[U-Boot] [PATCH 3/4] sf: Add configuration register writing

[Jagannadha Sutradharudu Teki]

This patch provides support to program a flash config register.

Configuration register contains the control bits used to configure
the different configurations and security features of a device.

User need to set these bits through spi_flash_cmd_write_config()
based on their usage.

Signed-off-by: Jagannadha Sutradharudu Teki <jagannadh.teki at gmail.com>
---
 drivers/mtd/spi/spi_flash.c          |   27 +++++++++++++++++++++++++++
 drivers/mtd/spi/spi_flash_internal.h |    3 +++
 2 files changed, 30 insertions(+), 0 deletions(-)

diff --git a/drivers/mtd/spi/spi_flash.c b/drivers/mtd/spi/spi_flash.c
index 800ed8b..a8f0af0 100644
--- a/drivers/mtd/spi/spi_flash.c
+++ b/drivers/mtd/spi/spi_flash.c
@@ -274,6 +274,33 @@ int spi_flash_cmd_write_status(struct spi_flash *flash, u8 sr)
 	return 0;
 }
 
+int spi_flash_cmd_write_config(struct spi_flash *flash, u16 cr)
+{
+	u8 cmd;
+	int ret;
+
+	ret = spi_flash_cmd_write_enable(flash);
+	if (ret < 0) {
+		debug("SF: enabling write failed\n");
+		return ret;
+	}
+
+	cmd = CMD_WRITE_STATUS;
+	ret = spi_flash_cmd_write(flash->spi, &cmd, 1, &cr, 2);
+	if (ret) {
+		debug("SF: fail to write config register\n");
+		return ret;
+	}
+
+	ret = spi_flash_cmd_wait_ready(flash, SPI_FLASH_PROG_TIMEOUT);
+	if (ret < 0) {
+		debug("SF: write config register timed out\n");
+		return ret;
+	}
+
+	return 0;
+}
+
 /*
  * The following table holds all device probe functions
  *
diff --git a/drivers/mtd/spi/spi_flash_internal.h b/drivers/mtd/spi/spi_flash_internal.h
index 141cfa8..9287778 100644
--- a/drivers/mtd/spi/spi_flash_internal.h
+++ b/drivers/mtd/spi/spi_flash_internal.h
@@ -77,6 +77,9 @@ static inline int spi_flash_cmd_write_disable(struct spi_flash *flash)
 /* Program the status register. */
 int spi_flash_cmd_write_status(struct spi_flash *flash, u8 sr);
 
+/* Program the config register. */
+int spi_flash_cmd_write_config(struct spi_flash *flash, u16 cr);
+
 /*
  * Same as spi_flash_cmd_read() except it also claims/releases the SPI
  * bus. Used as common part of the ->read() operation.
-- 
1.7.0.4