Find i801 i2c_adapter in other module

I have a Thecus N5550 NAS, on which I run CentOS 6.4. I have created a "board info" module which sets up the system's GPIOs and LEDs.

https://github.com/ipilcher/n5550/blob/master/modules/n5550_board.c

Some of the LEDs are driven by a couple of NXP PCA9532 dimmers, which are connected to the i801 SMBus. I am currently hardcoding the bus number, which is fragile. If the drivers are loaded in a different order, as they are on Debian, the bus gets a different number, and the module doesn't work.

#define N5550_PCA9532_I2C_BUS 5

static int __init n5550_pca9532_setup(void)

{
	struct i2c_adapter *adapter;

	adapter = i2c_get_adapter(N5550_PCA9532_I2C_BUS);
	if (adapter == NULL) {
		return -ENOMEM;
	}

	n5550_pca9532_0_client = i2c_new_device(adapter, &n5550_pca9532_0_info);
	if (n5550_pca9532_0_client == NULL) {
		i2c_put_adapter(adapter);
		return -ENOMEM;
	}

	n5550_pca9532_1_client = i2c_new_device(adapter, &n5550_pca9532_1_info);
	if (n5550_pca9532_1_client == NULL) {
		i2c_unregister_device(n5550_pca9532_0_client);
		i2c_put_adapter(adapter);
		return -ENOMEM;
	}

	i2c_put_adapter(adapter);
	return 0;
}

What is the best way to get the correct i2c_adapter, either by driver name or PCI address?

Thanks!

========================================================================
Ian Pilcher                                         [email protected]
           Sent from the cloud -- where it's already tomorrow
========================================================================