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by PhilE
Tue Sep 25, 2018 3:47 pm
Forum: Device Tree
Topic: SPI0 still having spidev0.1 after loading new modified overlay
Replies: 1
Views: 25

Re: SPI0 still having spidev0.1 after loading new modified overlay

When specify new properties for a DT node using an overlay, the properties are merged with the existing values (and frustratingly it isn't possible to delete properties from an overlay). Thus your fragment 1, as well as rewriting many properties with their existing values, is overwriting the whole s...
by PhilE
Tue Sep 25, 2018 8:25 am
Forum: Compute Module
Topic: CM3 and I2C pins
Replies: 8
Views: 96

Re: CM3 and I2C pins

Sadly there is no way to enable and configure the camera other than with a dt-blob. The DPI overlays do work, but the display isn't enabled until a few seconds after the kernel starts to boot, and if it fails in the early stages of booting you get no output.
by PhilE
Tue Sep 25, 2018 8:21 am
Forum: Troubleshooting
Topic: Raspberry Pi 3 B+ doesn't boot
Replies: 14
Views: 311

Re: Raspberry Pi 3 B+ doesn't boot

if grajasumant install boots on a pi3, than the pi3b+ should certainly also work with the same sdcard.
This is nonsense. There are many differences between the 3B and the 3B+, many of which mean that an old image that works on a 3B could never work on a 3B+.
by PhilE
Mon Sep 24, 2018 2:38 pm
Forum: Compute Module
Topic: CM3 and I2C pins
Replies: 8
Views: 96

Re: CM3 and I2C pins

Please be careful with the terminology - despite the name, dt-blob.bin is not Device Tree. It's a custom configuration file for the firmware, so call it the dt-blob. Overlays ARE Device Tree, and so are the ".dtb" files you'll find in /boot. A custom dt-blob.bin completely replaces the one that is b...
by PhilE
Mon Sep 24, 2018 1:02 pm
Forum: Compute Module
Topic: Compute Module I2C not working (I2Cdetect)
Replies: 24
Views: 3441

Re: Compute Module I2C not working (I2Cdetect)

Hi, just to know, where I can found this useful information inside the CM3 Datasheet (Rev2, June 2018)? It's not in the CM datasheet, but then neither is any mention of Device Tree overlays and parameters. The README for the overlays does cover it though: i2c_arm Set to "on" to enable the ARM's i2c...
by PhilE
Mon Sep 24, 2018 11:13 am
Forum: Compute Module
Topic: CM3 and I2C pins
Replies: 8
Views: 96

Re: CM3 and I2C pins

I2C3 is the I2C interface of the HDMI connector btw.
That's I2C2 - i2c3 is the default name for a bit-bashed GPIO I2C bus.
by PhilE
Mon Sep 24, 2018 11:03 am
Forum: Compute Module
Topic: CM3 and I2C pins
Replies: 8
Views: 96

Re: CM3 and I2C pins

Both I2C/BSC interfaces are available for general use by the OS (the third is reserved for HDMI) provided you aren't trying to drive a camera , but unless you need two I2C buses in your application you will find it more convenient to use I2C1 because the Device Tree overlays are designed for HATs (w...
by PhilE
Sat Sep 22, 2018 4:08 pm
Forum: Device Tree
Topic: gpio-poweroff doesn't work on Raspbian Lite
Replies: 3
Views: 91

Re: gpio-poweroff doesn't work on Raspbian Lite

There is an error in your config.txt - one of the parameter names is wrong. From the output of "sudo vcdbg log msg": 001980.108: brfs: File read: /mfs/sd/overlays/gpio-shutdown.dtbo 001989.340: Loaded overlay 'gpio-shutdown' 001989.399: dtparam: active_low=0 001990.085: dtparam: gpio_pin=20 002050.8...
by PhilE
Thu Sep 20, 2018 8:52 am
Forum: Camera board
Topic: RPi 3 Model B+ - camera connector assembly error?
Replies: 4
Views: 180

Re: RPi 3 Model B+ - camera connector assembly error?

Can you email a photo of the QR code sticker to [email protected]? Thank you.
by PhilE
Wed Sep 19, 2018 10:17 am
Forum: Troubleshooting
Topic: Broken Wireless on Raspberry Pi model 3B
Replies: 35
Views: 1035

Re: Broken Wireless on Raspberry Pi model 3B

Failure to bring up the WLAN interface is usually a sign of insufficient power being delivered to the Pi, either due to the power supply or the cable not being up to the job. Try running "vcgencmd get_throttled" after booting - a hard power-cycle is probably advisable to rule out reboot problems - a...
by PhilE
Wed Sep 19, 2018 8:53 am
Forum: Debian
Topic: Upstream driver snd-bcm2835
Replies: 6
Views: 189

Re: Upstream driver snd-bcm2835

by PhilE
Tue Sep 18, 2018 10:19 am
Forum: Device Tree
Topic: Overlay for GPIO connected fan
Replies: 15
Views: 374

Re: Overlay for GPIO connected fan

I think I've found the problematic commit that is causing crashes since rpi-4.14.63, but it needs some more soak testing before I push the reversion. If you want you can try reverting f6ec33f ("Bluetooth: hci_ldisc: Allow sleeping while proto locks are held.") yourself and seeing if the reboot crash...
by PhilE
Sun Sep 16, 2018 8:28 pm
Forum: Compute Module
Topic: CM3 sending RS232 Signals to base board
Replies: 2
Views: 100

Re: CM3 sending RS232 Signals to base board

This sounds like a fairly common question that would be better addressed to the supplier/manufacturer of the base board.
by PhilE
Fri Sep 14, 2018 8:12 am
Forum: Device Tree
Topic: Overlay for GPIO connected fan
Replies: 15
Views: 374

Re: Overlay for GPIO connected fan

Finding the commits in an rpi- branch for a particular kernel version is a bit tricky because of the way the upstream commits are merged into our tree, but it can be done. It's easiest if you stick to versions that correspond to merge points - sometimes a few versions are merged at once. "git log --...
by PhilE
Thu Sep 13, 2018 1:57 pm
Forum: Device Tree
Topic: Overlay for GPIO connected fan
Replies: 15
Views: 374

Re: Overlay for GPIO connected fan

There are reports of reboot problems in 4.14.67 (and later) - see https://github.com/Hexxeh/rpi-firmware/issues/186.
by PhilE
Thu Sep 13, 2018 12:40 pm
Forum: Device Tree
Topic: Overlay for GPIO connected fan
Replies: 15
Views: 374

Re: Overlay for GPIO connected fan

Nice!
by PhilE
Thu Sep 13, 2018 11:22 am
Forum: Device Tree
Topic: mcp9808 sensor device tree entry
Replies: 9
Views: 116

Re: mcp9808 sensor device tree entry

You're right - the overlay is missing the "/plugin/;" tag at the top, beneath "/dts-v1/;". This tag is actually what tells the compiler to allow unresolved symbols, but without the "[email protected]" parameter it won't generate the necessary symbol and fixup information to be able to resolve the symbols, making i...
by PhilE
Thu Sep 13, 2018 11:10 am
Forum: Device Tree
Topic: mcp9808 sensor device tree entry
Replies: 9
Views: 116

Re: mcp9808 sensor device tree entry

Copy and paste your complete command line (no retyping).
by PhilE
Thu Sep 13, 2018 10:31 am
Forum: Device Tree
Topic: mcp9808 sensor device tree entry
Replies: 9
Views: 116

Re: mcp9808 sensor device tree entry

You need to tell the dtc compiler to generate symbol information for unresolved symbols, rather than reporting an error. That is what the '[email protected]' command line parameter does: [email protected]:~$ dtc [email protected] -I dts -O dtb -o mcp9808.dtbo mcp9808-overlay.dts You may still see some warnings from dtc, but these a...
by PhilE
Thu Sep 13, 2018 10:12 am
Forum: Device Tree
Topic: mcp9808 sensor device tree entry
Replies: 9
Views: 116

Re: mcp9808 sensor device tree entry

Although I2C drivers can have full compatible strings, most don't. Instead the second part of the compatible string (after the comma) is looked up as an I2C driver name - the first part is ignored. In your case this would look like (I think - this is untested): /dts-v1/; / { compatible = "brcm,bcm27...
by PhilE
Thu Sep 13, 2018 9:14 am
Forum: Device Tree
Topic: Overlay for GPIO connected fan
Replies: 15
Views: 374

Re: Overlay for GPIO connected fan

You've reached the limits of my knowledge in this area, but there are a few things I would try: 1) See what effect changing the cooling-device declaration to "<&fan 0 1>" has. 2) Move the trip point and see if the 50C off point moves accordingly. 3) Change the hysteresis and see if the 50C off point...
by PhilE
Wed Sep 12, 2018 10:06 am
Forum: Compute Module
Topic: SOLVED: LAN9514 Ethernet issue after reboot
Replies: 19
Views: 624

Re: SOLVED: LAN9514 Ethernet issue after reboot

And it's usually software...
by PhilE
Wed Sep 12, 2018 8:38 am
Forum: Device Tree
Topic: rtc on i2c0 dmesg dev_err meaning
Replies: 2
Views: 67

Re: rtc on i2c0 dmesg dev_err meaning

It isn't currently possible (in any clean way) to parameterise the i2c-rtc overlay with an indication of which bus to use, so you'll have to roll your own: // Definitions for several I2C based Real Time Clocks /dts-v1/; /plugin/; / { compatible = "brcm,bcm2708"; [email protected] { target = <&i2c_vc>; __do...
by PhilE
Tue Sep 11, 2018 2:55 pm
Forum: Device Tree
Topic: Overlay for GPIO connected fan
Replies: 15
Views: 374

Re: Overlay for GPIO connected fan

Neither of those fan drivers is enabled by default in the RPi kernel configurations. You will need to add CONFIG_SENSORS_GPIO_FAN=m and CONFIG_SENSORS_PWM_FAN=m. Once you've built a kernel with those modules, start with the gpio-fan overlay and watch for changes on GPIO12.
by PhilE
Tue Sep 11, 2018 12:40 pm
Forum: Device Tree
Topic: i2c-gpio dtoverlay bus number
Replies: 19
Views: 1905

Re: i2c-gpio dtoverlay bus number

That's progress. The remaining problem is that the ability to specify the bus number was only added in rpi-4.14.y. The commit in question (32e356678ebe "i2c-gpio: Also set bus numbers from reg property") should back-port easily, but it isn't there by default.

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