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> Reviewed-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx> --- drivers/i2c/i2c-core.c | 172 ++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 134 insertions(+), 38 deletions(-) diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index af11b65..d083f17 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)) { + acpi_device_set_enumerated(adev); + + 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 @@ -1089,6 +1179,8 @@ void i2c_unregister_device(struct i2c_client *client) { if (client->dev.of_node) of_node_clear_flag(client->dev.of_node, OF_POPULATED); + if (ACPI_COMPANION(&client->dev)) + acpi_device_clear_enumerated(ACPI_COMPANION(&client->dev)); device_unregister(&client->dev); } EXPORT_SYMBOL_GPL(i2c_unregister_device); @@ -2117,6 +2209,8 @@ 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; @@ -2132,6 +2226,8 @@ 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); -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html