From 210fab8eae3a194bacbcbc7b24ad85c657699783 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?King=20K=C3=A9vin?= <kingkevin@cuvoodoo.info>
Date: Fri, 12 Mar 2021 13:10:59 +0100
Subject: [PATCH] swd: expose release pins

---
 lib/swd.c | 14 ++++++++++++--
 lib/swd.h |  2 ++
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/lib/swd.c b/lib/swd.c
index 2fe4be7..a4756ee 100644
--- a/lib/swd.c
+++ b/lib/swd.c
@@ -78,7 +78,7 @@ void swd_setup(uint32_t freq)
 }
 
 /** release used pins */
-static void swd_release_pins(void)
+void swd_release_pins(void)
 {
 	// release GPIO
 	gpio_mode_setup(swd_swclk_port, GPIO_MODE_INPUT, GPIO_PUPD_NONE, swd_swclk_pin); // put clock signal pin back to input floating
@@ -97,9 +97,19 @@ void swd_release(void)
 
 bool swd_set_pins(uint32_t swclk_port, uint32_t swclk_pin, uint32_t swdio_port, uint32_t swdio_pin)
 {
-	if (swclk_pin > (1 << 15) || swdio_pin > (1 << 15) || __builtin_popcount(swclk_pin) != 1 || __builtin_popcount(swdio_pin) != 1) { // check if pin exists and is unique
+	// check if pin exists and is unique
+	if (__builtin_popcount(swclk_pin) != 1 || __builtin_popcount(swdio_pin) != 1) {
 		return false;
 	}
+	// check if pin really exists
+	if (swclk_pin > (1 << 15) || swdio_pin > (1 << 15)) {
+		return false;
+	}
+	// ensure pin is different
+	if (swclk_port == swdio_port && swclk_pin == swdio_pin) {
+		return false;
+	}
+
 	uint32_t swclk_rcc = 0;
 	switch (swclk_port) {
 	case GPIOA:
diff --git a/lib/swd.h b/lib/swd.h
index 57bae6b..13a7bbe 100644
--- a/lib/swd.h
+++ b/lib/swd.h
@@ -90,6 +90,8 @@ void swd_setup(uint32_t freq);
 /** release 1-wire peripheral
  */
 void swd_release(void);
+/** release used pins */
+void swd_release_pins(void);
 /** set SWCLK and SWDIO pins
  *  @param[in] swclk_port port for SWCLK pin
  *  @param[in] swclk_pin pin for SWCLK pin