1.9 KiB
!!! notice Preliminary Info
RK3399 has SPI controller with following features:
-
6 on-chip SPI controllers
-
Support master and slave mode, software-configurable
-
DMA-based or interrupt-based operation
-
Embedded two 32x16bits FIFO for TX and RX operation respectively
On Helios64 the bus are divided into three types: unused, system (internal bus) and user application (external)
| Bus | Usage | Remarks |
|---|---|---|
| 0 | Not Used | |
| 1 | System | Bootable SPI Flash |
| 2 | External | User Application |
| 3 | Not Used | |
| 4 | Not Used | |
| 5 | System | Reserved for Production use only |
Internal Bus
| Bus | Chip Select | Device | Remarks |
|---|---|---|---|
| 1 | 0 | W25Q128JV | Bootable SPI Flash |
| 5 | 0 | W25X20CL | SATA Controller ROM |
Bootable SPI Flash
Helios64 is equipped with Winbond W25Q128JV 3V 128M-Bit Serial Flash Memory as a Bootable SPI NOR Flash.
This flash contains
- preloader & bootloader
| Binaries | Offset | Remarks |
|---|---|---|
| Preloader | 0x0040 | U-Boot TPL & SPL |
| Bootloader | 0x4000 | U-Boot & ATF |
- electronic nameplate data in Security Register
External Bus
| Bus | Chip Select | Remarks |
|---|---|---|
| 2 | 0 | User Application |
SPI Bus for user application is exposed on UEXT Connector (P2)
| Pin | Signal Name |
|---|---|
| 7 | MISO |
| 8 | MOSI |
| 9 | SCK |
| 10 | SSEL |
The pin voltage level is 3.3V
Usage in Linux
Enable SPIDEV in device tree
To make SPI device accessible by user space application, we need to create a device tree node. After the node has been created, user application can access the device at
/dev/spidev5.0
!!! note To Be Updated