本文记录如何在Android和linux上操作GPIO 。
ROM必须满足以下条件：
* Android M >= V170603 * Android N >= V170421 * Ubuntu Server >= V180712 * Ubuntu Mate >= V180531可以从GPIO Bank或 Pins 获取GPIO编号。 不同版本的内核将有所不同。
Linux 3.14 (Android M, N and Ubuntu)Banks:
# cat /sys/kernel/debug/pinctrl/c1109880.pinmux/gpio-ranges GPIO ranges handled: 0: banks GPIOS [155 - 255] PINS [10 - 110] 0: ao-bank GPIOS [145 - 154] PINS [ 0 - 9] Notice: ao-bank means GPIOAO_X gpiosPins:
# cat /sys/kernel/debug/pinctrl/c1109880.pinmux/pins ... pin 5 (GPIOAO_5) pin 6 (GPIOAO_6) ... pin 28 (GPIOH_2) pin 29 (GPIOH_3) pin 30 (GPIOH_4) pin 31 (GPIOH_5) pin 32 (GPIOH_6) pin 33 (GPIOH_7) pin 34 (GPIOH_8) pin 35 (GPIOH_9) ...例如，获取GPIOH_4，GPIOH_5和GPIOAO_6的编号。
Number(GPIOH_5) = bank + pin = 155 - 10 + 31 = 176 Number(GPIOH_4) = bank + pin = 155 - 10 + 30 = 175 Number(GPIOAO_6) = bank + pin = 145 - 0 + 6 = 151 Linux 4.9 (Android O and Ubuntu)aobus-banks: Banks:
root@Khadas:~# cat /sys/kernel/debug/pinctrl/pinctrl@14/gpio-ranges GPIO ranges handled: 0: aobus-banks GPIOS [0 - 10] PINS [0 - 10]Pins:
root@Khadas:~# cat /sys/kernel/debug/pinctrl/pinctrl@14/pins registered pins: 11 pin 0 (GPIOAO_0) pinctrl@14 pin 1 (GPIOAO_1) pinctrl@14 pin 2 (GPIOAO_2) pinctrl@14 pin 3 (GPIOAO_3) pinctrl@14 pin 4 (GPIOAO_4) pinctrl@14 pin 5 (GPIOAO_5) pinctrl@14 pin 6 (GPIOAO_6) pinctrl@14 pin 7 (GPIOAO_7) pinctrl@14 pin 8 (GPIOAO_8) pinctrl@14 pin 9 (GPIOAO_9) pinctrl@14 pin 10 (GPIO_TEST_N) pinctrl@14例如，获取 GPIOAO_6 的编号：
Number(GPIOAO_6) = bank + pin = 0 - 0 + 6 = 6
periphs-banks: Banks:
root@Khadas:~# cat /sys/kernel/debug/pinctrl/pinctrl@4b0/gpio-ranges GPIO ranges handled: 0: periphs-banks GPIOS [11 - 110] PINS [11 - 110]Pins:
root@Khadas:~# cat /sys/kernel/debug/pinctrl/pinctrl@4b0/pins registered pins: 100 pin 11 (GPIOZ_0) pinctrl@4b0 pin 12 (GPIOZ_1) pinctrl@4b0 pin 13 (GPIOZ_2) pinctrl@4b0 ... pin 27 (GPIOH_0) pinctrl@4b0 pin 28 (GPIOH_1) pinctrl@4b0 pin 29 (GPIOH_2) pinctrl@4b0 pin 30 (GPIOH_3) pinctrl@4b0 pin 31 (GPIOH_4) pinctrl@4b0 pin 32 (GPIOH_5) pinctrl@4b0 pin 33 (GPIOH_6) pinctrl@4b0 pin 34 (GPIOH_7) pinctrl@4b0 pin 35 (GPIOH_8) pinctrl@4b0 pin 36 (GPIOH_9) pinctrl@4b0 ... pin 81 (GPIODV_21) pinctrl@4b0 pin 82 (GPIODV_22) pinctrl@4b0 pin 83 (GPIODV_23) pinctrl@4b0 pin 84 (GPIODV_24) pinctrl@4b0 ...例如，获取GPIOH_5的编号: Number(GPIOH_5) = bank + pin = 11 - 11 + 32 = 32
GPIO List
PIN GPIO Number PIN37 GPIOH5 176 PIN33 GPIOAO6 151有两种访问GPIO的方法：
ADB 命令第三方应用ADB 命令
连接 adb:
$ adb connect IP_ADDR登录 VIMs:
$ adb shell获取root权限
$ su获取 gpio(GPIOH5)
$ echo 176 > /sys/class/gpio/export配置 gpio(GPIOH5) 为 output
$ echo out > /sys/class/gpio/gpio176/direction将gpio（GPIO 5）配置为高电平输出
$ echo 1 > /sys/class/gpio/gpio176/value将gpio（GPIO 5）配置为低电平输出
$ echo 0 > /sys/class/gpio/gpio176/value将gpio（GPIO 5）配置为输入
$ echo in > /sys/class/gpio/gpio176/direction获取gpio（GPIOH5）level
$ cat /sys/class/gpio/gpio176/valueRelease gpio(GPIOH5)
$ echo 176 > /sys/class/gpio/unexport第三方应用
获取root权限
Process mProcess = Runtime.getRuntime().exec("su");获取 gpio(GPIOH5)
DataOutputStream os = new DataOutputStream(mProcess.getOutputStream()); os.writeBytes("echo " + 176 + " > /sys/class/gpio/export\n");将gpio（GPIO 5）配置为高电平输出
os.writeBytes("echo out > /sys/class/gpio/gpio" + 176 + "/direction\n"); os.writeBytes("echo 1 > /sys/class/gpio/gpio" + 176 + "/value\n");将gpio（GPIO 5）配置为输入
os.writeBytes("echo in > /sys/class/gpio/gpio" + 176 + "/direction\n");获取gpio（GPIOH5）level
Runtime runtime = Runtime.getRuntime(); Process process = runtime.exec("cat " + "/sys/class/gpio/gpio" + 176 + "/value"); InputStream is = process.getInputStream(); InputStreamReader isr = new InputStreamReader(is); BufferedReader br = new BufferedReader(isr); String line ; while (null != (line = br.readLine())) { return Integer.parseInt(line.trim()); }Release gpio(GPIOH5)
os.writeBytes("echo " + 176 + " > /sys/class/gpio/unexport\n");GPIO 列表
列表**-3.14
PIN GPIO Number PIN37 GPIOH5 176 PIN33 GPIOAO6 151Linux-4.9.40
PIN GPIO Number PIN37 GPIOH5 32 PIN33 GPIOAO6 6**如何在终端上访问GPIO **
[如 linux-3.14] 获取 gpio(GPIOH5)
$ echo 176 > /sys/class/gpio/export配置 gpio(GPIOH5) 为 output
$ echo out > /sys/class/gpio/gpio176/direction将gpio（GPIO 5）配置为高电平输出
$ echo 1 > /sys/class/gpio/gpio176/value将gpio（GPIO 5）配置为低电平输出
$ echo 0 > /sys/class/gpio/gpio176/value将gpio（GPIO 5）配置为输入
$ echo in > /sys/class/gpio/gpio176/direction获取 level gpio(GPIOH5)
$ cat /sys/class/gpio/gpio176/valueRelease gpio(GPIOH5)
$ echo 176 > /sys/class/gpio/unexport