From c32449a161cb2280553bddc8346817c043e99f4f Mon Sep 17 00:00:00 2001
From: Giulio Benetti <giulio.benetti@benettiengineering.com>
Date: Fri, 10 Jan 2020 15:51:43 +0100
Subject: [PATCH] serial_lpuart: add support for i.MXRT

Add i.MXRT compatible string and cpu type support to lpuart driver,
to use little endian 32 bits configurations.

Also according to RM, the Receive RX FIFO Enable (RXFE) field in LPUART
FIFO register is bit 3, so this definition should change to 0x08 as done
for i.MX8. It needs also to set baudrate the same way as i.MX8 does.

Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
---
 drivers/serial/serial_lpuart.c | 15 +++++++++++----
 include/fsl_lpuart.h           |  3 ++-
 2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/drivers/serial/serial_lpuart.c b/drivers/serial/serial_lpuart.c
index b2ec56172e..ccb3ce6701 100644
--- a/drivers/serial/serial_lpuart.c
+++ b/drivers/serial/serial_lpuart.c
@@ -49,7 +49,7 @@
 #define FIFO_RXSIZE_MASK	0x7
 #define FIFO_RXSIZE_OFF	0
 #define FIFO_TXFE		0x80
-#ifdef CONFIG_ARCH_IMX8
+#if defined(CONFIG_ARCH_IMX8) || defined(CONFIG_ARCH_IMXRT)
 #define FIFO_RXFE		0x08
 #else
 #define FIFO_RXFE		0x40
@@ -67,7 +67,8 @@ enum lpuart_devtype {
 	DEV_VF610 = 1,
 	DEV_LS1021A,
 	DEV_MX7ULP,
-	DEV_IMX8
+	DEV_IMX8,
+	DEV_IMXRT,
 };
 
 struct lpuart_serial_platdata {
@@ -409,7 +410,8 @@ static int _lpuart32_serial_init(struct udevice *dev)
 
 	lpuart_write32(plat->flags, &base->match, 0);
 
-	if (plat->devtype == DEV_MX7ULP || plat->devtype == DEV_IMX8) {
+	if (plat->devtype == DEV_MX7ULP || plat->devtype == DEV_IMX8 ||
+	    plat->devtype == DEV_IMXRT) {
 		_lpuart32_serial_setbrg_7ulp(dev, gd->baudrate);
 	} else {
 		/* provide data bits, parity, stop bit, etc */
@@ -426,7 +428,8 @@ static int lpuart_serial_setbrg(struct udevice *dev, int baudrate)
 	struct lpuart_serial_platdata *plat = dev_get_platdata(dev);
 
 	if (is_lpuart32(dev)) {
-		if (plat->devtype == DEV_MX7ULP || plat->devtype == DEV_IMX8)
+		if (plat->devtype == DEV_MX7ULP || plat->devtype == DEV_IMX8 ||
+		    plat->devtype == DEV_IMXRT)
 			_lpuart32_serial_setbrg_7ulp(dev, baudrate);
 		else
 			_lpuart32_serial_setbrg(dev, baudrate);
@@ -530,6 +533,8 @@ static int lpuart_serial_ofdata_to_platdata(struct udevice *dev)
 		plat->devtype = DEV_VF610;
 	else if (!fdt_node_check_compatible(blob, node, "fsl,imx8qm-lpuart"))
 		plat->devtype = DEV_IMX8;
+	else if (!fdt_node_check_compatible(blob, node, "fsl,imxrt-lpuart"))
+		plat->devtype = DEV_IMXRT;
 
 	return 0;
 }
@@ -549,6 +554,8 @@ static const struct udevice_id lpuart_serial_ids[] = {
 	{ .compatible = "fsl,vf610-lpuart"},
 	{ .compatible = "fsl,imx8qm-lpuart",
 		.data = LPUART_FLAG_REGMAP_32BIT_REG },
+	{ .compatible = "fsl,imxrt-lpuart",
+		.data = LPUART_FLAG_REGMAP_32BIT_REG },
 	{ }
 };
 
diff --git a/include/fsl_lpuart.h b/include/fsl_lpuart.h
index fc517d4b7f..511fb84367 100644
--- a/include/fsl_lpuart.h
+++ b/include/fsl_lpuart.h
@@ -4,7 +4,8 @@
  *
  */
 
-#if defined(CONFIG_ARCH_MX7ULP) || defined(CONFIG_ARCH_IMX8)
+#if defined(CONFIG_ARCH_MX7ULP) || defined(CONFIG_ARCH_IMX8) || \
+	defined(CONFIG_ARCH_IMXRT)
 struct lpuart_fsl_reg32 {
 	u32 verid;
 	u32 param;