first and last commit

drivers/spi/gpio_spi.c

@@ -0,0 +1,103 @@
+/*
+ * Copyright (C) 2007 Apple Inc. All rights reserved.
+ * Copyright (C) 2006 Apple Computer, Inc. All rights reserved.
+ *
+ * This document is the property of Apple Inc.
+ * It is considered confidential and proprietary.
+ *
+ * This document may not be reproduced or transmitted in any form,
+ * in whole or in part, without the express written permission of
+ * Apple Inc.
+ */
+#include <debug.h>
+
+#include <target/gpiodef.h>
+#include <drivers/spi.h>
+
+static void spi_sample_start(void)
+{
+	/* Assert the clock to begin bit sample */
+	gpio_write(GPIO_SPI_SCK, 0);
+}
+
+static void spi_sample_end(void)
+{
+	/* Deassert the clock to end bit sample */
+	gpio_write(GPIO_SPI_SCK, 1);
+}
+
+static unsigned char spi_in(unsigned char bit)
+{
+	/* If the GPIO is set, then this bit is set, and we return the byte value */
+	return (gpio_read(GPIO_SPI_MISO) ? 1 : 0) << bit;
+}
+
+static void spi_out(unsigned char data, unsigned char bit)
+{
+	/* Write bit to GPIO */
+	gpio_write(GPIO_SPI_MOSI, data & (1 << bit));
+}
+
+void spi_init(void)
+{
+	/* Assert clock and deassert slave select */
+	spi_sample_start( );
+	spi_end();
+}
+
+void spi_start(void)
+{
+	/* Assert slave select to begin SPI transaction */
+	gpio_write(GPIO_SPI_SS, 0);
+}
+
+void spi_end(void)
+{
+	/* Deassert slave select to end SPI transaction */
+	gpio_write(GPIO_SPI_SS, 1);
+}
+
+void spi_read(unsigned char* data)
+{
+	signed int i;
+	
+	/* Start with initial state */
+	*data = 0;
+    
+	/* Loop every bit */
+	for (i = 7; i >= 0; i--)
+	{
+		/* Assert clock */
+		spi_sample_start();
+        
+		/* Dummy write cycle */
+		spi_out(0, 0);
+        
+		/* Read one bit */
+		*data |= spi_in(i);
+        
+		/* Deassert clock */
+		spi_sample_end();
+	}
+}
+
+void spi_write(unsigned char data)
+{
+	signed int i;
+	
+	/* Loop every bit */
+	for (i = 7; i >= 0; i--)
+	{
+		/* Assert clock */
+		spi_sample_start();
+        
+		/* Write one bit */
+		spi_out(data, i);
+        
+		/* Dummy read cycle */
+		spi_in(0);
+        
+		/* Deassert clock */
+		spi_sample_end();
+	}
+}

drivers/spi/rules.mk

@@ -0,0 +1,15 @@
+# Copyright (C) 2008 Apple Inc. All rights reserved.
+#
+# This document is the property of Apple Inc.
+# It is considered confidential and proprietary.
+#
+# This document may not be reproduced or transmitted in any form,
+# in whole or in part, without the express written permission of
+# Apple Inc.
+#
+LOCAL_DIR := $(GET_LOCAL_DIR)
+
+OPTIONS += \
+	WITH_SPI=1
+
+ALL_OBJS += $(LOCAL_DIR)/gpio_spi.o