[linux-usb-devel] EIZO monitor control

[Jan Steinhoff]

Hi,

I want to make a control program for an EIZO FlexScan T965 CRT monitor. The
monitor keys are reported to hiddev. Setting brightness, contrast etc is done
with control messages. I have attached a libusb program that does this, but
it only works if usbhid.ko is unloaded. I have not found an ioctl in hiddev.c
that can be used to send this kind of control messages.

What would be the right/preferred way to make such a monitor control?
Implement an ioctl in hiddev.c or put the device to hid_blacklist?
Make a user space program or a kernel module?

Is there anyone working on a monitor control for this or another monitor
already? I have only found tools for USV.

Thanks,
Jan


/*
 * EIZO FlexScan T965 USB Monitor Control
 *
 * based on set_led (see http://www.linuxjournal.com/article.php?sid=7466)
 * Copyright (C) 2004 Greg Kroah-Hartman ([EMAIL PROTECTED])
 *
 * Copyright (c) 2004 Jan Steinhoff <[EMAIL PROTECTED]>
 *
 * Currently only setting and reading monitor brightness are supported
 *
 * This program is free software; you can
 * redistribute it and/or modify it under the terms
 * of the GNU General Public License as published by
 * the Free Software Foundation, version 2 of the
 * License.
 *
 * Trademarks are the property of their respective owners.
 */

#include <stdio.h>
#include <usb.h>

#define EIZO_VENDOR_ID		0x056d
#define EIZO_T965_PRODUCT_ID	0x0002

static int set_brightness(struct usb_dev_handle *handle, unsigned int brightness)
{
	unsigned char data[3];

	data[0] = 0x01;
	data[1] = brightness & 0xff;
	data[2] = brightness >> 8;

	return usb_control_msg(handle, 0x21, 0x09, 0x0301, 0, (char*) &data,
							sizeof(data), 1000);
}

static int get_brightness(struct usb_dev_handle *handle)
{
	unsigned char data[3];
	int retval;

	retval = usb_control_msg(handle, 0xa1, 0x01, 0x0301, 0, (char*) &data,
							sizeof(data), 1000);
	if (retval < 0) {
		return retval;
	} else {
		return data[1] + (data[2] << 8);
	}
}

static struct usb_device *device_init(void)
{
	struct usb_bus *usb_bus;
	struct usb_device *dev;

	usb_init();
	usb_find_busses();
	usb_find_devices();

	for (usb_bus = usb_busses; usb_bus; usb_bus = usb_bus->next) {
		for (dev = usb_bus->devices; dev;dev = dev->next) {
			if ((dev->descriptor.idVendor == EIZO_VENDOR_ID) &&
			    (dev->descriptor.idProduct == EIZO_T965_PRODUCT_ID))
				return dev;
		}
	}
	return NULL;
}

static void print_usage()
{
	fprintf(stderr, "Syntax Error\n"
			"Usage: eizo-usb [brightness]\n");
}

int main(int argc, char **argv)
{
	struct usb_device *usb_dev;
	struct usb_dev_handle *usb_handle;
	int retval = 1;
	unsigned int brightness;

	usb_dev = device_init();
	if (usb_dev == NULL) {
		fprintf(stderr, "Device not found\n");
		return 1;
	}

	usb_handle = usb_open(usb_dev);
	if (usb_handle == NULL) {
		perror("Not able to claim the USB device");
		return 1;
	}

	if (argc > 2) {
		print_usage();
		goto error;
	}

	if (argc == 2) {
		if (sscanf(argv[1], "%u", &brightness) != 1) {
			print_usage();
			goto error;
		}
		if (brightness > 400) {
			fprintf(stderr, "Brightness out of range\n");
			goto error;
		}

		retval = set_brightness(usb_handle, brightness);
		if (retval < 0) {
			perror("Can not set brightness");
			goto error;
		}
	}

	retval = get_brightness(usb_handle);
	if (retval < 0) {
		perror("Can not get brightness");
		goto error;
	}
	printf("Brightness: %i\n", retval);
	retval = 0;
error:
	usb_close(usb_handle);
	return retval;
}