BayLibre contributions to Linux 6.4 and 6.5

Linux 6.4 was released on June 25th, 2023, and Linux 6.5 was released on August 27th, 2023.  BayLibre contributed to both of these releases.  LWN has great coverage of the 6.4 merge window (part 1, part 2) and 6.5 merge windows (part 1, part 2).

Here is a summary of our contributions per SoC family:

MediaTek SoCs

BayLibre continued to improve support of MediaTek SoCs during this kernel release.

Alexandre Mergnat and Bernhard Rosenkränzer contributed improved support for the MT8365 EVK board and the MT8365 SoC, also known as the Genio i350. The new functionality includes:

• Dynamic frequency and voltage scaling (DVFS) including generic Operating  Performance Points support (OPP) for cpufreq support
• MMC controller including AEMMC support on mmc0 (internal memory) and SD-UHS support on mmc1 (external memory).
• USB controller including Extensible Host Controller Interface (EHCI) for host mode, and SuperSpeed USB in OTG mode on the micro USB connector.  Markus Schneider-Pargmann also contributed a fix for USB in the MT8365 clock driver.
• Ethernet 10/100 MAC controller including power management with Energy Efficient Ethernet and Wake-on-LAN specification. Flow control is provided for half-duplex and full-duplex mode.
• MT6357 PMIC support to manage regulators along with Power and Home keys
• I2C controller including the four I2C master channels.  The I2C0 bus provides communication with integrated RT9466 switching battery charger and MT6691 LP4X buck converter.
• Support for the HDMI bridge (IT66121) and MIPI DSI panel (Startek,kd070fhfid015)
• Watchdog peripheral

Amjad Ouled-Ameur contributed MT8365 CPU Idle support including multi-core deep idle state.  Amjad also added support for the MT8365 thermal sensors.

Balsam Chihi added AP thermal domain support to LVTS Driver for the MediaTek MT8195 SoC.

Guillaume Ranquet added support for HDMI phy on MT8195 and fixed the clock rate calculation.

Amlogic SoCs

BayLibre continues to maintain and improve support for Amlogic SoCs in the kernel. 

Jerome Brunet made improvements to AXG SoC audio support. This changed the way slots are activated on the TDM lanes to follow what the HW does and make sure each channel always get mapped to the same slot/lane.

Jerome also enabled use of the MDIO mux driver on GXL SoCs.  This fixes a problem where the internal PHY path was broken. 

Carlo Caione relaxed the supported mode checks in the drm/meson/meson_venc driver.
This allows 480×1920 and 400×1280 resolutions to be used.

Texas Instruments SoCs

Markus Schneider-Pargmann improved the TI m_can driver and tested those changes on the TCAN455X CAN-FD controller. The optimizations included keeping interrupts enabled during peripheral read, disabling unused interrupts, and always acknowledging all interrupts.

Julien Panis, along with Jerome Neanne and Esteban Blanc, added support for the TI TPS6594 Power Management IC (PMIC), It provides regulators and others features like ESMs (Error Signal Monitor), and PFSM (Pre-configurable Finite State Machine). The SoC and the PMIC can communicate through the I2C or SPI interfaces.

Jerome Neanne added support the GPIO interface on the TPS65219 PMIC.  Jerome also added support for soft shutdown via sys-off API.  This allows the TI AM62-LP-SK dev board to take benefit of the latest released API for shutdown and reset management.