diff options
Diffstat (limited to 'drivers/media/rc/img-ir/img-ir-nec.c')
| -rw-r--r-- | drivers/media/rc/img-ir/img-ir-nec.c | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/drivers/media/rc/img-ir/img-ir-nec.c b/drivers/media/rc/img-ir/img-ir-nec.c new file mode 100644 index 000000000..2fc0678ad --- /dev/null +++ b/drivers/media/rc/img-ir/img-ir-nec.c @@ -0,0 +1,177 @@ +/* + * ImgTec IR Decoder setup for NEC protocol. + * + * Copyright 2010-2014 Imagination Technologies Ltd. + * + * 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. + */ + +#include "img-ir-hw.h" +#include <linux/bitrev.h> +#include <linux/log2.h> + +/* Convert NEC data to a scancode */ +static int img_ir_nec_scancode(int len, u64 raw, u64 enabled_protocols, + struct img_ir_scancode_req *request) +{ + unsigned int addr, addr_inv, data, data_inv; + /* a repeat code has no data */ + if (!len) + return IMG_IR_REPEATCODE; + if (len != 32) + return -EINVAL; + /* raw encoding: ddDDaaAA */ + addr = (raw >> 0) & 0xff; + addr_inv = (raw >> 8) & 0xff; + data = (raw >> 16) & 0xff; + data_inv = (raw >> 24) & 0xff; + if ((data_inv ^ data) != 0xff) { + /* 32-bit NEC (used by Apple and TiVo remotes) */ + /* scan encoding: as transmitted, MSBit = first received bit */ + request->scancode = bitrev8(addr) << 24 | + bitrev8(addr_inv) << 16 | + bitrev8(data) << 8 | + bitrev8(data_inv); + request->protocol = RC_PROTO_NEC32; + } else if ((addr_inv ^ addr) != 0xff) { + /* Extended NEC */ + /* scan encoding: AAaaDD */ + request->scancode = addr << 16 | + addr_inv << 8 | + data; + request->protocol = RC_PROTO_NECX; + } else { + /* Normal NEC */ + /* scan encoding: AADD */ + request->scancode = addr << 8 | + data; + request->protocol = RC_PROTO_NEC; + } + return IMG_IR_SCANCODE; +} + +/* Convert NEC scancode to NEC data filter */ +static int img_ir_nec_filter(const struct rc_scancode_filter *in, + struct img_ir_filter *out, u64 protocols) +{ + unsigned int addr, addr_inv, data, data_inv; + unsigned int addr_m, addr_inv_m, data_m, data_inv_m; + + data = in->data & 0xff; + data_m = in->mask & 0xff; + + protocols &= RC_PROTO_BIT_NEC | RC_PROTO_BIT_NECX | RC_PROTO_BIT_NEC32; + + /* + * If only one bit is set, we were requested to do an exact + * protocol. This should be the case for wakeup filters; for + * normal filters, guess the protocol from the scancode. + */ + if (!is_power_of_2(protocols)) { + if ((in->data | in->mask) & 0xff000000) + protocols = RC_PROTO_BIT_NEC32; + else if ((in->data | in->mask) & 0x00ff0000) + protocols = RC_PROTO_BIT_NECX; + else + protocols = RC_PROTO_BIT_NEC; + } + + if (protocols == RC_PROTO_BIT_NEC32) { + /* 32-bit NEC (used by Apple and TiVo remotes) */ + /* scan encoding: as transmitted, MSBit = first received bit */ + addr = bitrev8(in->data >> 24); + addr_m = bitrev8(in->mask >> 24); + addr_inv = bitrev8(in->data >> 16); + addr_inv_m = bitrev8(in->mask >> 16); + data = bitrev8(in->data >> 8); + data_m = bitrev8(in->mask >> 8); + data_inv = bitrev8(in->data >> 0); + data_inv_m = bitrev8(in->mask >> 0); + } else if (protocols == RC_PROTO_BIT_NECX) { + /* Extended NEC */ + /* scan encoding AAaaDD */ + addr = (in->data >> 16) & 0xff; + addr_m = (in->mask >> 16) & 0xff; + addr_inv = (in->data >> 8) & 0xff; + addr_inv_m = (in->mask >> 8) & 0xff; + data_inv = data ^ 0xff; + data_inv_m = data_m; + } else { + /* Normal NEC */ + /* scan encoding: AADD */ + addr = (in->data >> 8) & 0xff; + addr_m = (in->mask >> 8) & 0xff; + addr_inv = addr ^ 0xff; + addr_inv_m = addr_m; + data_inv = data ^ 0xff; + data_inv_m = data_m; + } + + /* raw encoding: ddDDaaAA */ + out->data = data_inv << 24 | + data << 16 | + addr_inv << 8 | + addr; + out->mask = data_inv_m << 24 | + data_m << 16 | + addr_inv_m << 8 | + addr_m; + return 0; +} + +/* + * NEC decoder + * See also http://www.sbprojects.com/knowledge/ir/nec.php + * http://wiki.altium.com/display/ADOH/NEC+Infrared+Transmission+Protocol + */ +struct img_ir_decoder img_ir_nec = { + .type = RC_PROTO_BIT_NEC | RC_PROTO_BIT_NECX | RC_PROTO_BIT_NEC32, + .control = { + .decoden = 1, + .code_type = IMG_IR_CODETYPE_PULSEDIST, + }, + /* main timings */ + .unit = 562500, /* 562.5 us */ + .timings = { + /* leader symbol */ + .ldr = { + .pulse = { 16 /* 9ms */ }, + .space = { 8 /* 4.5ms */ }, + }, + /* 0 symbol */ + .s00 = { + .pulse = { 1 /* 562.5 us */ }, + .space = { 1 /* 562.5 us */ }, + }, + /* 1 symbol */ + .s01 = { + .pulse = { 1 /* 562.5 us */ }, + .space = { 3 /* 1687.5 us */ }, + }, + /* free time */ + .ft = { + .minlen = 32, + .maxlen = 32, + .ft_min = 10, /* 5.625 ms */ + }, + }, + /* repeat codes */ + .repeat = 108, /* 108 ms */ + .rtimings = { + /* leader symbol */ + .ldr = { + .space = { 4 /* 2.25 ms */ }, + }, + /* free time */ + .ft = { + .minlen = 0, /* repeat code has no data */ + .maxlen = 0, + }, + }, + /* scancode logic */ + .scancode = img_ir_nec_scancode, + .filter = img_ir_nec_filter, +}; |