8958262af3
The multi-byte IO on various pca953x chips requires the auto-increment bit, while other chips toggle the LSbit automatically. Note that LSbit toggling only alternates between two registers during the IO, it is not the same as address auto-increment. The driver currently assumes that #gpios > 16 implies auto-increment, while #gpios <= 16 implies LSbit toggling. This is incorrect at there are chips with 16 GPIOs which require the auto-increment bit. The PCA9575, according to NXP datasheet rev. 4.2 from 16 April 2015, section 7.3 Command Register, the bit 7 in command register is the auto-increment bit, which allows programming multiple registers sequentially. Set this bit both in pca953x_gpio_set_multiple(), where it fixes the multi register programming, and in pca957x_write_regs_16(), where is simplifies the function. In fact, the pca957x_write_regs_16() now looks rather similar to pca953x_write_regs_24() and pca953x_write_regs_16(), which is intended for subsequent patches. Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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.