[U-Boot] [PATCH v2 3/6] spi: sf: Support byte program for sst spi flash

[Jagannadha Sutradharudu Teki]

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.

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>
Reviewed-by: Jagannadha Sutradharudu Teki <jagannadh.teki at gmail.com>
---
 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