ALSA: ppc: keywest: drop using attach adapter

As we now have deferred probing, we can use a custom mechanism and
finally get rid of this legacy interface from the i2c core.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Tested-by: Dan DeVoto <dand1972@yahoo.com>
Tested-by: Mark Elliott <txlitebeer@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/ppc/keywest.c

@@ -52,7 +52,7 @@ static int keywest_attach_adapter(struct i2c_adapter *adapter)
 		return -EINVAL;
 
 	if (strncmp(adapter->name, "mac-io", 6))
-		return 0; /* ignored */
+		return -EINVAL; /* ignored */
 
 	memset(&info, 0, sizeof(struct i2c_board_info));
 	strlcpy(info.type, "keywest", I2C_NAME_SIZE);
@@ -100,7 +100,6 @@ static struct i2c_driver keywest_driver = {
 	.driver = {
 		.name = "PMac Keywest Audio",
 	},
-	.attach_adapter = keywest_attach_adapter,
 	.probe = keywest_probe,
 	.remove = keywest_remove,
 	.id_table = keywest_i2c_id,
@@ -132,16 +131,32 @@ int snd_pmac_tumbler_post_init(void)
 /* exported */
 int snd_pmac_keywest_init(struct pmac_keywest *i2c)
 {
-	int err;
+	struct i2c_adapter *adap;
+	int err, i = 0;
 
 	if (keywest_ctx)
 		return -EBUSY;
 
+	adap = i2c_get_adapter(0);
+	if (!adap)
+		return -EPROBE_DEFER;
+
 	keywest_ctx = i2c;
 
 	if ((err = i2c_add_driver(&keywest_driver))) {
 		snd_printk(KERN_ERR "cannot register keywest i2c driver\n");
+		i2c_put_adapter(adap);
 		return err;
 	}
-	return 0;
+
+	/* We assume Macs have consecutive I2C bus numbers starting at 0 */
+	while (adap) {
+		err = keywest_attach_adapter(adap);
+		if (!err)
+			return 0;
+		i2c_put_adapter(adap);
+		adap = i2c_get_adapter(++i);
+	}
+
+	return -ENODEV;
 }