Re: [PATCH v2 10/18] pinctrl: madera: Add driver for Cirrus Logic Madera codecs

On Fri, Apr 28, 2017 at 3:39 AM, Linus Walleij [off-list ref] wrote:

On Mon, Apr 24, 2017 at 6:08 PM, Richard Fitzgerald
[off-list ref] wrote:

quoted

These codecs have a variable number of I/O lines each of which
is individually selectable to a wide range of possible functions.

The functionality is slightly different from the traditional muxed
GPIO since most of the functions can be mapped to any pin (and even
the same function to multiple pins). Most pins have a dedicated
"alternate" function that is only available on that pin. The
alternate functions are usually a group of signals, though it is
not always necessary to enable the full group, depending on the
alternate function and how it is to be used. The mapping between
alternate functions and GPIO pins varies between codecs depending
on the number of alternate functions and available pins.

Note on the Kconfig options:
The formula "default y if..." is used for PINCTRL_MADERA so that its
select options will be processed, allowing us to group selects for
pinctrl into the pinctrl Kconfig where they logically belong instead
of accumulating under the parent MFD Kconfig.

Signed-off-by: Richard Fitzgerald <redacted>
---
Changes since V1:
- dt binding moved to separate patch
- moved all source into a subdirectory drivers/pinctrl/cirrus
- split chip-specific tables into separate files
- codec-specific build options are now selected from MFD
- print useful information from madera_pin_dbg_show()
- added gpio_set_direciton / gpio_request_enable / gpio_disable_free functions
- added strict mode so GPIO and other functions are exclusive
- replace #ifdefs with if (IS_ENABLED(...)) in probe
- fixed bug reading registers in madera_pin_conf_get()

Reviewed-by: Linus Walleij <redacted>

If this hasn't been merged yet, can we get rid of all the
MODULE / module references, since the Kconfigs are
all bool type and hence we shouldn't need to use them.

Alternatively we can do it in a follow-on patch if needed.

Thanks,
Paul.
--

I guess you will apply this through MFD, so waiting for Lee to
pick it up. Alternatively I can apply it after the MFD core parts
are upstream.

Yours,
Linus Walleij