[PATCH 2/3] i2c-piix4: separate registration and probing code

[Andrew Armenia <andrew-Lwj1yN59in/Ib2jZbfQ/kQ@public.gmane.org>]

Some chipsets have multiple sets of SMBus registers each controlling a
separate SMBus. Supporting these chipsets properly will require registering
multiple I2C adapters for one piix4.

The code to initialize and register the i2c_adapter structure has been
separated from piix4_probe and allows registration of a piix4 adapter
given its base address. Note that the i2c_adapter and piix4_adapdata
structures are now dynamically allocated.

Signed-off-by: Andrew Armenia <andrew-Lwj1yN59in/Ib2jZbfQ/kQ@public.gmane.org>
---
 drivers/i2c/busses/i2c-piix4.c |   79 ++++++++++++++++++++++++++--------------
 1 file changed, 51 insertions(+), 28 deletions(-)

diff --git a/drivers/i2c/busses/i2c-piix4.c b/drivers/i2c/busses/i2c-piix4.c
index 7a5889c..8a87b3f 100644
--- a/drivers/i2c/busses/i2c-piix4.c
+++ b/drivers/i2c/busses/i2c-piix4.c
@@ -480,16 +480,6 @@ static const struct i2c_algorithm smbus_algorithm = {
 	.functionality	= piix4_func,
 };
 
-static struct i2c_adapter piix4_adapter = {
-	.owner		= THIS_MODULE,
-	.class		= I2C_CLASS_HWMON | I2C_CLASS_SPD,
-	.algo		= &smbus_algorithm,
-};
-
-static struct i2c_piix4_adapdata piix4_adapter_data = {
-	.smba		= 0,
-};
-
 static DEFINE_PCI_DEVICE_TABLE(piix4_ids) = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82371AB_3) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443MX_3) },
@@ -514,6 +504,48 @@ static DEFINE_PCI_DEVICE_TABLE(piix4_ids) = {
 
 MODULE_DEVICE_TABLE (pci, piix4_ids);
 
+static struct i2c_adapter *piix4_main_adapter;
+
+/* register piix4 I2C adapter at the given base address */
+static int piix4_add_adapter(struct pci_dev *dev, unsigned short smba,
+				struct i2c_adapter **padap) {
+	struct i2c_adapter *piix4_adapter;
+	struct i2c_piix4_adapdata *piix4_adapdata;
+	int retval;
+
+	piix4_adapter = kmalloc(sizeof(*piix4_adapter), GFP_KERNEL);
+	memset(piix4_adapter, 0, sizeof(*piix4_adapter));
+	piix4_adapter->owner = THIS_MODULE;
+	piix4_adapter->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
+	piix4_adapter->algo = &smbus_algorithm;
+
+	piix4_adapdata = kmalloc(sizeof(*piix4_adapdata), GFP_KERNEL);
+	memset(piix4_adapdata, 0, sizeof(*piix4_adapdata));
+	piix4_adapdata->smba = smba;
+
+	/* set up the sysfs linkage to our parent device */
+	piix4_adapter->dev.parent = &dev->dev;
+
+	snprintf(piix4_adapter->name, sizeof(piix4_adapter->name),
+		"SMBus PIIX4 adapter at %04x", smba);
+
+	piix4_adapdata->smba = smba;
+
+	i2c_set_adapdata(piix4_adapter, piix4_adapdata);
+
+	retval = i2c_add_adapter(piix4_adapter);
+	if (retval) {
+		dev_err(&dev->dev, "Couldn't register adapter!\n");
+		release_region(smba, SMBIOSIZE);
+		kfree(piix4_adapdata);
+		kfree(piix4_adapter);
+	}
+
+	*padap = piix4_adapter;
+
+	return retval;
+}
+
 static int __devinit piix4_probe(struct pci_dev *dev,
 				const struct pci_device_id *id)
 {
@@ -532,25 +564,10 @@ static int __devinit piix4_probe(struct pci_dev *dev,
 	if (retval)
 		return retval;
 
-	/* set up the sysfs linkage to our parent device */
-	piix4_adapter.dev.parent = &dev->dev;
-
-	snprintf(piix4_adapter.name, sizeof(piix4_adapter.name),
-		"SMBus PIIX4 adapter at %04x", smba);
-
-	piix4_adapter_data.smba = smba;
-
-	i2c_set_adapdata(&piix4_adapter, &piix4_adapter_data);
-
-	if ((retval = i2c_add_adapter(&piix4_adapter))) {
-		dev_err(&dev->dev, "Couldn't register adapter!\n");
-		release_region(smba, SMBIOSIZE);
-		piix4_adapter_data.smba = 0;
-	}
-
-	return retval;
+	return piix4_add_adapter(dev, smba, &piix4_main_adapter);
 }
 
+/* Remove the adapter and its associated IO region */
 static void piix4_adap_remove(struct i2c_adapter *adap)
 {
 	struct i2c_piix4_adapdata *adapdata;
@@ -561,11 +578,17 @@ static void piix4_adap_remove(struct i2c_adapter *adap)
 		release_region(adapdata->smba, SMBIOSIZE);
 		adapdata->smba = 0;
 	}
+
+	kfree(adapdata);
+	kfree(adap);
 }
 
 static void __devexit piix4_remove(struct pci_dev *dev)
 {
-	piix4_adap_remove(&piix4_adapter);
+	if (piix4_main_adapter) {
+		piix4_adap_remove(piix4_main_adapter);
+		piix4_main_adapter = NULL;
+	}
 }
 
 static struct pci_driver piix4_driver = {
-- 
1.7.10