SPI Flash subsystem

This adds a new SPI flash subsystem.

Currently, only AT45 DataFlash in non-power-of-two mode is supported,
but some preliminary support for other flash types is in place as
well.

Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>

1 files changed, 162 insertions, 0 deletions

diff --git a/drivers/mtd/spi/spi_flash.c b/drivers/mtd/spi/spi_flash.c
new file mode 100644
index 0000000..d581cb3
--- /dev/null
+++ b/drivers/mtd/spi/spi_flash.c
@@ -0,0 +1,162 @@
+/*
+ * SPI flash interface
+ *
+ * Copyright (C) 2008 Atmel Corporation
+ */
+#define DEBUG
+#include <common.h>
+#include <malloc.h>
+#include <spi.h>
+#include <spi_flash.h>
+
+#include "spi_flash_internal.h"
+
+int spi_flash_cmd(struct spi_slave *spi, u8 cmd, void *response, size_t len)
+{
+	unsigned long flags = SPI_XFER_BEGIN;
+	int ret;
+
+	if (len == 0)
+		flags |= SPI_XFER_END;
+
+	ret = spi_xfer(spi, 8, &cmd, NULL, flags);
+	if (ret) {
+		debug("SF: Failed to send command %02x: %d\n", cmd, ret);
+		return ret;
+	}
+
+	if (len) {
+		ret = spi_xfer(spi, len * 8, NULL, response, SPI_XFER_END);
+		if (ret)
+			debug("SF: Failed to read response (%zu bytes): %d\n",
+					len, ret);
+	}
+
+	return ret;
+}
+
+int spi_flash_cmd_read(struct spi_slave *spi, const u8 *cmd,
+		size_t cmd_len, void *data, size_t data_len)
+{
+	unsigned long flags = SPI_XFER_BEGIN;
+	int ret;
+
+	if (data_len == 0)
+		flags |= SPI_XFER_END;
+
+	ret = spi_xfer(spi, cmd_len * 8, cmd, NULL, flags);
+	if (ret) {
+		debug("SF: Failed to send read command (%zu bytes): %d\n",
+				cmd_len, ret);
+	} else if (data_len != 0) {
+		ret = spi_xfer(spi, data_len * 8, NULL, data, SPI_XFER_END);
+		if (ret)
+			debug("SF: Failed to read %zu bytes of data: %d\n",
+					data_len, ret);
+	}
+
+	return ret;
+}
+
+int spi_flash_cmd_write(struct spi_slave *spi, const u8 *cmd, size_t cmd_len,
+		const void *data, size_t data_len)
+{
+	unsigned long flags = SPI_XFER_BEGIN;
+	int ret;
+
+	if (data_len == 0)
+		flags |= SPI_XFER_END;
+
+	ret = spi_xfer(spi, cmd_len * 8, cmd, NULL, flags);
+	if (ret) {
+		debug("SF: Failed to send read command (%zu bytes): %d\n",
+				cmd_len, ret);
+	} else if (data_len != 0) {
+		ret = spi_xfer(spi, data_len * 8, data, NULL, SPI_XFER_END);
+		if (ret)
+			debug("SF: Failed to read %zu bytes of data: %d\n",
+					data_len, ret);
+	}
+
+	return ret;
+}
+
+
+int spi_flash_read_common(struct spi_flash *flash, const u8 *cmd,
+		size_t cmd_len, void *data, size_t data_len)
+{
+	struct spi_slave *spi = flash->spi;
+	int ret;
+
+	spi_claim_bus(spi);
+	ret = spi_flash_cmd_read(spi, cmd, cmd_len, data, data_len);
+	spi_release_bus(spi);
+
+	return ret;
+}
+
+struct spi_flash *spi_flash_probe(unsigned int bus, unsigned int cs,
+		unsigned int max_hz, unsigned int spi_mode)
+{
+	struct spi_slave *spi;
+	struct spi_flash *flash;
+	int ret;
+	u8 idcode[3];
+
+	spi = spi_setup_slave(bus, cs, max_hz, spi_mode);
+	if (!spi) {
+		debug("SF: Failed to set up slave\n");
+		return NULL;
+	}
+
+	ret = spi_claim_bus(spi);
+	if (ret) {
+		debug("SF: Failed to claim SPI bus: %d\n", ret);
+		goto err_claim_bus;
+	}
+
+	/* Read the ID codes */
+	ret = spi_flash_cmd(spi, CMD_READ_ID, &idcode, sizeof(idcode));
+	if (ret)
+		goto err_read_id;
+
+	debug("SF: Got idcode %02x %02x %02x\n", idcode[0],
+			idcode[1], idcode[2]);
+
+	switch (idcode[0]) {
+#ifdef CONFIG_SPI_FLASH_SPANSION
+	case 0x01:
+		flash = spi_flash_probe_spansion(spi, idcode);
+		break;
+#endif
+#ifdef CONFIG_SPI_FLASH_ATMEL
+	case 0x1F:
+		flash = spi_flash_probe_atmel(spi, idcode);
+		break;
+#endif
+	default:
+		debug("SF: Unsupported manufacturer %02X\n", idcode[0]);
+		flash = NULL;
+		break;
+	}
+
+	if (!flash)
+		goto err_manufacturer_probe;
+
+	spi_release_bus(spi);
+
+	return flash;
+
+err_manufacturer_probe:
+err_read_id:
+	spi_release_bus(spi);
+err_claim_bus:
+	spi_free_slave(spi);
+	return NULL;
+}
+
+void spi_flash_free(struct spi_flash *flash)
+{
+	spi_free_slave(flash->spi);
+	free(flash);
+}