2eaf5a533a
Add HS400 support for iMX7ULP B0. According to IC suggest, need to clear the STROBE_DLL_CTRL_RESET before any setting of STROBE_DLL_CTRL register. USDHC has register bits(bit[27~20] of register STROBE_DLL_CTRL) for slave sel value. If this register bits value is 0, it needs 256 ref_clk cycles to update slave sel value. IC suggest to set bit[27~20] to 0x4, it only need 4 ref_clk cycle to update slave sel value. This will short the lock time of slave. i.MX7ULP B0 will need more time to lock the REF and SLV, so change to add 5us delay. Signed-off-by: Haibo Chen <haibo.chen@nxp.com> Reviewed-by: Dong Aisheng <aisheng.dong@nxp.com> Acked-by: Adrian Hunter <adrian.hunter@intel.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.