iso7816_fidi: Add iso7816_3_ prefix to symbols; fix terminology

Fi/Di are not the index into the table, but the contents of the table
as resolved by Fi_index / Di_index.  Let's clarify the terminology.

Change-Id: If364e08e7c9a3a9707e6d54b9267c6a7c088e415

5 files changed, 19 insertions, 18 deletions

diff --git a/firmware/libcommon/include/iso7816_fidi.h b/firmware/libcommon/include/iso7816_fidi.h
index c56478b..19483b0 100644
--- a/firmware/libcommon/include/iso7816_fidi.h
+++ b/firmware/libcommon/include/iso7816_fidi.h
@@ -21,10 +21,10 @@
 #include <stdint.h>
 
 /* Table 7 of ISO 7816-3:2006 */
-extern const uint16_t fi_table[];
+extern const uint16_t iso7816_3_fi_table[16];
 
 /* Table 8 from ISO 7816-3:2006 */
-extern const uint8_t di_table[];
+extern const uint8_t iso7816_3_di_table[16];
 
-/* compute the F/D ratio based on Fi and Di values */
-int compute_fidi_ratio(uint8_t fi, uint8_t di);
+/* compute the F/D ratio based on F_index and D_index values */
+int iso7816_3_compute_fd_ratio(uint8_t f_index, uint8_t d_index);
diff --git a/firmware/libcommon/source/card_emu.c b/firmware/libcommon/source/card_emu.c
index 1193121..c5e4cfa 100644
--- a/firmware/libcommon/source/card_emu.c
+++ b/firmware/libcommon/source/card_emu.c
@@ -377,7 +377,7 @@ static void emu_update_fidi(struct card_handle *ch)
 {
 	int rc;
 
-	rc = compute_fidi_ratio(ch->F_index, ch->D_index);
+	rc = iso7816_3_compute_fd_ratio(ch->F_index, ch->D_index);
 	if (rc > 0 && rc < 0x400) {
 		TRACE_INFO("%u: computed F(%u)/D(%u) ratio: %d\r\n", ch->num,
 			   ch->F_index, ch->D_index, rc);
@@ -508,7 +508,7 @@ static int tx_byte_atr(struct card_handle *ch)
 			}
 		}
 		/* update waiting time (see ISO 7816-3 10.2) */
-		ch->waiting_time = ch->wi * 960 * fi_table[ch->F_index];
+		ch->waiting_time = ch->wi * 960 * iso7816_3_fi_table[ch->F_index];
 		tc_etu_set_wtime(ch->tc_chan, ch->waiting_time);
 		/* go to next state */
 		card_set_state(ch, ISO_S_WAIT_TPDU);
@@ -647,7 +647,7 @@ static int tx_byte_pts(struct card_handle *ch)
 		ch->F_index = byte >> 4;
 		ch->D_index = byte & 0xf;
 		TRACE_DEBUG("%u: found F=%u D=%u\r\n", ch->num,
-			    fi_table[ch->F_index], di_table[ch->D_index]);
+			    iso7816_3_fi_table[ch->F_index], iso7816_3_di_table[ch->D_index]);
 		/* FIXME: if F or D are 0, become unresponsive to signal error condition */
 		break;
 	case PTS_S_WAIT_RESP_PTS2:
diff --git a/firmware/libcommon/source/iso7816_fidi.c b/firmware/libcommon/source/iso7816_fidi.c
index 1c70467..033a325 100644
--- a/firmware/libcommon/source/iso7816_fidi.c
+++ b/firmware/libcommon/source/iso7816_fidi.c
@@ -23,38 +23,38 @@
 #include "iso7816_fidi.h"
 
 /* Table 7 of ISO 7816-3:2006 */
-const uint16_t fi_table[] = {
+const uint16_t iso7816_3_fi_table[] = {
 	372, 372, 558, 744, 1116, 1488, 1860, 0,
 	0, 512, 768, 1024, 1536, 2048, 0, 0
 };
 
 /* Table 8 from ISO 7816-3:2006 */
-const uint8_t di_table[] = {
+const uint8_t iso7816_3_di_table[] = {
 	0, 1, 2, 4, 8, 16, 32, 64,
 	12, 20, 2, 4, 8, 16, 32, 64,
 };
 
 /* compute the F/D ratio based on Fi and Di values */
-int compute_fidi_ratio(uint8_t fi, uint8_t di)
+int iso7816_3_compute_fd_ratio(uint8_t f_index, uint8_t d_index)
 {
 	uint16_t f, d;
 	int ret;
 
-	if (fi >= ARRAY_SIZE(fi_table) ||
-	    di >= ARRAY_SIZE(di_table))
+	if (f_index >= ARRAY_SIZE(iso7816_3_fi_table) ||
+	    d_index >= ARRAY_SIZE(iso7816_3_di_table))
 		return -EINVAL;
 
-	f = fi_table[fi];
+	f = iso7816_3_fi_table[f_index];
 	if (f == 0)
 		return -EINVAL;
 
-	d = di_table[di];
+	d = iso7816_3_di_table[d_index];
 	if (d == 0)
 		return -EINVAL;
 
 	/* See table 7 of ISO 7816-3: From 1000 on we divide by 1/d,
 	 * which equals a multiplication by d */
-	if (di < 8)
+	if (d_index < 8)
 		ret = f / d;
 	else
 		ret = f * d;
diff --git a/firmware/libcommon/source/simtrace_iso7816.c b/firmware/libcommon/source/simtrace_iso7816.c
index 8742696..27677a6 100644
--- a/firmware/libcommon/source/simtrace_iso7816.c
+++ b/firmware/libcommon/source/simtrace_iso7816.c
@@ -125,7 +125,7 @@ void update_fidi(Usart_info *usart, uint8_t fidi)
 
 	uint8_t fi = fidi >> 4;
 	uint8_t di = fidi & 0xf;
-	int ratio = compute_fidi_ratio(fi, di);
+	int ratio = iso7816_3_compute_fd_ratio(fi, di);
 
 	if (ratio > 0 && ratio < 0x8000) {
 		/* make sure USART uses new F/D ratio */
diff --git a/firmware/libcommon/source/sniffer.c b/firmware/libcommon/source/sniffer.c
index 08770e2..57e2daa 100644
--- a/firmware/libcommon/source/sniffer.c
+++ b/firmware/libcommon/source/sniffer.c
@@ -658,9 +658,10 @@ static void process_byte_pps(uint8_t byte)
 					fn = 1;
 					dn = 1;
 				}
-				TRACE_INFO("PPS negotiation successful: Fn=%u Dn=%u\n\r", fi_table[fn], di_table[dn]);
+				TRACE_INFO("PPS negotiation successful: Fn=%u Dn=%u\n\r",
+					   iso7816_3_fi_table[fn], iso7816_3_di_table[dn]);
 				update_fidi(&sniff_usart, pps_cur[2]);
-				update_wt(0, di_table[dn]);
+				update_wt(0, iso7816_3_di_table[dn]);
 				usb_send_fidi(pps_cur[2]); /* send Fi/Di change notification to host software over USB */
 			} else { /* checksum is invalid */
 				TRACE_INFO("PPS negotiation failed\n\r");