1 files changed, 183 insertions, 0 deletions
diff --git a/chip/lm4/flash.c b/chip/lm4/flash.c
new file mode 100644
index 0000000000..115747d7d9
--- /dev/null
+++ b/chip/lm4/flash.c
@@ -0,0 +1,183 @@
+/* Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+/* Flash memory module for Chrome EC */
+
+#include "flash.h"
+#include "gpio.h"
+#include "uart.h"
+#include "registers.h"
+#include "util.h"
+
+
+static int usable_flash_size;
+
+
+int flash_get_size(void)
+{
+	return usable_flash_size;
+}
+
+
+int flash_get_write_block_size(void)
+{
+	return FLASH_WRITE_BYTES;
+}
+
+
+int flash_get_erase_block_size(void)
+{
+	return FLASH_ERASE_BYTES;
+}
+
+
+int flash_get_protect_block_size(void)
+{
+	return FLASH_PROTECT_BYTES;
+}
+
+
+int flash_read(int offset, int size, char *data)
+{
+	if (size < 0 || offset > usable_flash_size ||
+	    offset + size > usable_flash_size)
+		return EC_ERROR_UNKNOWN;  /* Invalid range */
+
+	/* Just read the flash from its memory window. */
+	/* TODO: is this affected by data cache?  That is, if we read a
+	 * block, then alter it, then read it again, do we get the old
+	 * data? */
+	memcpy(data, (char *)offset, size);
+	return EC_SUCCESS;
+}
+
+
+/* Performs a write-buffer operation.  Buffer (FWB) and address (FMA)
+ * must be pre-loaded. */
+static int WriteBuffer(void)
+{
+	if (!LM4_FLASH_FWBVAL)
+		return EC_SUCCESS;  /* Nothing to do */
+
+	/* Clear previous error status */
+	LM4_FLASH_FCMISC = LM4_FLASH_FCRIS;
+
+	/* Start write operation at page boundary */
+	LM4_FLASH_FMC2 = 0xa4420001;
+
+	/* Wait for write to complete */
+	while (LM4_FLASH_FMC2 & 0x01) {}
+
+	/* Check for error conditions - program failed, erase needed,
+	 * voltage error. */
+	if (LM4_FLASH_FCRIS & 0x2600)
+		return EC_ERROR_UNKNOWN;
+
+	return EC_SUCCESS;
+}
+
+
+int flash_write(int offset, int size, const char *data)
+{
+	const uint32_t *data32 = (const uint32_t *)data;
+	int rv;
+	int i;
+
+	if (size < 0 || offset > usable_flash_size ||
+	    offset + size > usable_flash_size ||
+	    (offset | size) & (FLASH_WRITE_BYTES - 1))
+		return EC_ERROR_UNKNOWN;  /* Invalid range */
+
+	/* TODO - safety check - don't allow writing to the image we're
+	 * running from */
+
+	/* Get initial page and write buffer index */
+	LM4_FLASH_FMA = offset & ~(FLASH_FWB_BYTES - 1);
+	i = (offset >> 2) & (FLASH_FWB_WORDS - 1);
+
+	/* Copy words into buffer */
+	for ( ; size > 0; size -= 4) {
+		LM4_FLASH_FWB[i++] = *data32++;
+		if (i == FLASH_FWB_WORDS) {
+			rv = WriteBuffer();
+			if (rv != EC_SUCCESS)
+				return rv;
+
+			/* Advance to next page */
+			i = 0;
+			LM4_FLASH_FMA += FLASH_FWB_BYTES;
+		}
+	}
+
+	/* Handle final partial page, if any */
+	if (i > 0) {
+		rv = WriteBuffer();
+		if (rv != EC_SUCCESS)
+			return rv;
+	}
+	return EC_SUCCESS;
+}
+
+
+int flash_erase(int offset, int size)
+{
+	if (size < 0 || offset > usable_flash_size ||
+	    offset + size > usable_flash_size ||
+	    (offset | size) & (FLASH_ERASE_BYTES - 1))
+		return EC_ERROR_UNKNOWN;  /* Invalid range */
+
+	/* TODO - safety check - don't allow erasing the image we're running
+	 * from */
+
+	LM4_FLASH_FCMISC = LM4_FLASH_FCRIS;  /* Clear previous error status */
+	LM4_FLASH_FMA = offset;
+
+	for ( ; size > 0; size -= FLASH_ERASE_BYTES) {
+		/* Start erase */
+		LM4_FLASH_FMC = 0xa4420002;
+
+		/* Wait for erase to complete */
+		while (LM4_FLASH_FMC & 0x02) {}
+
+		/* Check for error conditions - erase failed, voltage error */
+		if (LM4_FLASH_FCRIS & 0x0a00)
+			return EC_ERROR_UNKNOWN;
+
+		LM4_FLASH_FMA += FLASH_ERASE_BYTES;
+	}
+
+	return EC_SUCCESS;
+}
+
+
+int flash_get_write_protect_range(int *offset, int *size)
+{
+	return EC_ERROR_UNIMPLEMENTED;
+}
+
+
+int flash_set_write_protect_range(int offset, int size)
+{
+	return EC_ERROR_UNIMPLEMENTED;
+}
+
+
+int flash_get_write_protect_status(void)
+{
+	return EC_ERROR_UNIMPLEMENTED;
+}
+
+
+int flash_init(void)
+{
+	/* Calculate usable flash size.  Reserve one protection block
+	 * at the top to hold the write protect range.  FSIZE already
+	 * returns one less than the number of protection pages. */
+	usable_flash_size = LM4_FLASH_FSIZE * FLASH_PROTECT_BYTES;
+
+	/* TODO - check WP# GPIO.  If it's set and the flash protect range
+	 * is set, write the flash protection registers. */
+	return EC_SUCCESS;
+}