cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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img-ir-nec.c (4607B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 * ImgTec IR Decoder setup for NEC protocol.
      4 *
      5 * Copyright 2010-2014 Imagination Technologies Ltd.
      6 */
      7
      8#include "img-ir-hw.h"
      9#include <linux/bitrev.h>
     10#include <linux/log2.h>
     11
     12/* Convert NEC data to a scancode */
     13static int img_ir_nec_scancode(int len, u64 raw, u64 enabled_protocols,
     14			       struct img_ir_scancode_req *request)
     15{
     16	unsigned int addr, addr_inv, data, data_inv;
     17	/* a repeat code has no data */
     18	if (!len)
     19		return IMG_IR_REPEATCODE;
     20	if (len != 32)
     21		return -EINVAL;
     22	/* raw encoding: ddDDaaAA */
     23	addr     = (raw >>  0) & 0xff;
     24	addr_inv = (raw >>  8) & 0xff;
     25	data     = (raw >> 16) & 0xff;
     26	data_inv = (raw >> 24) & 0xff;
     27	if ((data_inv ^ data) != 0xff) {
     28		/* 32-bit NEC (used by Apple and TiVo remotes) */
     29		/* scan encoding: as transmitted, MSBit = first received bit */
     30		request->scancode = bitrev8(addr)     << 24 |
     31				bitrev8(addr_inv) << 16 |
     32				bitrev8(data)     <<  8 |
     33				bitrev8(data_inv);
     34		request->protocol = RC_PROTO_NEC32;
     35	} else if ((addr_inv ^ addr) != 0xff) {
     36		/* Extended NEC */
     37		/* scan encoding: AAaaDD */
     38		request->scancode = addr     << 16 |
     39				addr_inv <<  8 |
     40				data;
     41		request->protocol = RC_PROTO_NECX;
     42	} else {
     43		/* Normal NEC */
     44		/* scan encoding: AADD */
     45		request->scancode = addr << 8 |
     46				data;
     47		request->protocol = RC_PROTO_NEC;
     48	}
     49	return IMG_IR_SCANCODE;
     50}
     51
     52/* Convert NEC scancode to NEC data filter */
     53static int img_ir_nec_filter(const struct rc_scancode_filter *in,
     54			     struct img_ir_filter *out, u64 protocols)
     55{
     56	unsigned int addr, addr_inv, data, data_inv;
     57	unsigned int addr_m, addr_inv_m, data_m, data_inv_m;
     58
     59	data       = in->data & 0xff;
     60	data_m     = in->mask & 0xff;
     61
     62	protocols &= RC_PROTO_BIT_NEC | RC_PROTO_BIT_NECX | RC_PROTO_BIT_NEC32;
     63
     64	/*
     65	 * If only one bit is set, we were requested to do an exact
     66	 * protocol. This should be the case for wakeup filters; for
     67	 * normal filters, guess the protocol from the scancode.
     68	 */
     69	if (!is_power_of_2(protocols)) {
     70		if ((in->data | in->mask) & 0xff000000)
     71			protocols = RC_PROTO_BIT_NEC32;
     72		else if ((in->data | in->mask) & 0x00ff0000)
     73			protocols = RC_PROTO_BIT_NECX;
     74		else
     75			protocols = RC_PROTO_BIT_NEC;
     76	}
     77
     78	if (protocols == RC_PROTO_BIT_NEC32) {
     79		/* 32-bit NEC (used by Apple and TiVo remotes) */
     80		/* scan encoding: as transmitted, MSBit = first received bit */
     81		addr       = bitrev8(in->data >> 24);
     82		addr_m     = bitrev8(in->mask >> 24);
     83		addr_inv   = bitrev8(in->data >> 16);
     84		addr_inv_m = bitrev8(in->mask >> 16);
     85		data       = bitrev8(in->data >>  8);
     86		data_m     = bitrev8(in->mask >>  8);
     87		data_inv   = bitrev8(in->data >>  0);
     88		data_inv_m = bitrev8(in->mask >>  0);
     89	} else if (protocols == RC_PROTO_BIT_NECX) {
     90		/* Extended NEC */
     91		/* scan encoding AAaaDD */
     92		addr       = (in->data >> 16) & 0xff;
     93		addr_m     = (in->mask >> 16) & 0xff;
     94		addr_inv   = (in->data >>  8) & 0xff;
     95		addr_inv_m = (in->mask >>  8) & 0xff;
     96		data_inv   = data ^ 0xff;
     97		data_inv_m = data_m;
     98	} else {
     99		/* Normal NEC */
    100		/* scan encoding: AADD */
    101		addr       = (in->data >>  8) & 0xff;
    102		addr_m     = (in->mask >>  8) & 0xff;
    103		addr_inv   = addr ^ 0xff;
    104		addr_inv_m = addr_m;
    105		data_inv   = data ^ 0xff;
    106		data_inv_m = data_m;
    107	}
    108
    109	/* raw encoding: ddDDaaAA */
    110	out->data = data_inv << 24 |
    111		    data     << 16 |
    112		    addr_inv <<  8 |
    113		    addr;
    114	out->mask = data_inv_m << 24 |
    115		    data_m     << 16 |
    116		    addr_inv_m <<  8 |
    117		    addr_m;
    118	return 0;
    119}
    120
    121/*
    122 * NEC decoder
    123 * See also http://www.sbprojects.com/knowledge/ir/nec.php
    124 *        http://wiki.altium.com/display/ADOH/NEC+Infrared+Transmission+Protocol
    125 */
    126struct img_ir_decoder img_ir_nec = {
    127	.type = RC_PROTO_BIT_NEC | RC_PROTO_BIT_NECX | RC_PROTO_BIT_NEC32,
    128	.control = {
    129		.decoden = 1,
    130		.code_type = IMG_IR_CODETYPE_PULSEDIST,
    131	},
    132	/* main timings */
    133	.unit = 562500, /* 562.5 us */
    134	.timings = {
    135		/* leader symbol */
    136		.ldr = {
    137			.pulse = { 16	/* 9ms */ },
    138			.space = { 8	/* 4.5ms */ },
    139		},
    140		/* 0 symbol */
    141		.s00 = {
    142			.pulse = { 1	/* 562.5 us */ },
    143			.space = { 1	/* 562.5 us */ },
    144		},
    145		/* 1 symbol */
    146		.s01 = {
    147			.pulse = { 1	/* 562.5 us */ },
    148			.space = { 3	/* 1687.5 us */ },
    149		},
    150		/* free time */
    151		.ft = {
    152			.minlen = 32,
    153			.maxlen = 32,
    154			.ft_min = 10,	/* 5.625 ms */
    155		},
    156	},
    157	/* repeat codes */
    158	.repeat = 108,			/* 108 ms */
    159	.rtimings = {
    160		/* leader symbol */
    161		.ldr = {
    162			.space = { 4	/* 2.25 ms */ },
    163		},
    164		/* free time */
    165		.ft = {
    166			.minlen = 0,	/* repeat code has no data */
    167			.maxlen = 0,
    168		},
    169	},
    170	/* scancode logic */
    171	.scancode = img_ir_nec_scancode,
    172	.filter = img_ir_nec_filter,
    173};