// SPDX-License-Identifier: GPL-2.0-only /* * A driver for the Griffin Technology, Inc. "PowerMate" USB controller dial. * * v1.1, (c)2002 William R Sowerbutts <[email protected]> * * 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 … #define POWERMATE_PRODUCT_NEW … #define POWERMATE_PRODUCT_OLD … #define CONTOUR_VENDOR … #define CONTOUR_JOG … /* these are the command codes we send to the device */ #define SET_STATIC_BRIGHTNESS … #define SET_PULSE_ASLEEP … #define SET_PULSE_AWAKE … #define SET_PULSE_MODE … /* these refer to bits in the powermate_device's requires_update field. */ #define UPDATE_STATIC_BRIGHTNESS … #define UPDATE_PULSE_ASLEEP … #define UPDATE_PULSE_AWAKE … #define UPDATE_PULSE_MODE … /* 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 … #define POWERMATE_PAYLOAD_SIZE_MIN … struct powermate_device { … }; static char pm_name_powermate[] = …; static char pm_name_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) { … } /* 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) { … } /* Called when our asynchronous control message completes. We may need to issue another immediately */ static void powermate_config_complete(struct urb *urb) { … } /* 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) { … } /* 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) { … } static int powermate_alloc_buffers(struct usb_device *udev, struct powermate_device *pm) { … } static void powermate_free_buffers(struct usb_device *udev, struct powermate_device *pm) { … } /* 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) { … } /* Called when a USB device we've accepted ownership of is removed */ static void powermate_disconnect(struct usb_interface *intf) { … } static const struct usb_device_id powermate_devices[] = …; MODULE_DEVICE_TABLE (usb, powermate_devices); static struct usb_driver powermate_driver = …; module_usb_driver(…) …; MODULE_AUTHOR(…) …; MODULE_DESCRIPTION(…) …; MODULE_LICENSE(…) …;
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