some initial code for PICC side

git-svn-id: https://svn.openpcd.org:2342/trunk@118 6dc7ffe9-61d6-0310-9af1-9938baff3ed1

6 files changed, 423 insertions, 0 deletions

diff --git a/openpcd/firmware/src/picc/decoder.c b/openpcd/firmware/src/picc/decoder.c
new file mode 100644
index 0000000..2ca051f
--- /dev/null
+++ b/openpcd/firmware/src/picc/decoder.c
@@ -0,0 +1,62 @@
+/* Decoder Core for OpenPCD / OpenPICC
+ * (C) 2006 by Harald Welte <hwelte@hmw-consulting.de>
+ */
+
+#include <sys/types.h>
+#include "decoder.h"
+
+static struct decoder_algo *decoder_algo[DECODER_NUM_ALGOS];
+
+static int get_next_data(struct decoder_state *st, u_int8_t *data)
+{
+	u_int8_t parity_sample;
+	u_int32_t bytesample;
+
+	bytesample = st->algo->get_next_bytesample(st, &parity_sample);
+
+	return st->algo->decode_sample(bytesample, data);
+}
+
+/* iterate over sample buffer (size N bytes) and decode data */
+int decoder_decode(u_int8_t algo, const char *sample_buf,
+	  	   int sample_buf_size, char *data_buf)
+{
+	int ret;
+	struct decoder_state st;
+
+	if (algo >= DECODER_NUM_ALGOS)
+		return -EINVAL;
+
+	st.buf = sample_buf;
+	st.buf32 = (u_int32_t *) st.buf;
+	st.bit_ofs = 0;
+	st.algo = decoder_algo[algo];
+
+	for (i = 0; i < (sample_buf_size*8)/st.algo->bits_per_sampled_char;
+	     i++) {
+		ret = get_next_data(&st, &data_buf[i]);
+		if (ret < 0) {
+			DEBUGPCR("decoder error %d at data byte %u",
+				 ret, i);
+			return ret;
+		}
+	}
+
+	return i+1;
+}
+
+int decoder_register(int algo, struct decoder_algo *algo)
+{
+	if (algo >= DECODER_NUM_ALGOS)
+		return -EINVAL;
+
+	decoder_algos[algo] = algo;
+
+	return 0;
+}
+
+int decoder_init(void)
+{
+	decoder_register(DECODER_MILLER, &miller_decoder);
+	decoder_register(DECODER_NRZL, &nrzl_decoder);
+}
diff --git a/openpcd/firmware/src/picc/decoder.h b/openpcd/firmware/src/picc/decoder.h
new file mode 100644
index 0000000..950efd2
--- /dev/null
+++ b/openpcd/firmware/src/picc/decoder.h
@@ -0,0 +1,32 @@
+#ifndef _DECODER_H
+#define _DECODER_H
+
+struct decoder_state;
+
+struct decoder_algo {
+	u_int8_t oversampling_rate;		
+	u_int8_t bits_per_sampled_char;
+	u_int8_t bytesample_mask;
+	int (*decode_sample)(const u_int32_t sample, u_int8_t data);
+	u_int32_t (*get_next_bytesample)(struct decoder_state *st, u_int8_t *parity_sample);
+};
+
+struct decoder_state {
+	struct decoder_algo *algo;
+	u_int8_t bit_ofs;
+	const char *buf;
+	const u_int32_t *buf32;
+};
+
+extern int decoder_register(int algo, struct decoder_algo *algo);
+extern int decoder_decode(u_int8_t algo, const char *sample_buf,
+		  	  int sample_buf_size, char *data_buf);
+
+#define DECODER_MILLER		0
+#define DECODER_NRZL		1
+#define DECODER_NUM_ALGOS 	2
+
+extern struct decoder_algo nrzl_decoder;
+extern struct decoder_algo miller_decoder;
+
+#endif
diff --git a/openpcd/firmware/src/picc/decoder_miller.c b/openpcd/firmware/src/picc/decoder_miller.c
new file mode 100644
index 0000000..4036511
--- /dev/null
+++ b/openpcd/firmware/src/picc/decoder_miller.c
@@ -0,0 +1,111 @@
+/* 
+ * ISO14443A modified Miller decoder
+ * (C) 2006 by Harald Welte <hwelte@hmw-consulting.de>
+ *
+ * 		LSB First	LSB 	hex
+ * Sequence X	0010		0100	0x4
+ * Sequence Y	0000		0000	0x0
+ * Sequence Z	1000		0001	0x1
+ *
+ * Logic 1	Sequence X
+ * Logic 0	Sequence Y with two exceptions:
+ * 		- if there are more contiguous 0, Z used from second one
+ * 		- if the first bit after SOF is 0, sequence Z used for all contig 0's
+ * SOF		Sequence Z
+ * EOF		Logic 0 followed by Sequence Y
+ *
+ * cmd	   hex	   bits            symbols              hex (quad-sampled)
+ *
+ * REQA    0x26    S 0110010 E     Z ZXXYZXY ZY		0x10410441
+ * WUPA    0x52    S 0100101 E     Z ZXYZXYX YY		0x04041041
+ *
+ * SOF is 'eaten' by SSC start condition (Compare 0). Remaining bits are
+ * mirrored, e.g. samples for LSB of first byte are & 0xf
+ *
+ */
+
+#include <sys/types.h>
+#include "decoder.h"
+
+
+#define OVERSAMPLING_RATE	4
+
+/* definitions for four-times oversampling */
+#define SEQ_X	0x4
+#define SEQ_Y	0x0
+#define SEQ_Z	0x1
+
+/* decode a single sampled bit */
+static u_int8_t miller_decode_sampled_bit(u_int32_t sampled_bit)
+{
+	switch (sampled_bit) {
+	case SEQ_X:
+		return 1;
+		break;
+	case SEQ_Z:
+	case SEQ_Y:
+		return 0;
+		break;
+	default:
+		DEBUGP("unknown sequence sample `%x' ", bit_sample);
+		return 2;
+		break;
+	}
+}
+
+/* decode a single 32bit data sample of an 8bit miller encoded word */
+static int miller_decode_sample(u_int32_t sample, u_int8_t *data)
+{
+	u_int8_t ret = 0;
+	int err, i;
+
+	for (i = 0; i < sizeof(sample)/OVERSAMPLING_RATE; i++) {
+		u_int8_t bit = miller_decode_sampled_bit(sample & 0xf);
+
+		if (bit == 1)
+			ret |= 1;
+		/* else do nothing since ret was initialized with 0 */
+
+		/* skip shifting in case of last data bit */
+		if (i == sizeof(sample)/OVERSAMPLING_RATE)
+			break;
+
+		sample = sample >> OVERSAMPLING_RATE;
+		ret = ret << 1;
+	}
+
+	*data = ret;
+
+	return ret;
+}
+
+static u_int32_t get_next_bytesample(struct decoder_state *ms,
+				     u_int8_t *parity_sample)
+{
+	u_int32_t ret = 0;
+	u_int8_t parity_sample;
+
+	/* get remaining bits from the current word */
+	ret = *(ms->buf32) >> ms->bit_ofs;
+	/* move to next word */
+	ms->buf32++;
+
+	/* if required, get remaining bits from next word */
+	if (bit_ofs)
+		ret |= *(ms->buf32) << (32 - ms->bit_ofs);
+	
+	*parity_sample = (*(ms->buf32) >> ms->bit_ofs & 0xf);
+
+	/* increment bit offset (modulo 32) */
+	ms->bit_ofs = (ms->bit_ofs + OVERSAMPLING_RATE) % 32;
+
+	return ret;
+}
+
+static struct decoder_algo miller_decoder = {
+	.oversampling_rate = OVERSAMPLING_RATE,
+	.bits_per_sampled_char = 9 * OVERSAMPLING_RATE,
+	.bytesample_mask = 0xffffffff,
+	.decode_sample = &miller_decode_sample,
+	.get_next_bytesample = &get_next_bytesample,
+};
diff --git a/openpcd/firmware/src/picc/decoder_nrzl.c b/openpcd/firmware/src/picc/decoder_nrzl.c
new file mode 100644
index 0000000..bb297db
--- /dev/null
+++ b/openpcd/firmware/src/picc/decoder_nrzl.c
@@ -0,0 +1,89 @@
+/* ISO 14443 B Rx (PCD->PICC) implementation
+ * (C) 2006 by Harald Welte <hwelte@hmw-consulting.de>
+ *
+ * speed(kbps)	106	212	424	848
+ * etu		128/fc	64/fc	32/fc	16/fc
+ * etu(usec)	9.4	4.7	2.35	1.18
+ *
+ * NRZ-L coding with logic level
+ *
+ * logic 1:	carrier high field amplitude (no modulation)
+ * logic 0:	carrier low field amplitude
+ *
+ * Character transmission format:
+ *	start bit:	logic 0
+ *	data:		eight bits, lsb first
+ *	stop bit	logic 1
+ *
+ * Frame Format:
+ *
+ * 		SOF char [EGT char, ...] EOF
+ *
+ * 	SOF: falling edge, 10..11 etu '0', rising edge in 1etu, 2..3etu '1'
+ *	EGT: between 0 and 57uS 
+ *	EOF: falling edge, 10..11 etu '0', rising edge in 1etu
+ *
+ *
+ * Sampling
+ * - sample once per bit clock, exactly in the middle of it
+ * - synchronize CARRIER_DIV TC0 to first falling edge
+ * - Configure CARRIER_DIV RA compare (rising edge) to be at
+ *   etu/2 carrier clocks.
+ * - problem: SOF 12..14etu length, therefore we cannot specify
+ *            SOF as full start condition and then sample with 10bit
+ *            frames :(
+ * 
+ */
+
+#include <sys/types.h>
+#include "decoder.h"
+
+/* currently this code will only work with oversampling_rate == 1 */
+#define OVERSAMPLING_RATE 1
+
+static u_int32_t get_next_bytesample(struct decoder_state *st,
+				     u_int8_t *parity_sample)
+{
+	u_int32_t ret = 0;
+	u_int8_t bits_per_sampled_char = st->algo->bits_per_sampled_char;
+	u_int8_t bytesample_mask = st->algo->bytesample_mask;
+
+	/* FIXME: shift start and stop bit into parity_sample and just
+	 * return plain 8-bit data word */
+	
+	/* first part of 10-databit bytesample */
+	ret = (*(st->buf32) >> st->bit_ofs) & bytesample_mask;
+
+	if (st->bit_ofs > 32 - bits_per_sampled_char) {
+		/* second half of 10-databit bytesample */
+		st->buf32++;
+		ret |= (*(st->buf32) << (32 - st->bit_ofs));
+	}
+	st->bit_ofs = (st->bit_ofs + bits_per_sampled_char) % 32;
+
+	return ret & bytesample_mask;
+}
+
+static int nrzl_decode_sample(const u_int32_t sample, u_int8_t data)
+{
+	*data = (sample >> 1) & 0xff;
+
+	if (!(sample & 0x01)) {
+		DEBUGPCRF("invalid start bit 0!");
+		return -EIO;
+	}
+	if (sample & 0x20) {
+		DEBUGPCRF("invalid stop bit 1!");
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static struct decoder_algo nrzl_decoder = {
+	.oversampling_rate = OVERSAMPLING_RATE,
+	.bits_per_sampled_char = 10 * OVERSAMPLING_RATE,
+	.bytesample_mask = 0x3ff;
+	.decode_sample = &nrzl_decode_sample,
+	.get_next_bytesample = &get_next_bytesample,
+};
diff --git a/openpcd/firmware/src/picc/iso14443a_manchester.c b/openpcd/firmware/src/picc/iso14443a_manchester.c
new file mode 100644
index 0000000..aca832c
--- /dev/null
+++ b/openpcd/firmware/src/picc/iso14443a_manchester.c
@@ -0,0 +1,106 @@
+/* 
+ * ISO14443A Manchester encoder
+ * (C) 2006 by Harald Welte <hwelte@hmw-consulting.de>
+ *
+ * Definitions for 106kBps, at sampling clock 1695kHz
+ *
+ * 		bit sample pattern for one bit cycle
+ * 		MSB first		LSB first	hex LSB first
+ * Sequence D	1010101000000000	0000000001010101	0x0055
+ * Sequence E	0000000010101010	0101010100000000	0x5500
+ * Sequence F	1010101010101010	0101010101010101	0x5555
+ *
+ * Logic 1	Sequence D
+ * Logic 0	Sequence E
+ * SOF		Sequence D
+ * EOF		Sequence F
+ *
+ * 212/424/848kBps: BPSK.
+ *
+ * SOF: 32 subcarrier clocks + bit '0'
+ *
+ * SOF:		hex LSB first: 0x55555555 55555555 + bit '0'
+ *
+ * EOF:		even parity of last byte (!)
+ *
+ */
+
+#define MANCHESTER_SEQ_D	0x0055
+#define MANCHESTER_SEQ_E	0x5500
+#define MANCHESTER_SEQ_F	0x5555
+
+static u_int32_t manchester_sample_size(u_int8_t frame_bytelen)
+{
+	/* 16 bits (2 bytes) per bit => 16 bytes samples per data byte,
+	 * plus 16bit (2 bytes) parity per data byte
+	 * plus 16bit (2 bytes) SOF plus 16bit (2 bytes) EOF */
+	return (frame_bytelen*18) + 2 + 2;
+
+	/* this results in a maximum samples-per-frame size of 4612 bytes
+	 * for a 256byte frame */
+}
+
+struct manch_enc_state {
+	const char *data;
+	char *samples;
+	u_int16_t *samples16;
+};
+
+static void manchester_enc_byte(struct manch_enc_state *mencs, u_int8_t data)
+{
+	int i;
+	u_int8_t sum_1 = 0;
+
+	/* append 8 sample blobs, one for each bit */
+	for (i = 0; i < 8; i++) {
+		if (data & (1 << i)) {
+			*(mencs->samples16) = MANCHESTER_SEQ_D;
+			sum_1++;
+		} else {
+			*(mencs->samples16) = MANCHESTER_SEQ_E;
+		}
+		mencs->samples16++
+	}
+	/* append odd parity */
+	if (sum_1 & 0x01)
+		*(mencs->samples16) = MANCHESTER_SEQ_E;
+	else
+		*(mencs->samples16) = MANCHESTER_SEQ_D;
+	mencs->samples16++
+}
+ 
+int manchester_encode(char *sample_buf, u_int16_t sample_buf_len, 
+		      const char *data, u_int8_t data_len)
+{
+	int i, enc_size;
+	struct manch_enc_state mencs
+
+	enc_size = manchester_sample_size(data_len);
+
+	if (sample_buf_len < enc_size)
+		return -EINVAL;
+
+	/* SOF */
+	*(mencs.samples16++) = MANCHESTER_SEQ_D;
+
+	for (i = 0; i < data_len; i++)
+		manchester_enc_byte(mencs, data[i]);
+		
+	/* EOF */
+	*(mencs.samples16++) = MANCHESTER_SEQ_F;
+
+	return enc_size;
+}
+
+#define BPSK_SPEED_212	
+
+
+static u_int32_t bpsk_sample_size(u_int8_t frame_bytelen)
+
+int bpsk_encode(char *sample_buf, u_int16_t sample_buf_len,
+		const char *data, u_int8_t data_len)
+{
+	/* burst of 32 sub carrier cycles */	
+	memset(sample_buf, 0x55, 8);
+
+}
diff --git a/openpcd/firmware/src/picc/piccsim.h b/openpcd/firmware/src/picc/piccsim.h
new file mode 100644
index 0000000..34c7bf0
--- /dev/null
+++ b/openpcd/firmware/src/picc/piccsim.h
@@ -0,0 +1,23 @@
+
+#include <librfdi/rfid_layer2_iso14443a.h>
+
+struct piccsim_state {
+	enum rfid_layer2_id l2prot;
+	unsigned char uid[10];
+	u_int8_t uid_len;
+	union {
+		struct {
+			enum iso14443a_state state;
+			enum iso14443a_level level;
+			u_int32_t flags;
+		} iso14443a;
+		struct {
+		} iso14443b;
+	} l2;
+
+	union {
+		u_int32_t flags;
+	} proto;
+}
+
+#define PICCSIM_PROT_F_AUTO_WTX		0x01