[PATCH] i2c: Allow i2c_add_numbered_adapter() to assign a bus id.

[Grant Likely <grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org>]

Currently, if an i2c bus driver supports both static and dynamic bus
ids, it needs to choose between calling i2c_add_numbered_adapter() and
i2c_add_adapter().  This patch makes i2c_add_numbered_adapter()
redirect to i2c_add_adapter() if the requested bus id is -1.

Signed-off-by: Grant Likely <grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org>
---
 drivers/i2c/busses/i2c-cpm.c   |    7 ++-----
 drivers/i2c/busses/i2c-pxa.c   |    7 ++-----
 drivers/i2c/busses/i2c-s6000.c |    5 +----
 drivers/i2c/i2c-core.c         |    5 +++++
 4 files changed, 10 insertions(+), 14 deletions(-)

diff --git a/drivers/i2c/busses/i2c-cpm.c b/drivers/i2c/busses/i2c-cpm.c
index 3a20961..b1d9cd2 100644
--- a/drivers/i2c/busses/i2c-cpm.c
+++ b/drivers/i2c/busses/i2c-cpm.c
@@ -662,11 +662,8 @@ static int __devinit cpm_i2c_probe(struct platform_device *ofdev)
 	/* register new adapter to i2c module... */
 
 	data = of_get_property(ofdev->dev.of_node, "linux,i2c-index", &len);
-	if (data && len == 4) {
-		cpm->adap.nr = *data;
-		result = i2c_add_numbered_adapter(&cpm->adap);
-	} else
-		result = i2c_add_adapter(&cpm->adap);
+	cpm->adap.nr = (data && len == 4) ? be32_to_cpup(data) : -1;
+	result = i2c_add_numbered_adapter(&cpm->adap);
 
 	if (result < 0) {
 		dev_err(&ofdev->dev, "Unable to register with I2C\n");
diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
index f59224a..d603646 100644
--- a/drivers/i2c/busses/i2c-pxa.c
+++ b/drivers/i2c/busses/i2c-pxa.c
@@ -1079,7 +1079,7 @@ static int i2c_pxa_probe(struct platform_device *dev)
 	 * The reason to do so is to avoid sysfs names that only make
 	 * sense when there are multiple adapters.
 	 */
-	i2c->adap.nr = dev->id != -1 ? dev->id : 0;
+	i2c->adap.nr = dev->id;
 	snprintf(i2c->adap.name, sizeof(i2c->adap.name), "pxa_i2c-i2c.%u",
 		 i2c->adap.nr);
 
@@ -1142,10 +1142,7 @@ static int i2c_pxa_probe(struct platform_device *dev)
 	i2c->adap.dev.of_node = dev->dev.of_node;
 #endif
 
-	if (i2c_type == REGS_CE4100)
-		ret = i2c_add_adapter(&i2c->adap);
-	else
-		ret = i2c_add_numbered_adapter(&i2c->adap);
+	ret = i2c_add_numbered_adapter(&i2c->adap);
 	if (ret < 0) {
 		printk(KERN_INFO "I2C: Failed to add bus\n");
 		goto eadapt;
diff --git a/drivers/i2c/busses/i2c-s6000.c b/drivers/i2c/busses/i2c-s6000.c
index cb5d01e..c64ba73 100644
--- a/drivers/i2c/busses/i2c-s6000.c
+++ b/drivers/i2c/busses/i2c-s6000.c
@@ -341,10 +341,7 @@ static int __devinit s6i2c_probe(struct platform_device *dev)
 	i2c_wr16(iface, S6_I2C_TXTL, 0);
 
 	platform_set_drvdata(dev, iface);
-	if (bus_num < 0)
-		rc = i2c_add_adapter(p_adap);
-	else
-		rc = i2c_add_numbered_adapter(p_adap);
+	rc = i2c_add_numbered_adapter(p_adap);
 	if (rc)
 		goto err_irq_free;
 	return 0;
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 9a58994..131079a 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -925,6 +925,9 @@ EXPORT_SYMBOL(i2c_add_adapter);
  * or otherwise built in to the system's mainboard, and where i2c_board_info
  * is used to properly configure I2C devices.
  *
+ * If the requested bus number is set to -1, then this function will behave
+ * identically to i2c_add_adapter, and will dynamically assign a bus number.
+ *
  * If no devices have pre-been declared for this bus, then be sure to
  * register the adapter before any dynamically allocated ones.  Otherwise
  * the required bus ID may not be available.
@@ -940,6 +943,8 @@ int i2c_add_numbered_adapter(struct i2c_adapter *adap)
 	int	id;
 	int	status;
 
+	if (adap->nr == -1) /* -1 means dynamically assign bus id */
+		return i2c_add_adapter(adap);
 	if (adap->nr & ~MAX_ID_MASK)
 		return -EINVAL;