This patch adds supports for I2C device enumeration and removal via
ACPI reconfiguration notifications that are send as a result of an
ACPI table load or unload operation.
Signed-off-by: Octavian Purdila <octavian.purdila@xxxxxxxxx>
---
drivers/i2c/i2c-core.c | 170 ++++++++++++++++++++++++++++++++++++++-----------
1 file changed, 132 insertions(+), 38 deletions(-)
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 0f2f848..5a340df 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -107,12 +107,11 @@ struct acpi_i2c_lookup {
acpi_handle device_handle;
};
-static int acpi_i2c_find_address(struct acpi_resource *ares, void *data)
+static int acpi_i2c_fill_info(struct acpi_resource *ares, void *data)
{
struct acpi_i2c_lookup *lookup = data;
struct i2c_board_info *info = lookup->info;
struct acpi_resource_i2c_serialbus *sb;
- acpi_handle adapter_handle;
acpi_status status;
if (info->addr || ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
@@ -122,80 +121,102 @@ static int acpi_i2c_find_address(struct acpi_resource *ares, void *data)
if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_I2C)
return 1;
- /*
- * Extract the ResourceSource and make sure that the handle matches
- * with the I2C adapter handle.
- */
status = acpi_get_handle(lookup->device_handle,
sb->resource_source.string_ptr,
- &adapter_handle);
- if (ACPI_SUCCESS(status) && adapter_handle == lookup->adapter_handle) {
- info->addr = sb->slave_address;
- if (sb->access_mode == ACPI_I2C_10BIT_MODE)
- info->flags |= I2C_CLIENT_TEN;
- }
+ &lookup->adapter_handle);
+ if (!ACPI_SUCCESS(status))
+ return 1;
+
+ info->addr = sb->slave_address;
+ if (sb->access_mode == ACPI_I2C_10BIT_MODE)
+ info->flags |= I2C_CLIENT_TEN;
return 1;
}
-static acpi_status acpi_i2c_add_device(acpi_handle handle, u32 level,
- void *data, void **return_value)
+static int acpi_i2c_get_info(struct acpi_device *adev,
+ struct i2c_board_info *info,
+ acpi_handle *adapter_handle)
{
- struct i2c_adapter *adapter = data;
struct list_head resource_list;
- struct acpi_i2c_lookup lookup;
struct resource_entry *entry;
- struct i2c_board_info info;
- struct acpi_device *adev;
+ struct acpi_i2c_lookup lookup;
int ret;
- if (acpi_bus_get_device(handle, &adev))
- return AE_OK;
- if (acpi_bus_get_status(adev) || !adev->status.present)
- return AE_OK;
+ if (acpi_bus_get_status(adev) || !adev->status.present ||
+ acpi_device_enumerated(adev))
+ return -EINVAL;
- memset(&info, 0, sizeof(info));
- info.fwnode = acpi_fwnode_handle(adev);
+ memset(info, 0, sizeof(*info));
+ info->fwnode = acpi_fwnode_handle(adev);
memset(&lookup, 0, sizeof(lookup));
- lookup.adapter_handle = ACPI_HANDLE(&adapter->dev);
- lookup.device_handle = handle;
- lookup.info = &info;
+ lookup.device_handle = acpi_device_handle(adev);
+ lookup.info = info;
- /*
- * Look up for I2cSerialBus resource with ResourceSource that
- * matches with this adapter.
- */
+ /* Look up for I2cSerialBus resource */
INIT_LIST_HEAD(&resource_list);
ret = acpi_dev_get_resources(adev, &resource_list,
- acpi_i2c_find_address, &lookup);
+ acpi_i2c_fill_info, &lookup);
acpi_dev_free_resource_list(&resource_list);
- if (ret < 0 || !info.addr)
- return AE_OK;
+ if (ret < 0 || !info->addr)
+ return -EINVAL;
+
+ *adapter_handle = lookup.adapter_handle;
/* Then fill IRQ number if any */
ret = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
if (ret < 0)
- return AE_OK;
+ return -EINVAL;
resource_list_for_each_entry(entry, &resource_list) {
if (resource_type(entry->res) == IORESOURCE_IRQ) {
- info.irq = entry->res->start;
+ info->irq = entry->res->start;
break;
}
}
acpi_dev_free_resource_list(&resource_list);
+ strlcpy(info->type, dev_name(&adev->dev), sizeof(info->type));
+
+ return 0;
+}
+
+static void acpi_i2c_register_device(struct i2c_adapter *adapter,
+ struct acpi_device *adev,
+ struct i2c_board_info *info)
+{
adev->power.flags.ignore_parent = true;
- strlcpy(info.type, dev_name(&adev->dev), sizeof(info.type));
- if (!i2c_new_device(adapter, &info)) {
+ adev->flags.visited = true;
+
+ if (!i2c_new_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 acpi_i2c_add_device(acpi_handle handle, u32 level,
+ void *data, void **return_value)
+{
+ struct i2c_adapter *adapter = data;
+ struct acpi_device *adev;
+ acpi_handle adapter_handle;
+ struct i2c_board_info info;
+
+ if (acpi_bus_get_device(handle, &adev))
+ return AE_OK;
+
+ if (acpi_i2c_get_info(adev, &info, &adapter_handle))
+ return AE_OK;
+
+ if (adapter_handle != ACPI_HANDLE(&adapter->dev))
+ return AE_OK;
+
+ acpi_i2c_register_device(adapter, adev, &info);
return AE_OK;
}
@@ -225,8 +246,77 @@ static void acpi_i2c_register_devices(struct i2c_adapter *adap)
dev_warn(&adap->dev, "failed to enumerate I2C slaves\n");
}
+static int acpi_i2c_match_adapter(struct device *dev, void *data)
+{
+ struct i2c_adapter *adapter = i2c_verify_adapter(dev);
+
+ if (!adapter)
+ return 0;
+
+ return ACPI_HANDLE(dev) == (acpi_handle)data;
+}
+
+static int acpi_i2c_match_device(struct device *dev, void *data)
+{
+ return ACPI_COMPANION(dev) == data;
+}
+
+static struct i2c_adapter *acpi_i2c_find_adapter_by_handle(acpi_handle handle)
+{
+ struct device *dev;
+
+ dev = bus_find_device(&i2c_bus_type, NULL, handle,
+ acpi_i2c_match_adapter);
+ return dev ? i2c_verify_adapter(dev) : NULL;
+}
+
+static struct i2c_client *acpi_i2c_find_client_by_adev(struct acpi_device *adev)
+{
+ struct device *dev;
+
+ dev = bus_find_device(&i2c_bus_type, NULL, adev, acpi_i2c_match_device);
+ return dev ? i2c_verify_client(dev) : NULL;
+}
+
+static int acpi_i2c_notify(struct notifier_block *nb, unsigned long value,
+ void *arg)
+{
+ struct acpi_device *adev = arg;
+ struct i2c_board_info info;
+ acpi_handle adapter_handle;
+ struct i2c_adapter *adapter;
+ struct i2c_client *client;
+
+ switch (value) {
+ case ACPI_RECONFIG_DEVICE_ADD:
+ if (acpi_i2c_get_info(adev, &info, &adapter_handle))
+ break;
+
+ adapter = acpi_i2c_find_adapter_by_handle(adapter_handle);
+ if (!adapter)
+ break;
+
+ acpi_i2c_register_device(adapter, adev, &info);
+ break;
+ case ACPI_RECONFIG_DEVICE_REMOVE:
+ client = acpi_i2c_find_client_by_adev(adev);
+ if (!client)
+ break;
+
+ i2c_unregister_device(client);
+ put_device(&client->dev);
+ break;
+ }
+
+ return NOTIFY_OK;
+}
+
+static struct notifier_block i2c_acpi_notifier = {
+ .notifier_call = acpi_i2c_notify,
+};
#else /* CONFIG_ACPI */
static inline void acpi_i2c_register_devices(struct i2c_adapter *adap) { }
+extern struct notifier_block i2c_acpi_notifier;
#endif /* CONFIG_ACPI */
#ifdef CONFIG_ACPI_I2C_OPREGION
@@ -2121,6 +2211,8 @@ static int __init i2c_init(void)
if (IS_ENABLED(CONFIG_OF_DYNAMIC))
WARN_ON(of_reconfig_notifier_register(&i2c_of_notifier));
+ if (IS_ENABLED(CONFIG_ACPI))
+ WARN_ON(acpi_reconfig_notifier_register(&i2c_acpi_notifier));
return 0;
@@ -2136,6 +2228,8 @@ bus_err:
static void __exit i2c_exit(void)
{
+ if (IS_ENABLED(CONFIG_ACPI))
+ WARN_ON(acpi_reconfig_notifier_unregister(&i2c_acpi_notifier));
if (IS_ENABLED(CONFIG_OF_DYNAMIC))
WARN_ON(of_reconfig_notifier_unregister(&i2c_of_notifier));
i2c_del_driver(&dummy_driver);
--
1.9.1
--
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