From: Stephen Warren <swarren@xxxxxxxxxx> Signed-off-by: Stephen Warren <swarren@xxxxxxxxxx> --- README.txt | 67 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 67 insertions(+) create mode 100644 README.txt diff --git a/README.txt b/README.txt new file mode 100644 index 000000000000..1c423d684f5e --- /dev/null +++ b/README.txt @@ -0,0 +1,67 @@ +Introduction +============ + +Many aspects of many of Tegra's pins can configure via the pinmux and GPIO +controllers. This project exists to assist with software's handling of the +configuration of those controllers. + +Data files +========== + +SoC definition + + The exact set of configurable options varies from chip to chip. This project + contains a data file for each chip, which describes the available pins on + the chip, along with their parameters, such as the set of available pinmux + functions the pin supports. + + An example is configs/tegra124.soc. + +Board configuration + + Much of the programming of these controllers is directly driven by the board + design. This project contains a data file for each board, which describes + the required configuration for each pin. + + An example is configs/jetson-tk1.board. + +Converter Scripts +================= + +soc-to-kernel-pinctrl-driver.py + + Reads an SoC definition data file, and emits the source code for a Linux + kernel pinctrl driver, e.g. drivers/pinctrl/pinctrl-tegra124.c. + +soc-to-uboot-driver.py + + Reads an SoC definition data file, and emits the source code for a U-Boot + pinmux driver, e.g. arch/arm/include/asm/arch-tegra124/pinmux.h, + arch/arm/cpu/tegra124-common/pinmux.c + +csv-to-board-tegra124-xlsx.py + + Part of the output from the board design process is a spreadsheet that + describes the required configuration for each pin. This script extracts the + final pinmux configuration from (a CSV representation of) such spreadsheets + and creates a board configuration such as configs/jetson-tk1.board. + +board-to-kernel-dt.py + + Reads a board configuration data file, and emits a device tree fragment + suitable for inclusion in a board's device tree file. For example, the + output may form part of arch/arm/boot/dts/tegra124-jetson-tk1.dts. + + Note that when at all possible, it is far preferable for the kernel not to + program the pinmux controller, but rather to rely upon system software to + have set it up. This reduces duplicate processing of pinmux data, and is + consistent with a model where the first software to touch any I/O controller + programs the pinmux configuration en mass, to avoid any potential output + data glitches. + +board-to-uboot.py + + Reads a board configuration data file, and emits a header file suitable for + use with U-Boot's pinmux driver. For example, + board/nvidia/jetson-tk1/pinmux-config-jetson-tk1.h. Note also the function + pinmux_init() in jetson-tk1.c in that same directory. -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
