关于 V831 linux 调用 gpio 的一些通用操作。

现在推荐看这个【参考学习用】基于全志芯片的GPIO及底层（C/Python）编程 与 linux下/dev/mem分析，这篇作为备份录用途，主要是关于 V831 sun8iw19p1 的 pinctrl gpio 等信息。

备忘一下：V831 对应 sun8iw19p1 的代号，关于 gpio 部分，我还没做到 Python ，只是在 linux sysfs 接口上验证了一遍。

我们可以在 SDK 里得知对应的映射关系文件在 /drivers/pinctrl/sunxi/pinctrl-sun8iw19p1.c 。

• /arch/arm/boot/dts/sun8iw19p1-pinctrl.dtsi

使用方法有如下：

https://thoughts.teambition.com/share/600659e9823a3d004a4e1c7a#6000f67283e1f200460df31c

https://zhuanlan.zhihu.com/p/265359362

ls -l /sys/class/gpio/ # show gpio
echo 238 > /sys/class/gpio/export  #export PH14(238), State_LED
ls -l /sys/class/gpio/ # show gpio
# output test
echo "out" > /sys/class/gpio/gpio238/direction # set gpio mode: direction
echo 0 > /sys/class/gpio/gpio238/value # set gpio output level: low
echo 1 > /sys/class/gpio/gpio238/value # set gpio output level: height
# input test
echo "in" > /sys/class/gpio/gpio238/direction #设置为输入
cat /sys/class/gpio/gpio192/value #读取电平

because A = 0 > l = 11 output 1 PL3 (11(L) * 32 == 352 + 3)

echo 355 > /sys/class/gpio/export
echo "out" > /sys/class/gpio/gpio355/direction
echo 1 > /sys/class/gpio/gpio355/value

设备树中 pinctrl 的使用

https://blog.csdn.net/u012830148/article/details/80609337

GPIO 实现的细节看这个文章解释该结构

https://blog.csdn.net/zhoutaopower/article/details/98082006

主要看 gpio_chip 和 gpio 的符号。

看这篇熟悉如何配置设备树中的驱动和具体的设备，链接到指定的 IO 引脚上。

https://www.cnblogs.com/aaronLinux/p/5551441.html

import gpiod
c = gpiod.chip("gpiochip1")
# pylint: disable=missing-docstring
import sys
import time
import pytest
from gpiod import chip, line, line_request

try:
    if len(sys.argv) > 2:
        LED_CHIP = sys.argv[1]
        LED_LINE_OFFSET = int(sys.argv[2])
    else:
        raise Exception()
# pylint: disable=broad-except
except Exception:
    print(
        """Usage:
    python3 -m gpiod.test.blink <chip> <line offset>"""
    )
    sys.exit()

c = chip(LED_CHIP)

print("chip name: ", c.name)
print("chip label: ", c.label)
print("number of lines: ", c.num_lines)

print()

led = c.get_line(LED_LINE_OFFSET)

print("line offset: ", led.offset)
print("line name: ", led.name)
print("line consumer: ", led.consumer)
print(
    "line direction: ",
    "input" if led.direction == line.DIRECTION_INPUT else "output",
)
print(
    "line active state: ",
    "active low" if led.active_state == line.ACTIVE_LOW else "active high",
)
print("is line used: ", led.is_used)
print("is line open drain: ", led.is_open_drain)
print("is_open_source: ", led.is_open_source)
print("is line requested: ", led.is_requested)

print("
request line
")

config = line_request()
config.consumer = "Blink"
config.request_type = line_request.DIRECTION_OUTPUT

led.request(config)

print("line consumer: ", led.consumer)
print(
    "line direction: ",
    "input" if led.direction == line.DIRECTION_INPUT else "output",
)
print(
    "line active state: ",
    "active low" if led.active_state == line.ACTIVE_LOW else "active high",
)
print("is line used: ", led.is_used)
print("is line open drain: ", led.is_open_drain)
print("is_open_source: ", led.is_open_source)
print("is line requested: ", led.is_requested)

while True:
    led.set_value(0)
    time.sleep(0.1)
    led.set_value(1)
    time.sleep(0.1)