| Message ID | 1360778532-7480-4-git-send-email-dianders@chromium.org |
|---|---|
| State | Rejected |
| Headers | show |
On Wed, Feb 13, 2013 at 10:02:12AM -0800, Doug Anderson wrote: > 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; Maybe this should be: int bus = mux->pdata->base_bus_num >= 0 ? (mux->pdata->base_bus_num + i) : -1; Otherwise you still can not assign bus number 0 as 1st bus. Also, if base_bus_num ends up being provided as -1, the result would be pretty much unpredictable. Thanks, Guenter -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 02/13/2013 11:02 AM, Doug Anderson wrote: > 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. IIRC (and I only vaguely do...) it's because: > 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; Here, mux->data.base_nr is platform data (or copied directly from it), and any field in a platform data struct stored in a global variable not explicitly initialized would be 0, hence 0 would typically mean "no explicit bus number desired". Since a mux can't exist without a parent I2C bus, it's unlikely anyone would want a mux to be I2C bus 0, but rather the parent to have that number. -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, 13 Feb 2013 14:09:08 -0700, Stephen Warren wrote: > On 02/13/2013 11:02 AM, Doug Anderson wrote: > > 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. > > IIRC (and I only vaguely do...) it's because: > > > 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; > > Here, mux->data.base_nr is platform data (or copied directly from it), > and any field in a platform data struct stored in a global variable not > explicitly initialized would be 0, hence 0 would typically mean "no > explicit bus number desired". Since a mux can't exist without a parent > I2C bus, it's unlikely anyone would want a mux to be I2C bus 0, but > rather the parent to have that number. Yes, as I recall this is exactly the reason why the current code is the way it is.
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),
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(-)