From c2973d196d1224a1253478dc29d5f8fa004eaab8 Mon Sep 17 00:00:00 2001 From: Furquan Shaikh Date: Tue, 29 Nov 2016 22:07:42 -0800 Subject: 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 Reviewed-on: https://review.coreboot.org/17681 Tested-by: build bot (Jenkins) Reviewed-by: Aaron Durbin --- src/soc/imgtec/pistachio/Kconfig | 1 - src/soc/imgtec/pistachio/spi.c | 7 ++----- 2 files changed, 2 insertions(+), 6 deletions(-) (limited to 'src/soc/imgtec') diff --git a/src/soc/imgtec/pistachio/Kconfig b/src/soc/imgtec/pistachio/Kconfig index da33cc5c96..1ce488c35b 100644 --- a/src/soc/imgtec/pistachio/Kconfig +++ b/src/soc/imgtec/pistachio/Kconfig @@ -22,7 +22,6 @@ config CPU_IMGTEC_PISTACHIO select GENERIC_UDELAY select HAVE_MONOTONIC_TIMER select HAVE_UART_SPECIAL - select SPI_ATOMIC_SEQUENCING select GENERIC_GPIO_LIB select HAVE_HARD_RESET select UART_OVERRIDE_REFCLK diff --git a/src/soc/imgtec/pistachio/spi.c b/src/soc/imgtec/pistachio/spi.c index e956e46f7a..2b706f0980 100644 --- a/src/soc/imgtec/pistachio/spi.c +++ b/src/soc/imgtec/pistachio/spi.c @@ -22,10 +22,6 @@ #include #include -#if !CONFIG_SPI_ATOMIC_SEQUENCING -#error "Unsupported SPI driver API" -#endif - /* Imgtec controller uses 16 bit packet length. */ #define IMGTEC_SPI_MAX_TRANSFER_SIZE ((1 << 16) - 1) @@ -496,7 +492,7 @@ static int do_spi_xfer(const struct spi_slave *slave, const void *dout, } static int spi_ctrlr_xfer(const struct spi_slave *slave, const void *dout, - size_t bytesout, void *din, size_t bytesin) + size_t bytesout, void *din, size_t bytesin) { unsigned int in_sz, out_sz; int ret; @@ -541,6 +537,7 @@ static const struct spi_ctrlr spi_ctrlr = { .claim_bus = spi_ctrlr_claim_bus, .release_bus = spi_ctrlr_release_bus, .xfer = spi_ctrlr_xfer, + .xfer_vector = spi_xfer_two_vectors, }; /* Set up communications parameters for a SPI slave. */ -- cgit v1.2.3