mainboard/opencellular/elgon: Add mainboard support

Tested on Elgon EVT board and boots into GNU/Linux.

TODO:
* Add hard reset function for VBOOT.
* Add EC code
* Add SPI flash write protection

Change-Id: I9b809306cc48facbade5dc63846c4532b397e0b5
Signed-off-by: Philipp Deppenwiese <zaolin@das-labor.org>
Reviewed-on: https://review.coreboot.org/28024
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Philipp Deppenwiese <zaolin.daisuki@gmail.com>

1 files changed, 56 insertions, 0 deletions

diff --git a/src/mainboard/opencellular/elgon/bootblock.c b/src/mainboard/opencellular/elgon/bootblock.c
new file mode 100644
index 0000000000..e6109f1072
--- /dev/null
+++ b/src/mainboard/opencellular/elgon/bootblock.c
@@ -0,0 +1,56 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2018 Facebook, Inc.
+ *
+ * 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.
+ */
+
+#include <bootblock_common.h>
+#include <soc/soc.h>
+#include <soc/spi.h>
+#include <soc/uart.h>
+#include <soc/gpio.h>
+#include "mainboard.h"
+
+void bootblock_mainboard_early_init(void)
+{
+	/* Route UART0 to CON1 */
+	gpio_output(ELGON_GPIO_UART_SEL, 0);
+
+	/* Turn off error LED */
+	gpio_output(ELGON_GPIO_ERROR_LED, 0);
+
+	if (IS_ENABLED(CONFIG_BOOTBLOCK_CONSOLE)) {
+		if (!uart_is_enabled(CONFIG_UART_FOR_CONSOLE))
+			uart_setup(CONFIG_UART_FOR_CONSOLE, CONFIG_TTYS0_BAUD);
+	}
+}
+
+static void configure_spi_flash(void)
+{
+	/* The maximum SPI frequency for error free transmission is at 30 Mhz */
+	spi_init_custom(0, // bus
+			28000000, // speed Hz
+			0, // idle low disabled
+			0, // zero idle cycles between transfers
+			0, // MSB first
+			0, // Chip select 0
+			1); // assert is high
+
+	/* Route SPI to SoC */
+	gpio_output(ELGON_GPIO_SPI_MUX, 1);
+}
+
+void bootblock_mainboard_init(void)
+{
+	configure_spi_flash();
+	// FIXME: Check SPI flash WP bits
+}