linux-surface/patches/4.19/0004-surface-buttons.patch

From be8bb5f93d32d3ac7f918cdbfb04b412673ff80b Mon Sep 17 00:00:00 2001
From: Maximilian Luz <luzmaximilian@gmail.com>
Date: Sat, 27 Jul 2019 17:51:37 +0200
Subject: [PATCH] platform/x86: surfacepro3_button: Fix device check

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>
Patchset: surface-buttons
---
 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 1b491690ce07..96627627060e 100644
--- a/drivers/platform/x86/surfacepro3_button.c
+++ b/drivers/platform/x86/surfacepro3_button.c
@@ -24,6 +24,12 @@
 #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
@@ -146,6 +152,44 @@ 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;
@@ -158,6 +202,9 @@ 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;
-- 
2.33.0

From dc6c755a5867401c03cb7ca17396f8d9b05df58d Mon Sep 17 00:00:00 2001
From: Maximilian Luz <luzmaximilian@gmail.com>
Date: Sat, 27 Jul 2019 17:52:01 +0200
Subject: [PATCH] Input: soc_button_array - Add support for newer surface
 devices

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>
Patchset: surface-buttons
---
 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 ca59a2be9bc5..ea69610370e8 100644
--- a/drivers/input/misc/Kconfig
+++ b/drivers/input/misc/Kconfig
@@ -781,10 +781,10 @@ 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 55cd6e0b409c..8f21c062c85d 100644
--- a/drivers/input/misc/soc_button_array.c
+++ b/drivers/input/misc/soc_button_array.c
@@ -29,6 +29,11 @@ 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
@@ -91,8 +96,13 @@ 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 },
+
 	{ }
 };
 
-- 
2.33.0

From 3495e149d8dc07d035fc87d0820b2e0938ed097b Mon Sep 17 00:00:00 2001
From: Hans de Goede <hdegoide@redhat.com>
Date: Sat, 5 Oct 2019 14:11:58 +0200
Subject: [PATCH] Input: soc_button_array - partial revert of support for newer
 surface devices

Commit c394159310d0 ("Input: soc_button_array - add support for newer
surface devices") not only added support for the MSHW0040 ACPI HID,
but for some reason it also makes changes to the error handling of the
soc_button_lookup_gpio() call in soc_button_device_create(). Note ideally
this seamingly unrelated change would have been made in a separate commit,
with a message explaining the what and why of this change.

I guess this change may have been added to deal with -EPROBE_DEFER errors,
but in case of the existing support for PNP0C40 devices, treating
-EPROBE_DEFER as any other error is deliberate, see the comment this
commit adds for why.

The actual returning of -EPROBE_DEFER to the caller of soc_button_probe()
introduced by the new error checking causes a serious regression:

On devices with so called virtual GPIOs soc_button_lookup_gpio() will
always return -EPROBE_DEFER for these fake GPIOs, when this happens
during the second call of soc_button_device_create() we already have
successfully registered our first child. This causes the kernel to think
we are making progress with probing things even though we unregister the
child before again before we return the -EPROBE_DEFER. Since we are making
progress the kernel will retry deferred-probes again immediately ending
up stuck in a loop with the following showing in dmesg:

[  124.022697] input: gpio-keys as /devices/platform/INTCFD9:00/gpio-keys.0.auto/input/input6537
[  124.040764] input: gpio-keys as /devices/platform/INTCFD9:00/gpio-keys.0.auto/input/input6538
[  124.056967] input: gpio-keys as /devices/platform/INTCFD9:00/gpio-keys.0.auto/input/input6539
[  124.072143] input: gpio-keys as /devices/platform/INTCFD9:00/gpio-keys.0.auto/input/input6540
[  124.092373] input: gpio-keys as /devices/platform/INTCFD9:00/gpio-keys.0.auto/input/input6541
[  124.108065] input: gpio-keys as /devices/platform/INTCFD9:00/gpio-keys.0.auto/input/input6542
[  124.128483] input: gpio-keys as /devices/platform/INTCFD9:00/gpio-keys.0.auto/input/input6543
[  124.147141] input: gpio-keys as /devices/platform/INTCFD9:00/gpio-keys.0.auto/input/input6544
[  124.165070] input: gpio-keys as /devices/platform/INTCFD9:00/gpio-keys.0.auto/input/input6545
[  124.179775] input: gpio-keys as /devices/platform/INTCFD9:00/gpio-keys.0.auto/input/input6546
[  124.202726] input: gpio-keys as /devices/platform/INTCFD9:00/gpio-keys.0.auto/input/input6547
<continues on and on and on>

And 1 CPU core being stuck at 100% and udev hanging since it is waiting
for the modprobe of soc_button_array to return.

This patch reverts the soc_button_lookup_gpio() error handling changes,
fixing this regression.

Fixes: c394159310d0 ("Input: soc_button_array - add support for newer surface devices")
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=205031
Cc: Maximilian Luz <luzmaximilian@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Patchset: surface-buttons
---
 drivers/input/misc/soc_button_array.c | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/drivers/input/misc/soc_button_array.c b/drivers/input/misc/soc_button_array.c
index 8f21c062c85d..5983733d78dd 100644
--- a/drivers/input/misc/soc_button_array.c
+++ b/drivers/input/misc/soc_button_array.c
@@ -96,11 +96,18 @@ soc_button_device_create(struct platform_device *pdev,
 			continue;
 
 		gpio = soc_button_lookup_gpio(&pdev->dev, info->acpi_index);
-		if (gpio < 0 && gpio != -ENOENT) {
-			error = gpio;
-			goto err_free_mem;
-		} else if (!gpio_is_valid(gpio)) {
-			/* Skip GPIO if not present */
+		if (!gpio_is_valid(gpio)) {
+			/*
+			 * Skip GPIO if not present. Note we deliberately
+			 * ignore -EPROBE_DEFER errors here. On some devices
+			 * Intel is using so called virtual GPIOs which are not
+			 * GPIOs at all but some way for AML code to check some
+			 * random status bits without need a custom opregion.
+			 * In some cases the resources table we parse points to
+			 * such a virtual GPIO, since these are not real GPIOs
+			 * we do not have a driver for these so they will never
+			 * show up, therefor we ignore -EPROBE_DEFER.
+			 */
 			continue;
 		}
 
-- 
2.33.0

From 97852be9f07614c8f49c9aaa7308d550d952207d Mon Sep 17 00:00:00 2001
From: "Tsuchiya Yuto (kitakar5525)" <kitakar@gmail.com>
Date: Mon, 11 May 2020 17:40:21 +0900
Subject: [PATCH] Input: soc_button_array - fix Wdiscarded-qualifiers for
 kernels below 4.20
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

There is a warning from compiler when building v4.19-surface kernel that
backported button patches from newer kernels.

    drivers/input/misc/soc_button_array.c: In function ‘soc_button_probe’:
    drivers/input/misc/soc_button_array.c:381:19: warning: passing argument 2 of ‘devm_kfree’ discards ‘const’ qualifier from pointer target type [-Wdiscarded-qualifiers]
      381 |   devm_kfree(dev, button_info);
          |                   ^~~~~~~~~~~
    In file included from ./include/linux/input.h:22,
                     from drivers/input/misc/soc_button_array.c:14:
    ./include/linux/device.h:695:50: note: expected ‘void *’ but argument is of type ‘const struct soc_button_info *’
      695 | extern void devm_kfree(struct device *dev, void *p);
          |                                            ~~~~~~^

This warning happens bacause commit 0571967dfb5d25 ("devres: constify p
in devm_kfree()") has not been applied to v4.19 series (available after
v4.20-rc1).

This commit casts button_info to (void *) when calling devm_kfree() to
avoid compiler warning.

Fixes: b892fc124285ba ("Input: soc_button_array - Add support for newer surface devices")
Signed-off-by: Tsuchiya Yuto (kitakar5525) <kitakar@gmail.com>
Patchset: surface-buttons
---
 drivers/input/misc/soc_button_array.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/input/misc/soc_button_array.c b/drivers/input/misc/soc_button_array.c
index 5983733d78dd..c564ea99f47d 100644
--- a/drivers/input/misc/soc_button_array.c
+++ b/drivers/input/misc/soc_button_array.c
@@ -378,7 +378,7 @@ static int soc_button_probe(struct platform_device *pdev)
 		return -ENODEV;
 
 	if (!device_data || !device_data->button_info)
-		devm_kfree(dev, button_info);
+		devm_kfree(dev, (void *)button_info);
 
 	return 0;
 }
-- 
2.33.0