[Intel-gfx] [PATCH] drm/i915/intel_dsi: Add acpi_gpio_mapping for the panel-enable GPIO

[Andy Shevchenko]

On Fri, 2018-06-29 at 14:51 +0300, Ville Syrjälä wrote:
> On Fri, Jun 29, 2018 at 01:32:58PM +0200, Hans de Goede wrote:

I saw that the change was discarded but I would comment about the GPIO
ACPI mapping tables.

> > +		devm_acpi_dev_add_driver_gpios(dev->dev,
> > panel_gpios);
> 
> Some explanation on what this actually does would be nice. There is no
> documentation that I can see so it's totally unclear why this is
> needed.

Documentation is here Documentation/acpi/gpio-properties.txt.

The key phrase is
"...the driver is supposed to know what to use the GpioIo()/GpioInt()
resources for once it has identified the device.  Having done that, it
can simply assign names to the GPIO lines it is going to use and provide
the GPIO subsystem with a mapping between those names and the ACPI GPIO
resources corresponding to them.

To do that, the driver needs to define a mapping table..."

-- 
Andy Shevchenko <andriy.shevchenko at linux.intel.com>
Intel Finland Oy