Fork of alistair23 Linux kernel for reMarkable from https://github.com/alistair23/linux
aa4bb8b883
Rework the MIPI interface startup sequence with the following changes:
- Remove MIPI bus initialization from the initial settings blob
- At set_power(1) time power up MIPI Tx/Rx and set data and clock lanes in
LP11 during 'sleep' and 'idle' with MIPI clock in non-continuous mode.
- At s_stream time enable/disable the MIPI interface output.
- Restore default settings at set_power(0) time.
Before this commit the sensor MIPI interface was initialized with settings
that require a start/stop sequence at power-up time in order to force lanes
into LP11 state, as they were initialized in LP00 when in 'sleep mode',
which is assumed to be the sensor manual definition for the D-PHY defined
stop mode.
The stream start/stop was performed by enabling disabling clock gating,
and had the side effect to change the lanes sleep mode configuration when
stream was stopped.
Clock gating/ungating:
- ret = ov5640_mod_reg(sensor, OV5640_REG_MIPI_CTRL00, BIT(5),
- on ? 0 : BIT(5));
- if (ret)
Set lanes in LP11 when in 'sleep mode':
- ret = ov5640_write_reg(sensor, OV5640_REG_PAD_OUTPUT00,
- on ? 0x00 : 0x70);
This commit fixes an issue reported by Jagan Teki on i.MX6 platforms that
prevents the host interface from powering up correctly:
https://lkml.org/lkml/2018/6/1/38
It also improves MIPI capture operations stability on my testing platform
where MIPI capture often failed and returned all-purple frames.
Fixes:
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| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| 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 | ||
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.
See Documentation/00-INDEX for a list of what is contained in each file.
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.