哇酷®开发者社区(WhyCan® Forum)

psst

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注册时间： 2019-01-22

已发帖子： 92

积分： 22.5

v3s 怎么使用gpio模拟iic

请教各位高手。我想用drivers/i2c/busses/i2c-gpio.c 模拟iic，硬件iic口没有使用，io被占用了。要怎么玩？

menuconfig配置如下
-*- I2C support
Enable compatibility bits for old user-space
<*> I2C device interface
<*> I2C bus multiplexing support
Multiplexer I2C Chip support --->
[**] Autoselect pertinent helper modules
I2C Hardware Bus support --->
*** I2C system bus drivers (mostly embedded / system-on-chip)
│ │ < > CBUS I2C driver
│ │ < > Synopsys DesignWare Platform
│ │ < > EMMA Mobile series I2C adapter
│ │ <*> GPIO-based bitbanging I2C
│ │ < > Marvell mv64xxx I2C Controller
│ │ < > OpenCores I2C Controller
│ │ < > PCA9564/PCA9665 as platform device
│ │ < > Rockchip RK3xxx I2C adapter
│ │ < > Simtec Generic I2C interface

dts如下

i2c0@0 {
compatible = "i2c-gpio";
gpios = <&pio 2 2 // sda
&pio 2 1 // scl

;

i2c-gpio,sda-open-drain;
i2c-gpio,scl-open-drain;
i2c-gpio,delay-us = <2>;
#address-cells = <1>;
#size-cells = <0>;
status = "okay";
//rv3029c2@56 {
//compatible = "rv3029c2";
//reg = <0x56>;
//};

};

启动后报错， OF: /soc/i2c0@0: could not get #gpio-cells for /soc/clock@01c20000
是不是gpio配置不对，
&pio 2 2 / sda /
&pio 2 1这两个口是串口，没有使用，应该不会被占用，

设备树怎么写？请教大家了

最近编辑记录 psst (2019-11-16 18:19:36)

kekemuyu

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注册时间： 2018-12-13

已发帖子： 856

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Re: v3s 怎么使用gpio模拟iic

软件模拟也需要定时器吧，否则时序无法控制

晕哥

管理员

所在地： wechat: whycan_cn

注册时间： 2017-09-06

已发帖子： 9,476

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Re: v3s 怎么使用gpio模拟iic

你的设备树配置有误， 来这里抄一个吧:

https://github.com/torvalds/linux/blob/master/arch/arm64/boot/dts/allwinner/sun50i-a64-amarula-relic.dts

	i2c {
		compatible = "i2c-gpio";
		sda-gpios = <&pio 4 13 GPIO_ACTIVE_HIGH>;
		scl-gpios = <&pio 4 12 GPIO_ACTIVE_HIGH>;
		i2c-gpio,delay-us = <5>;
		#address-cells = <1>;
		#size-cells = <0>;
...

---

taobao： V3s/F1C100s/F1C200s/D1/F133-A/F133-B/T113-S3/A523/A133/H133/V831/V851s/V853

liuy

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注册时间： 2020-06-24

已发帖子： 10

积分： 49

Re: v3s 怎么使用gpio模拟iic

我也在用模拟iic,请问启动了吗?

dmesg | grep i2c

[ 0.120130] i2c-gpio i2c-gpio: error trying to get descriptor: -2
[ 0.981720] i2c /dev entries driver
[ 6.656316] goodix-ts 1-005d: GTP i2c test failed time 1
[ 11.086325] goodix-ts 1-005d: GTP i2c test failed time 2
[ 15.516320] goodix-ts 1-005d: GTP i2c test failed time 3
[ 15.544682] i2c-gpio i2c-gpio: using lines 3 (SDA) and 0 (SCL),-1

一直是这个错误

lignin

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注册时间： 2020-03-21

已发帖子： 139

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Re: v3s 怎么使用gpio模拟iic

在pinctrl里面要声明使用的引脚，然后在使用它gpio模拟iic的，应该是类似的
可以参考一下这个gpio模拟spi的例子

在根节点下加入
spi2:spi2{
compatible = "spi-gpio";
#address-cells = <0x1>;
#size-cells = <0>;
//ranges;
gpio-sck = <&pio 3 0 1>;
gpio-miso = <&pio 3 1 1>;
gpio-mosi = <&pio 3 2 1>;
cs-gpios = <&pio 3 3 1>;
num-chipselects = <1>;

pinctrl-names = "default";//注意这两排
pinctrl-0 = <&spi2_pins_a>;//
spidev2 {
#address-cells = <1>;
#size-cells = <0>;
compatible = "rohm,dh2228fv";
spi-max-frequency = <20000000>;
reg = <0>;

};

};

在pinctrl里面加入
&pio{

spi2_pins_a: spi2-pins-pc {
pins = "PD0", "PD1", "PD2", "PD3";
function = "gpio_out";
bias-pull-up;
};
};

最近编辑记录 lignin (2020-08-02 20:05:48)

资本家大善人

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注册时间： 2021-03-26

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Re: v3s 怎么使用gpio模拟iic

就在两地方，毫无问题

 .config - Linux/arm 5.4.99 Kernel Configuration
 > Device Drivers > I2C support > I2C Hardware Bus support ────────────────────
  ┌─────────────────────── I2C Hardware Bus support ────────────────────────┐
  │  Arrow keys navigate the menu.  <Enter> selects submenus ---> (or empty │  
  │  submenus ----).  Highlighted letters are hotkeys.  Pressing <Y>        │  
  │  includes, <N> excludes, <M> modularizes features.  Press <Esc><Esc> to │  
  │  exit, <?> for Help, </> for Search.  Legend: [*] built-in  [ ]         │  
  │ ┌─────────────────────────────────────────────────────────────────────┐ │  
  │ │        *** I2C system bus drivers (mostly embedded / system-on-chip)│ │  
  │ │    < > CBUS I2C driver                                              │ │  
  │ │    < > Synopsys DesignWare Platform                                 │ │  
  │ │    < > EMMA Mobile series I2C adapter                               │ │  
  │ │    <*> GPIO-based bitbanging I2C

	i2c_gpio0: i2c-gpio-0 {
		compatible = "i2c-gpio";
		sda-gpios = <&pio 4 0 GPIO_ACTIVE_HIGH>;
		scl-gpios = <&pio 4 1 GPIO_ACTIVE_HIGH>;
		i2c-gpio,delay-us = <5>;
		#address-cells = <1>;
		#size-cells = <0>;
        ft6x06@38 {
                compatible = "focaltech,ft6236";
                reg = <0x38>;
                interrupt-parent = <&pio>;
                interrupts = <4 2 IRQ_TYPE_LEVEL_LOW>;
                reset-gpios = <&pio 4 3 GPIO_ACTIVE_LOW>;
                touchscreen-size-x = <240>;
                touchscreen-size-y = <240>;
          }; 

    };