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, 9 insertions, 8 deletions

diff --git a/src/soc/mediatek/mt8173/flash_controller.c b/src/soc/mediatek/mt8173/flash_controller.c
index 5d73f3aba2..dc64d4083c 100644
--- a/src/soc/mediatek/mt8173/flash_controller.c
+++ b/src/soc/mediatek/mt8173/flash_controller.c
@@ -157,7 +157,8 @@ static int pio_read(u32 addr, u8 *buf, u32 len)
 	return 0;
 }
 
-static int nor_read(struct spi_flash *flash, u32 addr, size_t len, void *buf)
+static int nor_read(const struct spi_flash *flash, u32 addr, size_t len,
+		void *buf)
 {
 	u32 next;
 
@@ -195,8 +196,8 @@ static int nor_read(struct spi_flash *flash, u32 addr, size_t len, void *buf)
 	return 0;
 }
 
-static int nor_write(struct spi_flash *flash, u32 addr, size_t len,
-		       const void *buf)
+static int nor_write(const struct spi_flash *flash, u32 addr, size_t len,
+		const void *buf)
 {
 	const u8 *buffer = (const u8 *)buf;
 
@@ -214,7 +215,7 @@ static int nor_write(struct spi_flash *flash, u32 addr, size_t len,
 	return 0;
 }
 
-static int nor_erase(struct spi_flash *flash, u32 offset, size_t len)
+static int nor_erase(const struct spi_flash *flash, u32 offset, size_t len)
 {
 	int sector_start = offset;
 	int sector_num = (u32)len / flash->sector_size;
@@ -242,10 +243,10 @@ struct spi_flash *mt8173_nor_flash_probe(struct spi_slave *spi)
 	write32(&mt8173_nor->wrprot, SFLASH_COMMAND_ENABLE);
 	flash.spi = spi;
 	flash.name = "mt8173 flash controller";
-	flash.write = nor_write;
-	flash.erase = nor_erase;
-	flash.read = nor_read;
-	flash.status = 0;
+	flash.internal_write = nor_write;
+	flash.internal_erase = nor_erase;
+	flash.internal_read = nor_read;
+	flash.internal_status = 0;
 	flash.sector_size = 0x1000;
 	flash.erase_cmd = SECTOR_ERASE_CMD;
 	flash.size = CONFIG_ROM_SIZE;