Hi Alexander, Thank you for the patch.
On Monday 15 December 2014 02:25:18 Alexander Sverdlin wrote: > of: i2c: Add DT bindings for idle states to PCA954x mux driver > > Introduce two new device tree bindings to specify idle state of PCA954x > family of I2C multiplexors: > - idle-state: specifies particular child bus to be selected in idle; > - idle-disconnect: signals that mux should disconnect all child buses in > idle; Could you please briefly explain your use case(s) for those two properties ? > Signed-off-by: Alexander Sverdlin <[email protected]> > --- > .../devicetree/bindings/i2c/i2c-mux-pca954x.txt | 3 + > drivers/i2c/muxes/i2c-mux-pca954x.c | 51 +++++++++++++++-- > 2 files changed, 48 insertions(+), 6 deletions(-) > > diff --git a/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt > b/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt index > 34a3fb6..1fbe287 100644 > --- a/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt > +++ b/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt > @@ -16,6 +16,9 @@ Required Properties: > Optional Properties: > > - reset-gpios: Reference to the GPIO connected to the reset input. > + - idle-state: Child bus connected in idle state (specified by its "reg" > value) + - idle-disconnect: Boolean; if defined, forces mux to disconnect > all children + in idle state > > > Example: > diff --git a/drivers/i2c/muxes/i2c-mux-pca954x.c > b/drivers/i2c/muxes/i2c-mux-pca954x.c index ec11b40..69cf603 100644 > --- a/drivers/i2c/muxes/i2c-mux-pca954x.c > +++ b/drivers/i2c/muxes/i2c-mux-pca954x.c > @@ -43,6 +43,7 @@ > #include <linux/module.h> > #include <linux/pm.h> > #include <linux/slab.h> > +#include <linux/of.h> Could you please keep headers sorted alphabetically ? > #define PCA954X_MAX_NCHANS 8 > > @@ -62,6 +63,8 @@ struct pca954x { > struct i2c_adapter *virt_adaps[PCA954X_MAX_NCHANS]; > > u8 last_chan; /* last register value */ > + bool idle_disconnect; > + s8 idle_chan; /* valid if not negative */ > }; > > struct chip_desc { > @@ -172,10 +175,20 @@ static int pca954x_deselect_mux(struct i2c_adapter > *adap, void *client, u32 chan) > { > struct pca954x *data = i2c_get_clientdata(client); > + struct pca954x_platform_data *pdata = > + dev_get_platdata(&((struct i2c_client *)client)->dev); > + > + if ((pdata && pdata->modes[chan].deselect_on_exit) || > + data->idle_disconnect) { I would copy pdata->modes[chan].deselect_on_exit to data->idle_disconnect in the probe function, so you could avoiding accessing pdata here. > + /* Deselect active channel */ > + data->last_chan = 0; > + return pca954x_reg_write(adap, client, data->last_chan); > + } > > - /* Deselect active channel */ > - data->last_chan = 0; > - return pca954x_reg_write(adap, client, data->last_chan); > + if (data->idle_chan >= 0) > + return pca954x_select_chan(adap, client, data->idle_chan); > + > + return 0; > } > > /* > @@ -186,6 +199,7 @@ static int pca954x_probe(struct i2c_client *client, > { > struct i2c_adapter *adap = to_i2c_adapter(client->dev.parent); > struct pca954x_platform_data *pdata = dev_get_platdata(&client->dev); > + struct device_node *of_node = client->dev.of_node; > struct gpio_desc *gpio; > int num, force, class; > struct pca954x *data; > @@ -216,6 +230,27 @@ static int pca954x_probe(struct i2c_client *client, > > data->type = id->driver_data; > data->last_chan = 0; /* force the first selection */ > + data->idle_chan = -1; /* no forced idle state */ > + > + if (of_node) { > + u32 ch; > + > + if (of_property_read_bool(of_node, "idle-disconnect")) > + data->idle_disconnect = true; > + > + if (!of_property_read_u32_index(of_node, "idle-state", 0, &ch)) > { > + if (ch < PCA954X_MAX_NCHANS) { > + data->idle_chan = ch; > + /* Force idle state from the beginning */ > + ret = pca954x_select_chan(adap, client, ch); > + if (ret) > + return ret; > + } else { > + dev_warn(&client->dev, > + "Invalid idle-state property\n"); > + } > + } > + } > > /* Now create an adapter for each channel */ > for (num = 0; num < chips[data->type].nchans; num++) { > @@ -234,8 +269,7 @@ static int pca954x_probe(struct i2c_client *client, > data->virt_adaps[num] = > i2c_add_mux_adapter(adap, &client->dev, client, > force, num, class, pca954x_select_chan, > - (pdata && pdata->modes[num].deselect_on_exit) > - ? pca954x_deselect_mux : NULL); > + pca954x_deselect_mux); > > if (data->virt_adaps[num] == NULL) { > ret = -ENODEV; > @@ -281,7 +315,12 @@ static int pca954x_resume(struct device *dev) > struct pca954x *data = i2c_get_clientdata(client); > > data->last_chan = 0; > - return i2c_smbus_write_byte(client, 0); > + /* Restore idle state on resume */ > + if (data->idle_chan >= 0) > + return pca954x_select_chan(to_i2c_adapter(client->dev.parent), > + client, data->idle_chan); > + else > + return i2c_smbus_write_byte(client, 0); > } > #endif -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
