On Tue, Apr 17, 2012 at 12:49:04PM -0600, Stephen Warren wrote: > From: Stephen Warren <[email protected]> > > * Define core portions of the DT binding for I2C bus muxes. > * Enhance i2c_add_mux_adapter(): > ** Add parameters required for DT support. Update all callers. > ** Set the appropriate adap->dev.of_node for the child bus. > ** Call of_i2c_register_devices() for the child bus. > > Signed-off-by: Stephen Warren <[email protected]>
David Daney (CCed) posted another variant [1]. Just looking at the patches (and not really using them), I tend to like the approach using <reg> better. But I am open for discussion, so I'd appreciate your feedback. Regards, Wolfram [1] http://lkml.org/lkml/2012/4/12/423 > --- > Note: This series depends on the 3 patches I just sent that affect > of_find_i2c_device_by_node and implement of_find_i2c_adapter_by_node. > It might be useful to put this patch (and the others I sent) in > a separate tree so it can be merged into any SoC trees that wish to use > this new feature. > > Documentation/devicetree/bindings/i2c/i2cmux.txt | 45 > ++++++++++++++++++++++ > drivers/i2c/i2c-mux.c | 23 +++++++++++- > drivers/i2c/muxes/gpio-i2cmux.c | 5 +- > drivers/i2c/muxes/pca9541.c | 4 +- > drivers/i2c/muxes/pca954x.c | 4 +- > include/linux/i2c-mux.h | 4 +- > 6 files changed, 77 insertions(+), 8 deletions(-) > create mode 100644 Documentation/devicetree/bindings/i2c/i2cmux.txt > > diff --git a/Documentation/devicetree/bindings/i2c/i2cmux.txt > b/Documentation/devicetree/bindings/i2c/i2cmux.txt > new file mode 100644 > index 0000000..1e4e2bc > --- /dev/null > +++ b/Documentation/devicetree/bindings/i2c/i2cmux.txt > @@ -0,0 +1,45 @@ > +Common I2C mux bindings > + > +An I2C mux is a device that connects a master I2C bus to one of a number of > +child I2C busses, under programmatic control. > + > +Each I2C mux may define the set of child busses it supports in a different > +way. Some devices may have a hard-coded set of child ports, whereas others > may > +support a varying set of child busses (especially when the bus mux is > +implemented using GPIOs or pin muxing). Any bindings required to represent > +this are the domain of the individual mux device. > + > +For each child bus, there shall be a node within the I2C mux's own node for > +that bus. This node will contain all the I2C devices on that bus, just like > +any other I2C bus. Each child bus shall be identified by some name. The set > +of child bus names is defined by the individual I2C mux's bindings. Bus names > +are used to construct the name of the bus's child node using the format > +i2c-bus-%s. Each child bus node needs the usual #address-cells and > #size-cells > +properties. > + > +Example: > + > + i2cmux { > + // properties here omitted from the example. > + > + i2c-bus-0 { > + #address-cells = <1>; > + #size-cells = <0>; > + > + eeprom { > + compatible = "eeprom"; > + reg = <0x50>; > + }; > + }; > + > + i2c-bus-1 { > + #address-cells = <1>; > + #size-cells = <0>; > + > + eeprom { > + compatible = "eeprom"; > + reg = <0x50>; > + }; > + }; > + }; > + > diff --git a/drivers/i2c/i2c-mux.c b/drivers/i2c/i2c-mux.c > index d7a4833..8adeeec 100644 > --- a/drivers/i2c/i2c-mux.c > +++ b/drivers/i2c/i2c-mux.c > @@ -24,6 +24,7 @@ > #include <linux/slab.h> > #include <linux/i2c.h> > #include <linux/i2c-mux.h> > +#include <linux/of_i2c.h> > > /* multiplexer per channel data */ > struct i2c_mux_priv { > @@ -86,8 +87,10 @@ static u32 i2c_mux_functionality(struct i2c_adapter *adap) > return parent->algo->functionality(parent); > } > > -struct i2c_adapter *i2c_add_mux_adapter(struct i2c_adapter *parent, > +struct i2c_adapter *i2c_add_mux_adapter(struct device *dev, > + struct i2c_adapter *parent, > void *mux_dev, u32 force_nr, u32 chan_id, > + const char *chan_name, > int (*select) (struct i2c_adapter *, > void *, u32), > int (*deselect) (struct i2c_adapter *, > @@ -124,6 +127,22 @@ struct i2c_adapter *i2c_add_mux_adapter(struct > i2c_adapter *parent, > priv->adap.algo_data = priv; > priv->adap.dev.parent = &parent->dev; > > + if (dev->of_node) { > + const char *name; > + > + if (chan_name) > + name = kasprintf(GFP_KERNEL, "i2c-bus-%s", > + chan_name); > + else > + name = kasprintf(GFP_KERNEL, "i2c-bus-%d", > + chan_id); > + > + priv->adap.dev.of_node = of_find_node_by_name(dev->of_node, > + name); > + > + kfree(name); > + } > + > if (force_nr) { > priv->adap.nr = force_nr; > ret = i2c_add_numbered_adapter(&priv->adap); > @@ -141,6 +160,8 @@ struct i2c_adapter *i2c_add_mux_adapter(struct > i2c_adapter *parent, > dev_info(&parent->dev, "Added multiplexed i2c bus %d\n", > i2c_adapter_id(&priv->adap)); > > + of_i2c_register_devices(&priv->adap); > + > return &priv->adap; > } > EXPORT_SYMBOL_GPL(i2c_add_mux_adapter); > diff --git a/drivers/i2c/muxes/gpio-i2cmux.c b/drivers/i2c/muxes/gpio-i2cmux.c > index e5fa695..7284c70 100644 > --- a/drivers/i2c/muxes/gpio-i2cmux.c > +++ b/drivers/i2c/muxes/gpio-i2cmux.c > @@ -105,8 +105,9 @@ static int __devinit gpiomux_probe(struct platform_device > *pdev) > for (i = 0; i < pdata->n_values; i++) { > u32 nr = pdata->base_nr ? (pdata->base_nr + i) : 0; > > - mux->adap[i] = i2c_add_mux_adapter(parent, mux, nr, i, > - gpiomux_select, deselect); > + mux->adap[i] = i2c_add_mux_adapter(&pdev->dev, parent, mux, nr, > + i, NULL, gpiomux_select, > + deselect); > if (!mux->adap[i]) { > ret = -ENODEV; > dev_err(&pdev->dev, "Failed to add adapter %d\n", i); > diff --git a/drivers/i2c/muxes/pca9541.c b/drivers/i2c/muxes/pca9541.c > index e0df9b6..e1777fb 100644 > --- a/drivers/i2c/muxes/pca9541.c > +++ b/drivers/i2c/muxes/pca9541.c > @@ -353,8 +353,8 @@ static int pca9541_probe(struct i2c_client *client, > force = 0; > if (pdata) > force = pdata->modes[0].adap_id; > - data->mux_adap = i2c_add_mux_adapter(adap, client, force, 0, > - pca9541_select_chan, > + data->mux_adap = i2c_add_mux_adapter(&client->dev, adap, client, force, > + 0, NULL, pca9541_select_chan, > pca9541_release_chan); > > if (data->mux_adap == NULL) { > diff --git a/drivers/i2c/muxes/pca954x.c b/drivers/i2c/muxes/pca954x.c > index 0e37ef2..736a803 100644 > --- a/drivers/i2c/muxes/pca954x.c > +++ b/drivers/i2c/muxes/pca954x.c > @@ -226,8 +226,8 @@ static int pca954x_probe(struct i2c_client *client, > } > > data->virt_adaps[num] = > - i2c_add_mux_adapter(adap, client, > - force, num, pca954x_select_chan, > + i2c_add_mux_adapter(&client->dev, adap, client, > + force, num, NULL, pca954x_select_chan, > (pdata && pdata->modes[num].deselect_on_exit) > ? pca954x_deselect_mux : NULL); > > diff --git a/include/linux/i2c-mux.h b/include/linux/i2c-mux.h > index 747f0cd..43fb11a 100644 > --- a/include/linux/i2c-mux.h > +++ b/include/linux/i2c-mux.h > @@ -33,8 +33,10 @@ > * and deselect callback functions to perform hardware-specific > * mux control. > */ > -struct i2c_adapter *i2c_add_mux_adapter(struct i2c_adapter *parent, > +struct i2c_adapter *i2c_add_mux_adapter(struct device *dev, > + struct i2c_adapter *parent, > void *mux_dev, u32 force_nr, u32 chan_id, > + const char *chan_name, > int (*select) (struct i2c_adapter *, > void *mux_dev, u32 chan_id), > int (*deselect) (struct i2c_adapter *, > -- > 1.7.0.4 > -- Pengutronix e.K. | Wolfram Sang | Industrial Linux Solutions | http://www.pengutronix.de/ |
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