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]> --- 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 -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
