1 files changed, 173 insertions, 12 deletions

diff --git a/drivers/input/misc/soc_button_array.c b/drivers/input/misc/soc_button_array.c
index ddb2f22fca7a..e37d37273182 100644
--- a/drivers/input/misc/soc_button_array.c
+++ b/drivers/input/misc/soc_button_array.c
@@ -20,13 +20,6 @@
 #include <linux/gpio.h>
 #include <linux/platform_device.h>
 
-/*
- * 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
- * Platforms"
- */
-#define MAX_NBUTTONS	5
-
 struct soc_button_info {
 	const char *name;
 	int acpi_index;
@@ -55,7 +48,7 @@ static int soc_button_lookup_gpio(struct device *dev, int acpi_index)
 	struct gpio_desc *desc;
 	int gpio;
 
-	desc = gpiod_get_index(dev, KBUILD_MODNAME, acpi_index, GPIOD_ASIS);
+	desc = gpiod_get_index(dev, NULL, acpi_index, GPIOD_ASIS);
 	if (IS_ERR(desc))
 		return PTR_ERR(desc);
 
@@ -79,14 +72,19 @@ soc_button_device_create(struct platform_device *pdev,
 	int gpio;
 	int error;
 
+	for (info = button_info; info->name; info++)
+		if (info->autorepeat == autorepeat)
+			n_buttons++;
+
 	gpio_keys_pdata = devm_kzalloc(&pdev->dev,
 				       sizeof(*gpio_keys_pdata) +
-					sizeof(*gpio_keys) * MAX_NBUTTONS,
+					sizeof(*gpio_keys) * n_buttons,
 				       GFP_KERNEL);
 	if (!gpio_keys_pdata)
 		return ERR_PTR(-ENOMEM);
 
 	gpio_keys = (void *)(gpio_keys_pdata + 1);
+	n_buttons = 0;
 
 	for (info = button_info; info->name; info++) {
 		if (info->autorepeat != autorepeat)
@@ -140,6 +138,153 @@ err_free_mem:
 	return ERR_PTR(error);
 }
 
+static int soc_button_get_acpi_object_int(const union acpi_object *obj)
+{
+	if (obj->type != ACPI_TYPE_INTEGER)
+		return -1;
+
+	return obj->integer.value;
+}
+
+/* Parse a single ACPI0011 _DSD button descriptor */
+static int soc_button_parse_btn_desc(struct device *dev,
+				     const union acpi_object *desc,
+				     int collection_uid,
+				     struct soc_button_info *info)
+{
+	int upage, usage;
+
+	if (desc->type != ACPI_TYPE_PACKAGE ||
+	    desc->package.count != 5 ||
+	    /* First byte should be 1 (control) */
+	    soc_button_get_acpi_object_int(&desc->package.elements[0]) != 1 ||
+	    /* Third byte should be collection uid */
+	    soc_button_get_acpi_object_int(&desc->package.elements[2]) !=
+							    collection_uid) {
+		dev_err(dev, "Invalid ACPI Button Descriptor\n");
+		return -ENODEV;
+	}
+
+	info->event_type = EV_KEY;
+	info->acpi_index =
+		soc_button_get_acpi_object_int(&desc->package.elements[1]);
+	upage = soc_button_get_acpi_object_int(&desc->package.elements[3]);
+	usage = soc_button_get_acpi_object_int(&desc->package.elements[4]);
+
+	/*
+	 * The UUID: fa6bd625-9ce8-470d-a2c7-b3ca36c4282e descriptors use HID
+	 * usage page and usage codes, but otherwise the device is not HID
+	 * compliant: it uses one irq per button instead of generating HID
+	 * input reports and some buttons should generate wakeups where as
+	 * others should not, so we cannot use the HID subsystem.
+	 *
+	 * Luckily all devices only use a few usage page + usage combinations,
+	 * so we can simply check for the known combinations here.
+	 */
+	if (upage == 0x01 && usage == 0x81) {
+		info->name = "power";
+		info->event_code = KEY_POWER;
+		info->wakeup = true;
+	} else if (upage == 0x07 && usage == 0xe3) {
+		info->name = "home";
+		info->event_code = KEY_LEFTMETA;
+		info->wakeup = true;
+	} else if (upage == 0x0c && usage == 0xe9) {
+		info->name = "volume_up";
+		info->event_code = KEY_VOLUMEUP;
+		info->autorepeat = true;
+	} else if (upage == 0x0c && usage == 0xea) {
+		info->name = "volume_down";
+		info->event_code = KEY_VOLUMEDOWN;
+		info->autorepeat = true;
+	} else {
+		dev_warn(dev, "Unknown button index %d upage %02x usage %02x, ignoring\n",
+			 info->acpi_index, upage, usage);
+		info->name = "unknown";
+		info->event_code = KEY_RESERVED;
+	}
+
+	return 0;
+}
+
+/* ACPI0011 _DSD btns descriptors UUID: fa6bd625-9ce8-470d-a2c7-b3ca36c4282e */
+static const u8 btns_desc_uuid[16] = {
+	0x25, 0xd6, 0x6b, 0xfa, 0xe8, 0x9c, 0x0d, 0x47,
+	0xa2, 0xc7, 0xb3, 0xca, 0x36, 0xc4, 0x28, 0x2e
+};
+
+/* Parse ACPI0011 _DSD button descriptors */
+static struct soc_button_info *soc_button_get_button_info(struct device *dev)
+{
+	struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
+	const union acpi_object *desc, *el0, *uuid, *btns_desc = NULL;
+	struct soc_button_info *button_info;
+	acpi_status status;
+	int i, btn, collection_uid = -1;
+
+	status = acpi_evaluate_object_typed(ACPI_HANDLE(dev), "_DSD", NULL,
+					    &buf, ACPI_TYPE_PACKAGE);
+	if (ACPI_FAILURE(status)) {
+		dev_err(dev, "ACPI _DSD object not found\n");
+		return ERR_PTR(-ENODEV);
+	}
+
+	/* Look for the Button Descriptors UUID */
+	desc = buf.pointer;
+	for (i = 0; (i + 1) < desc->package.count; i += 2) {
+		uuid = &desc->package.elements[i];
+
+		if (uuid->type != ACPI_TYPE_BUFFER ||
+		    uuid->buffer.length != 16 ||
+		    desc->package.elements[i + 1].type != ACPI_TYPE_PACKAGE) {
+			break;
+		}
+
+		if (memcmp(uuid->buffer.pointer, btns_desc_uuid, 16) == 0) {
+			btns_desc = &desc->package.elements[i + 1];
+			break;
+		}
+	}
+
+	if (!btns_desc) {
+		dev_err(dev, "ACPI Button Descriptors not found\n");
+		return ERR_PTR(-ENODEV);
+	}
+
+	/* The first package describes the collection */
+	el0 = &btns_desc->package.elements[0];
+	if (el0->type == ACPI_TYPE_PACKAGE &&
+	    el0->package.count == 5 &&
+	    /* First byte should be 0 (collection) */
+	    soc_button_get_acpi_object_int(&el0->package.elements[0]) == 0 &&
+	    /* Third byte should be 0 (top level collection) */
+	    soc_button_get_acpi_object_int(&el0->package.elements[2]) == 0) {
+		collection_uid = soc_button_get_acpi_object_int(
+						&el0->package.elements[1]);
+	}
+	if (collection_uid == -1) {
+		dev_err(dev, "Invalid Button Collection Descriptor\n");
+		return ERR_PTR(-ENODEV);
+	}
+
+	/* There are package.count - 1 buttons + 1 terminating empty entry */
+	button_info = devm_kcalloc(dev, btns_desc->package.count,
+				   sizeof(*button_info), GFP_KERNEL);
+	if (!button_info)
+		return ERR_PTR(-ENOMEM);
+
+	/* Parse the button descriptors */
+	for (i = 1, btn = 0; i < btns_desc->package.count; i++, btn++) {
+		if (soc_button_parse_btn_desc(dev,
+					      &btns_desc->package.elements[i],
+					      collection_uid,
+					      &button_info[btn]))
+			return ERR_PTR(-ENODEV);
+	}
+
+	return button_info;
+}
+
 static int soc_button_remove(struct platform_device *pdev)
 {
 	struct soc_button_data *priv = platform_get_drvdata(pdev);
@@ -167,11 +312,18 @@ static int soc_button_probe(struct platform_device *pdev)
 	if (!id)
 		return -ENODEV;
 
-	button_info = (struct soc_button_info *)id->driver_data;
+	if (!id->driver_data) {
+		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;
+	}
 
-	if (gpiod_count(dev, KBUILD_MODNAME) <= 0) {
+	error = gpiod_count(dev, NULL);
+	if (error < 0) {
 		dev_dbg(dev, "no GPIO attached, ignoring...\n");
-		return -ENODEV;
+		return error;
 	}
 
 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
@@ -197,9 +349,17 @@ static int soc_button_probe(struct platform_device *pdev)
 	if (!priv->children[0] && !priv->children[1])
 		return -ENODEV;
 
+	if (!id->driver_data)
+		devm_kfree(dev, button_info);
+
 	return 0;
 }
 
+/*
+ * 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
+ * Platforms"
+ */
 static struct soc_button_info soc_button_PNP0C40[] = {
 	{ "power", 0, EV_KEY, KEY_POWER, false, true },
 	{ "home", 1, EV_KEY, KEY_LEFTMETA, false, true },
@@ -211,6 +371,7 @@ static struct soc_button_info soc_button_PNP0C40[] = {
 
 static const struct acpi_device_id soc_button_acpi_match[] = {
 	{ "PNP0C40", (unsigned long)soc_button_PNP0C40 },
+	{ "ACPI0011", 0 },
 	{ }
 };