MaixII M2dock I2C gpio 调试

PIN_CTL

• lichee/linux-4.9/drivers/pinctrl/sunxi/pinctrl-sun8iw19p1-r.c

• lichee/linux-4.9/drivers/pinctrl/sunxi/pinctrl-sun8iw19p1.c

V831 Dock PIN Maps

• PINCTRL_PIN(64 + (0), "P" "C" "0")
• PINCTRL_PIN(96 + (0), "P" "D" "0")
• PINCTRL_PIN(128 + (0), "P" "E" "0")
• PINCTRL_PIN(160 + (0), "P" "F" "0")
• PINCTRL_PIN(192 + (0), "P" "G" "0")
• PINCTRL_PIN(224 + (0), "P" "H" "0")
• PINCTRL_PIN(256 + (0), "P" "I" "0")

sysfs 操作 GPIO

root@sipeed:/# ls -l /sys/class/gpio
--w-------    1 root     root          4096 Dec  9 08:54 export
lrwxrwxrwx    1 root     root             0 Dec  9 08:54 gpiochip0 -> ../../devices/platform/soc/pio/gpio/gpiochip0
lrwxrwxrwx    1 root     root             0 Dec  9 08:54 gpiochip352 -> ../../devices/platform/soc/r_pio/gpio/gpiochip352
--w-------    1 root     root          4096 Dec  9 08:54 unexport
root@sipeed:/#

/sys/class/gpio 目录下的三种文件：

• export/unexport 文件: /sys/class/gpio/export，只写，写入 GPIO 编号来向内核申请 GPIO 控制权（前提是没有内核代码申请这个 GPIO 端口）, 成功后会在目录下生成 gpioN 目录, /sys/class/gpio/unexport 和导出的效果相反。

• gpioN 指代具体的 gpio 引脚: 指代某个具体的 gpio 端口, 内有以下属性文件：

• gpiochipN 指代 gpio 控制器: gpiochipN 表示的就是一个 gpio_chip, 用来管理和控制一组 gpio 端口的控制器，该目录下存在以下属性文件：

LED 测试

使用 sysfs 操作 GPIO 的例子：

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

ll /sys/devices/platform/soc/r_pio/

Python-gpiod

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("\nrequest line\n")

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)

python test_blink.py gpiochip0 238