[PATCH 3/5] ARM: zynq: add driver for Zynq uarts

[Josh Cartwright]

Simple UART driver for Zynq SoCs, based loosely on the u-boot driver.

Signed-off-by: Josh Cartwright <joshc at eso.teric.us>
---
 drivers/serial/Kconfig       |   6 ++
 drivers/serial/Makefile      |   1 +
 drivers/serial/serial_zynq.c | 144 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 151 insertions(+)
 create mode 100644 drivers/serial/serial_zynq.c

diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index f61d670..608b616 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -113,4 +113,10 @@ config DRIVER_SERIAL_OMAP4_USBBOOT
 	help
 	  Enable this to get console support over the usb bus used to boot an OMAP4
 
+config DRIVER_SERIAL_ZYNQ
+	bool "driver for Zynq uarts"
+	default n
+	help
+	  Say Y here to get console out support with the Zynq uarts
+
 endmenu
diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
index 893e282..883394f 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_ZYNQ)		+= serial_zynq.o
diff --git a/drivers/serial/serial_zynq.c b/drivers/serial/serial_zynq.c
new file mode 100644
index 0000000..ec93b58
--- /dev/null
+++ b/drivers/serial/serial_zynq.c
@@ -0,0 +1,144 @@
+/*
+ * (C) Copyright 2013 Josh Cartwright
+ *
+ * Based very loosely on u-boot drivers/serial/serial_zynq.c.
+ *
+ * Copyright (C) 2012 Michal Simek <monstr at monstr.eu>
+ * Copyright (C) 2011-2012 Xilinx, Inc. All rights reserved.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+#include <common.h>
+#include <io.h>
+#include <init.h>
+#include <driver.h>
+#include <xfuncs.h>
+#include <console.h>
+#include <malloc.h>
+
+#include <linux/clk.h>
+
+#define UART_CR		0x00000000
+#define UART_CR_TXEN	(1<<4)
+#define UART_CR_RXEN	(1<<2)
+#define UART_CR_TXRST	(1<<1)
+#define UART_CR_RXRST	(1<<0)
+
+#define UART_SR		0x0000002C
+#define UART_SR_TXFULL	(1<<4)
+#define UART_SR_TXEMPTY	(1<<3)
+#define UART_SR_RXFULL	(1<<2)
+#define UART_SR_RXEMPTY	(1<<1)
+
+#define UART_FIFO	0x00000030
+
+struct zynq_serial_device {
+	struct console_device cdev;
+	struct clk *clk;
+	void __iomem *regs;
+};
+
+#define to_zynq_device(p) container_of(p, struct zynq_serial_device, cdev)
+
+static void zynq_serial_init_device(struct zynq_serial_device *dev)
+{
+	writel(UART_CR_TXEN | UART_CR_RXEN | UART_CR_TXEN | UART_CR_RXEN,
+	       dev->regs + UART_CR);
+}
+
+static int zynq_serial_tstc(struct console_device *cdev)
+{
+	struct zynq_serial_device *zynq = to_zynq_device(cdev);
+
+	return !(readl(zynq->regs + UART_SR) & UART_SR_RXEMPTY);
+}
+
+static void zynq_serial_putc(struct console_device *cdev, char c)
+{
+	struct zynq_serial_device *zynq = to_zynq_device(cdev);
+
+	while (readl(zynq->regs + UART_SR) & UART_SR_TXFULL);
+
+	writel(c, zynq->regs + UART_FIFO);
+}
+
+static int zynq_serial_getc(struct console_device *cdev)
+{
+	struct zynq_serial_device *zynq = to_zynq_device(cdev);
+
+	return readl(zynq->regs + UART_FIFO);
+}
+
+static void zynq_serial_flush(struct console_device *cdev)
+{
+	struct zynq_serial_device *zynq = to_zynq_device(cdev);
+
+	while (!(readl(zynq->regs + UART_SR) & UART_SR_TXEMPTY));
+}
+
+static int zynq_serial_probe(struct device_d *dev)
+{
+	struct zynq_serial_device *priv;
+	struct console_device *cdev;
+	int err;
+
+	priv = xzalloc(sizeof(*priv));
+	cdev = &priv->cdev;
+
+	priv->regs	= dev_request_mem_region(dev, 0);
+	cdev->dev	= dev;
+	cdev->f_caps	= CONSOLE_STDIN | CONSOLE_STDOUT | CONSOLE_STDERR;
+	cdev->tstc	= zynq_serial_tstc;
+	cdev->putc	= zynq_serial_putc;
+	cdev->getc	= zynq_serial_getc;
+	cdev->flush	= zynq_serial_flush;
+
+	priv->clk = clk_get(dev, NULL);
+
+	err = clk_enable(priv->clk);
+	if (err) {
+		free(priv);
+		return err;
+	}
+
+	zynq_serial_init_device(priv);
+
+	dev->priv = priv;
+
+	return console_register(cdev);
+}
+
+static void zynq_serial_remove(struct device_d *dev)
+{
+	struct zynq_serial_device *zynq = dev->priv;
+	clk_disable(zynq->clk);
+	free(zynq);
+}
+
+static struct driver_d zynq_serial_driver = {
+	.name	= "zynq_serial",
+	.probe	= zynq_serial_probe,
+	.remove = zynq_serial_remove,
+};
+
+static int zynq_serial_init(void)
+{
+	return platform_driver_register(&zynq_serial_driver);
+}
+console_initcall(zynq_serial_init);
-- 
1.8.1.2