diff options
Diffstat (limited to 'drivers/media/rc/ir-functions.c')
| -rw-r--r-- | drivers/media/rc/ir-functions.c | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/drivers/media/rc/ir-functions.c b/drivers/media/rc/ir-functions.c new file mode 100644 index 000000000000..ec021c92527a --- /dev/null +++ b/drivers/media/rc/ir-functions.c @@ -0,0 +1,120 @@ +/* + * 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); |