Add support for SMSC LPC47N207 SuperI/O chip

This includes only early serial support for now.

Change-Id: I9a2a439e1d17a989428033fdb4a4b813553dab6d
Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Signed-off-by: Stefan Reinauer <reinauer@google.com>
Reviewed-on: http://review.coreboot.org/823
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

2 files changed, 122 insertions, 0 deletions

diff --git a/src/superio/smsc/lpc47n207/early_serial.c b/src/superio/smsc/lpc47n207/early_serial.c
new file mode 100644
index 0000000000..e2ae49da66
--- /dev/null
+++ b/src/superio/smsc/lpc47n207/early_serial.c
@@ -0,0 +1,97 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2012 The ChromiumOS Authors.  All rights reserved.
+ *
+ * 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; version 2 of the License.
+ *
+ * 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/*
+ * This code tries to discover the SMSC LPC47N207 superio chip which can be
+ * connected over an LPC dongle. The chip could be bootstrap mapped to one of
+ * four LPC addresses: 0x2e, 0x4e, 0x162e, and 0x164e.
+ *
+ * Initializing the UART requires accesses to a few control registers. This
+ * structure includes the register offset and the value to write (along with
+ * the mask).
+ */
+typedef struct {
+	u8 conf_reg;
+	u8 value;
+	u8 mask;
+} uart_conf;
+
+/* All regs/values to write to initialize the LPC47N207 UART */
+static const uart_conf uart_conf_data [] = {
+	{2, (1 << 3), (1 << 3)},    /* cr02, enable Primary UART power */
+	{0xc, (1 << 6), (1 << 6)},  /* cr0c, enable Primary UART high speed */
+	{0x24, (CONFIG_TTYS0_BASE >> 3) << 1, 0xff},  /* cr24, base addr */
+};
+
+void try_enabling_LPC47N207_uart(void)
+{
+	u8 reg_value;
+	const uart_conf* conf_item;
+	u16 lpc_ports[] = {0x2e, 0x4e, 0x162e, 0x164e};
+	u16 lpc_port;
+	int i, j;
+
+#define CONFIG_ENABLE    0x55
+#define CONFIG_DISABLE   0xaa
+
+	for (j = 0; j < ARRAY_SIZE(lpc_ports); j++) {
+		lpc_port = lpc_ports[j];
+
+		/* enable CONFIG mode */
+		outb(CONFIG_ENABLE, lpc_port);
+		reg_value=inb(lpc_port);
+		if (reg_value != CONFIG_ENABLE) {
+			continue; /* There is no LPC device at this address */
+		}
+
+		do {
+			/*
+			 * Registers 12 and 13 hold config address, look for a
+			 * match.
+			 */
+			outb(0x12, lpc_port);
+			reg_value=inb(lpc_port + 1);
+			if (reg_value != (lpc_port & 0xff))
+			    break;
+
+			outb(0x13, lpc_port);
+			reg_value=inb(lpc_port + 1);
+			if (reg_value != (lpc_port >> 8))
+				break;
+
+			/* This must be the SMSC LPC 47N207, enable the UART. */
+			for (i = 0; i < ARRAY_SIZE(uart_conf_data); i++) {
+				u8 reg, value, mask;
+
+				conf_item = uart_conf_data + i;
+
+				reg = conf_item->conf_reg;
+				value = conf_item->value;
+				mask = conf_item->mask;
+
+				outb(reg, lpc_port);
+				reg_value = inb(lpc_port + 1);
+				reg_value &= ~mask;
+				reg_value |= (value & mask);
+				outb(reg_value, lpc_port + 1);
+			}
+		} while (0);
+		outb(CONFIG_DISABLE, lpc_port);
+	}
+}
diff --git a/src/superio/smsc/lpc47n207/lpc47n207.h b/src/superio/smsc/lpc47n207/lpc47n207.h
new file mode 100644
index 0000000000..69689a4dfe
--- /dev/null
+++ b/src/superio/smsc/lpc47n207/lpc47n207.h
@@ -0,0 +1,25 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2012 The ChromiumOS Authors.  All rights reserved.
+ *
+ * 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; version 2 of the License.
+ *
+ * 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef SUPERIO_SMSC_LPC47N207_LPC47N207_H
+#define SUPERIO_SMSC_LPC47N207_LPC47N207_H
+
+extern void try_enabling_LPC47N207_uart(void);
+
+#endif