9f4c8f9607
i.MX PWM module's ipg_clk_s is for PWM register access, on most of i.MX
SoCs, this ipg_clk_s is from system ipg clock or perclk which is always
enabled, but on i.MX7D, the ipg_clk_s is from PWM1_CLK_ROOT which is
controlled by CCGR132, that means the CCGR132 MUST be enabled first
before accessing PWM registers on i.MX7D. This patch adds ipg clock
operation to make sure register access successfully on i.MX7D and it
fixes Linux kernel boot up hang during PWM driver probe.
Fixes: 4a23e6ee9f69 ("ARM: dts: imx7d-sdb: Restore pwm backlight support")
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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.