VAR-SOM-MX6 I2C: Difference between revisions
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{{PageHeader|VAR-SOM-MX6 - I2C}} {{DocImage|category1=VAR-SOM-MX6 | {{PageHeader|VAR-SOM-MX6 - I2C}} {{DocImage|category1=Yocto|category2=Debian}} [[category:VAR-SOM-MX6]] __toc__ | ||
= I2C buses = | |||
= Available I2C buses = | |||
List I2C available devices: | |||
<pre> | <pre> | ||
root@var-som-mx6:~# ls -l /dev/i2c-* | root@var-som-mx6:~# ls -l /dev/i2c-* | ||
| Line 8: | Line 10: | ||
crw------- 1 root root 89, 1 Dec 6 10:31 /dev/i2c-1 | crw------- 1 root root 89, 1 Dec 6 10:31 /dev/i2c-1 | ||
crw------- 1 root root 89, 2 Dec 6 10:31 /dev/i2c-2 | crw------- 1 root root 89, 2 Dec 6 10:31 /dev/i2c-2 | ||
</pre> | |||
System class: | |||
<pre> | |||
root@var-som-mx6:~# ls /sys/class/i2c-dev/ | |||
i2c-0 i2c-1 i2c-2 | |||
</pre> | </pre> | ||
= I2C devices per bus = | |||
= I2C | Scan bus 0: | ||
<pre> | <pre> | ||
root@var-som-mx6:~# i2cdetect -y -r 0 | root@var-som-mx6:~# i2cdetect -y -r 0 | ||
| Line 24: | Line 31: | ||
70: -- -- -- -- -- -- -- -- | 70: -- -- -- -- -- -- -- -- | ||
</pre> | </pre> | ||
Scan bus 1: | |||
<pre> | <pre> | ||
root@var-som-mx6:~# i2cdetect -y -r 1 | root@var-som-mx6:~# i2cdetect -y -r 1 | ||
| Line 36: | Line 44: | ||
70: -- -- -- -- -- -- -- -- | 70: -- -- -- -- -- -- -- -- | ||
</pre> | </pre> | ||
Scan bus 2: | |||
<pre> | <pre> | ||
root@var-som-mx6:~# i2cdetect -y -r 2 | root@var-som-mx6:~# i2cdetect -y -r 2 | ||
| Line 48: | Line 57: | ||
70: -- -- -- -- -- -- -- -- | 70: -- -- -- -- -- -- -- -- | ||
</pre> | </pre> | ||
When the device is marked with "UU" it means that a driver is using it.<br> | |||
When the device is marked with numbers it means that no driver is using it.<br> | |||
= Reading / Writing from an I2C device= | |||
Variscite includes I2CTools as a part of the default file system build, examples of optional commands: <br> | |||
i2cdump - dump the content of an I2C device <br> | |||
i2cset - write a single character to an I2C device<br> | |||
i2cget - read a single character to an I2C device.<br> | |||
<br> | |||
In addition follow 'C' code example as describe in the linux kernel documentation : https://www.kernel.org/doc/Documentation/i2c/dev-interface | |||
= Variscite's system integrated I2C devices = | |||
{{note|Note: Do not write to Variscite's on-SOM EEPROM or you will damage the SOM!|info}} | |||
Variscite devices: | |||
I2C-0 0x3C - Camera | |||
I2C-1 0x08 - PMIC (not present on SOM-SOLO/DUAL) | |||
I2C-1 0x37 - HDMI | |||
I2C-1 0x49 - HDMI | |||
I2C-1 0x59 - HDMI | |||
I2C-1 0x50 | |||
I2C-1 0x52 - EEPROM on DART-MX6 - Do not alter! | |||
I2C-1 0x53 - EEPROM on DART-MX6 - Do not alter! | |||
I2C-1 0x56 - EEPROM on VAR-SOM-MX6 / SOM-SOLO/DUAL - Do not alter! | |||
I2C-1 0x57 - EEPROM on VAR-SOM-MX6 / SOM-SOLO/DUAL - Do not alter! | |||
I2C-2 0x38 - Capacitive touch panel | |||
I2C-2 0x68 - VAR-DVK-MX6 DS1307 RTC | |||
Latest revision as of 18:54, 28 April 2023
VAR-SOM-MX6 - I2C
Available I2C buses
List I2C available devices:
root@var-som-mx6:~# ls -l /dev/i2c-* crw------- 1 root root 89, 0 Dec 6 10:31 /dev/i2c-0 crw------- 1 root root 89, 1 Dec 6 10:31 /dev/i2c-1 crw------- 1 root root 89, 2 Dec 6 10:31 /dev/i2c-2
System class:
root@var-som-mx6:~# ls /sys/class/i2c-dev/ i2c-0 i2c-1 i2c-2
I2C devices per bus
Scan bus 0:
root@var-som-mx6:~# i2cdetect -y -r 0
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- UU -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --
Scan bus 1:
root@var-som-mx6:~# i2cdetect -y -r 1
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: -- -- -- -- -- UU -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- UU -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- 37 -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- 49 -- -- -- -- -- --
50: UU -- -- -- -- -- 56 57 -- 59 -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --
Scan bus 2:
root@var-som-mx6:~# i2cdetect -y -r 2
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- UU -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- UU -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --
When the device is marked with "UU" it means that a driver is using it.
When the device is marked with numbers it means that no driver is using it.
Reading / Writing from an I2C device
Variscite includes I2CTools as a part of the default file system build, examples of optional commands:
i2cdump - dump the content of an I2C device
i2cset - write a single character to an I2C device
i2cget - read a single character to an I2C device.
In addition follow 'C' code example as describe in the linux kernel documentation : https://www.kernel.org/doc/Documentation/i2c/dev-interface
Variscite's system integrated I2C devices
Note: Do not write to Variscite's on-SOM EEPROM or you will damage the SOM!
Variscite devices:
I2C-0 0x3C - Camera I2C-1 0x08 - PMIC (not present on SOM-SOLO/DUAL) I2C-1 0x37 - HDMI I2C-1 0x49 - HDMI I2C-1 0x59 - HDMI I2C-1 0x50 I2C-1 0x52 - EEPROM on DART-MX6 - Do not alter! I2C-1 0x53 - EEPROM on DART-MX6 - Do not alter! I2C-1 0x56 - EEPROM on VAR-SOM-MX6 / SOM-SOLO/DUAL - Do not alter! I2C-1 0x57 - EEPROM on VAR-SOM-MX6 / SOM-SOLO/DUAL - Do not alter! I2C-2 0x38 - Capacitive touch panel I2C-2 0x68 - VAR-DVK-MX6 DS1307 RTC