[PATCH] [Nios2]: Add Altera JTAG UART driver

[franck.jullien at gmail.com]

From: Franck Jullien <franck.jullien at gmail.com>

Add ALtera JTAG UART driver.

Signed-off-by: Franck Jullien <franck.jullien at gmail.com>
---
 drivers/serial/Kconfig              |   10 +++
 drivers/serial/Makefile             |    1 +
 drivers/serial/serial_altera_jtag.c |  106 +++++++++++++++++++++++++++++++++++
 3 files changed, 117 insertions(+), 0 deletions(-)
 create mode 100644 drivers/serial/serial_altera_jtag.c

diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index 9e05f4b..c8f9ecd 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -48,6 +48,16 @@ config DRIVER_SERIAL_ALTERA
 	default y
 	bool "Altera serial driver"
 
+config DRIVER_SERIAL_ALTERA_JTAG
+	depends on NIOS2
+	default n
+	bool "Altera JTAG serial driver"
+
+config ALTERA_JTAG_UART_BYPASS
+	depends on DRIVER_SERIAL_ALTERA_JTAG
+	default y
+	bool "Don't block on serial putc if JTAG is not connected"
+
 config DRIVER_SERIAL_NS16550
 	default n
 	bool "NS16550 serial driver"
diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
index df9e705..8b56d15 100644
--- a/drivers/serial/Makefile
+++ b/drivers/serial/Makefile
@@ -17,3 +17,4 @@ obj-$(CONFIG_DRIVER_SERIAL_NS16550)		+= serial_ns16550.o
 obj-$(CONFIG_DRIVER_SERIAL_PL010)		+= serial_pl010.o
 obj-$(CONFIG_DRIVER_SERIAL_S3C24X0)		+= serial_s3c24x0.o
 obj-$(CONFIG_DRIVER_SERIAL_ALTERA)		+= serial_altera.o
+obj-$(CONFIG_DRIVER_SERIAL_ALTERA_JTAG)		+= serial_altera_jtag.o
diff --git a/drivers/serial/serial_altera_jtag.c b/drivers/serial/serial_altera_jtag.c
new file mode 100644
index 0000000..70bc5a9
--- /dev/null
+++ b/drivers/serial/serial_altera_jtag.c
@@ -0,0 +1,106 @@
+/*
+ * (C) Copyright 2004, Psyent Corporation <www.psyent.com>
+ * Scott McNutt <smcnutt at psyent.com>
+ *
+ * (C) Copyright 2011 - Franck JULLIEN <elec4fun at gmail.com>
+ *
+ * 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 <driver.h>
+#include <init.h>
+#include <malloc.h>
+#include <asm/io.h>
+#include <asm/nios2-io.h>
+
+static int altera_serial_jtag_setbaudrate(struct console_device *cdev, int baudrate)
+{
+	return 0;
+}
+
+static void altera_serial_jtag_putc(struct console_device *cdev, char c)
+{
+	struct nios_jtag *jtag = (struct nios_jtag *)cdev->dev->map_base;
+	uint32_t st;
+
+	while (1) {
+		st = readl(&jtag->control);
+		if (NIOS_JTAG_WSPACE(st))
+			break;
+#ifdef CONFIG_ALTERA_JTAG_UART_BYPASS
+		if (!(st & NIOS_JTAG_AC)) /* no connection */
+			return;
+#endif
+	}
+
+	writel(c, &jtag->data);
+}
+
+static int altera_serial_jtag_tstc(struct console_device *cdev)
+{
+	struct nios_jtag *jtag = (struct nios_jtag *)cdev->dev->map_base;
+
+	return readl(&jtag->control) & NIOS_JTAG_RRDY;
+}
+
+static int altera_serial_jtag_getc(struct console_device *cdev)
+{
+	struct nios_jtag *jtag = (struct nios_jtag *)cdev->dev->map_base;
+	uint32_t val;
+	
+	while (1) {
+		val = readl(&jtag->data);
+		if (val & NIOS_JTAG_RVALID)
+			break;
+	}
+
+	return val & 0xFF;
+}
+
+static int altera_serial_jtag_probe(struct device_d *dev) {
+
+	struct console_device *cdev;
+
+	cdev = malloc(sizeof(struct console_device));
+	dev->type_data = cdev;
+	cdev->dev = dev;
+	cdev->f_caps = CONSOLE_STDIN | CONSOLE_STDOUT | CONSOLE_STDERR;
+	cdev->tstc = altera_serial_jtag_tstc;
+	cdev->putc = altera_serial_jtag_putc;
+	cdev->getc = altera_serial_jtag_getc;
+	cdev->setbrg = altera_serial_jtag_setbaudrate;
+
+	console_register(cdev);
+
+	return 0;
+}
+
+static struct driver_d altera_serial_jtag_driver = {
+	.name = "altera_serial_jtag",
+	.probe = altera_serial_jtag_probe,
+};
+
+static int altera_serial_jtag_init(void)
+{
+	return register_driver(&altera_serial_jtag_driver);
+}
+
+console_initcall(altera_serial_jtag_init);
+
-- 
1.7.0.4