spi: Clean up SPI flash driver interface

RW flag was added to spi_slave structure to get around a requirement on
some AMD flash controllers that need to group together all spi volatile
operations (write/erase). This rw flag is not a property or attribute of
the SPI slave or controller. Thus, instead of saving it in spi_slave
structure, clean up the SPI flash driver interface. This allows
chipsets/mainboards (that require volatile operations to be grouped) to
indicate beginning and end of such grouped operations.

New user APIs are added to allow users to perform probe, read, write,
erase, volatile group begin and end operations. Callbacks defined in
spi_flash structure are expected to be used only by the SPI flash
driver. Any chipset that requires grouping of volatile operations can
select the newly added Kconfig option SPI_FLASH_HAS_VOLATILE_GROUP and
define callbacks for chipset_volatile_group_{begin,end}.

spi_claim_bus/spi_release_bus calls have been removed from the SPI flash
chip drivers which end up calling do_spi_flash_cmd since it already has
required calls for claiming and releasing SPI bus before performing a
read/write operation.

BUG=None
BRANCH=None
TEST=Compiles successfully.

Change-Id: Idfc052e82ec15b6c9fa874cee7a61bd06e923fbf
Signed-off-by: Furquan Shaikh <furquan@chromium.org>
Reviewed-on: https://review.coreboot.org/17462
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

1 files changed, 6 insertions, 6 deletions

diff --git a/src/drivers/spi/spi_flash_internal.h b/src/drivers/spi/spi_flash_internal.h
index fec3dcc9cf..c75839357e 100644
--- a/src/drivers/spi/spi_flash_internal.h
+++ b/src/drivers/spi/spi_flash_internal.h
@@ -34,10 +34,10 @@
 /* Send a single-byte command to the device and read the response */
 int spi_flash_cmd(struct spi_slave *spi, u8 cmd, void *response, size_t len);
 
-int spi_flash_cmd_read_fast(struct spi_flash *flash, u32 offset,
+int spi_flash_cmd_read_fast(const struct spi_flash *flash, u32 offset,
 		size_t len, void *data);
 
-int spi_flash_cmd_read_slow(struct spi_flash *flash, u32 offset,
+int spi_flash_cmd_read_slow(const struct spi_flash *flash, u32 offset,
 		size_t len, void *data);
 
 /*
@@ -48,20 +48,20 @@ int spi_flash_cmd_write(struct spi_slave *spi, const u8 *cmd, size_t cmd_len,
 		const void *data, size_t data_len);
 
 /* Send a command to the device and wait for some bit to clear itself. */
-int spi_flash_cmd_poll_bit(struct spi_flash *flash, unsigned long timeout,
+int spi_flash_cmd_poll_bit(const struct spi_flash *flash, unsigned long timeout,
 			   u8 cmd, u8 poll_bit);
 
 /*
  * Send the read status command to the device and wait for the wip
  * (write-in-progress) bit to clear itself.
  */
-int spi_flash_cmd_wait_ready(struct spi_flash *flash, unsigned long timeout);
+int spi_flash_cmd_wait_ready(const struct spi_flash *flash, unsigned long timeout);
 
 /* Erase sectors. */
-int spi_flash_cmd_erase(struct spi_flash *flash, u32 offset, size_t len);
+int spi_flash_cmd_erase(const struct spi_flash *flash, u32 offset, size_t len);
 
 /* Read status register. */
-int spi_flash_cmd_status(struct spi_flash *flash, u8 *reg);
+int spi_flash_cmd_status(const struct spi_flash *flash, u8 *reg);
 
 /* Manufacturer-specific probe functions */
 struct spi_flash *spi_flash_probe_spansion(struct spi_slave *spi, u8 *idcode);