superio/winbond/*: Provide common romstage component

Following the reasoning of:
cf7b498 superio/fintek/*: Factor out generic romstage component

Change-Id: I3e889c0305c012e7556a5dd348e7f1e1ba629a9d
Signed-off-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Reviewed-on: http://review.coreboot.org/5587
Tested-by: build bot (Jenkins)
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>

2 files changed, 101 insertions, 0 deletions

diff --git a/src/superio/winbond/common/early_serial.c b/src/superio/winbond/common/early_serial.c
new file mode 100644
index 0000000000..747cc458d0
--- /dev/null
+++ b/src/superio/winbond/common/early_serial.c
@@ -0,0 +1,72 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2014 Edward O'Callaghan <eocallaghan@alterapraxis.com>
+ *
+ * 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/*
+ * A generic romstage (pre-ram) driver for Winbond variant Super I/O chips.
+ *
+ * The following is derived directly from the vendor Winbond's data-sheets:
+ *
+ * To toggle between `configuration mode` and `normal operation mode` as to
+ * manipulation the various LDN's in Winbond Super I/O's we are required to
+ * pass magic numbers `passwords keys`.
+ *
+ *  WINBOUND_ENTRY_KEY :=  enable  configuration : 0x87
+ *  WINBOUND_EXIT_KEY  :=  disable configuration : 0xAA
+ *
+ * To modify a LDN's configuration register, we use the index port to select
+ * the index of the LDN and then write to the data port to alter the
+ * parameters. A default index, data port pair is 0x4E, 0x4F respectively, a
+ * user modified pair is 0x2E, 0x2F respectively.
+ *
+ */
+
+#include <arch/io.h>
+#include <device/pnp.h>
+#include <stdint.h>
+#include "winbond.h"
+
+#define WINBOND_ENTRY_KEY 0x87
+#define WINBOND_EXIT_KEY 0xAA
+
+/* Enable configuration: pass entry key '0x87' into index port dev. */
+static void pnp_enter_conf_state(device_t 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(device_t 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(device_t 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);
+}
diff --git a/src/superio/winbond/common/winbond.h b/src/superio/winbond/common/winbond.h
new file mode 100644
index 0000000000..20eefc8029
--- /dev/null
+++ b/src/superio/winbond/common/winbond.h
@@ -0,0 +1,29 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2014 Edward O'Callaghan <eocallaghan@alterapraxis.com>
+ *
+ * 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef SUPERIO_WINBOND_COMMON_ROMSTAGE_H
+#define SUPERIO_WINBOND_COMMON_ROMSTAGE_H
+
+#include <arch/io.h>
+#include <stdint.h>
+
+void winbond_enable_serial(device_t dev, u16 iobase);
+
+#endif /* SUPERIO_WINBOND_COMMON_ROMSTAGE_H */