Hi,
On Tue, Jul 02, 2019 at 02:37:39AM +0200, Maximilian Luz wrote:
> Do not use the surfacepro3_button driver on newer Microsoft Surface
> models, only use it on the Surface Pro 3 and 4. Newer models (5th, 6th
> and possibly future generations) use the same device as the Surface Pro
> 4 to represent their volume and power buttons (MSHW0040), but their
> acutal implementation is significantly different. This patch ensures
> that the surfacepro3_button driver is only used on the Pro 3 and 4
> models, allowing a different driver to bind on other models.
>
This method overall looks ok to me.
> Signed-off-by: Maximilian Luz <luzmaximilian@xxxxxxxxx>
> ---
> drivers/platform/x86/surfacepro3_button.c | 38 +++++++++++++++++++++++
> 1 file changed, 38 insertions(+)
>
> diff --git a/drivers/platform/x86/surfacepro3_button.c b/drivers/platform/x86/surfacepro3_button.c
> index 47c6d000465a..0e2c7dfafd9f 100644
> --- a/drivers/platform/x86/surfacepro3_button.c
> +++ b/drivers/platform/x86/surfacepro3_button.c
> @@ -20,6 +20,12 @@
> #define SURFACE_BUTTON_OBJ_NAME "VGBI"
> #define SURFACE_BUTTON_DEVICE_NAME "Surface Pro 3/4 Buttons"
>
> +#define MSHW0040_DSM_REVISION 0x01
> +#define MSHW0040_DSM_GET_OMPR 0x02 // get OEM Platform Revision
> +static const guid_t MSHW0040_DSM_UUID =
> + GUID_INIT(0x6fd05c69, 0xcde3, 0x49f4, 0x95, 0xed, 0xab, 0x16, 0x65,
> + 0x49, 0x80, 0x35);
> +
> #define SURFACE_BUTTON_NOTIFY_TABLET_MODE 0xc8
>
> #define SURFACE_BUTTON_NOTIFY_PRESS_POWER 0xc6
> @@ -142,6 +148,34 @@ static int surface_button_resume(struct device *dev)
> }
> #endif
>
> +/*
> + * Surface Pro 4 and Surface Book 2 / Surface Pro 2017 use the same device
> + * ID (MSHW0040) for the power/volume buttons. Make sure this is the right
> + * device by checking for the _DSM method and OEM Platform Revision.
> + */
> +static int surface_button_check_MSHW0040(struct acpi_device *dev)
> +{
> + acpi_handle handle = dev->handle;
> + union acpi_object *result;
> + u64 oem_platform_rev = 0;
> +
> + // get OEM platform revision
> + result = acpi_evaluate_dsm_typed(handle, &MSHW0040_DSM_UUID,
> + MSHW0040_DSM_REVISION,
> + MSHW0040_DSM_GET_OMPR,
> + NULL, ACPI_TYPE_INTEGER);
> +
Does it mean, only 5th, 6th and newer platforms have OEM platform revision?
3rd/4th will get NULL result? Or the opposite?
> + if (result) {
> + oem_platform_rev = result->integer.value;
> + ACPI_FREE(result);
> + }
> +
> + dev_dbg(&dev->dev, "OEM Platform Revision %llu\n", oem_platform_rev);
> +
> + return oem_platform_rev == 0 ? 0 : -ENODEV;
if 3rd/4th do not have this oem rev information while 5th/newer have,
why the latter returns NODEV(it actually has this info)?
> +}
> +
> +
> static int surface_button_add(struct acpi_device *device)
> {
> struct surface_button *button;
> @@ -154,6 +188,10 @@ static int surface_button_add(struct acpi_device *device)
> strlen(SURFACE_BUTTON_OBJ_NAME)))
> return -ENODEV;
>
> + error = surface_button_check_MSHW0040(device);
> + if (error)
> + return error;
> +
ditto, 3rd/4th get error=0?
> button = kzalloc(sizeof(struct surface_button), GFP_KERNEL);
> if (!button)
> return -ENOMEM;
> --
> 2.22.0
>
Best,
Yu
