[PATCH v3 0/2] Support for buttons on newer MS Surface devices

[PATCH v3 0/2] Support for buttons on newer MS Surface devices

[Maximilian Luz]

This series adds support 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.

Changes in v3:
  - [PATCH 1/2] platform/x86: surfacepro3_button: Fix device check
    - Changed subject line to fit conventions.
    - Added comments to clarify ACPI/DSM specific behavior.
    - Change return type of introduced device check function to bool.

  - [PATCH 1/2] Input: soc_button_array - Add support for newer
      surface devices
    - Changed subject line to fit conventions.
    - Explicitly require CONFIG_ACPI via Kconfig instead of guarding
      with #ifdef CONFIG_ACPI in code.
    - Add supported Surface devices to module description in Kconfig.
    - Allow -EPROBE_DEFER and other errors to be propagated from
      gpiod_get.
    - Fix deferral process in case GPIO subsystem is not initialized.

Changes in v2:
  - [PATCH 1/2] platform: Fix device check for surfacepro3_button
    No changes.

  - [PATCH 2/2] input: soc_button_array for newer surface devices
    Ensure the patch compiles without CONFIG_ACPI.

Maximilian Luz (2):
  platform/x86: surfacepro3_button: Fix device check
  Input: soc_button_array - Add support for newer surface devices

 drivers/input/misc/Kconfig                |   6 +-
 drivers/input/misc/soc_button_array.c     | 141 ++++++++++++++++++++--
 drivers/platform/x86/surfacepro3_button.c |  47 ++++++++
 3 files changed, 178 insertions(+), 16 deletions(-)

-- 
2.22.0

[PATCH v3 1/2] platform/x86: surfacepro3_button: Fix device check

[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
actual 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 | 47 +++++++++++++++++++++++
 1 file changed, 47 insertions(+)

diff --git a/drivers/platform/x86/surfacepro3_button.c b/drivers/platform/x86/surfacepro3_button.c
index 47c6d000465a..ec515223f654 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 +148,44 @@ 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.
+ *
+ * Returns true if the driver should bind to this device, i.e. the device is
+ * either MSWH0028 (Pro 3) or MSHW0040 on a Pro 4 or Book 1.
+ */
+static bool surface_button_check_MSHW0040(struct acpi_device *dev)
+{
+	acpi_handle handle = dev->handle;
+	union acpi_object *result;
+	u64 oem_platform_rev = 0;	// valid revisions are nonzero
+
+	// 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 evaluating the _DSM fails, the method is not present. This means
+	 * that we have either MSHW0028 or MSHW0040 on Pro 4 or Book 1, so we
+	 * should use this driver. We use revision 0 indicating it is
+	 * unavailable.
+	 */
+
+	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;
+}
+
+
 static int surface_button_add(struct acpi_device *device)
 {
 	struct surface_button *button;
@@ -154,6 +198,9 @@ static int surface_button_add(struct acpi_device *device)
 	    strlen(SURFACE_BUTTON_OBJ_NAME)))
 		return -ENODEV;
 
+	if (!surface_button_check_MSHW0040(device))
+		return -ENODEV;
+
 	button = kzalloc(sizeof(struct surface_button), GFP_KERNEL);
 	if (!button)
 		return -ENOMEM;
-- 
2.22.0

Re: [PATCH v3 1/2] platform/x86: surfacepro3_button: Fix device check

[Andy Shevchenko]

On Sat, Jul 20, 2019 at 6:05 PM Maximilian Luz <luzmaximilian@gmail.com> 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
> actual 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.
>

Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>

assuming it will go thru Input subsystem.

> Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
> ---
>  drivers/platform/x86/surfacepro3_button.c | 47 +++++++++++++++++++++++
>  1 file changed, 47 insertions(+)
>
> diff --git a/drivers/platform/x86/surfacepro3_button.c b/drivers/platform/x86/surfacepro3_button.c
> index 47c6d000465a..ec515223f654 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 +148,44 @@ 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.
> + *
> + * Returns true if the driver should bind to this device, i.e. the device is
> + * either MSWH0028 (Pro 3) or MSHW0040 on a Pro 4 or Book 1.
> + */
> +static bool surface_button_check_MSHW0040(struct acpi_device *dev)
> +{
> +       acpi_handle handle = dev->handle;
> +       union acpi_object *result;
> +       u64 oem_platform_rev = 0;       // valid revisions are nonzero
> +
> +       // 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 evaluating the _DSM fails, the method is not present. This means
> +        * that we have either MSHW0028 or MSHW0040 on Pro 4 or Book 1, so we
> +        * should use this driver. We use revision 0 indicating it is
> +        * unavailable.
> +        */
> +
> +       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;
> +}
> +
> +
>  static int surface_button_add(struct acpi_device *device)
>  {
>         struct surface_button *button;
> @@ -154,6 +198,9 @@ static int surface_button_add(struct acpi_device *device)
>             strlen(SURFACE_BUTTON_OBJ_NAME)))
>                 return -ENODEV;
>
> +       if (!surface_button_check_MSHW0040(device))
> +               return -ENODEV;
> +
>         button = kzalloc(sizeof(struct surface_button), GFP_KERNEL);
>         if (!button)
>                 return -ENOMEM;
> --
> 2.22.0
>


-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v3 1/2] platform/x86: surfacepro3_button: Fix device check

[Dmitry Torokhov]

On Thu, Jul 25, 2019 at 08:57:53PM +0300, Andy Shevchenko wrote:
> On Sat, Jul 20, 2019 at 6:05 PM Maximilian Luz <luzmaximilian@gmail.com> 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
> > actual 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.
> >
> 
> Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
> 
> assuming it will go thru Input subsystem.

I can take it, but I do not think it is dependent on the other change
and thus can go through platform tree as well.

Thanks.

-- 
Dmitry

Re: [PATCH v3 1/2] platform/x86: surfacepro3_button: Fix device check

[Andy Shevchenko]

On Sat, Jul 27, 2019 at 12:15 PM Dmitry Torokhov
<dmitry.torokhov@gmail.com> wrote:
>
> On Thu, Jul 25, 2019 at 08:57:53PM +0300, Andy Shevchenko wrote:
> > On Sat, Jul 20, 2019 at 6:05 PM Maximilian Luz <luzmaximilian@gmail.com> 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
> > > actual 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.
> > >
> >
> > Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
> >
> > assuming it will go thru Input subsystem.
>
> I can take it, but I do not think it is dependent on the other change
> and thus can go through platform tree as well.

Pkease, take it. I do not expect any changes to the driver this cycle.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v3 1/2] platform/x86: surfacepro3_button: Fix device check

[Dmitry Torokhov]

On Sat, Jul 27, 2019 at 03:26:41PM +0300, Andy Shevchenko wrote:
> On Sat, Jul 27, 2019 at 12:15 PM Dmitry Torokhov
> <dmitry.torokhov@gmail.com> wrote:
> >
> > On Thu, Jul 25, 2019 at 08:57:53PM +0300, Andy Shevchenko wrote:
> > > On Sat, Jul 20, 2019 at 6:05 PM Maximilian Luz <luzmaximilian@gmail.com> 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
> > > > actual 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.
> > > >
> > >
> > > Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
> > >
> > > assuming it will go thru Input subsystem.
> >
> > I can take it, but I do not think it is dependent on the other change
> > and thus can go through platform tree as well.
> 
> Pkease, take it. I do not expect any changes to the driver this cycle.

OK, applied, thank you.

-- 
Dmitry

Re: [PATCH v3 1/2] platform/x86: surfacepro3_button: Fix device check

[Yu Chen]

On Sat, Jul 20, 2019 at 05:05:10PM +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
> actual 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>
> ---
Acked-by: Chen Yu <yu.c.chen@intel.com>

Thanks,
Chenyu

[PATCH v3 2/2] Input: soc_button_array - Add support for newer surface devices

[Maximilian Luz]

Power and volume button support for 5th and 6th generation 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/Kconfig            |   6 +-
 drivers/input/misc/soc_button_array.c | 141 +++++++++++++++++++++++---
 2 files changed, 131 insertions(+), 16 deletions(-)

diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
index d07c1eb15aa6..7d9ae394e597 100644
--- a/drivers/input/misc/Kconfig
+++ b/drivers/input/misc/Kconfig
@@ -813,10 +813,10 @@ config INPUT_IDEAPAD_SLIDEBAR
 
 config INPUT_SOC_BUTTON_ARRAY
 	tristate "Windows-compatible SoC Button Array"
-	depends on KEYBOARD_GPIO
+	depends on KEYBOARD_GPIO && ACPI
 	help
-	  Say Y here if you have a SoC-based tablet that originally
-	  runs Windows 8.
+	  Say Y here if you have a SoC-based tablet that originally runs
+	  Windows 8 or a Microsoft Surface Book 2, Pro 5, Laptop 1 or later.
 
 	  To compile this driver as a module, choose M here: the
 	  module will be called soc_button_array.
diff --git a/drivers/input/misc/soc_button_array.c b/drivers/input/misc/soc_button_array.c
index 5e59f8e57f8e..4d5150bebeef 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
@@ -87,8 +98,13 @@ soc_button_device_create(struct platform_device *pdev,
 			continue;
 
 		gpio = soc_button_lookup_gpio(&pdev->dev, info->acpi_index);
-		if (!gpio_is_valid(gpio))
+		if (gpio < 0 && gpio != -ENOENT) {
+			error = gpio;
+			goto err_free_mem;
+		} else if (!gpio_is_valid(gpio)) {
+			/* Skip GPIO if not present */
 			continue;
+		}
 
 		gpio_keys[n_buttons].type = info->event_type;
 		gpio_keys[n_buttons].code = info->event_code;
@@ -310,6 +326,7 @@ 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 +337,20 @@ 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 +376,32 @@ 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 +416,85 @@ 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;	// valid revisions are nonzero
+	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 the revision is zero here, the _DSM evaluation has failed. This
+	 * indicates that we have a Pro 4 or Book 1 and this driver should not
+	 * be used.
+	 */
+	if (oem_platform_rev == 0)
+		return -ENODEV;
+
+	dev_dbg(dev, "OEM Platform Revision %llu\n", oem_platform_rev);
+
+	gpios = gpiod_count(dev, NULL);
+	if (gpios < 0)
+		return -ENODEV;
+
+	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 v3 2/2] Input: soc_button_array - Add support for newer surface devices

[Enrico Weigelt, metux IT consult]

On 20.07.19 17:05, Maximilian Luz wrote:
> Power and volume button support for 5th and 6th generation 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.

Could this also used on the older (pre pro4) devices (also using the
gpios directly, and leave off acpi notifications) ?

--mtx

-- 
Enrico Weigelt, metux IT consult
Free software and Linux embedded engineering
info@metux.net -- +49-151-27565287

Re: [PATCH v3 2/2] Input: soc_button_array - Add support for newer surface devices

[Maximilian Luz]

On 7/22/19 10:00 AM, Enrico Weigelt, metux IT consult wrote:
> On 20.07.19 17:05, Maximilian Luz wrote:
>> Power and volume button support for 5th and 6th generation 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.
> 
> Could this also used on the older (pre pro4) devices (also using the
> gpios directly, and leave off acpi notifications) ?

As far as I can tell, no. The Pro 4 and Pro 3 don't have any GPIOs on
MSHW0028/MSHW0040. Book 1 has GPIOs but for a different purpose. The Pro
2 has a standard PNP0C0C power button (no idea how the volume buttons
are handled there, but also seems to be different from what I can gather
from DSDT). I can't say anything for the Pro 1 and non-Pro devices.

Maximilian

Re: [PATCH v3 2/2] Input: soc_button_array - Add support for newer surface devices

[Dmitry Torokhov]

Hi Maximilian,

On Sat, Jul 20, 2019 at 05:05:11PM +0200, Maximilian Luz wrote:
> -
> -	error = gpiod_count(dev, NULL);
> -	if (error < 0) {
> -		dev_dbg(dev, "no GPIO attached, ignoring...\n");
> -		return -ENODEV;

I do not think we need to move this into individual "check" functions.
It is needed in all cases so we should keep it here.

How about version below?

Input: soc_button_array - add support for newer surface devices

From: Maximilian Luz <luzmaximilian@gmail.com>

Power and volume button support for 5th and 6th generation 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>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
 drivers/input/misc/Kconfig            |    6 +-
 drivers/input/misc/soc_button_array.c |  105 +++++++++++++++++++++++++++++----
 2 files changed, 96 insertions(+), 15 deletions(-)

diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
index d07c1eb15aa6..7d9ae394e597 100644
--- a/drivers/input/misc/Kconfig
+++ b/drivers/input/misc/Kconfig
@@ -813,10 +813,10 @@ config INPUT_IDEAPAD_SLIDEBAR
 
 config INPUT_SOC_BUTTON_ARRAY
 	tristate "Windows-compatible SoC Button Array"
-	depends on KEYBOARD_GPIO
+	depends on KEYBOARD_GPIO && ACPI
 	help
-	  Say Y here if you have a SoC-based tablet that originally
-	  runs Windows 8.
+	  Say Y here if you have a SoC-based tablet that originally runs
+	  Windows 8 or a Microsoft Surface Book 2, Pro 5, Laptop 1 or later.
 
 	  To compile this driver as a module, choose M here: the
 	  module will be called soc_button_array.
diff --git a/drivers/input/misc/soc_button_array.c b/drivers/input/misc/soc_button_array.c
index 5e59f8e57f8e..6f0133fe1546 100644
--- a/drivers/input/misc/soc_button_array.c
+++ b/drivers/input/misc/soc_button_array.c
@@ -25,6 +25,11 @@ struct soc_button_info {
 	bool wakeup;
 };
 
+struct soc_device_data {
+	const 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
@@ -87,8 +92,13 @@ soc_button_device_create(struct platform_device *pdev,
 			continue;
 
 		gpio = soc_button_lookup_gpio(&pdev->dev, info->acpi_index);
-		if (!gpio_is_valid(gpio))
+		if (gpio < 0 && gpio != -ENOENT) {
+			error = gpio;
+			goto err_free_mem;
+		} else if (!gpio_is_valid(gpio)) {
+			/* Skip GPIO if not present */
 			continue;
+		}
 
 		gpio_keys[n_buttons].type = info->event_type;
 		gpio_keys[n_buttons].code = info->event_code;
@@ -309,23 +319,26 @@ static int soc_button_remove(struct platform_device *pdev)
 static int soc_button_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
-	const struct acpi_device_id *id;
-	struct soc_button_info *button_info;
+	const struct soc_device_data *device_data;
+	const struct soc_button_info *button_info;
 	struct soc_button_data *priv;
 	struct platform_device *pd;
 	int i;
 	int error;
 
-	id = acpi_match_device(dev->driver->acpi_match_table, dev);
-	if (!id)
-		return -ENODEV;
+	device_data = acpi_device_get_match_data(dev);
+	if (device_data && device_data->check) {
+		error = device_data->check(dev);
+		if (error)
+			return error;
+	}
 
-	if (!id->driver_data) {
+	if (device_data && device_data->button_info) {
+		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);
@@ -357,7 +370,7 @@ 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;
@@ -368,7 +381,7 @@ static int soc_button_probe(struct platform_device *pdev)
  * is defined in section 2.8.7.2 of "Windows ACPI Design Guide for SoC
  * Platforms"
  */
-static struct soc_button_info soc_button_PNP0C40[] = {
+static const struct soc_button_info soc_button_PNP0C40[] = {
 	{ "power", 0, EV_KEY, KEY_POWER, false, true },
 	{ "home", 1, EV_KEY, KEY_LEFTMETA, false, true },
 	{ "volume_up", 2, EV_KEY, KEY_VOLUMEUP, true, false },
@@ -377,9 +390,77 @@ static struct soc_button_info soc_button_PNP0C40[] = {
 	{ }
 };
 
+static const struct soc_device_data soc_device_PNP0C40 = {
+	.button_info = soc_button_PNP0C40,
+};
+
+/*
+ * 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;	// valid revisions are nonzero
+
+	// 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 the revision is zero here, the _DSM evaluation has failed. This
+	 * indicates that we have a Pro 4 or Book 1 and this driver should not
+	 * be used.
+	 */
+	if (oem_platform_rev == 0)
+		return -ENODEV;
+
+	dev_dbg(dev, "OEM Platform Revision %llu\n", oem_platform_rev);
+
+	return 0;
+}
+
+/*
+ * Button infos for Microsoft Surface Book 2 and Surface Pro (2017).
+ * Obtained from DSDT/testing.
+ */
+static const 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 const 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 },
+	{ "PNP0C40", (unsigned long)&soc_device_PNP0C40 },
 	{ "ACPI0011", 0 },
+
+	/* Microsoft Surface Devices (5th and 6th generation) */
+	{ "MSHW0040", (unsigned long)&soc_device_MSHW0040 },
+
 	{ }
 };
 

-- 
Dmitry

Re: [PATCH v3 2/2] Input: soc_button_array - Add support for newer surface devices

[Maximilian Luz]

On 7/27/19 11:14 AM, Dmitry Torokhov wrote:
> On Sat, Jul 20, 2019 at 05:05:11PM +0200, Maximilian Luz wrote:
>> -
>> -	error = gpiod_count(dev, NULL);
>> -	if (error < 0) {
>> -		dev_dbg(dev, "no GPIO attached, ignoring...\n");
>> -		return -ENODEV;
> 
> I do not think we need to move this into individual "check" functions.
> It is needed in all cases so we should keep it here.
> 
> How about version below?

Makes sense, looks good to me!

Maximilian

Re: [PATCH v3 2/2] Input: soc_button_array - Add support for newer surface devices

[Dmitry Torokhov]

On Sat, Jul 27, 2019 at 02:01:26PM +0200, Maximilian Luz wrote:
> On 7/27/19 11:14 AM, Dmitry Torokhov wrote:
> > On Sat, Jul 20, 2019 at 05:05:11PM +0200, Maximilian Luz wrote:
> > > -
> > > -	error = gpiod_count(dev, NULL);
> > > -	if (error < 0) {
> > > -		dev_dbg(dev, "no GPIO attached, ignoring...\n");
> > > -		return -ENODEV;
> > 
> > I do not think we need to move this into individual "check" functions.
> > It is needed in all cases so we should keep it here.
> > 
> > How about version below?
> 
> Makes sense, looks good to me!

OK, great, applied.

-- 
Dmitry