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Helios64: Update GPIO usage and SATA

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Aditya Prayoga 2020-10-27 18:07:35 +07:00
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80
docs/helios64/gpio.md
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@ -28,3 +28,83 @@ Helios64 provides 16 GPIOs via a 20-Pin header (P5). Those GPIOs are provided vi
| 18 | EXP_P1_6 | |
| 19 | EXP_P1_7 | |
| 20 | - | GND |
## Accessing GPIOs under Linux
If the kernel supports debugfs (*CONFIG_DEBUG_FS=y*), list of GPIOs can be retrieved with the following command
```bash
sudo cat /sys/kernel/debug/gpio
```
Look for the **gpiochip5: GPIOs XXX-YYY** section, whereas **XXX** is first GPIO number and **YYY** is last GPIO number of IO expander.
```
gpiochip5: GPIOs 496-511, parent: i2c/2-0020, 2-0020, can sleep:
```
Another way to get first GPIO number of the IO expander
```
cat /sys/bus/i2c/devices/2-0020/gpio/gpiochip*/base
```
Therefore the mapping between header P5 Pins and Sysfs GPIO numbers will be as described in the following table
### GPIO Table
| PIN | Sysfs GPIO number | Remarks |
|-----|------|-------------|
| 1 | - | 3.3V Supply |
| 2 | - | 5V Supply |
| 3 | - | GND |
| 4 | 496 | |
| 5 | 497 | |
| 6 | 498 | |
| 7 | 499 | |
| 8 | 500 | |
| 9 | 501 | |
| 10 | 502 | |
| 11 | 503 | |
| 12 | 504 | |
| 13 | 505 | |
| 14 | 506 | |
| 15 | 507 | |
| 16 | 508 | |
| 17 | 509 | |
| 18 | 510 | |
| 19 | 511 | |
| 20 | - | GND |
### GPIO Control
**1.** Export the GPIO number you want to use
```
echo N | sudo tee -a /sys/class/gpio/export
```
**2.** Set the direction, "out" for Output or "in" for Input
```
echo DIRECTION | sudo tee -a /sys/class/gpio/gpioN/direction
```
**3.** Now you can read or change the GPIO value
To read GPIO value
```
cat /sys/class/gpio/gpioN/value
```
To change GPIO value (only if GPIO set as Output)
```
echo VALUE | sudo tee -a /sys/class/gpio/gpioN/value
```
!!! notes
Pay attention to the path, /sys/class/gpio/gpio**N**/ where **N** is the GPIO number.

2
docs/helios64/sata.md
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@ -37,6 +37,8 @@ The power delivery of the HDDs is devided into two group:
Helios64 implements a power staggering approach where *HDD Rail A* will be powered up first, then few seconds later *HDD Rail B* will be powered up. This power control scenario is performed to reduce the inrush current during disk spin-up.
The power staggering mechanism is not user configurable. It is done by bootloader.
### J8 Pinout
![J8 Location](/helios64/img/sata/j8_pinout.jpg)