--- zzzz-none-000/linux-3.10.107/sound/ppc/keywest.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/sound/ppc/keywest.c	2021-02-04 17:41:59.000000000 +0000
@@ -22,6 +22,7 @@
 #include <linux/init.h>
 #include <linux/i2c.h>
 #include <linux/delay.h>
+#include <linux/module.h>
 #include <sound/core.h>
 #include "pmac.h"
 
@@ -31,10 +32,15 @@
  */
 static struct pmac_keywest *keywest_ctx;
 
+static bool keywest_probed;
 
 static int keywest_probe(struct i2c_client *client,
 			 const struct i2c_device_id *id)
 {
+	keywest_probed = true;
+	/* If instantiated via i2c-powermac, we still need to set the client */
+	if (!keywest_ctx->client)
+		keywest_ctx->client = client;
 	i2c_set_clientdata(client, keywest_ctx);
 	return 0;
 }
@@ -52,7 +58,7 @@
 		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);
@@ -65,7 +71,7 @@
 	 * already bound. If not it means binding failed, and then there
 	 * is no point in keeping the device instantiated.
 	 */
-	if (!keywest_ctx->client->driver) {
+	if (!keywest_ctx->client->dev.driver) {
 		i2c_unregister_device(keywest_ctx->client);
 		keywest_ctx->client = NULL;
 		return -ENODEV;
@@ -76,7 +82,7 @@
 	 * This is safe because i2c-core holds the core_lock mutex for us.
 	 */
 	list_add_tail(&keywest_ctx->client->detected,
-		      &keywest_ctx->client->driver->clients);
+		      &to_i2c_driver(keywest_ctx->client->dev.driver)->clients);
 	return 0;
 }
 
@@ -92,15 +98,16 @@
 
 
 static const struct i2c_device_id keywest_i2c_id[] = {
-	{ "keywest", 0 },
+	{ "MAC,tas3004", 0 },		/* instantiated by i2c-powermac */
+	{ "keywest", 0 },		/* instantiated by us if needed */
 	{ }
 };
+MODULE_DEVICE_TABLE(i2c, keywest_i2c_id);
 
 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 +139,37 @@
 /* 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;
+
+	/* There was already a device from i2c-powermac. Great, let's return */
+	if (keywest_probed)
+		return 0;
+
+	/* We assume Macs have consecutive I2C bus numbers starting at 0 */
+	while (adap) {
+		/* Scan for devices to be bound to */
+		err = keywest_attach_adapter(adap);
+		if (!err)
+			return 0;
+		i2c_put_adapter(adap);
+		adap = i2c_get_adapter(++i);
+	}
+
+	return -ENODEV;
 }