powermate.c
/*
* 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/init.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 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;
int retval;
switch (urb->status) {
case 0:
/* success */
break;
case -ECONNRESET:
case -ENOENT:
case -ESHUTDOWN:
/* this urb is terminated, clean up */
dbg("%s - urb shutting down with status: %d", __func__, urb->status);
return;
default:
dbg("%s - nonzero urb status received: %d", __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)
err ("%s - usb_submit_urb failed with result %d",
__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->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,
};
static int __init powermate_init(void)
{
return usb_register(&powermate_driver);
}
static void __exit powermate_cleanup(void)
{
usb_deregister(&powermate_driver);
}
module_init(powermate_init);
module_exit(powermate_cleanup);
MODULE_AUTHOR( "William R Sowerbutts" );
MODULE_DESCRIPTION( "Griffin Technology, Inc PowerMate driver" );
MODULE_LICENSE("GPL");