[U-Boot] [PATCH 02/10] drivers: spi: add config to consider command bytes when writting to flash

[Álvaro Fernández Rojas]

Command bytes are part of the written bytes and they should be taken into
account when sending a spi transfer.

Signed-off-by: Álvaro Fernández Rojas <noltari at gmail.com>
---
 drivers/mtd/spi/spi_flash.c | 2 +-
 drivers/spi/Kconfig         | 3 +++
 include/spi.h               | 8 +++++++-
 3 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/spi/spi_flash.c b/drivers/mtd/spi/spi_flash.c
index e44c10f..748cc32 100644
--- a/drivers/mtd/spi/spi_flash.c
+++ b/drivers/mtd/spi/spi_flash.c
@@ -380,7 +380,7 @@ int spi_flash_cmd_write_ops(struct spi_flash *flash, u32 offset,
 
 		if (spi->max_write_size)
 			chunk_len = min(chunk_len,
-					(size_t)spi->max_write_size);
+					spi_max_write(spi, sizeof(cmd)));
 
 		spi_flash_addr(write_addr, cmd);
 
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index f3f7dbe..a00d401 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -13,6 +13,9 @@ config DM_SPI
 	  typically use driver-private data instead of extending the
 	  spi_slave structure.
 
+config SPI_MAX_WRITE_CMD_BYTES
+	bool "Include command bytes when determining max write size"
+
 if DM_SPI
 
 config ALTERA_SPI
diff --git a/include/spi.h b/include/spi.h
index 75a994c..310fa4d 100644
--- a/include/spi.h
+++ b/include/spi.h
@@ -63,6 +63,12 @@ struct dm_spi_slave_platdata {
 
 #endif /* CONFIG_DM_SPI */
 
+#ifdef CONFIG_SPI_MAX_WRITE_CMD_BYTES
+#define spi_max_write(spi, len)	(spi->max_write_size - len)
+#else
+#define spi_max_write(spi, len)	(spi->max_write_size)
+#endif
+
 /**
  * struct spi_slave - Representation of a SPI slave
  *
@@ -89,7 +95,7 @@ struct dm_spi_slave_platdata {
  * @max_read_size:	If non-zero, the maximum number of bytes which can
  *			be read at once.
  * @max_write_size:	If non-zero, the maximum number of bytes which can
- *			be written at once, excluding command bytes.
+ *			be written at once.
  * @memory_map:		Address of read-only SPI flash access.
  * @flags:		Indication of SPI flags.
  */
-- 
2.1.4