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--- products:sbc:common:applications:gpio:i2c [2022/06/29 21:51]
127.0.0.1 external edit
+++ products:sbc:common:applications:gpio:i2c [2023/11/07 04:51] (current)
nick [Enable I2C]
@@ Line 1: / Line 1: @@
 ====== I2C ======
+===== Introduction =====
+This page introduces the usage of I2C bus on [[products:sbc:common:applications:gpio:40pin-header|40-Pin Header]].
+===== I2C Information =====
+|           ^  I2C     ^  PIN      ^  GPIO Name  ^  DT Overlays Node  ^  Bus Number  ^  Device Node  ^
+^  VIM1/2   |  I2C A   |  22(SCL)  |  GPIODV_25  |  i2c0              |  0           |  /dev/i2c-0   |
+| :::       | :::      |  23(SDA)  |  GPIODV_24  | :::                | :::          | :::           |
+| :::       |  I2C B   |  25(SCL)  |  GPIODV_27  |  -                 |  1           |  /dev/i2c-1   |
+| :::       | :::      |  26(SDA)  |  GPIODV_26  | :::                | :::          | :::           |
+^  VIM3/3L  |  I2CM 3  |  22(SCL)  |  GPIOA_15   |  i2c3              |  3           |  /dev/i2c-3   |
+| :::       | :::      |  23(SDA)  |  GPIOA_14   | :::                | :::          | :::           |
+| :::       |  I2C AO  |  25(SCL)  |  GPIOAO_2   |  -                 |  4           |  /dev/i2c-4   |
+| :::       | :::      |  26(SDA)  |  GPIOAO_3   | :::                | :::          | :::           |
+^  VIM4     |  I2CM F  |  22(SCL)  |  GPIOY_17   |  i2cm_f            |  5           |  /dev/i2c-5   |
+| :::       | :::      |  23(SDA)  |  GPIOY_18   | :::                | :::          | :::           |
+| :::       |  I2CM A  |  25(SCL)  |  GPIOT_20   |  i2cm_a            |  0           |  /dev/i2c-0   |
+| :::       | :::      |  26(SDA)  |  GPIOT_21   | :::                | :::          | :::           |
+^  VIM1S    |  I2CM B  |  22(SCL)  |  GPIOD_7    |  -                 |  1           |  /dev/i2c-1   |
+| :::       | :::      |  23(SDA)  |  GPIOD_6    | :::                | :::          | :::           |
+| :::       |  I2CM E  |  25(SCL)  |  GPIOZ_11   |  i2cm_e            |  4           |  /dev/i2c-4   |
+| :::       | :::      |  26(SDA)  |  GPIOZ_12   | :::                | :::          | :::           |
+===== Enable I2C =====
+In order to use the I2C, you need to enable the I2C function via [[products:sbc:common:configurations:device-tree-overlay|Device Tree Overlay]].
+<tabbox VIM1/2/3/3L/Edge1>
+Edit ''/boot/env.txt'' to add the i2c node to ''overlays'' node if it doesn't exist.
+Take VIM3 as an example to enable ''I2CM 3'', you need to add ''i2c3'' node to ''overlays'' node if it doesn't exist.
+```shell
+overlays=uart4 pwm_ao_a pwm_f i2c3
+```
+After reboot, you will see the I2C device node.
+```shell
+$ ls /dev/i2c-3
+/dev/i2c-3
+```
+<tabbox VIM3 with 5.15 kernel>
+Edit ''/boot/dtb/amlogic/kvim3.dtb.overlay.env'' to add i2c node to ''fdt_overlays'' node if it doesn't exist.
+e.g. To enable ''I2CM 3'', you need to add ''i2c3'' to node ''fdt_overlays'' if it doesn't exist.
+```shell
+fdt_overlays=i2c3
+```
+After reboot, you will see the I2C device node.
+<tabbox VIM3L with 5.15 kernel>
+Edit ''/boot/dtb/amlogic/kvim3l.dtb.overlay.env'' to add i2c node to ''fdt_overlays'' node if it doesn't exist.
+e.g. To enable ''I2CM 3'', you need to add ''i2c3'' to node ''fdt_overlays'' if it doesn't exist.
+```shell
+fdt_overlays=i2c3
+```
+After reboot, you will see the I2C device node.
+<tabbox VIM4>
+Edit ''/boot/dtb/amlogic/kvim4.dtb.overlay.env'' to add i2c node to ''fdt_overlays'' node if it doesn't exist.
+e.g. To enable ''I2CM A'', you need to add ''i2cm_a'' to node ''fdt_overlays'' if it doesn't exist.
+```shell
+fdt_overlays=i2cm_a
+```
+After reboot, you will see the I2C device node.
+```shell
+$ ls /dev/i2c-0
+/dev/i2c-0
+```
+<tabbox VIM1S>
+Edit ''/boot/dtb/amlogic/kvim1s.dtb.overlay.env'' to add i2c node to ''fdt_overlays'' node if it doesn't exist.
+e.g. To enable ''I2CM E'', you need to add ''i2cm_e'' to node ''fdt_overlays'' if it doesn't exist.
+```shell
+fdt_overlays=i2cm_e
+```
+After reboot, you will see the I2C device node.
+```shell
+$ ls /dev/i2c-4
+/dev/i2c-4
+```
+</tabbox>
+===== I2C Usage =====
+Please check the [[https://manpages.ubuntu.com/manpages/jammy/en/man8/i2cdetect.8.html|I2C Usage]].
+===== Disable I2C to Use GPIO =====
+If you want to use normal GPIO instead of I2C, you can remove the I2C node in [[products:sbc:common:configurations:device-tree-overlay|Device Tree Overlay]].

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