From 71dc93b3b1239221c5dc92671f4d876dd569bd03 Mon Sep 17 00:00:00 2001
From: Sylvain Munaut <tnt@246tNt.com>
Date: Mon, 29 Apr 2024 20:50:59 +0200
Subject: [PATCH] icE1usb fw: Add AIS error flag and fill it along with LOS
 from linemon

Now that we monitor low level line status, we can fill in a proper
LOS signal along with the newly introduced AIS flag

Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
Change-Id: Ied28b6b3da74f6a63a007fae889b571cc2c1e835
---
 firmware/ice40-riscv/icE1usb/e1.c            | 33 ++++++++++++++++++--
 firmware/ice40-riscv/icE1usb/e1.h            |  1 +
 firmware/ice40-riscv/icE1usb/ice1usb_proto.h |  1 +
 3 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/firmware/ice40-riscv/icE1usb/e1.c b/firmware/ice40-riscv/icE1usb/e1.c
index 1582cec..6baee16 100644
--- a/firmware/ice40-riscv/icE1usb/e1.c
+++ b/firmware/ice40-riscv/icE1usb/e1.c
@@ -565,12 +565,18 @@ e1_poll(int port)
 	if (e1_regs->rx.csr & E1_RX_SR_ALIGNED) {
 		e1_platform_led_set(port, E1P_LED_GREEN, E1P_LED_ST_ON);
 		led_color(0, 48, 0);
-		e1->errors.flags &= ~(E1_ERR_F_LOS|E1_ERR_F_ALIGN_ERR);
+		e1->errors.flags &= ~(
+			E1_ERR_F_LOS |
+			E1_ERR_F_AIS |
+			E1_ERR_F_RAI |
+			E1_ERR_F_ALIGN_ERR
+		);
 	} else {
 		e1_platform_led_set(port, E1P_LED_GREEN, E1P_LED_ST_BLINK);
 		e1_platform_led_set(port, E1P_LED_YELLOW, E1P_LED_ST_OFF);
 		led_color(48, 0, 0);
-		e1->errors.flags |= E1_ERR_F_ALIGN_ERR;
+		e1->errors.flags |=  E1_ERR_F_ALIGN_ERR;
+		e1->errors.flags &= ~E1_ERR_F_RAI;
 		/* TODO: completely off if rx tick counter not incrementing */
 	}
 
@@ -748,7 +754,30 @@ e1_linemon_update(void)
 
 	/* Next cycle */
 	if (++cycle == 6)
+	{
+		/* We did one full cycle of data, update our local flags */
+		for (int port=0; port<NUM_E1_PORTS; port++)
+		{
+			struct e1_state *e1 = _get_state(port);
+			if (e1->linemon.rx_pulse < 16) {
+				/* No pulse ?  -> LOS */
+				e1->errors.flags |=  E1_ERR_F_LOS;
+				e1->errors.flags &= ~E1_ERR_F_AIS;
+			} else {
+				/* We have "some" pulses, so somone is talking */
+				e1->errors.flags &= ~E1_ERR_F_LOS;
+
+				/* If it's mostly ones, consider it AIS */
+				if (e1->linemon.rx_one > 2040)
+					e1->errors.flags |=  E1_ERR_F_AIS;
+				else
+					e1->errors.flags &= ~E1_ERR_F_AIS;
+			}
+		}
+
+		/* Start over */
 		cycle = 0;
+	}
 }
 
 void
diff --git a/firmware/ice40-riscv/icE1usb/e1.h b/firmware/ice40-riscv/icE1usb/e1.h
index 883e1ec..1e8e747 100644
--- a/firmware/ice40-riscv/icE1usb/e1.h
+++ b/firmware/ice40-riscv/icE1usb/e1.h
@@ -35,6 +35,7 @@ unsigned int e1_tx_level(int port);
 #define E1_ERR_F_ALIGN_ERR	0x01
 #define E1_ERR_F_LOS		0x02
 #define E1_ERR_F_RAI		0x04
+#define E1_ERR_F_AIS		0x08
 
 struct e1_error_count {
 	uint16_t crc;
diff --git a/firmware/ice40-riscv/icE1usb/ice1usb_proto.h b/firmware/ice40-riscv/icE1usb/ice1usb_proto.h
index 8cf8439..8bc8fbb 100644
--- a/firmware/ice40-riscv/icE1usb/ice1usb_proto.h
+++ b/firmware/ice40-riscv/icE1usb/ice1usb_proto.h
@@ -143,6 +143,7 @@ enum ice1usb_irq_type {
 #define ICE1USB_ERR_F_ALIGN_ERR	0x01
 #define ICE1USB_ERR_F_LOS	0x02
 #define ICE1USB_ERR_F_RAI	0x04
+#define ICE1USB_ERR_F_AIS	0x08
 
 struct ice1usb_irq_err {
 	/* 16-bit little-endian counters */