Messages in this thread | | | Date | Mon, 3 Nov 2014 14:22:10 +0100 | Subject | Re: [PATCH] ACPI / GPIO: Driver GPIO mappings for ACPI GPIOs | From | Linus Walleij <> |
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On Sat, Oct 25, 2014 at 12:05 AM, Rafael J. Wysocki <rjw@rjwysocki.net> wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > Provide a way for device drivers using GPIOs described by ACPI > GpioIo resources in _CRS to tell the GPIO subsystem what names > (connection IDs) to associate with specific GPIO pins defined > in there. > > To do that, a driver needs to define a mapping table as a > NULL-terminated array of struct acpi_gpio_mapping objects > that each contain a name, a pointer to an array of pin data > (struct acpi_gpio_params) objects and the size of that array. > > Each struct acpi_gpio_params object consists of three fields, > crs_entry_index, pin_index, active_low, representing the index of
I prefer that you call the second thing "line_index" rather than "pin_index". Not all GPIOs in the world are tied to physical pins. Also it is easy to confuse stuff with the pin control terminology if it's called "pin".
> the target GpioIo()/GpioInt() resource in _CRS starting from zero, > the index of the target pin in that resource starting from zero, > and the active-low flag for that pin, respectively. > > Next, the mapping table needs to be passed as the second argument to > acpi_dev_add_driver_gpios() that will register it with the ACPI device > object pointed to by its first argument. That object must represent > the ACPI namespace node containing the _CRS object referred to by the > GPIO mapping. That should be done in the driver's .probe() routine. > > On removal, the driver should unregister its GPIO mapping table > by calling acpi_dev_remove_driver_gpios() on the ACPI device > object where that table was previously registered. > > Included are fixes from Mika Westerberg. > > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
And "pin" is mentioned several times in the commit message. I prefer that we talk about "lines".
(...)
> +struct acpi_gpio_params { > + unsigned int crs_entry_index; > + unsigned int pin_index;
So line_index;
> + bool active_low; > +};
With that change: Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Yours, Linus Walleij
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