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What is the difference between device driver and board support package?
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STRUCT
SPI_BOARD_INF(9) Serial Peripheral Interface (S STRUCT SPI_BOARD_INF(9) NAME
struct_spi_board_info - board-specific template for a SPI device SYNOPSIS
struct spi_board_info { char modalias[SPI_NAME_SIZE]; const void * platform_data; void * controller_data; int irq; u32 max_speed_hz; u16 bus_num; u16 chip_select; u8 mode; }; MEMBERS
modalias[SPI_NAME_SIZE] Initializes spi_device.modalias; identifies the driver. platform_data Initializes spi_device.platform_data; the particular data stored there is driver-specific. controller_data Initializes spi_device.controller_data; some controllers need hints about hardware setup, e.g. for DMA. irq Initializes spi_device.irq; depends on how the board is wired. max_speed_hz Initializes spi_device.max_speed_hz; based on limits from the chip datasheet and board-specific signal quality issues. bus_num Identifies which spi_master parents the spi_device; unused by spi_new_device, and otherwise depends on board wiring. chip_select Initializes spi_device.chip_select; depends on how the board is wired. mode Initializes spi_device.mode; based on the chip datasheet, board wiring (some devices support both 3WIRE and standard modes), and possibly presence of an inverter in the chipselect path. DESCRIPTION
When adding new SPI devices to the device tree, these structures serve as a partial device template. They hold information which can't always be determined by drivers. Information that probe can establish (such as the default transfer wordsize) is not included here. These structures are used in two places. Their primary role is to be stored in tables of board-specific device descriptors, which are declared early in board initialization and then used (much later) to populate a controller's device tree after the that controller's driver initializes. A secondary (and atypical) role is as a parameter to spi_new_device call, which happens after those controller drivers are active in some dynamic board configuration models. COPYRIGHT
Kernel Hackers Manual 3.10 June 2014 STRUCT SPI_BOARD_INF(9)
