mainlining shenanigans
5d82e66139
When duty-cycle is at full level (100%), the TCNTn and TCMPn registers needs to be flushed in order to disable the signal. The PWM manual does not say anything about this, but states that only clearing the TCON auto-reload bit should be needed, and this seems to be true when the PWM duty-cycle is not at full level. This can be observed on an Axis ARTPEC-8, by running: echo <period> > pwm/period echo <period> > pwm/duty_cycle echo 1 > pwm/enable echo 0 > pwm/enable Since the TCNTn and TCMPn registers are activated when enabling the PWM (setting TCON auto-reload bit), and are not touched when disabling the PWM, the double buffered auto-reload function seems to be still active. Lowering duty-cycle, and restoring it again in between the enabling and disabling, makes the disable work since it triggers a reload of the TCNTn and TCMPn registers. Fix this by securing a reload of the TCNTn and TCMPn registers when disabling the PWM and having a full duty-cycle. Signed-off-by: Mårten Lindahl <marten.lindahl@axis.com> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com> |
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| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
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.