Documentation/spi/pxa2xx.rst

7 (see Documentation/spi/spi-summary.rst). The driver has the following features
9 - Support for any PXA2xx and compatible SSP.
10 - SSP PIO and SSP DMA data transfers.
11 - External and Internal (SSPFRM) chip selects.
12 - Per slave device (chip) configuration.
13 - Full suspend, freeze, resume support.
21 -----------------------------------
22 Typically, for a legacy platform, an SPI master is defined in the
23 arch/.../mach-*/board-*.c as a "platform device". The master configuration
37 Tx channel. The Rx channel has a higher DMA service priority than the Tx channel.
44 ------------------
45 Below is a sample configuration using the PXA255 NSSP for a legacy platform::
66 	.name = "pxa2xx-spi", /* MUST BE THIS VALUE, so device match driver */
85 -----------------------
86 Typically, for a legacy platform, each SPI slave (chip) is defined in the
87 arch/.../mach-*/board-*.c using the "spi_board_info" structure found in
88 "linux/spi/spi.h". See "Documentation/spi/spi-summary.rst" for additional
109 FIFO overruns (especially in PIO mode transfers). Good default values are::
119 to determine the correct value. An SSP configured for byte-wide transfers would
127 timeouts and must busy-wait any trailing bytes.
136 -----------------
137 For a legacy platform or in some other cases, the pxa2xx_spi_chip structure
185 -----------------------
187 transfers.  The driver defaults to PIO mode and DMA transfers must be enabled
191 mode supports both coherent and stream based DMA mappings.
204 	use coherent DMA mode
207 	use streaming DMA mode
213 ---------