x86: Add a simple superio driver for SMSC LPC47M
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: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/misc/smsc_lpc47m.c b/drivers/misc/smsc_lpc47m.c
new file mode 100644
index 0000000..d51f8e3
--- /dev/null
+++ b/drivers/misc/smsc_lpc47m.c
@@ -0,0 +1,33 @@
+/*
+ * Copyright (C) 2014, Bin Meng <bmeng.cn@gmail.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/pnp_def.h>
+
+static void pnp_enter_conf_state(u16 dev)
+{
+ u16 port = dev >> 8;
+
+ outb(0x55, port);
+}
+
+static void pnp_exit_conf_state(u16 dev)
+{
+ u16 port = dev >> 8;
+
+ outb(0xaa, port);
+}
+
+void lpc47m_enable_serial(u16 dev, u16 iobase)
+{
+ 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_enable(dev, 1);
+ pnp_exit_conf_state(dev);
+}