From 70762abb9f89d97603a04cc3438988ca0cf886eb Mon Sep 17 00:00:00 2001 From: Jarkko Nikula Date: Thu, 14 Nov 2013 14:03:52 +0200 Subject: [PATCH] i2c: Use stable dev_name for ACPI enumerated I2C slaves Current I2C adapter id - client address "x-00yy" based device naming scheme is not always stable enough to be used in name based matching, for instance within ALSA SoC subsystem. This is problematic in PC kind of platforms where I2C adapter numbers can change due variable amount of bus controllers, probe order, add-on cards or just because of BIOS settings. This patch addresses the problem by using the ACPI device name with "i2c-" prefix for ACPI enumerated I2C slaves. For them device name "x-00yz" becomes "i2c-INTABCD:ij" after this patch. Signed-off-by: Jarkko Nikula Acked-by: Wolfram Sang Signed-off-by: Rafael J. Wysocki --- drivers/i2c/i2c-core.c | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index f74af33f5ddc..bc9a294c07f7 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -618,6 +618,22 @@ void i2c_unlock_adapter(struct i2c_adapter *adapter) } EXPORT_SYMBOL_GPL(i2c_unlock_adapter); +static void i2c_dev_set_name(struct i2c_adapter *adap, + struct i2c_client *client) +{ + struct acpi_device *adev = ACPI_COMPANION(&client->dev); + + if (adev) { + dev_set_name(&client->dev, "i2c-%s", acpi_dev_name(adev)); + return; + } + + /* For 10-bit clients, add an arbitrary offset to avoid collisions */ + dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap), + client->addr | ((client->flags & I2C_CLIENT_TEN) + ? 0xa000 : 0)); +} + /** * i2c_new_device - instantiate an i2c device * @adap: the adapter managing the device @@ -676,10 +692,7 @@ i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info) client->dev.of_node = info->of_node; ACPI_COMPANION_SET(&client->dev, info->acpi_node.companion); - /* For 10-bit clients, add an arbitrary offset to avoid collisions */ - dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap), - client->addr | ((client->flags & I2C_CLIENT_TEN) - ? 0xa000 : 0)); + i2c_dev_set_name(adap, client); status = device_register(&client->dev); if (status) goto out_err; -- 2.20.1