Re: RPI4/8GB i2c not working?
Klaus Küchemann via freebsd-arm <[email protected]>
| Newsgroups | gmane.os.freebsd.devel.arm |
|---|---|
| Message-ID | <[email protected]> |
> Am 10.03.2021 um 18:26 schrieb Klaus Küchemann <[email protected]>: > > > Also possibly some things cood depend on loaded overlays/config.txt > and which corresponding GPIO-pins are configured > So let's give adding devices & gpio-pins a shot with an example : 1.: we place e.g. the following files in dtb/overlays into the msdos-partition : i2c1.dtbo i2c3.dtbo i2c4.dtbo i2c6.dtbo 2.: in config.txt we add them and assign pins to them: --- dtoverlay=i2c1,pins_2_3 dtoverlay=i2c3,pins_4_5 dtoverlay=i2c4,pins_6_7 dtoverlay=i2c6,pins_0_1 -- 3.: reboot the machine : root@generic:~ # dmesg ..... iicbus1: <OFW I2C bus> on iichb1 iic1: <I2C generic I/O> on iicbus1 iicbus2: <OFW I2C bus> on iichb2 iic2: <I2C generic I/O> on iicbus2 iicbus3: <OFW I2C bus> on iichb3 iic3: <I2C generic I/O> on iicbus3 ... root@generic:~ # ls /dev ... iic0 iic1 iic2 iic3 .. That's totally exciting ! :-) Ha Ha 4.: so let's probe again, this time on /dev/iic2 : root@generic:~ # ktrace -t+ i2c -s -f /dev/iic2 root@generic:~ # kdump …. 1246 i2c RET open 3 1246 i2c CALL read(0x3,0x4027cc18,0x80) 1246 i2c GIO fd 3 read 128 bytes 0x0000 4568 6e74 0100 0000 8000 0000 d500 0000 |Ehnt............| 0x0010 0000 0000 d400 0000 0000 0000 0000 0000 |................| 0x0020 0000 0000 0000 0000 0000 0000 0000 0000 |................| 0x0030 0000 0000 0000 0000 0000 0000 0000 0000 |................| 0x0040 0000 0000 0000 0000 0000 0000 0000 0000 |................| 0x0050 0000 0000 0000 0000 0000 0000 0000 0000 |................| 0x0060 0000 0000 0000 0000 0000 0000 0000 0000 |................| 0x0070 0000 0000 0000 0000 0000 0000 0000 0000 |................| 1246 i2c RET read 128/0x80 ... Wow, everything works as expected ! :-) I have no clue what happens when you assign the wrong pins to the wrong voltage ;-) Ha Ha K. _______________________________________________ [email protected] mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-arm To unsubscribe, send any mail to "[email protected]"