Linux and UNIX Man Pages

Linux & Unix Commands - Search Man Pages

spi_register_master(9) [centos man page]

SPI_REGISTER_MASTER(9)					  Serial Peripheral Interface (S				    SPI_REGISTER_MASTER(9)

NAME
spi_register_master - register SPI master controller SYNOPSIS
int spi_register_master(struct spi_master * master); ARGUMENTS
master initialized master, originally from spi_alloc_master CONTEXT
can sleep DESCRIPTION
SPI master controllers connect to their drivers using some non-SPI bus, such as the platform bus. The final stage of probe in that code includes calling spi_register_master to hook up to this SPI bus glue. SPI controllers use board specific (often SOC specific) bus numbers, and board-specific addressing for SPI devices combines those numbers with chip select numbers. Since SPI does not directly support dynamic device identification, boards need configuration tables telling which chip is at which address. This must be called from context that can sleep. It returns zero on success, else a negative error code (dropping the master's refcount). After a successful return, the caller is responsible for calling spi_unregister_master. COPYRIGHT
Kernel Hackers Manual 3.10 June 2014 SPI_REGISTER_MASTER(9)

Check Out this Related Man Page

STRUCT 
SPI_DEVICE(9) Serial Peripheral Interface (S STRUCT SPI_DEVICE(9) NAME
struct_spi_device - Master side proxy for an SPI slave device SYNOPSIS
struct spi_device { struct device dev; struct spi_master * master; u32 max_speed_hz; u8 chip_select; u8 mode; #define SPI_CPHA 0x01 #define SPI_CPOL 0x02 #define SPI_MODE_0 (0|0) #define SPI_MODE_1 (0|SPI_CPHA) #define SPI_MODE_2 (SPI_CPOL|0) #define SPI_MODE_3 (SPI_CPOL|SPI_CPHA) #define SPI_CS_HIGH 0x04 #define SPI_LSB_FIRST 0x08 #define SPI_3WIRE 0x10 #define SPI_LOOP 0x20 #define SPI_NO_CS 0x40 #define SPI_READY 0x80 u8 bits_per_word; int irq; void * controller_state; void * controller_data; char modalias[SPI_NAME_SIZE]; }; MEMBERS
dev Driver model representation of the device. master SPI controller used with the device. max_speed_hz Maximum clock rate to be used with this chip (on this board); may be changed by the device's driver. The spi_transfer.speed_hz can override this for each transfer. chip_select Chipselect, distinguishing chips handled by master. mode The spi mode defines how data is clocked out and in. This may be changed by the device's driver. The "active low" default for chipselect mode can be overridden (by specifying SPI_CS_HIGH) as can the "MSB first" default for each word in a transfer (by specifying SPI_LSB_FIRST). bits_per_word Data transfers involve one or more words; word sizes like eight or 12 bits are common. In-memory wordsizes are powers of two bytes (e.g. 20 bit samples use 32 bits). This may be changed by the device's driver, or left at the default (0) indicating protocol words are eight bit bytes. The spi_transfer.bits_per_word can override this for each transfer. irq Negative, or the number passed to request_irq to receive interrupts from this device. controller_state Controller's runtime state controller_data Board-specific definitions for controller, such as FIFO initialization parameters; from board_info.controller_data modalias[SPI_NAME_SIZE] Name of the driver to use with this device, or an alias for that name. This appears in the sysfs "modalias" attribute for driver coldplugging, and in uevents used for hotplugging DESCRIPTION
A spi_device is used to interchange data between an SPI slave (usually a discrete chip) and CPU memory. In dev, the platform_data is used to hold information about this device that's meaningful to the device's protocol driver, but not to its controller. One example might be an identifier for a chip variant with slightly different functionality; another might be information about how this particular board wires the chip's pins. COPYRIGHT
Kernel Hackers Manual 2.6. July 2010 STRUCT SPI_DEVICE(9)
Man Page

Featured Tech Videos