text: /*
   *   Copyright (c) 2006,2007 Daniel Mack, Tim Ruetz
   *
   *   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/init.h>
  #include <linux/module.h>
  #include <linux/moduleparam.h>
  #include <linux/input.h>
  #include <linux/usb.h>
  #include <linux/spinlock.h>
  #include <sound/driver.h>
  #include <sound/core.h>
  #include <sound/rawmidi.h>
  #include <sound/pcm.h>
  #include "caiaq-device.h"
  #include "caiaq-input.h"
  
  #ifdef CONFIG_SND_USB_CAIAQ_INPUT
  
  static unsigned char keycode_ak1[] =  { KEY_C, KEY_B, KEY_A };
  static unsigned char keycode_rk2[] =  { KEY_1, KEY_2, KEY_3, KEY_4, 
  					KEY_5, KEY_6, KEY_7 };
  
  #define DEG90  (range/2)
  #define DEG180 (range)
  #define DEG270 (DEG90 + DEG180)
  #define DEG360 (DEG180 * 2)
  #define HIGH_PEAK (268)
  #define LOW_PEAK (-7)
  
  /* some of these devices have endless rotation potentiometers
   * built in which use two tapers, 90 degrees phase shifted.
   * this algorithm decodes them to one single value, ranging
   * from 0 to 999 */
  static unsigned int decode_erp(unsigned char a, unsigned char b)
  {
  	int weight_a, weight_b;
  	int pos_a, pos_b;
  	int ret;
  	int range = HIGH_PEAK - LOW_PEAK;
  	int mid_value = (HIGH_PEAK + LOW_PEAK) / 2;
  
  	weight_b = abs(mid_value-a) - (range/2 - 100)/2;
  	
  	if (weight_b < 0)
  		weight_b = 0;
  
  	if (weight_b > 100)
  		weight_b = 100;
  
  	weight_a = 100 - weight_b;
  
  	if (a < mid_value) {
  		/* 0..90 and 270..360 degrees */
  		pos_b = b - LOW_PEAK + DEG270;
  		if (pos_b >= DEG360)
  			pos_b -= DEG360;
  	} else
  		/* 90..270 degrees */
  		pos_b = HIGH_PEAK - b + DEG90;
  
  
  	if (b > mid_value)
  		/* 0..180 degrees */
  		pos_a = a - LOW_PEAK;
  	else
  		/* 180..360 degrees */
  		pos_a = HIGH_PEAK - a + DEG180;
  
  	/* interpolate both slider values, depending on weight factors */
  	/* 0..99 x DEG360 */
  	ret = pos_a * weight_a + pos_b * weight_b;
  
  	/* normalize to 0..999 */
  	ret *= 10;
  	ret /= DEG360;
  
  	if (ret < 0)
  		ret += 1000;
  	
  	if (ret >= 1000)
  		ret -= 1000;
  
  	return ret;
  }
  
  #undef DEG90
  #undef DEG180
  #undef DEG270
  #undef DEG360
  #undef HIGH_PEAK
  #undef LOW_PEAK
  
  
  static void snd_caiaq_input_read_analog(struct snd_usb_caiaqdev *dev, 
  					const char *buf, unsigned int len)
  {
  	switch(dev->input_dev->id.product) {
  	case USB_PID_RIGKONTROL2:
  		input_report_abs(dev->input_dev, ABS_X, (buf[4] << 8) |buf[5]);
  		input_report_abs(dev->input_dev, ABS_Y, (buf[0] << 8) |buf[1]);
  		input_report_abs(dev->input_dev, ABS_Z, (buf[2] << 8) |buf[3]);
  		input_sync(dev->input_dev);
  		break;
  	}
  }
  
  static void snd_caiaq_input_read_erp(struct snd_usb_caiaqdev *dev, 
  				     const char *buf, unsigned int len)
  {
  	int i;
  
  	switch(dev->input_dev->id.product) {
  	case USB_PID_AK1:
  		i = decode_erp(buf[0], buf[1]);
  		input_report_abs(dev->input_dev, ABS_X, i);
  		input_sync(dev->input_dev);	
  		break;
  	}
  }
  
  static void snd_caiaq_input_read_io(struct snd_usb_caiaqdev *dev, 
  				    char *buf, unsigned int len)
  {
  	int i;
  	unsigned char *keycode = dev->input_dev->keycode;
  
  	if (!keycode)
  		return;
  
  	if (dev->input_dev->id.product == USB_PID_RIGKONTROL2)
  		for (i=0; i<len; i++)
  			buf[i] = ~buf[i];
  
  	for (i=0; (i<dev->input_dev->keycodemax) && (i < len); i++)
  		input_report_key(dev->input_dev, keycode[i], 
  					buf[i/8] & (1 << (i%8)));
  
  	input_sync(dev->input_dev);
  }
  
  void snd_usb_caiaq_input_dispatch(struct snd_usb_caiaqdev *dev, 
  				  char *buf, 
  				  unsigned int len)
  {
  	if (!dev->input_dev || (len < 1))
  		return;
  
  	switch (buf[0]) {
  	case EP1_CMD_READ_ANALOG:
  		snd_caiaq_input_read_analog(dev, buf+1, len-1);
  		break;
  	case EP1_CMD_READ_ERP:
  		snd_caiaq_input_read_erp(dev, buf+1, len-1);
  		break;
  	case EP1_CMD_READ_IO:
  		snd_caiaq_input_read_io(dev, buf+1, len-1);
  		break;
  	}
  }
  
  int snd_usb_caiaq_input_init(struct snd_usb_caiaqdev *dev)
  {
  	struct usb_device *usb_dev = dev->chip.dev;
  	struct input_dev *input;
  	int i, ret;
  
  	input = input_allocate_device();
  	if (!input)
  		return -ENOMEM;
  
  	input->name = dev->product_name;
  	input->id.bustype = BUS_USB;
  	input->id.vendor  = usb_dev->descriptor.idVendor;
  	input->id.product = usb_dev->descriptor.idProduct;
  	input->id.version = usb_dev->descriptor.bcdDevice;
  
          switch (dev->chip.usb_id) {
  	case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_RIGKONTROL2):
  		input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
  		input->absbit[0] = BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) |
  			BIT_MASK(ABS_Z);
  		input->keycode = keycode_rk2;
  		input->keycodesize = sizeof(char);
  		input->keycodemax = ARRAY_SIZE(keycode_rk2);
  		for (i=0; i<ARRAY_SIZE(keycode_rk2); i++)
  			set_bit(keycode_rk2[i], input->keybit);
  
  		input_set_abs_params(input, ABS_X, 0, 4096, 0, 10);
  		input_set_abs_params(input, ABS_Y, 0, 4096, 0, 10);
  		input_set_abs_params(input, ABS_Z, 0, 4096, 0, 10);
  		snd_usb_caiaq_set_auto_msg(dev, 1, 10, 0);
  		break;
  	case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_AK1):
  		input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
  		input->absbit[0] = BIT_MASK(ABS_X);
  		input->keycode = keycode_ak1;
  		input->keycodesize = sizeof(char);
  		input->keycodemax = ARRAY_SIZE(keycode_ak1);
  		for (i=0; i<ARRAY_SIZE(keycode_ak1); i++)
  			set_bit(keycode_ak1[i], input->keybit);
  
  		input_set_abs_params(input, ABS_X, 0, 999, 0, 10);
  		snd_usb_caiaq_set_auto_msg(dev, 1, 0, 5);
  		break;
  	default:
  		/* no input methods supported on this device */
  		input_free_device(input);
  		return 0;
  	}
  
  	ret = input_register_device(input);
  	if (ret < 0) {
  		input_free_device(input);
  		return ret;
  	}
  
  	dev->input_dev = input;
  	return 0;
  }
  
  void snd_usb_caiaq_input_free(struct snd_usb_caiaqdev *dev)
  {
  	if (!dev || !dev->input_dev)
  		return;
  
  	input_unregister_device(dev->input_dev);
  	input_free_device(dev->input_dev);
  	dev->input_dev = NULL;
  }
  
  #endif /* CONFIG_SND_USB_CAIAQ_INPUT */
  
  