[U-Boot] [PATCH 3/4] spi: sf: Support byte program for sst spi flash

Jagannadha Sutradharudu Teki jagannadh.teki at gmail.com
Tue Dec 9 16:29:39 CET 2014


From: Bin Meng <bmeng.cn at gmail.com>

Currently if SST flash advertises SST_WP flag in the params table
the word program command (ADh) with auto address increment will be
used for the flash write op. However some SPI controllers do not
support the word program command (like the Intel ICH 7), the byte
programm command (02h) has to be used.

A new TX operation mode SPI_OPM_TX_BP is introduced for such SPI
controller to use byte program op for SST flash.

Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
Acked-by: Simon Glass <sjg at chromium.org>
Tested-by: Simon Glass <sjg at chromium.org>
---
 drivers/mtd/spi/sf_internal.h |  2 ++
 drivers/mtd/spi/sf_ops.c      | 31 +++++++++++++++++++++++++++++++
 2 files changed, 33 insertions(+)

diff --git a/drivers/mtd/spi/sf_internal.h b/drivers/mtd/spi/sf_internal.h
index 7218e69..fb53cb0 100644
--- a/drivers/mtd/spi/sf_internal.h
+++ b/drivers/mtd/spi/sf_internal.h
@@ -110,6 +110,8 @@ enum {
 
 int sst_write_wp(struct spi_flash *flash, u32 offset, size_t len,
 		const void *buf);
+int sst_write_bp(struct spi_flash *flash, u32 offset, size_t len,
+		const void *buf);
 #endif
 
 /**
diff --git a/drivers/mtd/spi/sf_ops.c b/drivers/mtd/spi/sf_ops.c
index 759231f..34bc54e 100644
--- a/drivers/mtd/spi/sf_ops.c
+++ b/drivers/mtd/spi/sf_ops.c
@@ -517,4 +517,35 @@ int sst_write_wp(struct spi_flash *flash, u32 offset, size_t len,
 	spi_release_bus(flash->spi);
 	return ret;
 }
+
+int sst_write_bp(struct spi_flash *flash, u32 offset, size_t len,
+		const void *buf)
+{
+	size_t actual;
+	int ret;
+
+	ret = spi_claim_bus(flash->spi);
+	if (ret) {
+		debug("SF: Unable to claim SPI bus\n");
+		return ret;
+	}
+
+	for (actual = 0; actual < len; actual++) {
+		ret = sst_byte_write(flash, offset, buf + actual);
+		if (ret) {
+			debug("SF: sst byte program failed\n");
+			break;
+		}
+		offset++;
+	}
+
+	if (!ret)
+		ret = spi_flash_cmd_write_disable(flash);
+
+	debug("SF: sst: program %s %zu bytes @ 0x%zx\n",
+	      ret ? "failure" : "success", len, offset - actual);
+
+	spi_release_bus(flash->spi);
+	return ret;
+}
 #endif
-- 
1.9.1



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