spi: Add function to allocate a new SPI slave

At present it is difficult to extend the SPI structure since all
drivers allocate it themselves, and few of them zero all fields. Add
a new function spi_alloc_slave() which can be used by SPI drivers
to perform this allocation, and thus ensure that all drivers can
better cope with SPI structure changes.

Signed-off-by: Simon Glass <sjg@chromium.org>

1 files changed, 39 insertions, 0 deletions

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
new file mode 100644
index 000000000..cb36c5e6e
--- /dev/null
+++ b/drivers/spi/spi.c
@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2011 The Chromium OS Authors.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <malloc.h>
+#include <spi.h>
+
+void *spi_do_alloc_slave(int offset, int size, unsigned int bus,
+			 unsigned int cs)
+{
+	struct spi_slave *slave;
+	void *ptr;
+
+	ptr = malloc(size);
+	if (ptr) {
+		memset(ptr, '\0', size);
+		slave = (struct spi_slave *)(ptr + offset);
+		slave->bus = bus;
+		slave->cs = cs;
+	}
+
+	return ptr;
+}