driver/serial: add driver for the mxs application uart

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

3 files changed, 243 insertions, 0 deletions

diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index 5fb19bb452..48bea603e8 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -24,6 +24,10 @@ config DRIVER_SERIAL_STM378X
 	default y
 	bool "i.MX23/i.MX28 debug UART serial driver"
 
+config DRIVER_SERIAL_AUART
+	depends on ARCH_MXS
+	bool "i.MX23/i.MX28 application UART serial driver"
+
 config DRIVER_SERIAL_NETX
 	depends on ARCH_NETX
 	default y
diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
index 893e282c63..6b90593d23 100644
--- a/drivers/serial/Makefile
+++ b/drivers/serial/Makefile
@@ -21,3 +21,4 @@ obj-$(CONFIG_DRIVER_SERIAL_ALTERA)		+= serial_altera.o
 obj-$(CONFIG_DRIVER_SERIAL_ALTERA_JTAG)		+= serial_altera_jtag.o
 obj-$(CONFIG_DRIVER_SERIAL_PXA)			+= serial_pxa.o
 obj-$(CONFIG_DRIVER_SERIAL_OMAP4_USBBOOT)	+= serial_omap4_usbboot.o
+obj-$(CONFIG_DRIVER_SERIAL_AUART)		+= serial_auart.o
diff --git a/drivers/serial/serial_auart.c b/drivers/serial/serial_auart.c
new file mode 100644
index 0000000000..fa2e04f447
--- /dev/null
+++ b/drivers/serial/serial_auart.c
@@ -0,0 +1,238 @@
+/*
+ * (C) 2013 Marc Kleine-Budde <mkl@pengutronix.de>
+ *
+ * Based on the stm-serial driver:
+ *
+ * (C) Copyright 2010 Juergen Beisert - Pengutronix
+ *
+ * ...also based on the u-boot auart driver:
+ *
+ * (C) 2011 Wolfgang Ocker <weo@reccoware.de>
+ *
+ * Based on the standard DUART serial driver:
+ *
+ * (C) 2007 Sascha Hauer <s.hauer@pengutronix.de>
+ *
+ * (C) Copyright 2009-2010 Freescale Semiconductor, Inc.
+ *
+ * Further based on the Linux mxs-auart.c driver:
+ *
+ * Freescale STMP37XX/STMP378X Application UART driver
+ *
+ * Author: dmitry pervushin <dimka@embeddedalley.com>
+ *
+ * Copyright 2008-2010 Freescale Semiconductor, Inc.
+ * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <common.h>
+#include <gpio.h>
+#include <init.h>
+#include <io.h>
+#include <malloc.h>
+#include <notifier.h>
+
+#include <mach/clock.h>
+#include <mach/mxs.h>
+#include <mach/imx-regs.h>
+
+#define HW_UARTAPP_CTRL0		(0x00000000)
+
+#define HW_UARTAPP_CTRL2		(0x00000020)
+#define HW_UARTAPP_CTRL2_SET		(0x00000024)
+#define HW_UARTAPP_CTRL2_CLR		(0x00000028)
+#define BM_UARTAPP_CTRL2_CTSEN		(0x00008000)
+#define BM_UARTAPP_CTRL2_RTSEN		(0x00004000)
+#define BM_UARTAPP_CTRL2_RXE		(0x00000200)
+#define BM_UARTAPP_CTRL2_TXE		(0x00000100)
+#define BM_UARTAPP_CTRL2_USE_LCR2	(0x00000040)
+#define BM_UARTAPP_CTRL2_UARTEN		(0x00000001)
+
+#define HW_UARTAPP_LINECTRL		(0x00000030)
+#define BM_UARTAPP_LINECTRL_FEN		(0x00000010)
+
+#define BM_UARTAPP_LINECTRL_BAUD_DIVFRAC (0x00003F00)
+#define BF_UARTAPP_LINECTRL_BAUD_DIVFRAC(v) \
+	(((v) << 8) & BM_UARTAPP_LINECTRL_BAUD_DIVFRAC)
+
+#define BP_UARTAPP_LINECTRL_BAUD_DIVINT	(16)
+#define BM_UARTAPP_LINECTRL_BAUD_DIVINT	(0xFFFF0000)
+#define BF_UARTAPP_LINECTRL_BAUD_DIVINT(v) \
+	(((v) << 16) & BM_UARTAPP_LINECTRL_BAUD_DIVINT)
+
+#define BP_UARTAPP_LINECTRL_WLEN	(5)
+#define BM_UARTAPP_LINECTRL_WLEN	(0x00000060)
+#define BF_UARTAPP_LINECTRL_WLEN(v) \
+	(((v) << 5) & BM_UARTAPP_LINECTRL_WLEN)
+
+#define HW_UARTAPP_LINECTRL2_SET	(0x00000044)
+
+#define HW_UARTAPP_INTR			(0x00000050)
+
+#define HW_UARTAPP_DATA			(0x00000060)
+#define BM_UARTAPP_STAT_RXFE		(0x01000000)
+#define BM_UARTAPP_STAT_TXFE		(0x08000000)
+
+#define HW_UARTAPP_STAT			(0x00000070)
+#define BM_UARTAPP_STAT_TXFF		(0x02000000)
+
+struct auart_priv {
+	struct console_device cdev;
+	int baudrate;
+	struct notifier_block notify;
+	void __iomem *base;
+};
+
+static void auart_serial_putc(struct console_device *cdev, char c)
+{
+	struct auart_priv *priv = container_of(cdev, struct auart_priv, cdev);
+
+	/* Wait for room in TX FIFO */
+	while (readl(priv->base + HW_UARTAPP_STAT) & BM_UARTAPP_STAT_TXFF)
+		;
+
+	writel(c, priv->base + HW_UARTAPP_DATA);
+}
+
+static int auart_serial_tstc(struct console_device *cdev)
+{
+	struct auart_priv *priv = container_of(cdev, struct auart_priv, cdev);
+
+	/* Check if RX FIFO is not empty */
+	return !(readl(priv->base + HW_UARTAPP_STAT) & BM_UARTAPP_STAT_RXFE);
+}
+
+static int auart_serial_getc(struct console_device *cdev)
+{
+	struct auart_priv *priv = container_of(cdev, struct auart_priv, cdev);
+
+	/* Wait while RX FIFO is empty */
+	while (!auart_serial_tstc(cdev))
+		;
+
+	return readl(priv->base + HW_UARTAPP_DATA) & 0xff;
+}
+
+static void auart_serial_flush(struct console_device *cdev)
+{
+	struct auart_priv *priv = container_of(cdev, struct auart_priv, cdev);
+
+	/* Wait for TX FIFO empty */
+	while (readl(priv->base + HW_UARTAPP_STAT) & BM_UARTAPP_STAT_TXFE)
+		;
+}
+
+static int auart_serial_setbaudrate(struct console_device *cdev, int new_baudrate)
+{
+	struct auart_priv *priv = container_of(cdev, struct auart_priv, cdev);
+	uint32_t ctrl2, quot, reg;
+
+	/* Disable everything */
+	ctrl2 = readl(priv->base + HW_UARTAPP_CTRL2);
+	writel(0x0, priv->base + HW_UARTAPP_CTRL2);
+
+	/* Calculate and set baudrate */
+	quot = (imx_get_xclk() * 32) / new_baudrate;
+	reg = BF_UARTAPP_LINECTRL_BAUD_DIVFRAC(quot & 0x3F) |
+		BF_UARTAPP_LINECTRL_BAUD_DIVINT(quot >> 6) |
+		BF_UARTAPP_LINECTRL_WLEN(3) |
+		BM_UARTAPP_LINECTRL_FEN;
+
+	writel(reg, priv->base + HW_UARTAPP_LINECTRL);
+
+	/* Re-enable UART */
+	writel(ctrl2, priv->base + HW_UARTAPP_CTRL2);
+
+	priv->baudrate = new_baudrate;
+
+	return 0;
+}
+
+static int auart_clocksource_clock_change(struct notifier_block *nb, unsigned long event, void *data)
+{
+	struct auart_priv *priv = container_of(nb, struct auart_priv, notify);
+
+	return auart_serial_setbaudrate(&priv->cdev, priv->baudrate);
+}
+
+static void auart_serial_init_port(struct auart_priv *priv)
+{
+	mxs_reset_block(priv->base + HW_UARTAPP_CTRL0, 0);
+
+	/* Disable UART */
+	writel(0x0, priv->base + HW_UARTAPP_CTRL2);
+	/* Mask interrupts */
+	writel(0x0, priv->base + HW_UARTAPP_INTR);
+}
+
+static int auart_serial_probe(struct device_d *dev)
+{
+	struct auart_priv *priv;
+	struct console_device *cdev;
+
+	priv = xzalloc(sizeof *priv);
+	cdev = &priv->cdev;
+
+	cdev->f_caps = CONSOLE_STDIN | CONSOLE_STDOUT | CONSOLE_STDERR;
+	cdev->tstc = auart_serial_tstc;
+	cdev->putc = auart_serial_putc;
+	cdev->getc = auart_serial_getc;
+	cdev->flush = auart_serial_flush;
+	cdev->setbrg = auart_serial_setbaudrate;
+	cdev->dev = dev;
+
+	dev->priv = priv;
+	priv->base = dev_request_mem_region(dev, 0);
+
+	auart_serial_init_port(priv);
+	auart_serial_setbaudrate(cdev, CONFIG_BAUDRATE);
+
+	/* Disable RTS/CTS, enable Rx, Tx, UART */
+	writel(BM_UARTAPP_CTRL2_RTSEN | BM_UARTAPP_CTRL2_CTSEN |
+	       BM_UARTAPP_CTRL2_USE_LCR2,
+	       priv->base + HW_UARTAPP_CTRL2_CLR);
+	writel(BM_UARTAPP_CTRL2_RXE | BM_UARTAPP_CTRL2_TXE |
+	       BM_UARTAPP_CTRL2_UARTEN,
+	       priv->base + HW_UARTAPP_CTRL2_SET);
+
+	console_register(cdev);
+	priv->notify.notifier_call = auart_clocksource_clock_change;
+	clock_register_client(&priv->notify);
+
+	return 0;
+}
+
+
+static void auart_serial_remove(struct device_d *dev)
+{
+	struct auart_priv *priv = dev->priv;
+
+	auart_serial_flush(&priv->cdev);
+	console_unregister(&priv->cdev);
+	free(priv);
+}
+
+static struct driver_d auart_serial_driver = {
+	.name = "auart_serial",
+	.probe = auart_serial_probe,
+	.remove = auart_serial_remove,
+};
+
+static int auart_serial_init(void)
+{
+	platform_driver_register(&auart_serial_driver);
+	return 0;
+}
+
+console_initcall(auart_serial_init);