From bb2767721945fa3496f777aa95eaab0137795137 Mon Sep 17 00:00:00 2001
From: Ahmed BOUDJELIDA <aboudjelida@nanoxplore.com>
Date: Mon, 16 Oct 2023 11:05:59 +0200
Subject: [PATCH] contrib/firmware: add 'send not acknowledged' function to the
 i2c bit-banging implementation

Change-Id: I60597ebc126da4acb00654513b96f52261253e12
Signed-off-by: Ahmed BOUDJELIDA <aboudjelida@nanoxplore.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/7811
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>
---
 contrib/firmware/angie/c/include/i2c.h |  1 +
 contrib/firmware/angie/c/src/i2c.c     | 10 ++++++++++
 contrib/firmware/angie/c/src/usb.c     |  3 +++
 3 files changed, 14 insertions(+)

diff --git a/contrib/firmware/angie/c/include/i2c.h b/contrib/firmware/angie/c/include/i2c.h
index 06185efb4d..d0404923b3 100644
--- a/contrib/firmware/angie/c/include/i2c.h
+++ b/contrib/firmware/angie/c/include/i2c.h
@@ -19,6 +19,7 @@ void repeated_start(void);
 void stop_cd(void);
 void clock_cd(void);
 void send_ack(void);
+void send_nack(void);
 bool get_ack(void);
 
 uint8_t get_address(uint8_t adr, uint8_t rdwr);
diff --git a/contrib/firmware/angie/c/src/i2c.c b/contrib/firmware/angie/c/src/i2c.c
index a7004bfac9..53840100b9 100644
--- a/contrib/firmware/angie/c/src/i2c.c
+++ b/contrib/firmware/angie/c/src/i2c.c
@@ -60,6 +60,16 @@ void send_ack(void)
 	delay_us(1);
 }
 
+void send_nack(void)
+{
+	PIN_SDA = 1;
+	delay_us(1);
+	PIN_SCL = 1;
+	delay_us(1);
+	PIN_SCL = 0;
+	delay_us(1);
+}
+
 bool get_ack(void)
 {
 	PIN_SDA_DIR = 1;
diff --git a/contrib/firmware/angie/c/src/usb.c b/contrib/firmware/angie/c/src/usb.c
index 0a43ff9f65..1b7aa47658 100644
--- a/contrib/firmware/angie/c/src/usb.c
+++ b/contrib/firmware/angie/c/src/usb.c
@@ -798,6 +798,9 @@ void i2c_recieve(void)
 
 		EP8FIFOBUF[count - 1] = receive_byte();
 
+		/*  send Nack:  */
+		send_nack();
+
 		/*   stop   */
 		stop_cd();