linux/drivers/hid/hid-icade.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  ION iCade input driver
 *
 *  Copyright (c) 2012 Bastien Nocera <[email protected]>
 *  Copyright (c) 2012 Benjamin Tissoires <[email protected]>
 */

/*
 */

#include <linux/device.h>
#include <linux/hid.h>
#include <linux/module.h>

#include "hid-ids.h"

/*
 *   ↑      A C Y L
 *  ← →
 *   ↓      B X Z R
 *
 *
 *  UP ON,OFF  = w,e
 *  RT ON,OFF  = d,c
 *  DN ON,OFF  = x,z
 *  LT ON,OFF  = a,q
 *  A  ON,OFF  = y,t
 *  B  ON,OFF  = h,r
 *  C  ON,OFF  = u,f
 *  X  ON,OFF  = j,n
 *  Y  ON,OFF  = i,m
 *  Z  ON,OFF  = k,p
 *  L  ON,OFF  = o,g
 *  R  ON,OFF  = l,v
 */

/* The translation code uses HID usage instead of input layer
 * keys. This code generates a lookup table that makes
 * translation quick.
 *
 * #include <linux/input.h>
 * #include <stdio.h>
 * #include <assert.h>
 *
 * #define unk     KEY_UNKNOWN
 *
 * < copy of hid_keyboard[] from hid-input.c >
 *
 * struct icade_key_translation {
 *     int         from;
 *     const char *to;
 *     int         press;
 * };
 *
 * static const struct icade_key_translation icade_keys[] = {
 *    { KEY_W,        "KEY_UP",         1 },
 *    { KEY_E,        "KEY_UP",         0 },
 *    { KEY_D,        "KEY_RIGHT",      1 },
 *    { KEY_C,        "KEY_RIGHT",      0 },
 *    { KEY_X,        "KEY_DOWN",       1 },
 *    { KEY_Z,        "KEY_DOWN",       0 },
 *    { KEY_A,        "KEY_LEFT",       1 },
 *    { KEY_Q,        "KEY_LEFT",       0 },
 *    { KEY_Y,        "BTN_A",          1 },
 *    { KEY_T,        "BTN_A",          0 },
 *    { KEY_H,        "BTN_B",          1 },
 *    { KEY_R,        "BTN_B",          0 },
 *    { KEY_U,        "BTN_C",          1 },
 *    { KEY_F,        "BTN_C",          0 },
 *    { KEY_J,        "BTN_X",          1 },
 *    { KEY_N,        "BTN_X",          0 },
 *    { KEY_I,        "BTN_Y",          1 },
 *    { KEY_M,        "BTN_Y",          0 },
 *    { KEY_K,        "BTN_Z",          1 },
 *    { KEY_P,        "BTN_Z",          0 },
 *    { KEY_O,        "BTN_THUMBL",     1 },
 *    { KEY_G,        "BTN_THUMBL",     0 },
 *    { KEY_L,        "BTN_THUMBR",     1 },
 *    { KEY_V,        "BTN_THUMBR",     0 },
 *
 *    { }
 * };
 *
 * static int
 * usage_for_key (int key)
 * {
 *     int i;
 *     for (i = 0; i < 256; i++) {
 *     if (hid_keyboard[i] == key)
 *         return i;
 *     }
 *     assert(0);
 * }
 *
 * int main (int argc, char **argv)
 * {
 *     const struct icade_key_translation *trans;
 *     int max_usage = 0;
 *
 *     for (trans = icade_keys; trans->from; trans++) {
 *         int usage = usage_for_key (trans->from);
 *         max_usage = usage > max_usage ? usage : max_usage;
 *     }
 *
 *     printf ("#define ICADE_MAX_USAGE %d\n\n", max_usage);
 *     printf ("struct icade_key {\n");
 *     printf ("\tu16 to;\n");
 *     printf ("\tu8 press:1;\n");
 *     printf ("};\n\n");
 *     printf ("static const struct icade_key "
 *             "icade_usage_table[%d] = {\n", max_usage + 1);
 *     for (trans = icade_keys; trans->from; trans++) {
 *         printf ("\t[%d] = { %s, %d },\n",
 *                 usage_for_key (trans->from), trans->to, trans->press);
 *     }
 *     printf ("};\n");
 *
 *     return 0;
 * }
 */

#define ICADE_MAX_USAGE …

struct icade_key { … };

static const struct icade_key icade_usage_table[30] = …;

static const struct icade_key *icade_find_translation(u16 from)
{ … }

static int icade_event(struct hid_device *hdev, struct hid_field *field,
		struct hid_usage *usage, __s32 value)
{ … }

static int icade_input_mapping(struct hid_device *hdev, struct hid_input *hi,
		struct hid_field *field, struct hid_usage *usage,
		unsigned long **bit, int *max)
{ … }

static int icade_input_mapped(struct hid_device *hdev, struct hid_input *hi,
		struct hid_field *field, struct hid_usage *usage,
		unsigned long **bit, int *max)
{ … }

static const struct hid_device_id icade_devices[] = …;
MODULE_DEVICE_TABLE(hid, icade_devices);

static struct hid_driver icade_driver = …;
module_hid_driver(…) …;

MODULE_LICENSE(…) …;
MODULE_AUTHOR(…) …;
MODULE_DESCRIPTION(…) …;