1 files changed, 159 insertions, 72 deletions

diff --git a/drivers/i2c/i2c-core-acpi.c b/drivers/i2c/i2c-core-acpi.c
index 2ade99b105b9..ed90858a27b7 100644
--- a/drivers/i2c/i2c-core-acpi.c
+++ b/drivers/i2c/i2c-core-acpi.c
@@ -26,7 +26,7 @@ struct gsb_buffer {
 	union {
 		u16	wdata;
 		u8	bdata;
-		u8	data[0];
+		DECLARE_FLEX_ARRAY(u8, data);
 	};
 } __packed;
 
@@ -69,6 +69,38 @@ bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
 }
 EXPORT_SYMBOL_GPL(i2c_acpi_get_i2c_resource);
 
+static int i2c_acpi_resource_count(struct acpi_resource *ares, void *data)
+{
+	struct acpi_resource_i2c_serialbus *sb;
+	int *count = data;
+
+	if (i2c_acpi_get_i2c_resource(ares, &sb))
+		*count = *count + 1;
+
+	return 1;
+}
+
+/**
+ * i2c_acpi_client_count - Count the number of I2cSerialBus resources
+ * @adev:	ACPI device
+ *
+ * Returns the number of I2cSerialBus resources in the ACPI-device's
+ * resource-list; or a negative error code.
+ */
+int i2c_acpi_client_count(struct acpi_device *adev)
+{
+	int ret, count = 0;
+	LIST_HEAD(r);
+
+	ret = acpi_dev_get_resources(adev, &r, i2c_acpi_resource_count, &count);
+	if (ret < 0)
+		return ret;
+
+	acpi_dev_free_resource_list(&r);
+	return count;
+}
+EXPORT_SYMBOL_GPL(i2c_acpi_client_count);
+
 static int i2c_acpi_fill_info(struct acpi_resource *ares, void *data)
 {
 	struct i2c_acpi_lookup *lookup = data;
@@ -105,6 +137,11 @@ static const struct acpi_device_id i2c_acpi_ignored_device_ids[] = {
 	{}
 };
 
+struct i2c_acpi_irq_context {
+	int irq;
+	bool wake_capable;
+};
+
 static int i2c_acpi_do_lookup(struct acpi_device *adev,
 			      struct i2c_acpi_lookup *lookup)
 {
@@ -112,9 +149,12 @@ static int i2c_acpi_do_lookup(struct acpi_device *adev,
 	struct list_head resource_list;
 	int ret;
 
-	if (acpi_bus_get_status(adev) || !adev->status.present)
+	if (acpi_bus_get_status(adev))
 		return -EINVAL;
 
+	if (!acpi_dev_ready_for_enumeration(adev))
+		return -ENODEV;
+
 	if (acpi_match_device_ids(adev, i2c_acpi_ignored_device_ids) == 0)
 		return -ENODEV;
 
@@ -133,13 +173,19 @@ static int i2c_acpi_do_lookup(struct acpi_device *adev,
 	return 0;
 }
 
-static int i2c_acpi_add_resource(struct acpi_resource *ares, void *data)
+static int i2c_acpi_add_irq_resource(struct acpi_resource *ares, void *data)
 {
-	int *irq = data;
+	struct i2c_acpi_irq_context *irq_ctx = data;
 	struct resource r;
 
-	if (*irq <= 0 && acpi_dev_resource_interrupt(ares, 0, &r))
-		*irq = i2c_dev_irq_from_resources(&r, 1);
+	if (irq_ctx->irq > 0)
+		return 1;
+
+	if (!acpi_dev_resource_interrupt(ares, 0, &r))
+		return 1;
+
+	irq_ctx->irq = i2c_dev_irq_from_resources(&r, 1);
+	irq_ctx->wake_capable = r.flags & IORESOURCE_IRQ_WAKECAPABLE;
 
 	return 1; /* No need to add resource to the list */
 }
@@ -147,31 +193,40 @@ static int i2c_acpi_add_resource(struct acpi_resource *ares, void *data)
 /**
  * i2c_acpi_get_irq - get device IRQ number from ACPI
  * @client: Pointer to the I2C client device
+ * @wake_capable: Set to true if the IRQ is wake capable
  *
  * Find the IRQ number used by a specific client device.
  *
  * Return: The IRQ number or an error code.
  */
-int i2c_acpi_get_irq(struct i2c_client *client)
+int i2c_acpi_get_irq(struct i2c_client *client, bool *wake_capable)
 {
 	struct acpi_device *adev = ACPI_COMPANION(&client->dev);
 	struct list_head resource_list;
-	int irq = -ENOENT;
+	struct i2c_acpi_irq_context irq_ctx = {
+		.irq = -ENOENT,
+	};
 	int ret;
 
 	INIT_LIST_HEAD(&resource_list);
 
 	ret = acpi_dev_get_resources(adev, &resource_list,
-				     i2c_acpi_add_resource, &irq);
+				     i2c_acpi_add_irq_resource, &irq_ctx);
 	if (ret < 0)
 		return ret;
 
 	acpi_dev_free_resource_list(&resource_list);
 
-	if (irq == -ENOENT)
-		irq = acpi_dev_gpio_irq_get(adev, 0);
+	if (irq_ctx.irq == -ENOENT)
+		irq_ctx.irq = acpi_dev_gpio_irq_wake_get(adev, 0, &irq_ctx.wake_capable);
+
+	if (irq_ctx.irq < 0)
+		return irq_ctx.irq;
+
+	if (wake_capable)
+		*wake_capable = irq_ctx.wake_capable;
 
-	return irq;
+	return irq_ctx.irq;
 }
 
 static int i2c_acpi_get_info(struct acpi_device *adev,
@@ -195,13 +250,14 @@ static int i2c_acpi_get_info(struct acpi_device *adev,
 
 	if (adapter) {
 		/* The adapter must match the one in I2cSerialBus() connector */
-		if (ACPI_HANDLE(&adapter->dev) != lookup.adapter_handle)
+		if (!device_match_acpi_handle(&adapter->dev, lookup.adapter_handle))
 			return -ENODEV;
 	} else {
 		struct acpi_device *adapter_adev;
 
 		/* The adapter must be present */
-		if (acpi_bus_get_device(lookup.adapter_handle, &adapter_adev))
+		adapter_adev = acpi_fetch_acpi_dev(lookup.adapter_handle);
+		if (!adapter_adev)
 			return -ENODEV;
 		if (acpi_bus_get_status(adapter_adev) ||
 		    !adapter_adev->status.present)
@@ -222,28 +278,28 @@ static void i2c_acpi_register_device(struct i2c_adapter *adapter,
 				     struct acpi_device *adev,
 				     struct i2c_board_info *info)
 {
+	/*
+	 * Skip registration on boards where the ACPI tables are
+	 * known to contain bogus I2C devices.
+	 */
+	if (acpi_quirk_skip_i2c_client_enumeration(adev))
+		return;
+
 	adev->power.flags.ignore_parent = true;
 	acpi_device_set_enumerated(adev);
 
-	if (IS_ERR(i2c_new_client_device(adapter, info))) {
+	if (IS_ERR(i2c_new_client_device(adapter, info)))
 		adev->power.flags.ignore_parent = false;
-		dev_err(&adapter->dev,
-			"failed to add I2C device %s from ACPI\n",
-			dev_name(&adev->dev));
-	}
 }
 
 static acpi_status i2c_acpi_add_device(acpi_handle handle, u32 level,
 				       void *data, void **return_value)
 {
 	struct i2c_adapter *adapter = data;
-	struct acpi_device *adev;
+	struct acpi_device *adev = acpi_fetch_acpi_dev(handle);
 	struct i2c_board_info info;
 
-	if (acpi_bus_get_device(handle, &adev))
-		return AE_OK;
-
-	if (i2c_acpi_get_info(adev, &info, adapter, NULL))
+	if (!adev || i2c_acpi_get_info(adev, &info, adapter, NULL))
 		return AE_OK;
 
 	i2c_acpi_register_device(adapter, adev, &info);
@@ -263,6 +319,7 @@ static acpi_status i2c_acpi_add_device(acpi_handle handle, u32 level,
  */
 void i2c_acpi_register_devices(struct i2c_adapter *adap)
 {
+	struct acpi_device *adev;
 	acpi_status status;
 
 	if (!has_acpi_companion(&adap->dev))
@@ -274,16 +331,15 @@ void i2c_acpi_register_devices(struct i2c_adapter *adap)
 				     adap, NULL);
 	if (ACPI_FAILURE(status))
 		dev_warn(&adap->dev, "failed to enumerate I2C slaves\n");
-}
 
-const struct acpi_device_id *
-i2c_acpi_match_device(const struct acpi_device_id *matches,
-		      struct i2c_client *client)
-{
-	if (!(client && matches))
-		return NULL;
+	if (!adap->dev.parent)
+		return;
+
+	adev = ACPI_COMPANION(adap->dev.parent);
+	if (!adev)
+		return;
 
-	return acpi_match_device(matches, &client->dev);
+	acpi_dev_clear_dependencies(adev);
 }
 
 static const struct acpi_device_id i2c_acpi_force_400khz_device_ids[] = {
@@ -299,16 +355,33 @@ static const struct acpi_device_id i2c_acpi_force_400khz_device_ids[] = {
 	{}
 };
 
+static const struct acpi_device_id i2c_acpi_force_100khz_device_ids[] = {
+	/*
+	 * When a 400KHz freq is used on this model of ELAN touchpad in Linux,
+	 * excessive smoothing (similar to when the touchpad's firmware detects
+	 * a noisy signal) is sometimes applied. As some devices' (e.g, Lenovo
+	 * V15 G4) ACPI tables specify a 400KHz frequency for this device and
+	 * some I2C busses (e.g, Designware I2C) default to a 400KHz freq,
+	 * force the speed to 100KHz as a workaround.
+	 *
+	 * For future investigation: This problem may be related to the default
+	 * HCNT/LCNT values given by some busses' drivers, because they are not
+	 * specified in the aforementioned devices' ACPI tables, and because
+	 * the device works without issues on Windows at what is expected to be
+	 * a 400KHz frequency. The root cause of the issue is not known.
+	 */
+	{ "DLL0945", 0 },
+	{ "ELAN06FA", 0 },
+	{}
+};
+
 static acpi_status i2c_acpi_lookup_speed(acpi_handle handle, u32 level,
 					   void *data, void **return_value)
 {
 	struct i2c_acpi_lookup *lookup = data;
-	struct acpi_device *adev;
+	struct acpi_device *adev = acpi_fetch_acpi_dev(handle);
 
-	if (acpi_bus_get_device(handle, &adev))
-		return AE_OK;
-
-	if (i2c_acpi_do_lookup(adev, lookup))
+	if (!adev || i2c_acpi_do_lookup(adev, lookup))
 		return AE_OK;
 
 	if (lookup->search_handle != lookup->adapter_handle)
@@ -320,6 +393,9 @@ static acpi_status i2c_acpi_lookup_speed(acpi_handle handle, u32 level,
 	if (acpi_match_device_ids(adev, i2c_acpi_force_400khz_device_ids) == 0)
 		lookup->force_speed = I2C_MAX_FAST_MODE_FREQ;
 
+	if (acpi_match_device_ids(adev, i2c_acpi_force_100khz_device_ids) == 0)
+		lookup->force_speed = I2C_MAX_STANDARD_MODE_FREQ;
+
 	return AE_OK;
 }
 
@@ -370,41 +446,31 @@ u32 i2c_acpi_find_bus_speed(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(i2c_acpi_find_bus_speed);
 
-static int i2c_acpi_find_match_adapter(struct device *dev, const void *data)
-{
-	struct i2c_adapter *adapter = i2c_verify_adapter(dev);
-
-	if (!adapter)
-		return 0;
-
-	return ACPI_HANDLE(dev) == (acpi_handle)data;
-}
-
 struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
 {
+	struct i2c_adapter *adapter;
 	struct device *dev;
 
-	dev = bus_find_device(&i2c_bus_type, NULL, handle,
-			      i2c_acpi_find_match_adapter);
+	dev = bus_find_device(&i2c_bus_type, NULL, handle, device_match_acpi_handle);
+	if (!dev)
+		return NULL;
+
+	adapter = i2c_verify_adapter(dev);
+	if (!adapter)
+		put_device(dev);
 
-	return dev ? i2c_verify_adapter(dev) : NULL;
+	return adapter;
 }
 EXPORT_SYMBOL_GPL(i2c_acpi_find_adapter_by_handle);
 
 static struct i2c_client *i2c_acpi_find_client_by_adev(struct acpi_device *adev)
 {
-	struct device *dev;
-	struct i2c_client *client;
-
-	dev = bus_find_device_by_acpi_dev(&i2c_bus_type, adev);
-	if (!dev)
-		return NULL;
-
-	client = i2c_verify_client(dev);
-	if (!client)
-		put_device(dev);
+	return i2c_find_device_by_fwnode(acpi_fwnode_handle(adev));
+}
 
-	return client;
+static struct i2c_adapter *i2c_acpi_find_adapter_by_adev(struct acpi_device *adev)
+{
+	return i2c_find_adapter_by_fwnode(acpi_fwnode_handle(adev));
 }
 
 static int i2c_acpi_notify(struct notifier_block *nb, unsigned long value,
@@ -426,17 +492,24 @@ static int i2c_acpi_notify(struct notifier_block *nb, unsigned long value,
 			break;
 
 		i2c_acpi_register_device(adapter, adev, &info);
+		put_device(&adapter->dev);
 		break;
 	case ACPI_RECONFIG_DEVICE_REMOVE:
 		if (!acpi_device_enumerated(adev))
 			break;
 
 		client = i2c_acpi_find_client_by_adev(adev);
-		if (!client)
-			break;
+		if (client) {
+			i2c_unregister_device(client);
+			put_device(&client->dev);
+		}
+
+		adapter = i2c_acpi_find_adapter_by_adev(adev);
+		if (adapter) {
+			acpi_unbind_one(&adapter->dev);
+			put_device(&adapter->dev);
+		}
 
-		i2c_unregister_device(client);
-		put_device(&client->dev);
 		break;
 	}
 
@@ -448,8 +521,8 @@ struct notifier_block i2c_acpi_notifier = {
 };
 
 /**
- * i2c_acpi_new_device - Create i2c-client for the Nth I2cSerialBus resource
- * @dev:     Device owning the ACPI resources to get the client from
+ * i2c_acpi_new_device_by_fwnode - Create i2c-client for the Nth I2cSerialBus resource
+ * @fwnode:  fwnode with the ACPI resources to get the client from
  * @index:   Index of ACPI resource to get
  * @info:    describes the I2C device; note this is modified (addr gets set)
  * Context: can sleep
@@ -465,15 +538,20 @@ struct notifier_block i2c_acpi_notifier = {
  * Returns a pointer to the new i2c-client, or error pointer in case of failure.
  * Specifically, -EPROBE_DEFER is returned if the adapter is not found.
  */
-struct i2c_client *i2c_acpi_new_device(struct device *dev, int index,
-				       struct i2c_board_info *info)
+struct i2c_client *i2c_acpi_new_device_by_fwnode(struct fwnode_handle *fwnode,
+						 int index,
+						 struct i2c_board_info *info)
 {
-	struct acpi_device *adev = ACPI_COMPANION(dev);
 	struct i2c_acpi_lookup lookup;
 	struct i2c_adapter *adapter;
+	struct acpi_device *adev;
 	LIST_HEAD(resource_list);
 	int ret;
 
+	adev = to_acpi_device_node(fwnode);
+	if (!adev)
+		return ERR_PTR(-ENODEV);
+
 	memset(&lookup, 0, sizeof(lookup));
 	lookup.info = info;
 	lookup.device_handle = acpi_device_handle(adev);
@@ -495,7 +573,17 @@ struct i2c_client *i2c_acpi_new_device(struct device *dev, int index,
 
 	return i2c_new_client_device(adapter, info);
 }
-EXPORT_SYMBOL_GPL(i2c_acpi_new_device);
+EXPORT_SYMBOL_GPL(i2c_acpi_new_device_by_fwnode);
+
+bool i2c_acpi_waive_d0_probe(struct device *dev)
+{
+	struct i2c_driver *driver = to_i2c_driver(dev->driver);
+	struct acpi_device *adev = ACPI_COMPANION(dev);
+
+	return driver->flags & I2C_DRV_ACPI_WAIVE_D0_PROBE &&
+		adev && adev->power.state_for_enumeration >= adev->power.state;
+}
+EXPORT_SYMBOL_GPL(i2c_acpi_waive_d0_probe);
 
 #ifdef CONFIG_ACPI_I2C_OPREGION
 static int acpi_gsb_i2c_read_bytes(struct i2c_client *client,
@@ -729,7 +817,6 @@ int i2c_acpi_install_space_handler(struct i2c_adapter *adapter)
 		return -ENOMEM;
 	}
 
-	acpi_walk_dep_device_list(handle);
 	return 0;
 }