Re: [RFC PATCH 0/9] Add ACPI _DSD and unified device properties support

[Darren Hart]

On 8/15/14, 23:53, "Mika Westerberg" <mika.westerberg@xxxxxxxxxxxxxxx>
wrote:

>The recent publication of the ACPI 5.1 specification [1] adds a reserved
>name
>for Device Specific Data (_DSD, Section 6.2.5). This mechanism allows for
>passing arbitrary hardware description data to the OS. The exact format
>of the
>_DSD data is specific to the UUID paired with it [2].
>
>An ACPI Device Properties UUID has been defined [3] to provide a format
>compatible with existing device tree schemas. The purpose for this was to
>allow
>for the reuse of the existing schemas and encourage the development of
>firmware
>agnostic device drivers.
>
>This series accomplishes the following (as well as some other
>dependencies):
>
> * Add _DSD support to the ACPI core
>   This simply reads the UUID and the accompanying Package
>
> * Add ACPI Device Properties _DSD format support
>   This understands the hierarchical key:value pair structure
>   defined by the Device Properties UUID
>
> * Add a unified device properties API with ACPI and OF backends
>   This provides for the firmware agnostic device properties
>   Interface to be used by drivers
>
> * Provides 2 example drivers that were previously Device Tree aware that
>   can now be used with either Device Tree or ACPI Device Properties. The
>   both drivers use an arbitrary _HID.
>
>This has been tested on Minnowboard with relevant parts of the modified
>DSDT at the end of this email.


This eliminates the need for the board files that were the subject of my
"How not to write x86 platform drivers" talk at ELC-E last year. With
These ACPI core changes and the small changes to the two example drivers,
the Minnowboard can now use the GPIO buttons and LEDs through these
drivers by adding the ASL fragment below to the DSDT.

--
Darren

>
>------ DSDT For Minnowboard ------
>
>    Scope (\_SB.PCI0.LPC)
>    {
>        Device (LEDS)
>        {
>            Name (_HID, "MNW0001")
>
>            Name (_CRS, ResourceTemplate ()
>            {
>                GpioIo (Exclusive, PullDown, 0, 0,
>IoRestrictionOutputOnly,
>                        "\\_SB.PCI0.LPC", 0, ResourceConsumer) {10}
>                GpioIo (Exclusive, PullDown, 0, 0,
>IoRestrictionOutputOnly,
>                        "\\_SB.PCI0.LPC", 0, ResourceConsumer) {11}
>            })
>
>            Device (LEDH)
>            {
>                Name (_HID, "PRP0000")
>                Name (_DSD, Package ()
>                {
>                    ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
>                    Package ()
>                    {
>                        Package () {"label", "Heartbeat"},
>                        Package () {"gpios", Package () {^^LEDS, 0, 0,
>0}},
>                        Package () {"linux,default-trigger", "heartbeat"},
>                        Package () {"linux,default-state", "off"},
>                        Package () {"linux,retain-state-suspended", 1},
>                    }
>                })
>            }
>
>            Device (LEDM)
>            {
>                Name (_HID, "PRP0000")
>                Name (_DSD, Package ()
>                {
>                    ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
>                    Package ()
>                    {
>                        Package () {"label", "MMC0 Activity"},
>                        Package () {"gpios", Package () {^^LEDS, 1, 0,
>0}},
>                        Package () {"linux,default-trigger", "mmc0"},
>                        Package () {"linux,default-state", "on"},
>                        Package () {"linux,retain-state-suspended", 1},
>                    }
>                })
>            }
>        }
>        
>        Device (BTNS)
>        {
>            Name (_HID, "MNW0002")
>
>            Name (_CRS, ResourceTemplate ()
>            {
>                GpioIo (Exclusive, PullUp, 0, 0, IoRestrictionInputOnly,
>                        "\\_SB.PCI0.LPC", 0, ResourceConsumer) {0}
>                GpioIo (Exclusive, PullUp, 0, 0, IoRestrictionInputOnly,
>                        "\\_SB.PCI0.LPC", 0, ResourceConsumer) {1}
>                GpioIo (Exclusive, PullUp, 0, 0, IoRestrictionInputOnly,
>                        "\\_SB.PCI0.LPC", 0, ResourceConsumer) {2}
>                GpioIo (Exclusive, PullUp, 0, 0, IoRestrictionInputOnly,
>                        "\\_SB.PCI0.LPC", 0, ResourceConsumer) {3}
>            })
>
>            Name (_DSD, Package ()
>            {
>                ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
>                Package ()
>                {
>                    Package () {"poll-interval", 100},
>                    Package () {"autorepeat", 1}
>                }
>            })
>
>            Device (BTN0)
>            {
>                Name (_HID, "PRP0000")
>                Name (_DSD, Package ()
>                {
>                    ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
>                    Package ()
>                    {
>                        Package () {"linux,code", 105},
>                        Package () {"linux,input-type", 1},
>                        Package () {"gpios", Package () {^^BTNS, 0, 0,
>1}},
>                    }
>                })
>            }
>
>            Device (BTN1)
>            {
>                Name (_HID, "PRP0000")
>                Name (_DSD, Package ()
>                {
>                    ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
>                    Package ()
>                    {
>                        Package () {"linux,code", 108},
>                        Package () {"linux,input-type", 1},
>                        Package () {"gpios", Package (4) {^^BTNS, 1, 0,
>1}},
>                    }
>                })
>            }
>            
>            Device (BTN2)
>            {
>                Name (_HID, "PRP0000")
>                Name (_DSD, Package ()
>                {
>                    ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
>                    Package ()
>                    {
>                        Package () {"linux,code", 103},
>                        Package () {"linux,input-type", 1},
>                        Package () {"gpios", Package () {^^BTNS, 2, 0,
>1}},
>                    }
>                })
>            }
>            
>            Device (BTN3)
>            {
>                Name (_HID, "PRP0000")
>                Name (_DSD, Package ()
>                {
>                    ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
>                    Package ()
>                    {
>                        Package () {"linux,code", 106},
>                        Package () {"linux,input-type", 1},
>                        Package () {"gpios", Package (4) {^^BTNS, 3, 0,
>1}},
>                    }
>                })
>            }
>
>        }
>
>    }
>
>-- 
>2.1.0.rc1
>
>


-- 
Darren Hart					Open Source Technology Center
darren.hart@xxxxxxxxx				            Intel Corporation



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