From 38f549d78aa83ee574a65e14f45e5363e44b68cf Mon Sep 17 00:00:00 2001
From: Peter van der Perk <info@petervanderperk.nl>
Date: Tue, 7 May 2024 21:44:40 +0200
Subject: [PATCH] lpuart: IMXRT/S32K3XX implement TIOCSSINGLEWIREDUPLEX

---
 arch/arm/src/imxrt/imxrt_serial.c     | 28 ++++++++++++++++++++++++++-
 arch/arm/src/s32k3xx/s32k3xx_serial.c | 26 +++++++++++++++++++++++++
 2 files changed, 53 insertions(+), 1 deletion(-)

diff --git a/arch/arm/src/imxrt/imxrt_serial.c b/arch/arm/src/imxrt/imxrt_serial.c
index f91be50d254bc..30cbcd2ab4e50 100644
--- a/arch/arm/src/imxrt/imxrt_serial.c
+++ b/arch/arm/src/imxrt/imxrt_serial.c
@@ -2629,7 +2629,7 @@ static int imxrt_ioctl(struct file *filep, int cmd, unsigned long arg)
 
         if ((arg & SER_SINGLEWIRE_ENABLED) != 0)
           {
-            uint32_t gpio_val = IOMUX_OPENDRAIN;
+            uint32_t gpio_val = 0;
             gpio_val |= (arg & SER_SINGLEWIRE_PULL_MASK) ==
                          SER_SINGLEWIRE_PULLUP ?
                                         IOMUX_PULL_UP : IOMUX_PULL_NONE;
@@ -2653,6 +2653,32 @@ static int imxrt_ioctl(struct file *filep, int cmd, unsigned long arg)
         spin_unlock_irqrestore(NULL, flags);
       }
       break;
+
+    case TIOCSSINGLEWIREDUPLEX:
+      {
+        uint32_t regval;
+        irqstate_t flags;
+        struct imxrt_uart_s *priv = (struct imxrt_uart_s *)dev;
+
+        flags  = spin_lock_irqsave(NULL);
+        regval   = imxrt_serialin(priv, IMXRT_LPUART_CTRL_OFFSET);
+
+        if ((arg & SER_SINGLEWIRE_DUPLEX_TX) != 0)
+          {
+            regval &= ~(LPUART_CTRL_RSRC);
+            regval |= (LPUART_CTRL_TXDIR);
+          }
+        else /* RX Mode */
+          {
+            regval |= LPUART_CTRL_RSRC;
+            regval &= ~(LPUART_CTRL_TXDIR);
+          }
+
+        imxrt_serialout(priv, IMXRT_LPUART_CTRL_OFFSET, regval);
+
+        spin_unlock_irqrestore(NULL, flags);
+      }
+      break;
 #endif
 
 #ifdef CONFIG_IMXRT_LPUART_INVERT
diff --git a/arch/arm/src/s32k3xx/s32k3xx_serial.c b/arch/arm/src/s32k3xx/s32k3xx_serial.c
index e64152e4a2461..b4b520f4de2b3 100644
--- a/arch/arm/src/s32k3xx/s32k3xx_serial.c
+++ b/arch/arm/src/s32k3xx/s32k3xx_serial.c
@@ -3529,6 +3529,32 @@ static int s32k3xx_ioctl(struct file *filep, int cmd, unsigned long arg)
         spin_unlock_irqrestore(NULL, flags);
       }
       break;
+
+    case TIOCSSINGLEWIREDUPLEX:
+      {
+        uint32_t regval;
+        irqstate_t flags;
+        struct s32k3xx_uart_s *priv = (struct s32k3xx_uart_s *)dev->priv;
+
+        flags  = spin_lock_irqsave(NULL);
+        regval   = s32k3xx_serialin(priv, S32K3XX_LPUART_CTRL_OFFSET);
+
+        if ((arg & SER_SINGLEWIRE_DUPLEX_TX) != 0)
+          {
+            regval &= ~(LPUART_CTRL_RSRC);
+            regval |= (LPUART_CTRL_TXDIR);
+          }
+        else /* RX Mode */
+          {
+            regval |= LPUART_CTRL_RSRC;
+            regval &= ~(LPUART_CTRL_TXDIR);
+          }
+
+        s32k3xx_serialout(priv, S32K3XX_LPUART_CTRL_OFFSET, regval);
+
+        spin_unlock_irqrestore(NULL, flags);
+      }
+      break;
 #endif
 
 #ifdef CONFIG_S32K3XX_LPUART_INVERT