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.
• SPI.
• SD/eMMC.
• 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?