- leds-gpio: drivers/leds/leds-gpio.c will handle LEDs connected to GPIO
lines, giving you the LED sysfs interface

- ledtrig-gpio: drivers/leds/trigger/ledtrig-gpio.c will provide a LED trigger,
i.e. a LED will turn on/off in response to a GPIO line going high or low
(and that LED may in turn use the leds-gpio as per above).

- gpio-keys: drivers/input/keyboard/gpio_keys.c is used when your GPIO line
can generate interrupts in response to a key press. Also supports debounce.

- gpio-keys-polled: drivers/input/keyboard/gpio_keys_polled.c is used when your
GPIO line cannot generate interrupts, so it needs to be periodically polled
by a timer.

- gpio_mouse: drivers/input/mouse/gpio_mouse.c is used to provide a mouse with
up to three buttons by simply using GPIOs and no mouse port. You can cut the
mouse cable and connect the wires to GPIO lines or solder a mouse connector
to the lines for a more permanent solution of this type.

- gpio-beeper: drivers/input/misc/gpio-beeper.c is used to provide a beep from
an external speaker connected to a GPIO line.

- gpio-tilt-polled: drivers/input/misc/gpio_tilt_polled.c provides tilt
detection switches using GPIO, which is useful for your homebrewn pinball
machine if for nothing else. It can detect different tilt angles of the
monitored object.

- extcon-gpio: drivers/extcon/extcon-gpio.c is used when you need to read an
external connector status, such as a headset line for an audio driver or an
HDMI connector. It will provide a better userspace sysfs interface than GPIO.

- restart-gpio: drivers/power/reset/gpio-restart.c is used to restart/reboot
the system by pulling a GPIO line and will register a restart handler so
userspace can issue the right system call to restart the system.

- poweroff-gpio: drivers/power/reset/gpio-poweroff.c is used to power the
system down by pulling a GPIO line and will register a pm_power_off()
callback so that userspace can issue the right system call to power down the
system.

- gpio-gate-clock: drivers/clk/clk-gpio.c is used to control a gated clock
(off/on) that uses a GPIO, and integrated with the clock subsystem.

- i2c-gpio: drivers/i2c/busses/i2c-gpio.c is used to drive an I2C bus
(two wires, SDA and SCL lines) by hammering (bitbang) two GPIO lines. It will
appear as any other I2C bus to the system and makes it possible to connect
drivers for the I2C devices on the bus like any other I2C bus driver.

- spi_gpio: drivers/spi/spi-gpio.c is used to drive an SPI bus (variable number
of wires, at least SCK and optionally MISO, MOSI and chip select lines) using
GPIO hammering (bitbang). It will appear as any other SPI bus on the system
and makes it possible to connect drivers for SPI devices on the bus like
any other SPI bus driver. For example any MMC/SD card can then be connected
to this SPI by using the mmc_spi host from the MMC/SD card subsystem.

- w1-gpio: drivers/w1/masters/w1-gpio.c is used to drive a one-wire bus using
a GPIO line, integrating with the W1 subsystem and handling devices on
the bus like any other W1 device.

- gpio-fan: drivers/hwmon/gpio-fan.c is used to control a fan for cooling the
system, connected to a GPIO line (and optionally a GPIO alarm line),
presenting all the right in-kernel and sysfs interfaces to make your system
not overheat.

- gpio-regulator: drivers/regulator/gpio-regulator.c is used to control a
regulator providing a certain voltage by pulling a GPIO line, integrating
with the regulator subsystem and giving you all the right interfaces.

- gpio-wdt: drivers/watchdog/gpio_wdt.c is used to provide a watchdog timer
that will periodically "ping" a hardware connected to a GPIO line by toggling
it from 1-to-0-to-1. If that hardware does not receive its "ping"
periodically, it will reset the system.

- gpio-nand: drivers/mtd/nand/gpio.c is used to connect a NAND flash chip to
a set of simple GPIO lines: RDY, NCE, ALE, CLE, NWP. It interacts with the
NAND flash MTD subsystem and provides chip access and partition parsing like
any other NAND driving hardware.

&iomuxc {
	pinctrl_gpio_keys: gpiokeysgrp {
		fsl,pins = <
			MX6QDL_PAD_SD3_DAT6__GPIO6_IO18		0x1b0b0
			MX6QDL_PAD_CSI0_DAT10__GPIO5_IO28	0x1b0b0
		>;
	};
};
 
/ {
	gpio-keys {
		compatible = "gpio-keys";
		pinctrl-names = "default";
		pinctrl-0 = <&pinctrl_gpio_keys>;
		status = "disabled";
 
		home {
			label = "Home";
			gpios = <&gpio6 18 GPIO_ACTIVE_LOW>;
			linux,code = <KEY_HOME>;
		};
 
		power {
			label = "Power Button";
			gpios = <&gpio5 28 GPIO_ACTIVE_LOW>;
			linux,code = <KEY_POWER>;
			gpio-key,wakeup;
		};
	};
};

$ evtest
No device specified, trying to scan all of /dev/input/event*
Available devices:
/dev/input/event0:      stmpe-ts
/dev/input/event1:      gpio-keys
Select the device event number [0-1]:1

&iomuxc {
	pinctrl_user_leds: userledsgrp {
		fsl,pins = <
			MX6QDL_PAD_SD3_DAT4__GPIO7_IO01		0x1b0b0
			MX6QDL_PAD_SD3_DAT5__GPIO7_IO00		0x1b0b0
			MX6QDL_PAD_CSI0_DAT11__GPIO5_IO29	0x1b0b0
		>;
	};
};
 
/ {
	user_leds: user-leds {
		compatible = "gpio-leds";
		pinctrl-names = "default";
		pinctrl-0 = <&pinctrl_user_leds>;
		status = "disabled";
 
		user-led1 {
			gpios = <&gpio7 1 GPIO_ACTIVE_HIGH>;
			linux,default-trigger = "gpio";
			default-state = "on";
		};
 
		user-led2 {
			gpios = <&gpio7 0 GPIO_ACTIVE_HIGH>;
			linux,default-trigger = "gpio";
			default-state = "on";
		};
 
		user-led3 {
			gpios = <&gpio5 29 GPIO_ACTIVE_HIGH>;
			linux,default-trigger = "gpio";
			default-state = "on";
		};
	};
};

$ ls /sys/class/leds
mira-blue      mira-red       mmc1::         user-led1      user-led3
mira-green     mmc0::         phycore-green  user-led2

$ echo 255 > /sys/class/leds/user-led1/brightness

如果该led硬件上不支持亮度选择的话, 输出任何一个非零数值都能点亮该led.

$ echo 0 > /sys/class/leds/user-led1/brightness

$ echo timer > /sys/class/leds/user-led1/trigger
$ echo 200 > /sys/class/leds/user-led1/delay_on						#设置打开led时间
$ echo 200 > /sys/class/leds/user-led1/delay_off					#设置关闭led时间

stty -F /dev/ttyO2 115200 raw

echo "hello~tty device" > /dev/ttyO2

cat /dev/ttyO2

stty -F /dev/ttyO2 115200 -onlcr -iexten -echo -echoe -echok -echoctl -echoke raw

cansend can0 123#45.67

candump can0

ip -d -s link show can0


2: can0: <NOARP,UP,LOWER_UP,ECHO> mtu 16 qdisc pfifo_fast state UNKNOWN mode DEFAULT group default qlen 10
    link/can  promiscuity 0
    can state ERROR-ACTIVE (berr-counter tx 0 rx 0) restart-ms 0
          bitrate 500000 sample-point 0.800
          tq 400 prop-seg 1 phase-seg1 2 phase-seg2 1 sjw 1
          c_can: tseg1 2..16 tseg2 1..8 sjw 1..4 brp 1..1024 brp-inc 1
          clock 25000000
          re-started bus-errors arbit-lost error-warn error-pass bus-off
          0          0          0          0          0          0         numtxqueues 1 gso_max_size 65536 gso_max_segs 65535
    RX: bytes  packets  errors  dropped overrun mcast
    0          0        0       0       0       0
    TX: bytes  packets  errors  dropped carrier collsns
    0          0        0       0       0       0

root@phycore-am335x-1:~# cd /   
root@phycore-am335x-1:/# find . -name eeprom
./sys/devices/platform/ocp/44e0b000.i2c/i2c-0/0-0052/eeprom

root@phycore-am335x-1:/# dd if=/sys/devices/platform/ocp/44e0b000.i2c/i2c-0/0-0052/eeprom bs=1 count=1024 | od -x
0000000     55aa    6850    7479    6365    4d2d    7365    7473    6365
0000020     6e68    6b69    ffff    ffff    ffff    ffff    ffff    ffff
0000040     ffff    ffff    ffff    ffff    ffff    ffff    ffff    ffff
*
0002000
1024+0 records in
1024+0 records out

root@phycore-am335x-1:/# dd if=/dev/zero of=/sys/devices/platform/ocp/44e0b000.i2c/i2c-0/0-0052/eeprom bs=4096 count=1
1+0 records in
1+0 records out
root@phycore-am335x-1:/# dd if=/sys/devices/platform/ocp/44e0b000.i2c/i2c-0/0-0052/eeprom bs=1 count=1024 | od -x
0000000     0000    0000    0000    0000    0000    0000    0000    0000
*
0002000
1024+0 records in
1024+0 records out

hdparm -Tt /dev/sda

dd if=/dev/zero of=/tmp/output bs=8k count=10k

iozone -a -g 256M -s 256M -b file.xls

date -s "2017-7-17 15:44"

hwclock -w -u

[    1.943438] rtc-m41t80 0-0068: Oscillator failure, data is invalid.
[    1.950394] rtc-m41t80 0-0068: rtc core: registered rv4162 as rtc0

oot@phyboard-mira-imx6-3:/sys/class/rtc# cat rtc*/name
rtc-m41t80 0-0068
da9063-rtc da9062-rtc
snvs_rtc 20cc000.snvs:snvs-rtc-lp

 aliases {
 	rtc1 = &da9062_rtc;
	rtc2 = &snvs_rtc;
};

读取入系统：
hwclock -s -u -f /dev/rtc#
写入RTC：
hwclock -w -u -f /dev/rtc#

imx7d-phyboard-zeta-001:~# i2cdetect 1
WARNING! This program can confuse your I2C bus, cause data loss and worse!
I will probe file /dev/i2c-1.
I will probe address range 0x03-0x77.
Continue? [Y/n] y
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:          -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- UU -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- UU -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --

imx7d-phyboard-zeta-001:~# i2cdump 1 0x41
No size specified (using byte-data access)
Error: Could not set address to 0x41: Device or resource busy

ls /sys/devices/system/cpu  -1

echo 0 > /sys/devices/system/cpu/cpu3/online