path: root/drivers/hid/hid-ntrig.c

/*
 *  HID driver for N-Trig touchscreens
 *
 *  Copyright (c) 2008-2010 Rafi Rubin
 *  Copyright (c) 2009-2010 Stephane Chatty
 *
 */

/*
 * 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; either version 2 of the License, or (at your option)
 * any later version.
 */

#include <linux/device.h>
#include <linux/hid.h>
#include <linux/usb.h>
#include "usbhid/usbhid.h"
#include <linux/module.h>
#include <linux/slab.h>

#include "hid-ids.h"

#define NTRIG_DUPLICATE_USAGES	0x001

static unsigned int min_width;
module_param(min_width, uint, 0644);
MODULE_PARM_DESC(min_width, "Minimum touch contact width to accept.");

static unsigned int min_height;
module_param(min_height, uint, 0644);
MODULE_PARM_DESC(min_height, "Minimum touch contact height to accept.");

static unsigned int activate_slack = 1;
module_param(activate_slack, uint, 0644);
MODULE_PARM_DESC(activate_slack, "Number of touch frames to ignore at "
		 "the start of touch input.");

static unsigned int deactivate_slack = 4;
module_param(deactivate_slack, uint, 0644);
MODULE_PARM_DESC(deactivate_slack, "Number of empty frames to ignore before "
		 "deactivating touch.");

static unsigned int activation_width = 64;
module_param(activation_width, uint, 0644);
MODULE_PARM_DESC(activation_width, "Width threshold to immediately start "
		 "processing touch events.");

static unsigned int activation_height = 32;
module_param(activation_height, uint, 0644);
MODULE_PARM_DESC(activation_height, "Height threshold to immediately start "
		 "processing touch events.");

struct ntrig_data {
	/* Incoming raw values for a single contact */
	__u16 x, y, w, h;
	__u16 id;

	bool tipswitch;
	bool confidence;
	bool first_contact_touch;

	bool reading_mt;

	__u8 mt_footer[4];
	__u8 mt_foot_count;

	/* The current activation state. */
	__s8 act_state;

	/* Empty frames to ignore before recognizing the end of activity */
	__s8 deactivate_slack;

	/* Frames to ignore before acknowledging the start of activity */
	__s8 activate_slack;

	/* Minimum size contact to accept */
	__u16 min_width;
	__u16 min_height;

	/* Threshold to override activation slack */
	__u16 activation_width;
	__u16 activation_height;

	__u16 sensor_logical_width;
	__u16 sensor_logical_height;
	__u16 sensor_physical_width;
	__u16 sensor_physical_height;
};


/*
 * This function converts the 4 byte raw firmware code into
 * a string containing 5 comma separated numbers.
 */
static int ntrig_version_string(unsigned char *raw, char *buf)
{
	__u8 a =  (raw[1] & 0x0e) >> 1;
	__u8 b =  (raw[0] & 0x3c) >> 2;
	__u8 c = ((raw[0] & 0x03) << 3) | ((raw[3] & 0xe0) >> 5);
	__u8 d = ((raw[3] & 0x07) << 3) | ((raw[2] & 0xe0) >> 5);
	__u8 e =   raw[2] & 0x07;

	/*
	 * As yet unmapped bits:
	 * 0b11000000 0b11110001 0b00011000 0b00011000
	 */

	return sprintf(buf, "%u.%u.%u.%u.%u", a, b, c, d, e);
}

static void ntrig_report_version(struct hid_device *hdev)
{
	int ret;
	char buf[20];
	struct usb_device *usb_dev = hid_to_usb_dev(hdev);
	unsigned char *data = kmalloc(8, GFP_KERNEL);

	if (!data)
		goto err_free;

	ret = usb_control_msg(usb_dev, usb_rcvctrlpipe(usb_dev, 0),
			      USB_REQ_CLEAR_FEATURE,
			      USB_TYPE_CLASS | USB_RECIP_INTERFACE |
			      USB_DIR_IN,
			      0x30c, 1, data, 8,
			      USB_CTRL_SET_TIMEOUT);

	if (ret == 8) {
		ret = ntrig_version_string(&data[2], buf);

		dev_info(&hdev->dev,
			 "Firmware version: %s (%02x%02x %02x%02x)\n",
			 buf, data[2], data[3], data[4], data[5]);
	}

err_free:
	kfree(data);
}

static ssize_t show_phys_width(struct device *dev,
			       struct device_attribute *attr,
			       char *buf)
{
	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
	struct ntrig_data *nd = hid_get_drvdata(hdev);

	return sprintf(buf, "%d\n", nd->sensor_physical_width);
}

static DEVICE_ATTR(sensor_physical_width, S_IRUGO, show_phys_width, NULL);

static ssize_t show_phys_height(struct device *dev,
				struct device_attribute *