On Mon, Feb 28, 2022 at 11:39 PM Andy Shevchenko
<andriy.shevchenko@xxxxxxxxxxxxxxx> wrote:
>
> Since we have _DSD established and specified (ACPI v5.1+) there is no
> need to use custom _DSM methods. Rewrite documentation to use _DSD.
>
> Fixes: f60e7074902a ("misc: at25: Make use of device property API")
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> ---
> .../firmware-guide/acpi/enumeration.rst | 48 ++++++++-----------
> 1 file changed, 21 insertions(+), 27 deletions(-)
>
> diff --git a/Documentation/firmware-guide/acpi/enumeration.rst b/Documentation/firmware-guide/acpi/enumeration.rst
> index d0022567c022..3b221cc9ff5f 100644
> --- a/Documentation/firmware-guide/acpi/enumeration.rst
> +++ b/Documentation/firmware-guide/acpi/enumeration.rst
> @@ -227,43 +227,37 @@ to at25 SPI eeprom driver (this is meant for the above ACPI snippet)::
> };
>
> Note that this driver actually needs more information like page size of the
> -eeprom etc. but at the time writing this there is no standard way of
> -passing those. One idea is to return this in _DSM method like::
> +eeprom, etc. This information can be passed via _DSD method like::
>
> Device (EEP0)
> {
> ...
> - Method (_DSM, 4, NotSerialized)
> + Name (_DSD, Package ()
> {
> - Store (Package (6)
> + ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
> + Package ()
> {
> - "byte-len", 1024,
> - "addr-mode", 2,
> - "page-size, 32
> - }, Local0)
> -
> - // Check UUIDs etc.
> -
> - Return (Local0)
> - }
> -
> -Then the at25 SPI driver can get this configuration by calling _DSM on its
> -ACPI handle like::
> -
> - struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
> - struct acpi_object_list input;
> - acpi_status status;
> + Package () { "size", 1024 },
> + Package () { "pagesize", 32 },
> + Package () { "address-width", 16 },
> + }
> + })
> + }
>
> - /* Fill in the input buffer */
> +Then the at25 SPI driver can get this configuration by calling device property
> +APIs during ->probe() phase like::
>
> - status = acpi_evaluate_object(ACPI_HANDLE(&spi->dev), "_DSM",
> - &input, &output);
> - if (ACPI_FAILURE(status))
> - /* Handle the error */
> + err = device_property_read_u32(dev, "size", &size);
> + if (err)
> + ...error handling...
>
> - /* Extract the data here */
> + err = device_property_read_u32(dev, "pagesize", &page_size);
> + if (err)
> + ...error handling...
>
> - kfree(output.pointer);
> + err = device_property_read_u32(dev, "address-width", &addr_width);
> + if (err)
> + ...error handling...
>
> I2C serial bus support
> ======================
> --
Applied as 5.18 material along with the rest of the series, but I
dropped the first hunk in patch [6/7] which didn't apply.
Thanks!
