Add EM100 'hyper term' spi console support in ramstage & smm

The EM100Pro allows the debug console to be sent over the SPI bus.
This is not yet working in romstage due to the use of static variables
in the SPI driver code.  It is also not working on chipsets that have
SPI write buffers of less than 10 characters due to the 9 byte
command/header length specified by the EM100 protocol.

While this currently works only with the EM100, it seems like it would
be useful on any logic analyzer with SPI debug - just filter on command
bytes of 0x11.

Change-Id: Icd42ccd96cab0a10a4e70f4b02ecf9de8169564b
Signed-off-by: Martin Roth <martinroth@google.com>
Reviewed-on: http://review.coreboot.org/11743
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

src/Kconfig

@@ -777,6 +777,7 @@ config DEBUG_SMI
 	bool "Output verbose SMI debug messages"
 	default n
 	depends on HAVE_SMI_HANDLER
+	select SPI_FLASH_SMM if SPI_CONSOLE
 	help
 	  This option enables additional SMI related debug messages.
 

src/console/Kconfig

@@ -211,6 +211,14 @@ config CONSOLE_QEMU_DEBUGCON_PORT
 	depends on CONSOLE_QEMU_DEBUGCON
 	default 0x402
 
+config SPI_CONSOLE
+	bool "SPI debug console output"
+	depends on HAVE_SPI_CONSOLE_SUPPORT && !DEBUG_SPI_FLASH
+	help
+	  Enable support for the debug console on the Dediprog EM100Pro.
+	  This is currently working only in ramstage due to how the spi
+	  drivers are written.
+
 choice
 	prompt "Default console log level"
 	default DEFAULT_CONSOLE_LOGLEVEL_8

src/console/console.c

@@ -24,6 +24,7 @@
 #include <console/streams.h>
 #include <console/uart.h>
 #include <console/usb.h>
+#include <console/spi.h>
 #include <rules.h>
 
 void console_hw_init(void)
@@ -35,6 +36,7 @@ void console_hw_init(void)
 	__uart_init();
 	__ne2k_init();
 	__usbdebug_init();
+	__spiconsole_init();
 }
 
 void console_tx_byte(unsigned char byte)
@@ -54,6 +56,7 @@ void console_tx_byte(unsigned char byte)
 	__uart_tx_byte(byte);
 	__ne2k_tx_byte(byte);
 	__usb_tx_byte(byte);
+	__spiconsole_tx_byte(byte);
 }
 
 void console_tx_flush(void)

src/drivers/spi/Kconfig

@@ -137,3 +137,7 @@ config SPI_FLASH_FAST_READ_DUAL_OUTPUT_3B
 	  to the chip on MOSI and data is received on both MOSI and MISO.
 
 endif # SPI_FLASH
+
+config HAVE_SPI_CONSOLE_SUPPORT
+	def_bool n
+

src/drivers/spi/Makefile.inc

@@ -1,5 +1,10 @@
 # SPI flash driver interface
 
+ifeq ($(CONFIG_SPI_CONSOLE),y)
+ramstage-y += spiconsole.c
+smm-$(CONFIG_DEBUG_SMI) += spiconsole.c
+endif
+
 ifeq ($(CONFIG_COMMON_CBFS_SPI_WRAPPER),y)
 bootblock-y += spi_flash.c
 bootblock-$(CONFIG_SPI_FLASH_EON) += eon.c

src/drivers/spi/spiconsole.c

@@ -0,0 +1,71 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2015 Google 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.
+ *
+ * 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.
+ */
+
+#include <spi-generic.h>
+#include <spi_flash.h>
+#include <console/spi.h>
+
+void spiconsole_init(void) {
+	spi_init();
+	return;
+}
+
+/*
+ * The EM100 'hyper terminal' specification defines a header of 9 characters.
+ * Because of this, devices with a spi_crop_chunk of less than 10 characters
+ * can't be supported by this standard.
+ *
+ * To add support in romstage, the static struct here and the ones used by
+ * spi_xfer will need to be modified - removed, or mapped into cbmem.
+ *
+ * Because the Dediprog software expects strings, not single characters, and
+ * because of the header overhead, this builds up a buffer to send.
+ */
+void spiconsole_tx_byte(unsigned char c) {
+	static struct em100_msg msg = {
+		.header.spi_command = EM100_DEDICATED_CMD,
+		.header.em100_command = EM100_UFIFO_CMD,
+		.header.msg_signature = EM100_MSG_SIGNATURE,
+		.header.msg_type = EM100_MSG_ASCII,
+		.header.msg_length = 0
+	};
+
+	/* Verify the spi buffer is big enough to send even a single byte */
+	if (spi_crop_chunk(0,MAX_MSG_LENGTH) <
+			sizeof(struct em100_msg_header) + 1)
+		return;
+
+	msg.data[msg.header.msg_length] = c;
+	msg.header.msg_length++;
+
+	/* Send the data on newline or when the max spi length is reached */
+	if (c == '\n' || (sizeof(struct em100_msg_header) +
+			msg.header.msg_length == spi_crop_chunk(0,
+			MAX_MSG_LENGTH))) {
+		struct spi_slave spi = {.rw = SPI_READ_FLAG};
+
+		spi_xfer(&spi, &msg, sizeof(struct em100_msg_header) +
+				msg.header.msg_length, NULL, 0);
+
+		msg.header.msg_length = 0;
+	}
+
+	return;
+}
+

src/include/console/spi.h

@@ -0,0 +1,72 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2015 Google 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.
+ *
+ * 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.
+ */
+
+#ifndef CONSOLE_SPI_H
+#define CONSOLE_SPI_H 1
+
+#include <rules.h>
+#include <stdint.h>
+
+void spiconsole_init(void);
+void spiconsole_tx_byte(unsigned char c);
+
+#define __CONSOLE_SPI_ENABLE__	CONFIG_SPI_CONSOLE && \
+	(ENV_RAMSTAGE || (ENV_SMM && CONFIG_DEBUG_SMI))
+
+#if __CONSOLE_SPI_ENABLE__
+static inline void __spiconsole_init(void)	{ spiconsole_init(); }
+static inline void __spiconsole_tx_byte(u8 data)	{ spiconsole_tx_byte(data); }
+#else
+static inline void __spiconsole_init(void)	{}
+static inline void __spiconsole_tx_byte(u8 data)	{}
+#endif /* __CONSOLE_SPI_ENABLE__ */
+
+#define MAX_MSG_LENGTH	128
+
+#define EM100_DEDICATED_CMD	0x11
+#define EM100_UFIFO_CMD		0xC0
+#define EM100_MSG_SIGNATURE	0x47364440
+
+enum em100_message_types {
+	EM100_MSG_CHECKPOINT_1B = 0x01,
+	EM100_MSG_CHECKPOINT_2B,
+	EM100_MSG_CHECKPOINT_4B,
+	EM100_MSG_HEX,
+	EM100_MSG_ASCII,
+	EM100_MSG_TIMESTAMP,
+	EM100_MSG_LOOKUP
+};
+
+struct em100_msg_header {
+	uint8_t		spi_command;
+	uint8_t		reserved;
+	uint8_t		em100_command;
+	uint32_t	msg_signature;
+	uint8_t		msg_type;
+	uint8_t		msg_length;
+} __attribute__ ((packed));
+
+struct em100_msg {
+	struct em100_msg_header header;
+	char data[MAX_MSG_LENGTH];
+} __attribute__ ((packed));
+
+
+
+#endif /* CONSOLE_SPI_H */

src/soc/intel/baytrail/Kconfig

@@ -36,6 +36,7 @@ config CPU_SPECIFIC_OPTIONS
 	select UDELAY_TSC
 	select SOC_INTEL_COMMON
 	select HAVE_INTEL_FIRMWARE
+	select HAVE_SPI_CONSOLE_SUPPORT
 
 config BOOTBLOCK_CPU_INIT
 	string

src/soc/intel/braswell/Kconfig

@@ -49,6 +49,7 @@ config CPU_SPECIFIC_OPTIONS
 	select UDELAY_TSC
 	select USE_GENERIC_FSP_CAR_INC
 	select HAVE_INTEL_FIRMWARE
+	select HAVE_SPI_CONSOLE_SUPPORT
 
 config BOOTBLOCK_CPU_INIT
 	string

src/soc/intel/broadwell/Kconfig

@@ -43,6 +43,7 @@ config CPU_SPECIFIC_OPTIONS
 	select SOC_INTEL_COMMON
 	select HAVE_INTEL_FIRMWARE
 	select SOC_INTEL_COMMON_ACPI_WAKE_SOURCE
+	select HAVE_SPI_CONSOLE_SUPPORT
 
 config BOOTBLOCK_CPU_INIT
 	string

src/soc/intel/fsp_baytrail/Kconfig

@@ -48,6 +48,7 @@ config CPU_SPECIFIC_OPTIONS
 	select UDELAY_TSC
 	select SUPPORT_CPU_UCODE_IN_CBFS
 	select HAVE_INTEL_FIRMWARE
+	select HAVE_SPI_CONSOLE_SUPPORT
 
 config SOC_INTEL_FSP_BAYTRAIL_MD
 	bool

src/southbridge/intel/lynxpoint/Kconfig

@@ -33,6 +33,7 @@ config SOUTH_BRIDGE_OPTIONS # dummy
 	select PCIEXP_COMMON_CLOCK
 	select SPI_FLASH
 	select HAVE_INTEL_FIRMWARE
+	select HAVE_SPI_CONSOLE_SUPPORT
 
 config INTEL_LYNXPOINT_LP
 	bool