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authorFurquan Shaikh <furquan@chromium.org>2016-11-29 22:07:42 -0800
committerFurquan Shaikh <furquan@google.com>2016-12-23 04:54:55 +0100
commitc2973d196d1224a1253478dc29d5f8fa004eaab8 (patch)
tree2377f357ee09f147b3f413949057306ca1839bab /src/drivers/spi/Kconfig
parent42cfdf5184b3e94805958a3368f2e049c09119ac (diff)
downloadcoreboot-c2973d196d1224a1253478dc29d5f8fa004eaab8.tar.xz
spi: Get rid of SPI_ATOMIC_SEQUENCING
SPI_ATOMIC_SEQUENCING was added to accomodate spi flash controllers with the ability to perform tx and rx of flash command and response at the same time. Instead of introducing this notion at SPI flash driver layer, clean up the interface to SPI used by flash. Flash uses a command-response kind of communication. Thus, even though SPI is duplex, flash command needs to be sent out on SPI bus and then flash response should be received on the bus. Some specialized x86 flash controllers are capable of handling command and response in a single transaction. In order to support all the varied cases: 1. Add spi_xfer_vector that takes as input a vector of SPI operations and calls back into SPI controller driver to process these operations. 2. In order to accomodate flash command-response model, use two vectors while calling into spi_xfer_vector -- one with dout set to non-NULL(command) and other with din set to non-NULL(response). 3. For specialized SPI flash controllers combine two successive vectors if the transactions look like a command-response pair. 4. Provide helper functions for common cases like supporting only 2 vectors at a time, supporting n vectors at a time, default vector operation to cycle through all SPI op vectors one by one. BUG=chrome-os-partner:59832 BRANCH=None TEST=Compiles successfully Change-Id: I4c9e78c585ad95c40c0d5af078ff8251da286236 Signed-off-by: Furquan Shaikh <furquan@chromium.org> Reviewed-on: https://review.coreboot.org/17681 Tested-by: build bot (Jenkins) Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Diffstat (limited to 'src/drivers/spi/Kconfig')
-rw-r--r--src/drivers/spi/Kconfig10
1 files changed, 0 insertions, 10 deletions
diff --git a/src/drivers/spi/Kconfig b/src/drivers/spi/Kconfig
index b55de58962..c8d86ff104 100644
--- a/src/drivers/spi/Kconfig
+++ b/src/drivers/spi/Kconfig
@@ -61,16 +61,6 @@ config SPI_FLASH_INCLUDE_ALL_DRIVERS
default n if COMMON_CBFS_SPI_WRAPPER
default y
-config SPI_ATOMIC_SEQUENCING
- bool
- default y if ARCH_X86
- default n if !ARCH_X86
- help
- Select this option if the SPI controller uses "atomic sequencing."
- Atomic sequencing is when the sequence of commands is pre-programmed
- in the SPI controller. Hardware manages the transaction instead of
- software. This is common on x86 platforms.
-
config SPI_FLASH_SMM
bool "SPI flash driver support in SMM"
default n