Purism and Linux 5.16

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Martin Kepplinger

Latest posts by Martin Kepplinger (see all)

• PureOS Unaffected by ext4 Data Corruption Bug - January 2, 2024
• Purism and Linux 6.5 to 6.7 - December 22, 2023
• Purism and Linux 6.2 to 6.4 - July 13, 2023

The Purism team is continuously working on improving the hardware and software support for the Librem 5. These innovations contribute directly to the mainline, upstream kernel so that the hardware can be supported as part of the development community in the future.

Following up on our report for Linux 5.14 and 5.15 this summarizes the progress on mainline support for the Librem 5 phone and its development kit during the 5.16 development cycle. This summary is only about code flowing upstream.

Librem 5 updates

In order to maintain support for the phone, we continuously update the mainline hardware description and default configuration.

• arm64: dts: imx8mq-librem5: set debounce interval of volume buttons to 50ms
• arm64: dts: imx8mq-librem5: Fix led_r and led_g pinctrl assignments
• arm64: dts: imx8mq-librem5: Limit the max sdio frequency
• arm64: dts: imx8mq-librem5: add power sequencing for M.2 cards
• arm64: dts: imx8mq-librem5: delay the startup of the SDIO
• arm64: dts: imx8mq-librem5: wire up the wifi regulator
• arm64: dts: imx8mq-librem5: add reset gpio to mantix panel description

Display stack fixes

The panel, LCD interface and DRM bridge drivers saw minor additions that are needed partly due to internal kernel API changes:

• drm: mxsfb: Set fallback bus format when the bridge doesn’t provide one
• drm: mxsfb: Print failed bus format in hex
• drm/panel: st7703: Add media bus format
• drm/panel: mantix: Add media bus format
• drm/bridge: nwl-dsi: Add atomic_get_input_bus_fmts

The Librem 5 selfie cam

The driver we’ve been writing for the Librem 5 front facing camera sensor is merged along with minor additions to the i.MX media device driver. Stay tuned for the addition to the device tree board files that will conclude this journey and allow one to take a photo on a mainline kernel.

• media: Documentation: i2c-cardlist: add the Hynix hi846 sensor
• media: i2c: add driver for the SK Hynix Hi-846 8M pixel camera
• media: dt-bindings: media: document SK Hynix Hi-846 MIPI CSI-2 8M pixel sensor
• media: dt-bindings: vendor-prefixes: Add SK Hynix Inc.
• media: imx: set a media_device bus_info string
• media: hantro: Fix media device bus_info string
• media: hi846: remove the of_match_ptr macro
• media: hi846: include property.h instead of of_graph.h

Battery and charge controller

A few cleanups and bugfixes to the drivers for charging the phone were added:

• power: supply: max17042_battery: Prevent int underflow in set_soc_threshold
• power: supply: max17042_battery: Clear status bits in interrupt handler
• power: bq25890: add return values to error messages

Other additions and fixes

If you’ve ever seen [sda] No Caching mode page found in the kernel error logs you’re not alone. We remove this very common message that describes that a device is being used without a special caching mechanism from the error messages and print it as a warning instead:

• scsi: sd: Print write through due to no caching mode page as warning

Code review

During this round we contributed only 2 Reviewed-by: or Tested-by: tag to patches by other authors. This definitely leaves some room for improvement! Again we would like to thank everybody who reviewed our patches and helped us supporting the hardware in mainline Linux – especially Sakari and again Laurent for reviewing the camera driver and even adding the initial data for it to libcamera.

Sources

Have a look at our Linux tree to see what is currently being worked on and tested (or help if you feel like joining the fun).

Discover the Librem 5

Purism believes building the Librem 5 is just one step on the road to launching a digital rights movement, where we—the-people stand up for our digital rights, where we place the control of your data and your family’s data back where it belongs: in your own hands.

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