linux-imx

/*

 * 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: