[PATCH 0/2] Support for buttons on newer MS Surface devices

[PATCH 0/2] Support for buttons on newer MS Surface devices

[Maximilian Luz]

This series adds suport for power and volume buttons on 5th and 6th
generation Microsoft Surface devices. Specifically, it adds support for
the power-button on the Surface Laptop 1 and Laptop 2, as well as
support for power- and (on-device) volume-buttons on the Surface Pro 5
(2017), Pro 6, and Book 2.

These devices use the same MSHW0040 device as on the Surface Pro 4,
however, whereas the Pro 4 uses an ACPI notify handler, the newer
devices use GPIO interrupts to signal these events.

The first patch of this series ensures that the surfacepro3_button
driver, used for MSHW0040 on the Pro 4, does not probe for the newer
devices. The second patch adapts soc_button_array to implement the
actual button support.

I think the changes to soc_button_array in the second patch warrant a
thorough review. I've tried to make things a bit more generic to be able
to integrate arbitrary ACPI GPIO power-/volume-button devices more
easily, I'm not sure if there may be reasons against this.

These patches have also been tested on various Surface devices via the
github.com/jakeday/linux-surface patchset.

Maximilian Luz (2):
  platform: Fix device check for surfacepro3_button
  input: soc_button_array for newer surface devices

 drivers/input/misc/soc_button_array.c     | 134 ++++++++++++++++++++--
 drivers/platform/x86/surfacepro3_button.c |  38 ++++++
 2 files changed, 160 insertions(+), 12 deletions(-)

-- 
2.22.0

[PATCH 1/2] platform: Fix device check for surfacepro3_button

[Maximilian Luz]

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.

Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
---
 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);
+
+	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;
+}
+
+
 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;
+
 	button = kzalloc(sizeof(struct surface_button), GFP_KERNEL);
 	if (!button)
 		return -ENOMEM;
-- 
2.22.0

[PATCH 2/2] input: soc_button_array for newer surface devices

[Maximilian Luz]

Power and volume button support for 5th and 6th genration Microsoft
Surface devices via soc_button_array.

Note that these devices use the same MSHW0040 device as on the Surface
Pro 4, however the implementation is different (GPIOs vs. ACPI
notifications). Thus some checking is required to ensure we only load
this driver on the correct devices.

Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
---
 drivers/input/misc/soc_button_array.c | 134 +++++++++++++++++++++++---
 1 file changed, 122 insertions(+), 12 deletions(-)

diff --git a/drivers/input/misc/soc_button_array.c b/drivers/input/misc/soc_button_array.c
index 5e59f8e57f8e..157f53a2bd51 100644
--- a/drivers/input/misc/soc_button_array.c
+++ b/drivers/input/misc/soc_button_array.c
@@ -25,6 +25,17 @@ struct soc_button_info {
 	bool wakeup;
 };
 
+/**
+ * struct soc_device_data - driver data for different device types
+ * @button_info: specifications of buttons, if NULL specification is assumed to
+ *               be present in _DSD
+ * @check: device-specific check (NULL means all will be accepted)
+ */
+struct soc_device_data {
+	struct soc_button_info *button_info;
+	int (*check)(struct device *dev);
+};
+
 /*
  * Some of the buttons like volume up/down are auto repeat, while others
  * are not. To support both, we register two platform devices, and put
@@ -310,6 +321,7 @@ static int soc_button_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	const struct acpi_device_id *id;
+	struct soc_device_data *device_data;
 	struct soc_button_info *button_info;
 	struct soc_button_data *priv;
 	struct platform_device *pd;
@@ -320,18 +332,20 @@ static int soc_button_probe(struct platform_device *pdev)
 	if (!id)
 		return -ENODEV;
 
-	if (!id->driver_data) {
+	device_data = (struct soc_device_data *)id->driver_data;
+	if (device_data && device_data->check) {
+		error = device_data->check(dev);
+		if (error)
+			return error;
+	}
+
+	if (device_data && device_data->button_info) {
+		button_info = (struct soc_button_info *)
+				device_data->button_info;
+	} else {
 		button_info = soc_button_get_button_info(dev);
 		if (IS_ERR(button_info))
 			return PTR_ERR(button_info);
-	} else {
-		button_info = (struct soc_button_info *)id->driver_data;
-	}
-
-	error = gpiod_count(dev, NULL);
-	if (error < 0) {
-		dev_dbg(dev, "no GPIO attached, ignoring...\n");
-		return -ENODEV;
 	}
 
 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
@@ -357,12 +371,32 @@ static int soc_button_probe(struct platform_device *pdev)
 	if (!priv->children[0] && !priv->children[1])
 		return -ENODEV;
 
-	if (!id->driver_data)
+	if (!device_data || !device_data->button_info)
 		devm_kfree(dev, button_info);
 
 	return 0;
 }
 
+
+static int soc_device_check_generic(struct device *dev)
+{
+	int gpios;
+
+	gpios = gpiod_count(dev, NULL);
+	if (gpios < 0) {
+		dev_dbg(dev, "no GPIO attached, ignoring...\n");
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static struct soc_device_data soc_device_ACPI0011 = {
+	.button_info = NULL,
+	.check = soc_device_check_generic,
+};
+
+
 /*
  * Definition of buttons on the tablet. The ACPI index of each button
  * is defined in section 2.8.7.2 of "Windows ACPI Design Guide for SoC
@@ -377,9 +411,85 @@ static struct soc_button_info soc_button_PNP0C40[] = {
 	{ }
 };
 
+static struct soc_device_data soc_device_PNP0C40 = {
+	.button_info = soc_button_PNP0C40,
+	.check = soc_device_check_generic,
+};
+
+
+/*
+ * Special device check for Surface Book 2 and Surface Pro (2017).
+ * Both, the Surface Pro 4 (surfacepro3_button.c) and the above mentioned
+ * devices use MSHW0040 for power and volume buttons, however the way they
+ * have to be addressed differs. Make sure that we only load this drivers
+ * for the correct devices by checking the OEM Platform Revision provided by
+ * the _DSM method.
+ */
+#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);
+
+static int soc_device_check_MSHW0040(struct device *dev)
+{
+	acpi_handle handle = ACPI_HANDLE(dev);
+	union acpi_object *result;
+	u64 oem_platform_rev = 0;
+	int gpios;
+
+	// get OEM platform revision
+	result = acpi_evaluate_dsm_typed(handle, &MSHW0040_DSM_UUID,
+					 MSHW0040_DSM_REVISION,
+					 MSHW0040_DSM_GET_OMPR, NULL,
+					 ACPI_TYPE_INTEGER);
+
+	if (result) {
+		oem_platform_rev = result->integer.value;
+		ACPI_FREE(result);
+	}
+
+	if (oem_platform_rev == 0)
+		return -ENODEV;
+
+	dev_dbg(dev, "OEM Platform Revision %llu\n", oem_platform_rev);
+
+	/*
+	 * We are _really_ expecting GPIOs here. If we do not get any, this
+	 * means the GPIO driver has not been loaded yet (which can happen).
+	 * Try again later.
+	 */
+	gpios = gpiod_count(dev, NULL);
+	if (gpios < 0)
+		return -EAGAIN;
+
+	return 0;
+}
+
+/*
+ * Button infos for Microsoft Surface Book 2 and Surface Pro (2017).
+ * Obtained from DSDT/testing.
+ */
+static struct soc_button_info soc_button_MSHW0040[] = {
+	{ "power", 0, EV_KEY, KEY_POWER, false, true },
+	{ "volume_up", 2, EV_KEY, KEY_VOLUMEUP, true, false },
+	{ "volume_down", 4, EV_KEY, KEY_VOLUMEDOWN, true, false },
+	{ }
+};
+
+static struct soc_device_data soc_device_MSHW0040 = {
+	.button_info = soc_button_MSHW0040,
+	.check = soc_device_check_MSHW0040,
+};
+
+
 static const struct acpi_device_id soc_button_acpi_match[] = {
-	{ "PNP0C40", (unsigned long)soc_button_PNP0C40 },
-	{ "ACPI0011", 0 },
+	{ "PNP0C40", (unsigned long)&soc_device_PNP0C40 },
+	{ "ACPI0011", (unsigned long)&soc_device_ACPI0011 },
+
+	/* Microsoft Surface Devices (5th and 6th generation) */
+	{ "MSHW0040", (unsigned long)&soc_device_MSHW0040 },
+
 	{ }
 };
 
-- 
2.22.0

Re: [PATCH 0/2] Support for buttons on newer MS Surface devices

[Andy Shevchenko]

On Thu, Jun 20, 2019 at 2:51 PM Maximilian Luz <luzmaximilian@gmail.com> wrote:
>
> This series adds suport for power and volume buttons on 5th and 6th
> generation Microsoft Surface devices. Specifically, it adds support for
> the power-button on the Surface Laptop 1 and Laptop 2, as well as
> support for power- and (on-device) volume-buttons on the Surface Pro 5
> (2017), Pro 6, and Book 2.
>
> These devices use the same MSHW0040 device as on the Surface Pro 4,
> however, whereas the Pro 4 uses an ACPI notify handler, the newer
> devices use GPIO interrupts to signal these events.
>
> The first patch of this series ensures that the surfacepro3_button
> driver, used for MSHW0040 on the Pro 4, does not probe for the newer
> devices. The second patch adapts soc_button_array to implement the
> actual button support.
>
> I think the changes to soc_button_array in the second patch warrant a
> thorough review. I've tried to make things a bit more generic to be able
> to integrate arbitrary ACPI GPIO power-/volume-button devices more
> easily, I'm not sure if there may be reasons against this.
>
> These patches have also been tested on various Surface devices via the
> github.com/jakeday/linux-surface patchset.
>

Pushed to my review and testing queue, thanks!

> Maximilian Luz (2):
>   platform: Fix device check for surfacepro3_button
>   input: soc_button_array for newer surface devices
>
>  drivers/input/misc/soc_button_array.c     | 134 ++++++++++++++++++++--
>  drivers/platform/x86/surfacepro3_button.c |  38 ++++++
>  2 files changed, 160 insertions(+), 12 deletions(-)
>
> --
> 2.22.0
>


-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH 2/2] input: soc_button_array for newer surface devices

[Andy Shevchenko]

On Thu, Jun 20, 2019 at 2:51 PM Maximilian Luz <luzmaximilian@gmail.com> wrote:
>
> Power and volume button support for 5th and 6th genration Microsoft
> Surface devices via soc_button_array.
>
> Note that these devices use the same MSHW0040 device as on the Surface
> Pro 4, however the implementation is different (GPIOs vs. ACPI
> notifications). Thus some checking is required to ensure we only load
> this driver on the correct devices.
>

Either I need an Ack from Dmitry, or it should go via his tree.

> Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
> ---
>  drivers/input/misc/soc_button_array.c | 134 +++++++++++++++++++++++---
>  1 file changed, 122 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/input/misc/soc_button_array.c b/drivers/input/misc/soc_button_array.c
> index 5e59f8e57f8e..157f53a2bd51 100644
> --- a/drivers/input/misc/soc_button_array.c
> +++ b/drivers/input/misc/soc_button_array.c
> @@ -25,6 +25,17 @@ struct soc_button_info {
>         bool wakeup;
>  };
>
> +/**
> + * struct soc_device_data - driver data for different device types
> + * @button_info: specifications of buttons, if NULL specification is assumed to
> + *               be present in _DSD
> + * @check: device-specific check (NULL means all will be accepted)
> + */
> +struct soc_device_data {
> +       struct soc_button_info *button_info;
> +       int (*check)(struct device *dev);
> +};
> +
>  /*
>   * Some of the buttons like volume up/down are auto repeat, while others
>   * are not. To support both, we register two platform devices, and put
> @@ -310,6 +321,7 @@ static int soc_button_probe(struct platform_device *pdev)
>  {
>         struct device *dev = &pdev->dev;
>         const struct acpi_device_id *id;
> +       struct soc_device_data *device_data;
>         struct soc_button_info *button_info;
>         struct soc_button_data *priv;
>         struct platform_device *pd;
> @@ -320,18 +332,20 @@ static int soc_button_probe(struct platform_device *pdev)
>         if (!id)
>                 return -ENODEV;
>
> -       if (!id->driver_data) {
> +       device_data = (struct soc_device_data *)id->driver_data;
> +       if (device_data && device_data->check) {
> +               error = device_data->check(dev);
> +               if (error)
> +                       return error;
> +       }
> +
> +       if (device_data && device_data->button_info) {
> +               button_info = (struct soc_button_info *)
> +                               device_data->button_info;
> +       } else {
>                 button_info = soc_button_get_button_info(dev);
>                 if (IS_ERR(button_info))
>                         return PTR_ERR(button_info);
> -       } else {
> -               button_info = (struct soc_button_info *)id->driver_data;
> -       }
> -
> -       error = gpiod_count(dev, NULL);
> -       if (error < 0) {
> -               dev_dbg(dev, "no GPIO attached, ignoring...\n");
> -               return -ENODEV;
>         }
>
>         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> @@ -357,12 +371,32 @@ static int soc_button_probe(struct platform_device *pdev)
>         if (!priv->children[0] && !priv->children[1])
>                 return -ENODEV;
>
> -       if (!id->driver_data)
> +       if (!device_data || !device_data->button_info)
>                 devm_kfree(dev, button_info);
>
>         return 0;
>  }
>
> +
> +static int soc_device_check_generic(struct device *dev)
> +{
> +       int gpios;
> +
> +       gpios = gpiod_count(dev, NULL);
> +       if (gpios < 0) {
> +               dev_dbg(dev, "no GPIO attached, ignoring...\n");
> +               return -ENODEV;
> +       }
> +
> +       return 0;
> +}
> +
> +static struct soc_device_data soc_device_ACPI0011 = {
> +       .button_info = NULL,
> +       .check = soc_device_check_generic,
> +};
> +
> +
>  /*
>   * Definition of buttons on the tablet. The ACPI index of each button
>   * is defined in section 2.8.7.2 of "Windows ACPI Design Guide for SoC
> @@ -377,9 +411,85 @@ static struct soc_button_info soc_button_PNP0C40[] = {
>         { }
>  };
>
> +static struct soc_device_data soc_device_PNP0C40 = {
> +       .button_info = soc_button_PNP0C40,
> +       .check = soc_device_check_generic,
> +};
> +
> +
> +/*
> + * Special device check for Surface Book 2 and Surface Pro (2017).
> + * Both, the Surface Pro 4 (surfacepro3_button.c) and the above mentioned
> + * devices use MSHW0040 for power and volume buttons, however the way they
> + * have to be addressed differs. Make sure that we only load this drivers
> + * for the correct devices by checking the OEM Platform Revision provided by
> + * the _DSM method.
> + */
> +#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);
> +
> +static int soc_device_check_MSHW0040(struct device *dev)
> +{
> +       acpi_handle handle = ACPI_HANDLE(dev);
> +       union acpi_object *result;
> +       u64 oem_platform_rev = 0;
> +       int gpios;
> +
> +       // get OEM platform revision
> +       result = acpi_evaluate_dsm_typed(handle, &MSHW0040_DSM_UUID,
> +                                        MSHW0040_DSM_REVISION,
> +                                        MSHW0040_DSM_GET_OMPR, NULL,
> +                                        ACPI_TYPE_INTEGER);
> +
> +       if (result) {
> +               oem_platform_rev = result->integer.value;
> +               ACPI_FREE(result);
> +       }
> +
> +       if (oem_platform_rev == 0)
> +               return -ENODEV;
> +
> +       dev_dbg(dev, "OEM Platform Revision %llu\n", oem_platform_rev);
> +
> +       /*
> +        * We are _really_ expecting GPIOs here. If we do not get any, this
> +        * means the GPIO driver has not been loaded yet (which can happen).
> +        * Try again later.
> +        */
> +       gpios = gpiod_count(dev, NULL);
> +       if (gpios < 0)
> +               return -EAGAIN;
> +
> +       return 0;
> +}
> +
> +/*
> + * Button infos for Microsoft Surface Book 2 and Surface Pro (2017).
> + * Obtained from DSDT/testing.
> + */
> +static struct soc_button_info soc_button_MSHW0040[] = {
> +       { "power", 0, EV_KEY, KEY_POWER, false, true },
> +       { "volume_up", 2, EV_KEY, KEY_VOLUMEUP, true, false },
> +       { "volume_down", 4, EV_KEY, KEY_VOLUMEDOWN, true, false },
> +       { }
> +};
> +
> +static struct soc_device_data soc_device_MSHW0040 = {
> +       .button_info = soc_button_MSHW0040,
> +       .check = soc_device_check_MSHW0040,
> +};
> +
> +
>  static const struct acpi_device_id soc_button_acpi_match[] = {
> -       { "PNP0C40", (unsigned long)soc_button_PNP0C40 },
> -       { "ACPI0011", 0 },
> +       { "PNP0C40", (unsigned long)&soc_device_PNP0C40 },
> +       { "ACPI0011", (unsigned long)&soc_device_ACPI0011 },
> +
> +       /* Microsoft Surface Devices (5th and 6th generation) */
> +       { "MSHW0040", (unsigned long)&soc_device_MSHW0040 },
> +
>         { }
>  };
>
> --
> 2.22.0
>


-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH 0/2] Support for buttons on newer MS Surface devices

[Maximilian Luz]

On 6/29/19 4:18 PM, Andy Shevchenko wrote:
> Pushed to my review and testing queue, thanks!

Sorry for my rookie mistake of not checking that this works without
CONFIG_ACPI. I have updated and re-sent the patches to fix this.

Maximilian