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
======================
--
2.34.1
