MLK-18577-4 serial: add simple xen debug output

Add simple debug output when uboot runs in a VM.
Needs DM_SERIAL disabled, and XEN_DEBUG_SERIAL enabled.

Signed-off-by: Peng Fan <peng.fan@nxp.com>

4 files changed, 79 insertions, 0 deletions

diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index b11f3ff89eb..6140c4b7613 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -413,4 +413,10 @@ config PXA_SERIAL
 	  If you have a machine based on a Marvell XScale PXA2xx CPU you
 	  can enable its onboard serial ports by enabling this option.
 
+config XEN_DEBUG_SERIAL
+	bool "XEN debug serial support"
+	depends on XEN
+	help
+	  This is not pv console, it needs CONFIG_VERBOSE_DEBUG in XEN.
+
 endmenu
diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
index 8430668bf98..290030fe3ab 100644
--- a/drivers/serial/Makefile
+++ b/drivers/serial/Makefile
@@ -46,6 +46,7 @@ obj-$(CONFIG_STM32X7_SERIAL) += serial_stm32x7.o
 obj-$(CONFIG_BCM283X_MU_SERIAL) += serial_bcm283x_mu.o
 obj-$(CONFIG_MSM_SERIAL) += serial_msm.o
 obj-$(CONFIG_MVEBU_A3700_UART) += serial_mvebu_a3700.o
+obj-$(CONFIG_XEN_DEBUG_SERIAL) += serial_xen.o
 
 ifndef CONFIG_SPL_BUILD
 obj-$(CONFIG_USB_TTY) += usbtty.o
diff --git a/drivers/serial/serial.c b/drivers/serial/serial.c
index f1bd15b002d..69809a9f02f 100644
--- a/drivers/serial/serial.c
+++ b/drivers/serial/serial.c
@@ -154,6 +154,7 @@ serial_initfunc(sconsole_serial_initialize);
 serial_initfunc(sh_serial_initialize);
 serial_initfunc(stm32_serial_initialize);
 serial_initfunc(uartlite_serial_initialize);
+serial_initfunc(xen_debug_serial_initialize);
 serial_initfunc(zynq_serial_initialize);
 
 /**
@@ -245,6 +246,7 @@ void serial_initialize(void)
 	sh_serial_initialize();
 	stm32_serial_initialize();
 	uartlite_serial_initialize();
+	xen_debug_serial_initialize();
 	zynq_serial_initialize();
 
 	serial_assign(default_serial_console()->name);
diff --git a/drivers/serial/serial_xen.c b/drivers/serial/serial_xen.c
new file mode 100644
index 00000000000..ce0c36319b5
--- /dev/null
+++ b/drivers/serial/serial_xen.c
@@ -0,0 +1,70 @@
+/*
+ * Copyright 2018 NXP
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <serial.h>
+
+extern void xenprintf(const char *buf);
+extern void xenprintc(const char c);
+#ifndef CONFIG_DM_SERIAL
+
+static void xen_debug_serial_putc(const char c)
+{
+	/* If \n, also do \r */
+	if (c == '\n')
+		serial_putc('\r');
+
+	xenprintc(c);
+}
+
+static void xen_debug_serial_puts(const char *buf)
+{
+	xenprintf(buf);
+}
+
+static int xen_debug_serial_start(void)
+{
+	return 0;
+}
+
+static void xen_debug_serial_setbrg(void)
+{
+
+}
+
+static int xen_debug_serial_getc(void)
+{
+	return 0;
+}
+
+static int xen_debug_serial_tstc(void)
+{
+	return 0;
+}
+
+static struct serial_device xen_debug_serial_drv = {
+	.name	= "xen_debug_serial",
+	.start	= xen_debug_serial_start,
+	.stop	= NULL,
+	.setbrg	= xen_debug_serial_setbrg,
+	.putc	= xen_debug_serial_putc,
+	.puts	= xen_debug_serial_puts,
+	.getc	= xen_debug_serial_getc,
+	.tstc	= xen_debug_serial_tstc,
+};
+
+void xen_debug_serial_initialize(void)
+{
+	serial_register(&xen_debug_serial_drv);
+}
+
+__weak struct serial_device *default_serial_console(void)
+{
+	return &xen_debug_serial_drv;
+}
+#endif