Tegra/Mainline SW/Linux kernel
NVIDIA Tegra SoCs are well supported by mainline kernels.
Kernel releases may be obtained from:
- https://www.kernel.org/ releases, via download.
- https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/ releases, via git.
- https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/ absolute latest development code, via git.
The following mainline kernel releases introduced support for Tegra SoCs:
- Tegra20 has been upstream for many years.
- Tegra30 support was added in v3.3.
- Tegra114 support was added in v3.9.
- Tegra124 support was added in v3.13.
The first kernel release to support a given SoC has historically contained extremely minimal support. One or two kernel releases later will typically be the first useful version.
Features that already work are:
- It boots!
- Serial console.
- CPU hotplug.
- CPU frequency scaling (basic, for Tegra20 only).
- I2C master.
- Regulators, PMICs, RTCs.
- USB Host.
- Display controller (not all I/O interfaces on all SoCs; see below):
- RGB/LVDS for Tegra20/30 (for LCD panel support).
- DSI for Tegra114 (for LCD panel support).
- eDP for Tegra124 (for LCD panel support).
- HDMI for Tegra20/30/114/124.
- PCIe (Tegra20/30).
A probably-incomplete list of features that are not yet implemented is:
- Kepler GPU support via Nouvea (work in progress).
- Advanced (high-speed) transfer modes for SD and eMMC. IO voltage scaling.
- PCIe on Tegra124.
- USB device mode and OTG.
- SKU awareness (SKU-specific clock and thermal limits).
- POR (Plan Of Record) clocks.
- cpufreq for SoCs other than Tegra20.
- EMC (memory controller) frequency scaling.
- DVFS (Dynamic Voltage and Frequency Scaling).
- Thermal management.
- USB bus power saving.
- I2C slave support. The Toshiba AC100 NVEC driver could be generalized to provide this.
- SPI slave support?