bb36a883e3
[ Upstream commit 697529091ac7a0a90ca349b914bb30641c13c753 ]
Before commit bb29b9cccd95 ("leds: pca963x: Add bindings to invert
polarity") Mode register 2 was initialized directly with either 0x01
or 0x05 for open-drain or totem pole (push-pull) configuration.
Afterwards, MODE2 initialization started using bitwise operations on
top of the default MODE2 register value (0x05). Using bitwise OR for
setting OUTDRV with 0x01 and 0x05 does not produce correct results.
When open-drain is used, instead of setting OUTDRV to 0, the driver
keeps it as 1:
Open-drain: 0x05 | 0x01 -> 0x05 (0b101 - incorrect)
Totem pole: 0x05 | 0x05 -> 0x05 (0b101 - correct but still wrong)
Now OUTDRV setting uses correct bitwise operations for initialization:
Open-drain: 0x05 & ~0x04 -> 0x01 (0b001 - correct)
Totem pole: 0x05 | 0x04 -> 0x05 (0b101 - correct)
Additional MODE2 register definitions are introduced now as well.
Fixes: bb29b9cccd95 ("leds: pca963x: Add bindings to invert polarity")
Signed-off-by: Zahari Petkov <zahari@balena.io>
Signed-off-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. 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.