From 87fda7e878cd948bb21905afa1fce9296cb4b912 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?King=20K=C3=A9vin?= <kingkevin@cuvoodoo.info>
Date: Fri, 5 Aug 2022 15:15:59 +0200
Subject: [PATCH] =?UTF-8?q?implement=20I=C2=B2C=20bus=20clear?=
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---
 main.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/main.c b/main.c
index 2d36126..a6e6eca 100644
--- a/main.c
+++ b/main.c
@@ -336,6 +336,16 @@ we will only be able to provide 1 extension block since we can only respond to o
 		SCL_SNK_PU_PORT->ODR.reg |= SCL_SNK_PU_PIN; // pull up SCL line
 		SCL_SNK_PU_PORT->CR1.reg |= SCL_SNK_PU_PIN; // switch pin to push pull
 		SCL_SNK_PU_PORT->DDR.reg |= SCL_SNK_PU_PIN; // switch pin to output
+		if (0 == (SDA_SNK_PORT->IDR.reg & SDA_SNK_PIN)) { // SDA line is stuck
+			puts ("bus clear ");
+			// perform bus clear
+			for (uint8_t i = 0; i < 9; i++) {
+				SCL_SNK_PORT->ODR.reg &= ~SCL_SNK_PIN;
+				wait_10us(1);
+				SCL_SNK_PORT->ODR.reg |= SCL_SNK_PIN;
+				wait_10us(1);
+			}
+		}
 		uint8_t i2c_rc = 1; // if the complete read succeeded
 		if (!softi2c_master_setup(400)) { // start the I²C master to talk to sink
 			i2c_rc = 2;