;
	}else if (pm->requires_update & UPDATE_PULSE_MODE){
	int op, arg;
	/* the powermate takes an operation and an argument for its pulse algorithm.
	the operation can be:
	0: divide the speed
	1: pulse at normal speed
	2: multiply the speed
	the argument only has an effect for operations 0 and 2, and ranges between
	1 (least effect) to 255 (maximum effect).

	thus, several states are equivalent and are coalesced into one state.

	we map this onto a range from 0 to 510, with:
	0 -- 254 -- use divide (0 = slowest)
	255 -- use normal speed
	256 -- 510 -- use multiple (510 = fastest).

	Only values of 'arg' quite close to 255 are particularly useful/spectacular.
	*/
	if (pm->pulse_speed < 255) {
	op = 0; // divide
	arg = 255 - pm->pulse_speed;
	} else if (pm->pulse_speed > 255) {
	op = 2; // multiply
	arg = pm->pulse_speed - 255;
	} else {
	op = 1; // normal speed
	arg = 0; // can be any value
	}
	pm->configcr->wValue = cpu_to_le16( (pm->pulse_table << 8) \| SET_PULSE_MODE );
	pm->configcr->wIndex = cpu_to_le16( (arg << 8) \| op );
	pm->requires_update &= ~UPDATE_PULSE_MODE;
	} else if (pm->requires_update & UPDATE_STATIC_BRIGHTNESS) {
	pm->configcr->wValue = cpu_to_le16( SET_STATIC_BRIGHTNESS );
	pm->configcr->wIndex = cpu_to_le16( pm->static_brightness );
	pm->requires_update &= ~UPDATE_STATIC_BRIGHTNESS;
	} else {
	printk(KERN_ERR "powermate: unknown update required");
	pm->requires_update = 0; /* fudge the bug */
	return;
	}

	/* printk("powermate: %04x %04x\n", pm->configcr->wValue, pm->configcr->wIndex); */

	pm->configcr->bRequestType = 0x41; /* vendor request */
	pm->configcr->bRequest = 0x01;
	pm->configcr->wLength = 0;

	usb_fill_control_urb(pm->config, pm->udev, usb_sndctrlpipe(pm->udev, 0),
	(void *) pm->configcr, NULL, 0,
	powermate_config_complete, pm);

	if (usb_submit_urb(pm->config, GFP_ATOMIC))
	printk(KERN_ERR "powermate: usb_submit_urb(config) failed");
	}

	/* Called when our asynchronous control message completes. We may need to issue another immediately */
	static void powermate_config_complete(struct urb *urb)
	{
	struct powermate_device *pm = urb->context;
	unsigned long flags;

	if (urb->status)
	printk(KERN_ERR "powermate: config urb returned %d\n", urb->status);

	spin_lock_irqsave(&pm->lock, flags);
	powermate_sync_state(pm);
	spin_unlock_irqrestore(&pm->lock, flags);
	}

	/* Set the LED up as described and begin the sync with the hardware if required */
	static void powermate_pulse_led(struct powermate_device *pm, int static_brightness, int pulse_speed,
	int pulse_table, int pulse_asleep, int pulse_awake)
	{
	unsigned long flags;

	if (pulse_speed < 0)
	pulse_speed = 0;
	if (pulse_table < 0)
	pulse_table = 0;
	if (pulse_speed > 510)
	pulse_speed = 510;
	if (pulse_table > 2)
	pulse_table = 2;

	pulse_asleep = !!pulse_asleep;
	pulse_awake = !!pulse_awake;


	spin_lock_irqsave(&pm->lock, flags);

	/* mark state updates which are required */
	if (static_brightness != pm->static_brightness) {
	pm->static_brightness = static_brightness;
	pm->requires_update \|= UPDATE_STATIC_BRIGHTNESS;
	}
	if (pulse_asleep != pm->pulse_asleep) {
	pm->pulse_asleep = pulse_asleep;
	pm->requires_update \|= (UPDATE_PULSE_ASLEEP \| UPDATE_STATIC_BRIGHTNESS);
	}
	if (pulse_awake != pm->pulse_awake) {
	pm->pulse_awake = pulse_awake;
	pm->requires_update \|= (UPDATE_PULSE_AWAKE \| UPDATE_STATIC_BRIGHTNESS);
	}
	if (pulse_speed != pm->pulse_speed \|\| pulse_table != pm->pulse_table) {
	pm->pulse_speed = pulse_speed;
	pm->pulse_table = pulse_table;
	pm->requires_update \|= UPDATE_PULSE_MODE;
	}

	powermate_sync_state(pm);

	spin_unlock_irqrestore(&pm->lock, flags);
	}

	/* Callback from the Input layer when an event arrives from userspace to configure the LED */
	static int powermate_input_event(struct input_dev *dev, unsigned int type, unsigned int code, int _value)
	{
	unsigned int command = (unsigned int)_value;
	struct powermate_device *pm = input_get_drvdata(dev);

	if (type == EV_MSC && code == MSC_PULSELED){
	/*
	bits 0- 7: 8 bits: LED brightness
	bits 8-16: 9 bits: pulsing speed modifier (0 ... 510); 0-254 = slower, 255 = standard, 256-510 = faster.
	bits 17-18: 2 bits: pulse table (0, 1, 2 valid)
	bit 19: 1 bit : pulse whilst asleep?
	bit 20: 1 bit : pulse constantly?
	*/
	int static_brightness = command & 0xFF; // bits 0-7
	int pulse_speed = (command >> 8) & 0x1FF; // bits 8-16
	int pulse_table = (command >> 17) & 0x3; // bits 17-18
	int pulse_asleep = (command >> 19) & 0x1; // bit 19
	int pulse_awake = (command >> 20) & 0x1; // bit 20

	powermate_pulse_led(pm, static_brightness, pulse_speed, pulse_table, pulse_asleep, pulse_awake);
	}

	return 0;
	}

	static int powermate_alloc_buffers(struct usb_device udev, struct powermate_device pm)
	{
	pm->data = usb_alloc_coherent(udev, POWERMATE_PAYLOAD_SIZE_MAX,
	GFP_ATOMIC, &pm->data_dma);
	if (!pm->data)
	return -1;

	pm->configcr = kmalloc(sizeof(*(pm->configcr)), GFP_KERNEL);
	if (!pm->configcr)
	return -ENOMEM;

	return 0;
	}

	static void powermate_free_buffers(struct usb_device udev, struct powermate_device pm)
	{
	usb_free_coherent(udev, POWERMATE_PAYLOAD_SIZE_MAX,
	pm->data, pm->data_dma);
	kfree(pm->configcr);
	}

	/* Called whenever a USB device matching one in our supported devices table is connected */
	static int powermate_probe(struct usb_interface intf, const struct usb_device_id id)
	{
	struct usb_device *udev = interface_to_usbdev (intf);
	struct usb_host_interface *interface;
	struct usb_endpoint_descriptor *endpoint;
	struct powermate_device *pm;
	struct input_dev *input_dev;
	int pipe, maxp;
	int error = -ENOMEM;

	interface = intf->cur_altsetting;
	endpoint = &interface->endpoint[0].desc;
	if (!usb_endpoint_is_int_in(endpoint))
	return -EIO;

	usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
	0x0a, USB_TYPE_CLASS \| USB_RECIP_INTERFACE,
	0, interface->desc.bInterfaceNumber, NULL, 0,
	USB_CTRL_SET_TIMEOUT);

	pm = kzalloc(sizeof(struct powermate_device), GFP_KERNEL);
	input_dev = input_allocate_device();
	if (!pm \|\| !input_dev)
	goto fail1;

	if (powermate_alloc_buffers(udev, pm))
	goto fail2;

	pm->irq = usb_alloc_urb(0, GFP_KERNEL);
	if (!pm->irq)
	goto fail2;

	pm->config = usb_alloc_urb(0, GFP_KERNEL);
	if (!pm->config)
	goto fail3;

	pm->udev = udev;
	pm->intf = intf;
	pm->input = input_dev;

	usb_make_path(udev, pm->phys, sizeof(pm->phys));
	strlcat(pm->phys, "/input0", sizeof(pm->phys));

	spin_lock_init(&pm->lock);

	switch (le16_to_cpu(udev->descriptor.idProduct)) {
	case POWERMATE_PRODUCT_NEW:
	input_dev->name = pm_name_powermate;
	break;
	case POWERMATE_PRODUCT_OLD:
	input_dev->name = pm_name_soundknob;
	break;
	default:
	input_dev->name = pm_name_soundknob;
	printk(KERN_WARNING "powermate: unknown product id %04x\n",
	le16_to_cpu(udev->descriptor.idProduct));
	}

	input_dev->phys = pm->phys;
	usb_to_input_id(udev, &input_dev->id);
	input_dev->dev.parent = &intf->dev;

	input_set_drvdata(input_dev, pm);

	input_dev->event = powermate_input_event;

	input_dev->evbit[0] = BIT_MASK(EV_KEY) \| BIT_MASK(EV_REL) \|
	BIT_MASK(EV_MSC);
	input_dev->keybit[BIT_WORD(BTN_0)] = BIT_MASK(BTN_0);
	input_dev->relbit[BIT_WORD(REL_DIAL)] = BIT_MASK(REL_DIAL);
	input_dev->mscbit[BIT_WORD(MSC_PULSELED)] = BIT_MASK(MSC_PULSELED);

	/* get a handle to the interrupt data pipe */
	pipe = usb_rcvintpipe(udev, endpoint->bEndpointAddress);
	maxp = usb_maxpacket(udev, pipe, usb_pipeout(pipe));

	if (maxp < POWERMATE_PAYLOAD_SIZE_MIN \|\| maxp > POWERMATE_PAYLOAD_SIZE_MAX) {
	printk(KERN_WARNING "powermate: Expected payload of %d--%d bytes, found %d bytes!\n",
	POWERMATE_PAYLOAD_SIZE_MIN, POWERMATE_PAYLOAD_SIZE_MAX, maxp);
	maxp = POWERMATE_PAYLOAD_SIZE_MAX;
	}

	usb_fill_int_urb(pm->irq, udev, pipe, pm->data,
	maxp, powermate_irq,
	pm, endpoint->bInterval);
	pm->irq->transfer_dma = pm->data_dma;
	pm->irq->transfer_flags \|= URB_NO_TRANSFER_DMA_MAP;

	/* register our interrupt URB with the USB system */
	if (usb_submit_urb(pm->irq, GFP_KERNEL)) {
	error = -EIO;
	goto fail4;
	}

	error = input_register_device(pm->input);
	if (error)
	goto fail5;


	/* force an update of everything */
	pm->requires_update = UPDATE_PULSE_ASLEEP \| UPDATE_PULSE_AWAKE \| UPDATE_PULSE_MODE \| UPDATE_STATIC_BRIGHTNESS;
	powermate_pulse_led(pm, 0x80, 255, 0, 1, 0); // set default pulse parameters

	usb_set_intfdata(intf, pm);
	return 0;

	fail5: usb_kill_urb(pm->irq);
	fail4: usb_free_urb(pm->config);
	fail3: usb_free_urb(pm->irq);
	fail2: powermate_free_buffers(udev, pm);
	fail1: input_free_device(input_dev);
	kfree(pm);
	return error;
	}

	/* Called when a USB device we've accepted ownership of is removed */
	static void powermate_disconnect(struct usb_interface *intf)
	{
	struct powermate_device *pm = usb_get_intfdata (intf);

	usb_set_intfdata(intf, NULL);
	if (pm) {
	pm->requires_update = 0;
	usb_kill_urb(pm->irq);
	input_unregister_device(pm->input);
	usb_free_urb(pm->irq);
	usb_free_urb(pm->config);
	powermate_free_buffers(interface_to_usbdev(intf), pm);

	kfree(pm);
	}
	}

	static struct usb_device_id powermate_devices [] = {
	{ USB_DEVICE(POWERMATE_VENDOR, POWERMATE_PRODUCT_NEW) },
	{ USB_DEVICE(POWERMATE_VENDOR, POWERMATE_PRODUCT_OLD) },
	{ USB_DEVICE(CONTOUR_VENDOR, CONTOUR_JOG) },
	{ } /* Terminating entry */
	};

	MODULE_DEVICE_TABLE (usb, powermate_devices);

	static struct usb_driver powermate_driver = {
	.name = "powermate",
	.probe = powermate_probe,
	.disconnect = powermate_disconnect,
	.id_table = powermate_devices,
	};

	module_usb_driver(powermate_driver);

	MODULE_AUTHOR( "William R Sowerbutts" );
	MODULE_DESCRIPTION( "Griffin Technology, Inc PowerMate driver" );
	MODULE_LICENSE("GPL");