original_kernel/drivers/media/rc/ir-functions.c

121 lines
3.2 KiB
C

/*
* some common functions to handle infrared remote protocol decoding for
* drivers which have not yet been (or can't be) converted to use the
* regular protocol decoders...
*
* (c) 2003 Gerd Knorr <kraxel@bytesex.org> [SuSE Labs]
*
* 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/module.h>
#include <linux/string.h>
#include <linux/jiffies.h>
#include <media/ir-common.h>
#include "ir-core-priv.h"
/* -------------------------------------------------------------------------- */
MODULE_AUTHOR("Gerd Knorr <kraxel@bytesex.org> [SuSE Labs]");
MODULE_LICENSE("GPL");
/* RC5 decoding stuff, moved from bttv-input.c to share it with
* saa7134 */
/* decode raw bit pattern to RC5 code */
static u32 ir_rc5_decode(unsigned int code)
{
unsigned int org_code = code;
unsigned int pair;
unsigned int rc5 = 0;
int i;
for (i = 0; i < 14; ++i) {
pair = code & 0x3;
code >>= 2;
rc5 <<= 1;
switch (pair) {
case 0:
case 2:
break;
case 1:
rc5 |= 1;
break;
case 3:
IR_dprintk(1, "ir-common: ir_rc5_decode(%x) bad code\n", org_code);
return 0;
}
}
IR_dprintk(1, "ir-common: code=%x, rc5=%x, start=%x, toggle=%x, address=%x, "
"instr=%x\n", rc5, org_code, RC5_START(rc5),
RC5_TOGGLE(rc5), RC5_ADDR(rc5), RC5_INSTR(rc5));
return rc5;
}
void ir_rc5_timer_end(unsigned long data)
{
struct card_ir *ir = (struct card_ir *)data;
struct timeval tv;
unsigned long current_jiffies;
u32 gap;
u32 rc5 = 0;
/* get time */
current_jiffies = jiffies;
do_gettimeofday(&tv);
/* avoid overflow with gap >1s */
if (tv.tv_sec - ir->base_time.tv_sec > 1) {
gap = 200000;
} else {
gap = 1000000 * (tv.tv_sec - ir->base_time.tv_sec) +
tv.tv_usec - ir->base_time.tv_usec;
}
/* signal we're ready to start a new code */
ir->active = 0;
/* Allow some timer jitter (RC5 is ~24ms anyway so this is ok) */
if (gap < 28000) {
IR_dprintk(1, "ir-common: spurious timer_end\n");
return;
}
if (ir->last_bit < 20) {
/* ignore spurious codes (caused by light/other remotes) */
IR_dprintk(1, "ir-common: short code: %x\n", ir->code);
} else {
ir->code = (ir->code << ir->shift_by) | 1;
rc5 = ir_rc5_decode(ir->code);
/* two start bits? */
if (RC5_START(rc5) != ir->start) {
IR_dprintk(1, "ir-common: rc5 start bits invalid: %u\n", RC5_START(rc5));
/* right address? */
} else if (RC5_ADDR(rc5) == ir->addr) {
u32 toggle = RC5_TOGGLE(rc5);
u32 instr = RC5_INSTR(rc5);
/* Good code */
ir_keydown(ir->dev, instr, toggle);
IR_dprintk(1, "ir-common: instruction %x, toggle %x\n",
instr, toggle);
}
}
}
EXPORT_SYMBOL_GPL(ir_rc5_timer_end);