Re: [PATCH] Support intel-vbtn based tablet mode switch

Dmitry Torokhov
2018-01-22T23:46:14Z

On Mon, Jan 22, 2018 at 01:48:01PM +0100, Marco Martin wrote:
> some laptops such as Dell Inspiron 7000 series have the
> tablet mode switch implemented in intel acpi,
> the events to enter and exit the tablet mode are 0xCC and 0xCD
>
> CC: platform-driver-x86@vger.kernel.org
> CC: Matthew Garrett <mjg59@srcf.ucam.org>
> CC: "Pali Rohár" <pali.rohar@gmail.com>
> CC: Darren Hart <dvhart@infradead.org>
> CC: Mario Limonciello <mario_limonciello@dell.com>
> CC: Andy Shevchenko <andy@infradead.org>
>
> Signed-off-by: Marco Martin <notmart@gmail.com>
> ---
> drivers/platform/x86/intel-vbtn.c | 28 ++++++++++++++++++++++++++++
> 1 file changed, 28 insertions(+)
>
> diff --git a/drivers/platform/x86/intel-vbtn.c b/drivers/platform/x86/intel-vbtn.c
> index 4809267..c4362df 100644
> --- a/drivers/platform/x86/intel-vbtn.c
> +++ b/drivers/platform/x86/intel-vbtn.c
> @@ -26,6 +26,9 @@
> #include <linux/suspend.h>
> #include <acpi/acpi_bus.h>
>
> +/* When NOT in tablet mode, VBDS has the flag 0x40 */
> +#define TABLET_MODE_FLAG 0x40
> +
> MODULE_LICENSE("GPL");
> MODULE_AUTHOR("AceLan Kao");
>
> @@ -42,6 +45,8 @@ static const struct key_entry intel_vbtn_keymap[] = {
> { KE_IGNORE, 0xC5, { KEY_VOLUMEUP } }, /* volume-up key release */
> { KE_KEY, 0xC6, { KEY_VOLUMEDOWN } }, /* volume-down key press */
> { KE_IGNORE, 0xC7, { KEY_VOLUMEDOWN } }, /* volume-down key release */
> + { KE_SW, 0xCC, { .sw = { SW_TABLET_MODE, 1 } } }, /* Tabletmode in */
> + { KE_SW, 0xCD, { .sw = { SW_TABLET_MODE, 0 } } }, /* Tabletmode out */
> { KE_END },
> };
>
> @@ -81,6 +86,7 @@ static void notify_handler(acpi_handle handle, u32 event, void *context)
> return;
> }
> } else if (sparse_keymap_report_event(priv->input_dev, event, 1, true)) {
> + input_sync(priv->input_dev);

I do not understand why this is needed, as sparse keymap should issue
sync for you. From sparse_keymap_report_entry():

case KE_SW:
value = ke->sw.value;
/* fall through */

case KE_VSW:
input_report_switch(dev, ke->sw.code, value);
input_sync(dev);

^^^^^^^^^- here is the sync.

break;
}
}

> return;
> }
> dev_info(&device->dev, "unknown event index 0x%x\n", event);
> @@ -92,6 +98,7 @@ static int intel_vbtn_probe(struct platform_device *device)
> struct intel_vbtn_priv *priv;
> acpi_status status;
> int err;
> + struct acpi_buffer vgbs_output = { ACPI_ALLOCATE_BUFFER, NULL };
>
> status = acpi_evaluate_object(handle, "VBDL", NULL, NULL);
> if (ACPI_FAILURE(status)) {
> @@ -110,6 +117,27 @@ static int intel_vbtn_probe(struct platform_device *device)
> return err;
> }
>
> + status = acpi_evaluate_object(handle, "VGBS", NULL, &vgbs_output);
> + /* VGBS being present and returning something means
> + * we have a tablet mode switch
> + */
> + if (ACPI_SUCCESS(status)) {
> + union acpi_object *obj = vgbs_output.pointer;
> +
> + input_set_capability(priv->input_dev, EV_SW, SW_TABLET_MODE);
> +
> + if (obj && obj->type == ACPI_TYPE_INTEGER) {

Do you want to set the capability if you do not get 'obj' or it is of
different type?

> + if (obj->integer.value & TABLET_MODE_FLAG)
> + input_report_switch(priv->input_dev,
> + SW_TABLET_MODE,
> + 0);
> + else
> + input_report_switch(priv->input_dev,
> + SW_TABLET_MODE,
> + 1);

Can be shorter:

input_report_switch(priv->input_dev, SW_TABLET_MODE,
obj->integer.value & TABLET_MODE_FLAG);

You also need:

input_sync(priv->input_dev);

Thanks.

--
Dmitry