platform/chrome: chromeos_laptop - supply properties for ACPI devices

BayTrail-based and newer Chromebooks describe their peripherals in ACPI;
unfortunately their description is not complete, and peripherals
drivers, such as driver for Atmel Touch controllers, has to resort to
DMI-matching to configure the peripherals properly. To avoid polluting
peripheral driver code, let's teach chromeos_laptop driver to supply
missing data via generic device properties.

Note we supply "compatible" string for Atmel peripherals not because it is
needed for matching devices and driver (matching is still done on ACPI HID
entries), but because peripherals driver will be using presence of
"compatible" property to determine if device properties have been attached
to the device, and fail to bind if they are absent.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Benson Leung <bleung@chromium.org>
diff --git a/drivers/platform/chrome/chromeos_laptop.c b/drivers/platform/chrome/chromeos_laptop.c
index 5c47f45..3cecf79 100644
--- a/drivers/platform/chrome/chromeos_laptop.c
+++ b/drivers/platform/chrome/chromeos_laptop.c
@@ -6,6 +6,7 @@
 
 #define pr_fmt(fmt)		KBUILD_MODNAME ": " fmt
 
+#include <linux/acpi.h>
 #include <linux/dmi.h>
 #include <linux/i2c.h>
 #include <linux/input.h>
@@ -54,6 +55,11 @@
 	struct i2c_client *client;
 };
 
+struct acpi_peripheral {
+	char hid[ACPI_ID_LEN];
+	const struct property_entry *properties;
+};
+
 struct chromeos_laptop {
 	/*
 	 * Note that we can't mark this pointer as const because
@@ -61,6 +67,9 @@
 	 */
 	struct i2c_peripheral *i2c_peripherals;
 	unsigned int num_i2c_peripherals;
+
+	const struct acpi_peripheral *acpi_peripherals;
+	unsigned int num_acpi_peripherals;
 };
 
 static const struct chromeos_laptop *cros_laptop;
@@ -148,6 +157,38 @@
 	}
 }
 
+static bool chromeos_laptop_adjust_client(struct i2c_client *client)
+{
+	const struct acpi_peripheral *acpi_dev;
+	struct acpi_device_id acpi_ids[2] = { };
+	int i;
+	int error;
+
+	if (!has_acpi_companion(&client->dev))
+		return false;
+
+	for (i = 0; i < cros_laptop->num_acpi_peripherals; i++) {
+		acpi_dev = &cros_laptop->acpi_peripherals[i];
+
+		memcpy(acpi_ids[0].id, acpi_dev->hid, ACPI_ID_LEN);
+
+		if (acpi_match_device(acpi_ids, &client->dev)) {
+			error = device_add_properties(&client->dev,
+						      acpi_dev->properties);
+			if (error) {
+				dev_err(&client->dev,
+					"failed to add properties: %d\n",
+					error);
+				break;
+			}
+
+			return true;
+		}
+	}
+
+	return false;
+}
+
 static void chromeos_laptop_detach_i2c_client(struct i2c_client *client)
 {
 	struct i2c_peripheral *i2c_dev;
@@ -170,6 +211,8 @@
 	case BUS_NOTIFY_ADD_DEVICE:
 		if (dev->type == &i2c_adapter_type)
 			chromeos_laptop_check_adapter(to_i2c_adapter(dev));
+		else if (dev->type == &i2c_client_type)
+			chromeos_laptop_adjust_client(to_i2c_client(dev));
 		break;
 
 	case BUS_NOTIFY_REMOVED_DEVICE:
@@ -191,6 +234,12 @@
 	.num_i2c_peripherals	= ARRAY_SIZE(_name##_peripherals),	\
 }
 
+#define DECLARE_ACPI_CROS_LAPTOP(_name)					\
+static const struct chromeos_laptop _name __initconst = {		\
+	.acpi_peripherals	= _name##_peripherals,			\
+	.num_acpi_peripherals	= ARRAY_SIZE(_name##_peripherals),	\
+}
+
 static struct i2c_peripheral samsung_series_5_550_peripherals[] __initdata = {
 	/* Touchpad. */
 	{
@@ -234,16 +283,25 @@
 
 static const struct property_entry
 chromebook_pixel_trackpad_props[] __initconst = {
+	PROPERTY_ENTRY_STRING("compatible", "atmel,maxtouch"),
 	PROPERTY_ENTRY_U32_ARRAY("linux,gpio-keymap", chromebook_pixel_tp_keys),
 	{ }
 };
 
+static const struct property_entry
+chromebook_atmel_touchscreen_props[] __initconst = {
+	PROPERTY_ENTRY_STRING("compatible", "atmel,maxtouch"),
+	{ }
+};
+
 static struct i2c_peripheral chromebook_pixel_peripherals[] __initdata = {
 	/* Touch Screen. */
 	{
 		.board_info	= {
 			I2C_BOARD_INFO("atmel_mxt_ts",
 					ATMEL_TS_I2C_ADDR),
+			.properties	=
+				chromebook_atmel_touchscreen_props,
 			.flags		= I2C_CLIENT_WAKE,
 		},
 		.dmi_name	= "touchscreen",
@@ -354,6 +412,8 @@
 		.board_info	= {
 			I2C_BOARD_INFO("atmel_mxt_ts",
 					ATMEL_TS_I2C_ADDR),
+			.properties	=
+				chromebook_atmel_touchscreen_props,
 			.flags		= I2C_CLIENT_WAKE,
 		},
 		.dmi_name	= "touchscreen",
@@ -419,6 +479,47 @@
 };
 DECLARE_CROS_LAPTOP(cr48);
 
+static const u32 samus_touchpad_buttons[] __initconst = {
+	KEY_RESERVED,
+	KEY_RESERVED,
+	KEY_RESERVED,
+	BTN_LEFT
+};
+
+static const struct property_entry samus_trackpad_props[] __initconst = {
+	PROPERTY_ENTRY_STRING("compatible", "atmel,maxtouch"),
+	PROPERTY_ENTRY_U32_ARRAY("linux,gpio-keymap", samus_touchpad_buttons),
+	{ }
+};
+
+static struct acpi_peripheral samus_peripherals[] __initdata = {
+	/* Touchpad */
+	{
+		.hid		= "ATML0000",
+		.properties	= samus_trackpad_props,
+	},
+	/* Touchsceen */
+	{
+		.hid		= "ATML0001",
+		.properties	= chromebook_atmel_touchscreen_props,
+	},
+};
+DECLARE_ACPI_CROS_LAPTOP(samus);
+
+static struct acpi_peripheral generic_atmel_peripherals[] __initdata = {
+	/* Touchpad */
+	{
+		.hid		= "ATML0000",
+		.properties	= chromebook_pixel_trackpad_props,
+	},
+	/* Touchsceen */
+	{
+		.hid		= "ATML0001",
+		.properties	= chromebook_atmel_touchscreen_props,
+	},
+};
+DECLARE_ACPI_CROS_LAPTOP(generic_atmel);
+
 static const struct dmi_system_id chromeos_laptop_dmi_table[] __initconst = {
 	{
 		.ident = "Samsung Series 5 550",
@@ -502,17 +603,64 @@
 		},
 		.driver_data = (void *)&cr48,
 	},
+	/* Devices with peripherals incompletely described in ACPI */
+	{
+		.ident = "Chromebook Pro",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Google"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "Caroline"),
+		},
+		.driver_data = (void *)&samus,
+	},
+	{
+		.ident = "Google Pixel 2 (2015)",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "GOOGLE"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "Samus"),
+		},
+		.driver_data = (void *)&samus,
+	},
+	{
+		/*
+		 * Other Chromebooks with Atmel touch controllers:
+		 * - Celes, Winky (touchpad)
+		 * - Clapper, Expresso, Rambi, Glimmer (touchscreen)
+		 */
+		.ident = "Other Chromebook",
+		.matches = {
+			/*
+			 * This will match all Google devices, not only devices
+			 * with Atmel, but we will validate that the device
+			 * actually has matching peripherals.
+			 */
+			DMI_MATCH(DMI_SYS_VENDOR, "GOOGLE"),
+		},
+		.driver_data = (void *)&generic_atmel,
+	},
 	{ }
 };
 MODULE_DEVICE_TABLE(dmi, chromeos_laptop_dmi_table);
 
-static int __init chromeos_laptop_scan_adapter(struct device *dev, void *data)
+static int __init chromeos_laptop_scan_peripherals(struct device *dev, void *data)
 {
-	struct i2c_adapter *adapter;
+	int error;
 
-	adapter = i2c_verify_adapter(dev);
-	if (adapter)
-		chromeos_laptop_check_adapter(adapter);
+	if (dev->type == &i2c_adapter_type) {
+		chromeos_laptop_check_adapter(to_i2c_adapter(dev));
+	} else if (dev->type == &i2c_client_type) {
+		if (chromeos_laptop_adjust_client(to_i2c_client(dev))) {
+			/*
+			 * Now that we have needed properties re-trigger
+			 * driver probe in case driver was initialized
+			 * earlier and probe failed.
+			 */
+			error = device_attach(dev);
+			if (error < 0)
+				dev_warn(dev,
+					 "%s: device_attach() failed: %d\n",
+					 __func__, error);
+		}
+	}
 
 	return 0;
 }
@@ -556,27 +704,24 @@
 	return 0;
 }
 
-static struct chromeos_laptop * __init
-chromeos_laptop_prepare(const struct chromeos_laptop *src)
+static int __init
+chromeos_laptop_prepare_i2c_peripherals(struct chromeos_laptop *cros_laptop,
+					const struct chromeos_laptop *src)
 {
-	struct chromeos_laptop *cros_laptop;
 	struct i2c_peripheral *i2c_dev;
 	struct i2c_board_info *info;
-	int error;
 	int i;
+	int error;
 
-	cros_laptop = kzalloc(sizeof(*cros_laptop), GFP_KERNEL);
-	if (!cros_laptop)
-		return ERR_PTR(-ENOMEM);
+	if (!src->num_i2c_peripherals)
+		return 0;
 
 	cros_laptop->i2c_peripherals = kmemdup(src->i2c_peripherals,
 					       src->num_i2c_peripherals *
 						sizeof(*src->i2c_peripherals),
 					       GFP_KERNEL);
-	if (!cros_laptop->i2c_peripherals) {
-		error = -ENOMEM;
-		goto err_free_cros_laptop;
-	}
+	if (!cros_laptop->i2c_peripherals)
+		return -ENOMEM;
 
 	cros_laptop->num_i2c_peripherals = src->num_i2c_peripherals;
 
@@ -586,7 +731,7 @@
 
 		error = chromeos_laptop_setup_irq(i2c_dev);
 		if (error)
-			goto err_destroy_cros_peripherals;
+			goto err_out;
 
 		/* We need to deep-copy properties */
 		if (info->properties) {
@@ -594,14 +739,14 @@
 				property_entries_dup(info->properties);
 			if (IS_ERR(info->properties)) {
 				error = PTR_ERR(info->properties);
-				goto err_destroy_cros_peripherals;
+				goto err_out;
 			}
 		}
 	}
 
-	return cros_laptop;
+	return 0;
 
-err_destroy_cros_peripherals:
+err_out:
 	while (--i >= 0) {
 		i2c_dev = &cros_laptop->i2c_peripherals[i];
 		info = &i2c_dev->board_info;
@@ -609,13 +754,74 @@
 			property_entries_free(info->properties);
 	}
 	kfree(cros_laptop->i2c_peripherals);
-err_free_cros_laptop:
-	kfree(cros_laptop);
-	return ERR_PTR(error);
+	return error;
+}
+
+static int __init
+chromeos_laptop_prepare_acpi_peripherals(struct chromeos_laptop *cros_laptop,
+					const struct chromeos_laptop *src)
+{
+	struct acpi_peripheral *acpi_peripherals;
+	struct acpi_peripheral *acpi_dev;
+	const struct acpi_peripheral *src_dev;
+	int n_peripherals = 0;
+	int i;
+	int error;
+
+	for (i = 0; i < src->num_acpi_peripherals; i++) {
+		if (acpi_dev_present(src->acpi_peripherals[i].hid, NULL, -1))
+			n_peripherals++;
+	}
+
+	if (!n_peripherals)
+		return 0;
+
+	acpi_peripherals = kcalloc(n_peripherals,
+				   sizeof(*src->acpi_peripherals),
+				   GFP_KERNEL);
+	if (!acpi_peripherals)
+		return -ENOMEM;
+
+	acpi_dev = acpi_peripherals;
+	for (i = 0; i < src->num_acpi_peripherals; i++) {
+		src_dev = &src->acpi_peripherals[i];
+		if (!acpi_dev_present(src_dev->hid, NULL, -1))
+			continue;
+
+		*acpi_dev = *src_dev;
+
+		/* We need to deep-copy properties */
+		if (src_dev->properties) {
+			acpi_dev->properties =
+				property_entries_dup(src_dev->properties);
+			if (IS_ERR(acpi_dev->properties)) {
+				error = PTR_ERR(acpi_dev->properties);
+				goto err_out;
+			}
+		}
+
+		acpi_dev++;
+	}
+
+	cros_laptop->acpi_peripherals = acpi_peripherals;
+	cros_laptop->num_acpi_peripherals = n_peripherals;
+
+	return 0;
+
+err_out:
+	while (--i >= 0) {
+		acpi_dev = &acpi_peripherals[i];
+		if (acpi_dev->properties)
+			property_entries_free(acpi_dev->properties);
+	}
+
+	kfree(acpi_peripherals);
+	return error;
 }
 
 static void chromeos_laptop_destroy(const struct chromeos_laptop *cros_laptop)
 {
+	const struct acpi_peripheral *acpi_dev;
 	struct i2c_peripheral *i2c_dev;
 	struct i2c_board_info *info;
 	int i;
@@ -631,10 +837,41 @@
 			property_entries_free(info->properties);
 	}
 
+	for (i = 0; i < cros_laptop->num_acpi_peripherals; i++) {
+		acpi_dev = &cros_laptop->acpi_peripherals[i];
+
+		if (acpi_dev->properties)
+			property_entries_free(acpi_dev->properties);
+	}
+
 	kfree(cros_laptop->i2c_peripherals);
+	kfree(cros_laptop->acpi_peripherals);
 	kfree(cros_laptop);
 }
 
+static struct chromeos_laptop * __init
+chromeos_laptop_prepare(const struct chromeos_laptop *src)
+{
+	struct chromeos_laptop *cros_laptop;
+	int error;
+
+	cros_laptop = kzalloc(sizeof(*cros_laptop), GFP_KERNEL);
+	if (!cros_laptop)
+		return ERR_PTR(-ENOMEM);
+
+	error = chromeos_laptop_prepare_i2c_peripherals(cros_laptop, src);
+	if (!error)
+		error = chromeos_laptop_prepare_acpi_peripherals(cros_laptop,
+								 src);
+
+	if (error) {
+		chromeos_laptop_destroy(cros_laptop);
+		return ERR_PTR(error);
+	}
+
+	return cros_laptop;
+}
+
 static int __init chromeos_laptop_init(void)
 {
 	const struct dmi_system_id *dmi_id;
@@ -652,21 +889,33 @@
 	if (IS_ERR(cros_laptop))
 		return PTR_ERR(cros_laptop);
 
+	if (!cros_laptop->num_i2c_peripherals &&
+	    !cros_laptop->num_acpi_peripherals) {
+		pr_debug("no relevant devices detected\n");
+		error = -ENODEV;
+		goto err_destroy_cros_laptop;
+	}
+
 	error = bus_register_notifier(&i2c_bus_type,
 				      &chromeos_laptop_i2c_notifier);
 	if (error) {
-		pr_err("failed to register i2c bus notifier: %d\n", error);
-		chromeos_laptop_destroy(cros_laptop);
-		return error;
+		pr_err("failed to register i2c bus notifier: %d\n",
+		       error);
+		goto err_destroy_cros_laptop;
 	}
 
 	/*
-	 * Scan adapters that have been registered before we installed
-	 * the notifier to make sure we do not miss any devices.
+	 * Scan adapters that have been registered and clients that have
+	 * been created before we installed the notifier to make sure
+	 * we do not miss any devices.
 	 */
-	i2c_for_each_dev(NULL, chromeos_laptop_scan_adapter);
+	i2c_for_each_dev(NULL, chromeos_laptop_scan_peripherals);
 
 	return 0;
+
+err_destroy_cros_laptop:
+	chromeos_laptop_destroy(cros_laptop);
+	return error;
 }
 
 static void __exit chromeos_laptop_exit(void)