[PATCH v2 0/2] platform/x86: Add new Dell UART backlight driver

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hi All,

I recently learned that some Dell AIOs (1) use a backlight controller board
connected to an UART. Canonical even submitted a driver for this in 2017:
https://lkml.org/lkml/2017/10/26/78

This UART has a DELL0501 HID with CID set to PNP0501 so that the UART is
still handled by 8250_pnp.c. Unfortunately there is no separate ACPI device
with an UartSerialBusV2() resource to model the backlight-controller. An
ACPI quirk has been merged recently to deal with this and create a serdev
controller for the UART despite the missing UartSerialBusV2() resource:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=99b572e6136eab69a8c91d72cf8595b256e304b5

Patch 1 in this series adds a driver binding to the "dell-uart-backlight"
device created by this quirk. This drivers creates a serdev-device for
the DELL0501 serdev-controller and registers a serdev backlight driver
which binds to this serdev-device.

Patch 2 contains a small emulator for the UART attached backlight
controller found on this Dell AOIs, I wrote and used this to develop
the driver since I did not have access to such an AOI myself.

This has been successfully tested by Roman Bogoyev (who originally
reported the missing driver to me by email) on a Dell Inspiron 27 7000
(7790) and by Kai-Heng Feng on a newer Dell AOI model.

Changes in v2:
- Address all the review-remarks Ilpo and Andy had on Patch 1/2,
  thank you for the extensive review Ilpo and Andy

Regards,

Hans


Hans de Goede (2):
  platform/x86: Add new Dell UART backlight driver
  tools arch x86: Add dell-uart-backlight-emulator

 drivers/platform/x86/dell/Kconfig             |  15 +
 drivers/platform/x86/dell/Makefile            |   1 +
 .../platform/x86/dell/dell-uart-backlight.c   | 409 ++++++++++++++++++
 .../dell-uart-backlight-emulator/.gitignore   |   1 +
 .../x86/dell-uart-backlight-emulator/Makefile |  19 +
 .../x86/dell-uart-backlight-emulator/README   |  46 ++
 .../dell-uart-backlight-emulator.c            | 167 +++++++
 7 files changed, 658 insertions(+)
 create mode 100644 drivers/platform/x86/dell/dell-uart-backlight.c
 create mode 100644 tools/arch/x86/dell-uart-backlight-emulator/.gitignore
 create mode 100644 tools/arch/x86/dell-uart-backlight-emulator/Makefile
 create mode 100644 tools/arch/x86/dell-uart-backlight-emulator/README
 create mode 100644 tools/arch/x86/dell-uart-backlight-emulator/dell-uart-backlight-emulator.c

-- 
2.44.0





[Index of Archives]     [Linux Kernel Development]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux