swdptap: Handle no_delay parity/turnaround as well

* This allows dropping the 0-loops check from delay_busy

src/platforms/common/swdptap.c

@@ -58,8 +58,6 @@ void swdptap_init(void)
 static inline void platform_delay_busy(const uint32_t loops)
 {
 #if 1
-	if (loops < 1U)
-		return;
 	register uint32_t i = loops;
 	do {
 		__asm__("nop");
@@ -86,11 +84,13 @@ static void swdptap_turnaround(const swdio_status_t dir)
 		SWDIO_MODE_FLOAT();
 	} else {
 		gpio_clear(SWCLK_PORT, SWCLK_PIN);
-		platform_delay_busy(target_clk_divider + 1);
+		if (target_clk_divider != UINT32_MAX)
+			platform_delay_busy(target_clk_divider);
 	}
 
 	gpio_set(SWCLK_PORT, SWCLK_PIN);
-	platform_delay_busy(target_clk_divider + 1);
+	if (target_clk_divider != UINT32_MAX)
+		platform_delay_busy(target_clk_divider);
 
 	if (dir == SWDIO_STATUS_DRIVE) {
 		SWDIO_MODE_DRIVE();
@@ -141,13 +141,15 @@ static uint32_t swdptap_seq_in(size_t clock_cycles)
 static bool swdptap_seq_in_parity(uint32_t *ret, size_t clock_cycles)
 {
 	const uint32_t result = swdptap_seq_in(clock_cycles);
-	platform_delay_busy(target_clk_divider + 1);
+	if (target_clk_divider != UINT32_MAX)
+		platform_delay_busy(target_clk_divider);
 
 	size_t parity = __builtin_popcount(result);
 	parity += gpio_get(SWDIO_IN_PORT, SWDIO_IN_PIN) ? 1U : 0U;
 
 	gpio_set(SWCLK_PORT, SWCLK_PIN);
-	platform_delay_busy(target_clk_divider + 1);
+	if (target_clk_divider != UINT32_MAX)
+		platform_delay_busy(target_clk_divider);
 
 	*ret = result;
 	/* Terminate the read cycle now */
@@ -197,11 +199,16 @@ static void swdptap_seq_out(const uint32_t tms_states, const size_t clock_cycles
 
 static void swdptap_seq_out_parity(const uint32_t tms_states, const size_t clock_cycles)
 {
-	int parity = __builtin_popcount(tms_states);
+	const int parity = __builtin_popcount(tms_states);
 	swdptap_seq_out(tms_states, clock_cycles);
+
 	gpio_set_val(SWDIO_PORT, SWDIO_PIN, parity & 1U);
-	platform_delay_busy(target_clk_divider + 1);
+	if (target_clk_divider != UINT32_MAX)
+		platform_delay_busy(target_clk_divider);
+
 	gpio_set(SWCLK_PORT, SWCLK_PIN);
-	platform_delay_busy(target_clk_divider + 1);
+	if (target_clk_divider != UINT32_MAX)
+		platform_delay_busy(target_clk_divider);
+
 	gpio_clear(SWCLK_PORT, SWCLK_PIN);
 }