Enabling SPI1 and SPI3 on Linux (Naon)

Info Box Applies to Naon Applies to Linux

Contents

IntroductionEdit

This article shows how to enable the SPI1 and SPI3 (with CS1 chip select) interfaces which can be used in a standard Linux application.

Pin Mux OptionEdit

SPI signals are available at different Naon pins. Please note that the NaonEVB-Mid carrier board provides the SPI1 and SPI3 signals at the J21 connector.

The following configuration can be used:

Option 1Edit

Signal	Naon Connector Phisical Pin	CPU Ball
SPI1_SCLK	J1.34	AC3
SPI1_SCS1n	J2.112	W6
SPI1_D0	J1.37	AA6
SPI1_D1	J1.90	AA3
SPI3_SCLK	J2.99	AC26
SPI3_SCS1n	J2.111	AG27
SPI3_D0	J2.89	V22
SPI3_D1	J2.87	AA25

U-Boot patchesEdit

The patches below applies to NELK 4.0.0 and above U-Boot source tree.

The files arch/arm/mach-omap2/board-diva.c and arch/arm/mach-omap2/diva_pinmux_table.h must be modified according to the following patches:

U-Boot must be rebuilt to make these modifications effective.

Linux kernel patchesEdit

The patches below applies to NELK 4.0.0 and above Linux source tree.

The files arch/arm/mach-omap2/board-diva.c and arch/arm/mach-omap2/diva_pinmux_table.h must be modified according to the following patches:

The kernel must be rebuilt to make these modifications effective.

Using the interfacesEdit

Users can access the peripherals connected to the SP1 and SPI3 buses through the spidev interface. For further information, please refer to

• https://www.kernel.org/doc/Documentation/spi/spidev
• https://www.kernel.org/doc/Documentation/spi/spidev_test.c

Patch downloadEdit

• U-Boot: File:U-boot-nelk-spi1-cs1-spi3-cs1.patch.zip
• Linux: File:Linux-nelk-spi1-cs1-spi3-cs1.patch.zip