====== SPI interface using the IO-Port #2 ======
This page introduces how you can SPI interface using IO-Port on **ODROID-U3**.\\
**Note that SPI port supports only master mode and 1.8 Volt interface like other IO ports on Exynos processor.**\\

{{:en:u3:u3ioport_num.png?500|}}

**J5 - 2x2 pins(IO Port #2)**\\
This socket is not provides at revision 0.3 
^ Pin Number ^ Expansion Net Name ^ Export Number ^ Pin Number ^ Expansion Net Name ^ Export Number ^
|1|XSPICLK_1 (GPB.4) | #21 |2|XSPICSN_1 (GPB.5) | #22 |
|3|XSPIMOSI_1 (GPB.7) | #24 |4|XSPIMISO_1 (GPB.6)| #23 | 
<WRAP left round tip 100%>
If your ODROID-U3 have old version kernel you need to update using odroid-utility.
  sudo odroid-utility.sh
</WRAP>

**How to load the SPI driver module for generic SPI usage**\\
Load the module to activate the SPI host.\\
  sudo modprobe spi-s3c64xx
Load the module to activate the generic SPI.
  sudo modprobe spidev
And you will have a standard SPI node.
  ls /dev/spidev1.0

**How to load the SPI driver module for serial Flash**\\
Load the module to activate the SPI host.
  sudo modprobe spi-s3c64xx
Load the serial flash (misc) driver.
  sudo modprobe odroid-ioboard
And you will have a Serial Flash node.
  ls /dev/ioboard-spi-misc

**Where are the SPI device drivers in Kernel 3.8.y?**\\
{{https://github.com/hardkernel/linux/blob/odroid-3.8.y/drivers/spi/spi-s3c64xx.c|SPI host interface driver}}\\
{{https://github.com/hardkernel/linux/blob/odroid-3.8.y/drivers/spi/spidev.c|SPI generic driver}}\\
{{https://github.com/hardkernel/linux/blob/odroid-3.8.y/drivers/hardkernel/ioboard-spi-misc.c|Serial SPI Flash add-on driver example}}

We have tested the ioboard-spi-misc.ko with a Serial SPI Flash memory SST25WF020A on the new IO Shield and the maximum speed was 40Mhz of SPI clock.

**How to change SPI clock **\\
{{https://github.com/hardkernel/linux/blob/odroid-3.8.y/arch/arm/mach-exynos/mach-hkdk4412.c#L538|SPI Clock configuration}}\\
{{http://dn.odroid.com/wiki_image/odroid-u3-spi-clock-40MHz.jpg?500|}}

Refer this link to know the generic SPIDEV driver usage in detail.\\
[[https://www.kernel.org/doc/Documentation/spi/spidev]]