Documentation/spi/pxa2xx.rst

2 PXA2xx SPI on SSP driver HOWTO
6 synchronous serial port into a SPI master controller
7 (see Documentation/spi/spi-summary.rst). The driver has the following features
9 - Support for any PXA2xx 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.
17 (pump_transfer) is responsible for queuing SPI transactions and setting up and
21 -----------------------------------
22 Typically a SPI master is defined in the arch/.../mach-*/board-*.c as a
24 found in include/linux/spi/pxa2xx_spi.h::
32 slave device (chips) attached to this SPI master.
40 ------------------
62 	.name = "pxa2xx-spi", /* MUST BE THIS VALUE, so device match driver */
80 Declaring Slave Devices
81 -----------------------
82 Typically each SPI slave (chip) is defined in the arch/.../mach-*/board-*.c
83 using the "spi_board_info" structure found in "linux/spi/spi.h". See
84 "Documentation/spi/spi-summary.rst" for additional information.
86 Each slave device attached to the PXA must provide slave specific configuration
88 "include/linux/spi/pxa2xx_spi.h".  The pxa2xx_spi master controller driver
89 will uses the configuration whenever the driver communicates with the slave
116 to determine the correct value. An SSP configured for byte-wide transfers would
122 dependent on the SPI bus speed ("spi_board_info.max_speed_hz") and the specific
123 slave device.  Please note that the PXA2xx SSP 1 does not support trailing byte
124 timeouts and must busy-wait any trailing bytes.
132 function for asserting/deasserting a slave device chip select.  If the field is
136 NOTE: the SPI driver cannot control the chip select if SSPFRM is used, so the
142 NSSP SLAVE SAMPLE
143 -----------------
150   /* Chip Select control for the CS8415A SPI slave device */
159   /* Chip Select control for the CS8405A SPI slave device */
192 		.irq = STREETRACER_APCI_IRQ, /* Slave device interrupt */
200 		.irq = STREETRACER_APCI_IRQ, /* Slave device interrupt */
212 -----------------------
238 ---------