Re: [PATCH v2 1/3] acpi: Export acpi_of_modalias equiv of of_modalias_node

From: Rafael J. Wysocki
Date: Wed Jul 13 2016 - 08:21:04 EST


On Wed, Jul 13, 2016 at 1:53 PM, Crestez Dan Leonard
<leonard.crestez@xxxxxxxxx> wrote:
> When using devicetree stuff like i2c_client.name or spi_device.modalias
> is initialized to the first DT compatible id with the vendor prefix
> stripped. Since some drivers rely on this try to replicate it when using
> ACPI with DT ids.
>
> Signed-off-by: Crestez Dan Leonard <leonard.crestez@xxxxxxxxx>
> ---
> drivers/acpi/bus.c | 36 ++++++++++++++++++++++++++++++++++++
> include/acpi/acpi_bus.h | 1 +
> 2 files changed, 37 insertions(+)
>
> diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
> index cb9558e..77a1a80 100644
> --- a/drivers/acpi/bus.c
> +++ b/drivers/acpi/bus.c
> @@ -654,6 +654,42 @@ static bool acpi_of_match_device(struct acpi_device *adev,
> return false;
> }
>
> +/**
> + * acpi_of_modalias - Like of_modalias_node for ACPI with DT ids
> + * @adev: ACPI device object to match.
> + * @outstr: Pointer to buffer for result
> + * @outlen: Length of outstr value
> + *
> + * If we have a DT id set outstr to the first compatible string with the vendor
> + * prefix stripped, just like of_modalias_node does for devicetree.

I'd say

"This is a counterpart of of_modalias_node() for struct acpi_device
objects. If there is a compatible string for @adev, copy it to the
@outstr location with the vendor prefix stripped."

> + *
> + * Returns 0 on success or negative errno on failure.
> + */
> +int acpi_of_modalias(struct acpi_device *adev, char *outstr, size_t outlen)
> +{
> + const union acpi_object *of_compatible;
> + const union acpi_object *obj;
> + const char *str, *chr;
> +
> + of_compatible = adev->data.of_compatible;
> + if (!of_compatible)
> + return -ENODEV;
> +
> + if (of_compatible->type == ACPI_TYPE_PACKAGE)
> + obj = of_compatible->package.elements;
> + else /* Must be ACPI_TYPE_STRING. */
> + obj = of_compatible;
> +
> + str = obj->string.pointer;
> + chr = strchr(str, ',');
> + if (chr)
> + str = chr + 1;
> + strlcpy(outstr, str, outlen);

I would prefer

strlcpy(outstr, chr ? chr + 1 : str, outlen);

ie. without the extra assignment.

> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(acpi_of_modalias);
> +
> static bool __acpi_match_device_cls(const struct acpi_device_id *id,
> struct acpi_hardware_id *hwid)
> {
> diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
> index 788c6c35..1d8ff0d 100644
> --- a/include/acpi/acpi_bus.h
> +++ b/include/acpi/acpi_bus.h
> @@ -515,6 +515,7 @@ void acpi_bus_trim(struct acpi_device *start);
> acpi_status acpi_bus_get_ejd(acpi_handle handle, acpi_handle * ejd);
> int acpi_match_device_ids(struct acpi_device *device,
> const struct acpi_device_id *ids);
> +int acpi_of_modalias(struct acpi_device *adev, char *outstr, size_t outlen);
> int acpi_create_dir(struct acpi_device *);
> void acpi_remove_dir(struct acpi_device *);
>
> --

Thanks,
Rafael