m68knommu: Freescale/Motorola Coldfire QSPI driver
PATCH 1/1 m68knommu: Freescale/Motorola Coldfire QSPI driver
Add support for the QSPI controller found some on Freescale/Motorola Coldfire MCUs.
Full duplex, active high cs, spi modes 0-3 and word sizes 8-16 bits are supported. The hardware drives the MISO, MOSI and SCLK lines, but the chip selects are managed via GPIO and must be configured by the board code.
The QSPI controller has an 80 byte buffer which allows us to transfer up to 16 words at a time. For transfers longer than 16 words, we split the buffer in half so we can update in one half while the controller is operating on the other half. Interrupt latencies then ultimately limits our sustained thru-put to something less than half the maximum speed supported by the part.
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drivers/spi/Kconfig | 10 + drivers/spi/Makefile | 1 + drivers/spi/coldfire_qspi.c | 640 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 651 insertions(+), 0 deletions(-)
drivers/spi/Kconfig +10 -0
@@ -100,6 +100,16 @@ config SPI_BUTTERFLY inexpensive battery powered microcontroller evaluation board. This same cable can be used to flash new firmware. +config SPI_COLDFIRE_QSPI + tristate "Freescale Coldfire QSPI controller" + depends on (M520x || M523x || M5249 || M527x || M528x || M532x) + help + This enables support for the Coldfire QSPI controller in master + mode. + + This driver can also be built as a module. If so, the module + will be called coldfire_qspi. + config SPI_GPIO tristate "GPIO-based bitbanging SPI Master" depends on GENERIC_GPIO
drivers/spi/Makefile +1 -0
@@ -16,6 +16,7 @@ obj-$(CONFIG_SPI_BFIN) += spi_bfin5xx.o obj-$(CONFIG_SPI_BITBANG) += spi_bitbang.o obj-$(CONFIG_SPI_AU1550) += au1550_spi.o obj-$(CONFIG_SPI_BUTTERFLY) += spi_butterfly.o +obj-$(CONFIG_SPI_COLDFIRE_QSPI) += coldfire_qspi.o obj-$(CONFIG_SPI_DESIGNWARE) += dw_spi.o obj-$(CONFIG_SPI_DW_PCI) += dw_spi_pci.o obj-$(CONFIG_SPI_GPIO) += spi_gpio.o
drivers/spi/coldfire_qspi.c new file +640 -0
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