[PATCH v1 4/4] i2c-mux: i2c_add_mux_adapter() should use -1 for auto bus num

[Doug Anderson <dianders@chromium.org>]

The force_nr parameter to i2c_add_mux_adapter() uses 0 to signify that
we don't want to force the bus number of the adapter.  This is
non-ideal because:
* 0 is actually a valid bus number to request
* i2c_add_numbered_adapter() (which i2c_add_mux_adapter() calls) uses
  -1 to mean the same thing.  That means extra logic in
  i2c_add_mux_adapter().

Fix i2c_add_mux_adapter() to use -1 and update all mux drivers
accordingly.

Signed-off-by: Doug Anderson <dianders@chromium.org>
---
Notes:
- If there's a good reason that force_nr uses 0 for auto then feel
  free to drop this patch.  I've place it at the end of the series to
  make it easy to just drop it.

 drivers/i2c/i2c-mux.c               | 10 +++-------
 drivers/i2c/muxes/i2c-arbitrator.c  |  2 +-
 drivers/i2c/muxes/i2c-mux-gpio.c    |  2 +-
 drivers/i2c/muxes/i2c-mux-pca9541.c |  2 +-
 drivers/i2c/muxes/i2c-mux-pca954x.c |  2 +-
 drivers/i2c/muxes/i2c-mux-pinctrl.c |  4 ++--
 include/linux/i2c-mux.h             |  2 +-
 7 files changed, 10 insertions(+), 14 deletions(-)

diff --git a/drivers/i2c/i2c-mux.c b/drivers/i2c/i2c-mux.c
index d94e0ce..8ad1a56 100644
--- a/drivers/i2c/i2c-mux.c
+++ b/drivers/i2c/i2c-mux.c
@@ -103,7 +103,7 @@ static unsigned int i2c_mux_parent_classes(struct i2c_adapter *parent)
 
 struct i2c_adapter *i2c_add_mux_adapter(struct i2c_adapter *parent,
 				struct device *mux_dev,
-				void *mux_priv, u32 force_nr, u32 chan_id,
+				void *mux_priv, int force_nr, u32 chan_id,
 				unsigned int class,
 				int (*select) (struct i2c_adapter *,
 					       void *, u32),
@@ -168,12 +168,8 @@ struct i2c_adapter *i2c_add_mux_adapter(struct i2c_adapter *parent,
 		}
 	}
 
-	if (force_nr) {
-		priv->adap.nr = force_nr;
-		ret = i2c_add_numbered_adapter(&priv->adap);
-	} else {
-		ret = i2c_add_adapter(&priv->adap);
-	}
+	priv->adap.nr = force_nr;
+	ret = i2c_add_numbered_adapter(&priv->adap);
 	if (ret < 0) {
 		dev_err(&parent->dev,
 			"failed to add mux-adapter (error=%d)\n",
diff --git a/drivers/i2c/muxes/i2c-arbitrator.c b/drivers/i2c/muxes/i2c-arbitrator.c
index c3bbdf7..89d0d06 100644
--- a/drivers/i2c/muxes/i2c-arbitrator.c
+++ b/drivers/i2c/muxes/i2c-arbitrator.c
@@ -173,7 +173,7 @@ static int i2c_arbitrator_probe(struct platform_device *pdev)
 		arb->wait_free_us = 50000;
 
 	/* Actually add the mux adapter */
-	arb->child = i2c_add_mux_adapter(arb->parent, &pdev->dev, arb, 0, 0, 0,
+	arb->child = i2c_add_mux_adapter(arb->parent, &pdev->dev, arb, -1, 0, 0,
 					 i2c_arbitrator_select,
 					 i2c_arbitrator_deselect);
 	if (WARN_ON(!arb->child)) {
diff --git a/drivers/i2c/muxes/i2c-mux-gpio.c b/drivers/i2c/muxes/i2c-mux-gpio.c
index 9f50ef0..301ed0b 100644
--- a/drivers/i2c/muxes/i2c-mux-gpio.c
+++ b/drivers/i2c/muxes/i2c-mux-gpio.c
@@ -208,7 +208,7 @@ static int i2c_mux_gpio_probe(struct platform_device *pdev)
 	}
 
 	for (i = 0; i < mux->data.n_values; i++) {
-		u32 nr = mux->data.base_nr ? (mux->data.base_nr + i) : 0;
+		int nr = mux->data.base_nr ? (mux->data.base_nr + i) : -1;
 		unsigned int class = mux->data.classes ? mux->data.classes[i] : 0;
 
 		mux->adap[i] = i2c_add_mux_adapter(parent, &pdev->dev, mux, nr,
diff --git a/drivers/i2c/muxes/i2c-mux-pca9541.c b/drivers/i2c/muxes/i2c-mux-pca9541.c
index f3b8f9a..a58b3c2 100644
--- a/drivers/i2c/muxes/i2c-mux-pca9541.c
+++ b/drivers/i2c/muxes/i2c-mux-pca9541.c
@@ -350,7 +350,7 @@ static int pca9541_probe(struct i2c_client *client,
 
 	/* Create mux adapter */
 
-	force = 0;
+	force = -1;
 	if (pdata)
 		force = pdata->modes[0].adap_id;
 	data->mux_adap = i2c_add_mux_adapter(adap, &client->dev, client,
diff --git a/drivers/i2c/muxes/i2c-mux-pca954x.c b/drivers/i2c/muxes/i2c-mux-pca954x.c
index 8e43872..4663ce6 100644
--- a/drivers/i2c/muxes/i2c-mux-pca954x.c
+++ b/drivers/i2c/muxes/i2c-mux-pca954x.c
@@ -215,7 +215,7 @@ static int pca954x_probe(struct i2c_client *client,
 
 	/* Now create an adapter for each channel */
 	for (num = 0; num < chips[data->type].nchans; num++) {
-		force = 0;			  /* dynamic adap number */
+		force = -1;			  /* dynamic adap number */
 		class = 0;			  /* no class by default */
 		if (pdata) {
 			if (num < pdata->num_modes) {
diff --git a/drivers/i2c/muxes/i2c-mux-pinctrl.c b/drivers/i2c/muxes/i2c-mux-pinctrl.c
index a43c0ce..401ff5d 100644
--- a/drivers/i2c/muxes/i2c-mux-pinctrl.c
+++ b/drivers/i2c/muxes/i2c-mux-pinctrl.c
@@ -217,8 +217,8 @@ static int i2c_mux_pinctrl_probe(struct platform_device *pdev)
 	}
 
 	for (i = 0; i < mux->pdata->bus_count; i++) {
-		u32 bus = mux->pdata->base_bus_num ?
-				(mux->pdata->base_bus_num + i) : 0;
+		int bus = mux->pdata->base_bus_num ?
+				(mux->pdata->base_bus_num + i) : -1;
 
 		mux->busses[i] = i2c_add_mux_adapter(mux->parent, &pdev->dev,
 						     mux, bus, i, 0,
diff --git a/include/linux/i2c-mux.h b/include/linux/i2c-mux.h
index 40cb05a..a7bfb55 100644
--- a/include/linux/i2c-mux.h
+++ b/include/linux/i2c-mux.h
@@ -35,7 +35,7 @@
  */
 struct i2c_adapter *i2c_add_mux_adapter(struct i2c_adapter *parent,
 				struct device *mux_dev,
-				void *mux_priv, u32 force_nr, u32 chan_id,
+				void *mux_priv, int force_nr, u32 chan_id,
 				unsigned int class,
 				int (*select) (struct i2c_adapter *,
 					       void *mux_dev, u32 chan_id),
-- 
1.8.1