Version: v4.11.2

linux/drivers/input/joystick/zhenhua.c

    1 
    2 
    3 
    4 
    5 
    6 
    7 
    8 
    9 
   10 
   11 
   12 
   13 
   14 
   15 
   16 
   17 
   18 
   19 
   20 
   21 
   22 
   23 
   24 
   25 
   26 
   27 
   28 
   29 
   30 
   31 
   32 
   33 
   34 
   35 
   36 
   37 
   38 
   39 
   40 
   41 
   42 
   43 
   44 
   45 
   46 
   47 
   48 
   49 
   50 
   51 
   52 
   53 
   54 
   55 
   56 
   57 
   58 
   59 
   60 
   61 
   62 
   63 
   64 
   65 
   66 
   67 
   68 
   69 
   70 
   71 
   72 
   73 
   74 
   75 
   76 
   77 
   78 
   79 
   80 
   81 
   82 
   83 
   84 
   85 
   86 
   87 
   88 
   89 
   90 
   91 
   92 
   93 
   94 
   95 
   96 
   97 
   98 
   99 
  100 
  101 
  102 
  103 
  104 
  105 
  106 
  107 
  108 
  109 
  110 
  111 
  112 
  113 
  114 
  115 
  116 
  117 
  118 
  119 
  120 
  121 
  122 
  123 
  124 
  125 
  126 
  127 
  128 
  129 
  130 
  131 
  132 
  133 
  134 
  135 
  136 
  137 
  138 
  139 
  140 
  141 
  142 
  143 
  144 
  145 
  146 
  147 
  148 
  149 
  150 
  151 
  152 
  153 
  154 
  155 
  156 
  157 
  158 
  159 
  160 
  161 
  162 
  163 
  164 
  165 
  166 
  167 
  168 
  169 
  170 
  171 
  172 
  173 
  174 
  175 
  176 
  177 
  178 
  179 
  180 
  181 
  182 
  183 
  184 
  185 
  186 
  187 
  188 
  189 
  190 
  191 
  192 
  193 
  194 
  195 
  196 
  197 
  198 
  199 
  200 
  201 
  202 
  203 
  204 
  205 
  206 
  207 
  208 
  209 
  210 
  211 
  212 
  213 
  214 
  215 
  216 
  217 
  218 
/*
 *  derived from "twidjoy.c"
 *
 *  Copyright (c) 2008 Martin Kebert
 *  Copyright (c) 2001 Arndt Schoenewald
 *  Copyright (c) 2000-2001 Vojtech Pavlik
 *  Copyright (c) 2000 Mark Fletcher
 *
 */

/*
 * Driver to use 4CH RC transmitter using Zhen Hua 5-byte protocol (Walkera Lama,
 * EasyCopter etc.) as a joystick under Linux.
 *
 * RC transmitters using Zhen Hua 5-byte protocol are cheap four channels
 * transmitters for control a RC planes or RC helicopters with possibility to
 * connect on a serial port.
 * Data coming from transmitter is in this order:
 * 1. byte = synchronisation byte
 * 2. byte = X axis
 * 3. byte = Y axis
 * 4. byte = RZ axis
 * 5. byte = Z axis
 * (and this is repeated)
 *
 * For questions or feedback regarding this driver module please contact:
 * Martin Kebert <gkmarty@gmail.com> - but I am not a C-programmer nor kernel
 * coder :-(
 */

/*
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/bitrev.h>
#include <linux/input.h>
#include <linux/serio.h>

#define DRIVER_DESC	"RC transmitter with 5-byte Zhen Hua protocol joystick driver"

MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");

/*
 * Constants.
 */

#define ZHENHUA_MAX_LENGTH 5

/*
 * Zhen Hua data.
 */

struct zhenhua {
	struct input_dev *dev;
	int idx;
	unsigned char data[ZHENHUA_MAX_LENGTH];
	char phys[32];
};

/*
 * zhenhua_process_packet() decodes packets the driver receives from the
 * RC transmitter. It updates the data accordingly.
 */

static void zhenhua_process_packet(struct zhenhua *zhenhua)
{
	struct input_dev *dev = zhenhua->dev;
	unsigned char *data = zhenhua->data;

	input_report_abs(dev, ABS_Y, data[1]);
	input_report_abs(dev, ABS_X, data[2]);
	input_report_abs(dev, ABS_RZ, data[3]);
	input_report_abs(dev, ABS_Z, data[4]);

	input_sync(dev);
}

/*
 * zhenhua_interrupt() is called by the low level driver when characters
 * are ready for us. We then buffer them for further processing, or call the
 * packet processing routine.
 */

static irqreturn_t zhenhua_interrupt(struct serio *serio, unsigned char data, unsigned int flags)
{
	struct zhenhua *zhenhua = serio_get_drvdata(serio);

	/* All Zhen Hua packets are 5 bytes. The fact that the first byte
	 * is allways 0xf7 and all others are in range 0x32 - 0xc8 (50-200)
	 * can be used to check and regain sync. */

	if (data == 0xef)
		zhenhua->idx = 0;	/* this byte starts a new packet */
	else if (zhenhua->idx == 0)
		return IRQ_HANDLED;	/* wrong MSB -- ignore this byte */

	if (zhenhua->idx < ZHENHUA_MAX_LENGTH)
		zhenhua->data[zhenhua->idx++] = bitrev8(data);

	if (zhenhua->idx == ZHENHUA_MAX_LENGTH) {
		zhenhua_process_packet(zhenhua);
		zhenhua->idx = 0;
	}

	return IRQ_HANDLED;
}

/*
 * zhenhua_disconnect() is the opposite of zhenhua_connect()
 */

static void zhenhua_disconnect(struct serio *serio)
{
	struct zhenhua *zhenhua = serio_get_drvdata(serio);

	serio_close(serio);
	serio_set_drvdata(serio, NULL);
	input_unregister_device(zhenhua->dev);
	kfree(zhenhua);
}

/*
 * zhenhua_connect() is the routine that is called when someone adds a
 * new serio device. It looks for the Twiddler, and if found, registers
 * it as an input device.
 */

static int zhenhua_connect(struct serio *serio, struct serio_driver *drv)
{
	struct zhenhua *zhenhua;
	struct input_dev *input_dev;
	int err = -ENOMEM;

	zhenhua = kzalloc(sizeof(struct zhenhua), GFP_KERNEL);
	input_dev = input_allocate_device();
	if (!zhenhua || !input_dev)
		goto fail1;

	zhenhua->dev = input_dev;
	snprintf(zhenhua->phys, sizeof(zhenhua->phys), "%s/input0", serio->phys);

	input_dev->name = "Zhen Hua 5-byte device";
	input_dev->phys = zhenhua->phys;
	input_dev->id.bustype = BUS_RS232;
	input_dev->id.vendor = SERIO_ZHENHUA;
	input_dev->id.product = 0x0001;
	input_dev->id.version = 0x0100;
	input_dev->dev.parent = &serio->dev;

	input_dev->evbit[0] = BIT(EV_ABS);
	input_set_abs_params(input_dev, ABS_X, 50, 200, 0, 0);
	input_set_abs_params(input_dev, ABS_Y, 50, 200, 0, 0);
	input_set_abs_params(input_dev, ABS_Z, 50, 200, 0, 0);
	input_set_abs_params(input_dev, ABS_RZ, 50, 200, 0, 0);

	serio_set_drvdata(serio, zhenhua);

	err = serio_open(serio, drv);
	if (err)
		goto fail2;

	err = input_register_device(zhenhua->dev);
	if (err)
		goto fail3;

	return 0;

 fail3:	serio_close(serio);
 fail2:	serio_set_drvdata(serio, NULL);
 fail1:	input_free_device(input_dev);
	kfree(zhenhua);
	return err;
}

/*
 * The serio driver structure.
 */

static struct serio_device_id zhenhua_serio_ids[] = {
	{
		.type	= SERIO_RS232,
		.proto	= SERIO_ZHENHUA,
		.id	= SERIO_ANY,
		.extra	= SERIO_ANY,
	},
	{ 0 }
};

MODULE_DEVICE_TABLE(serio, zhenhua_serio_ids);

static struct serio_driver zhenhua_drv = {
	.driver		= {
		.name	= "zhenhua",
	},
	.description	= DRIVER_DESC,
	.id_table	= zhenhua_serio_ids,
	.interrupt	= zhenhua_interrupt,
	.connect	= zhenhua_connect,
	.disconnect	= zhenhua_disconnect,
};

module_serio_driver(zhenhua_drv);

This page was automatically generated by Elixir 0.1.2 (source)  •  Please report bugs by mail or directly through the issue tracker.