device: Add a new "SPI" device type

Add support for a new "SPI" device type in the devicetree to bind a
device on the SPI bus. Allow device to provide chip select number for
the device as a parameter.

Add spi_bus_operations with operation dev_to_bus which allows SoCs to
define a translation method for converting "struct device" into a unique
SPI bus number.

BUG=chrome-os-partner:59832
BRANCH=None
TEST=Compiles successfully.

Change-Id: I86f09516d3cddd619fef23a4659c9e4eadbcf3fa
Signed-off-by: Furquan Shaikh <furquan@chromium.org>
Reviewed-on: https://review.coreboot.org/18340
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
Tested-by: build bot (Jenkins)

1 files changed, 30 insertions, 0 deletions

diff --git a/src/include/device/spi.h b/src/include/device/spi.h
new file mode 100644
index 0000000000..4315ebce14
--- /dev/null
+++ b/src/include/device/spi.h
@@ -0,0 +1,30 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2017 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.
+ */
+
+#ifndef __DEVICE_SPI_H__
+#define __DEVICE_SPI_H__
+
+struct device;
+struct spi_bus_operations {
+	/*
+	 * This is a SoC-specific method that can be provided to translate the
+	 * 'struct device' for a SPI controller into a unique SPI bus
+	 * number. Returns -1 if the bus number for this bus cannot be
+	 * determined.
+	 */
+	int (*dev_to_bus)(struct device *dev);
+};
+
+#endif	/* __DEVICE_SPI_H__ */