misc: Add simple driver to enable the legacy UART on Winbond Super IO chips
On most x86 boards, the legacy serial ports (io address 0x3f8/0x2f8)
are provided by a superio chip connected to the LPC bus. We must
program the superio chip so that serial ports are available for us.
Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Bin Meng <bmeng.cn@gmail.com>
Cc: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index cba2363..af8667f 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -130,4 +130,12 @@
effect a reset. The uclass will try all available drivers when
reset_walk() is called.
+config WINBOND_W83627
+ bool "Enable Winbond Super I/O driver"
+ help
+ If you say Y here, you will get support for the Winbond
+ W83627 Super I/O driver. This can be used to enable the
+ legacy UART or other devices in the Winbond Super IO chips
+ on X86 platforms.
+
endmenu
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index cd4846b..e1e3c6b 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -41,3 +41,4 @@
obj-$(CONFIG_PCA9551_LED) += pca9551_led.o
obj-$(CONFIG_RESET) += reset-uclass.o
obj-$(CONFIG_FSL_DEVICE_DISABLE) += fsl_devdis.o
+obj-$(CONFIG_WINBOND_W83627) += winbond_w83627.o
diff --git a/drivers/misc/winbond_w83627.c b/drivers/misc/winbond_w83627.c
new file mode 100644
index 0000000..59db7d9
--- /dev/null
+++ b/drivers/misc/winbond_w83627.c
@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2016 Stefan Roese <sr@denx.de>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/pnp_def.h>
+
+#define WINBOND_ENTRY_KEY 0x87
+#define WINBOND_EXIT_KEY 0xaa
+
+/* Enable configuration: pass entry key '0x87' into index port dev twice */
+static void pnp_enter_conf_state(u16 dev)
+{
+ u16 port = dev >> 8;
+
+ outb(WINBOND_ENTRY_KEY, port);
+ outb(WINBOND_ENTRY_KEY, port);
+}
+
+/* Disable configuration: pass exit key '0xAA' into index port dev */
+static void pnp_exit_conf_state(u16 dev)
+{
+ u16 port = dev >> 8;
+
+ outb(WINBOND_EXIT_KEY, port);
+}
+
+/* Bring up early serial debugging output before the RAM is initialized */
+void winbond_enable_serial(uint dev, uint iobase, uint irq)
+{
+ pnp_enter_conf_state(dev);
+ pnp_set_logical_device(dev);
+ pnp_set_enable(dev, 0);
+ pnp_set_iobase(dev, PNP_IDX_IO0, iobase);
+ pnp_set_irq(dev, PNP_IDX_IRQ0, irq);
+ pnp_set_enable(dev, 1);
+ pnp_exit_conf_state(dev);
+}