8d62fa831f
The emmc2 interface on the bcm2711 supports DDR modes for eMMC devices running at 3.3V. This allows to run eMMC module with 3.3V signaling voltage at DDR52 mode on the Raspberry Pi 4 using a SD adapter: clock: 52000000 Hz actual clock: 50000000 Hz vdd: 21 (3.3 ~ 3.4 V) bus mode: 2 (push-pull) chip select: 0 (don't care) power mode: 2 (on) bus width: 2 (4 bits) timing spec: 8 (mmc DDR52) signal voltage: 0 (3.30 V) driver type: 0 (driver type B) Link: https://github.com/raspberrypi/linux/issues/3802 Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com> Link: https://lore.kernel.org/r/1598651234-29826-1-git-send-email-stefan.wahren@i2se.com Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.