On Mon, Feb 04, 2013 at 12:26:06PM -0800, Guenter Roeck wrote: > Provide bindings and parse OF data during initialization. > > Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx> Note: One of the parameters to the dummy function of_iio_channel_get_by_name() used when CONFIG_OF is undefined is wrong. I'll fix that in the next version of the patch. > --- > One open question is how to assign of_node to the iio device. We can either do it > in each driver (which turns out to be a huge patchset), or add something like the > following to iio_device_register. > > if (!indio_dev->dev.of_node && indio_dev->dev.parent) > indio_dev->dev.of_node = indio_dev->dev.parent->of_node; > > v3: > - Cleaned up documentation (formatting, left-over clock references) > - Updated bindings description to permit sub-devices > - When searching for iio devices, use the pointer to the iio device type instead > of strcmp. Rename iio_dev_type to iio_device_type (to match other device > types) and make it global for that purpose. Check the OF node first, then the > device type, as the node is less likely to match. > - Move the common code in of_iio_channel_get and of_iio_channel_get_all to > __of_iio_channel_get. > - Return NULL from of_iio_channel_get_by_name if nothing is found, or > an error if there is a problem with consistency or if the provider device is > not yet available. > - In iio_channel_get, return if of_iio_channel_get_by_name() returns a channel > or an error, and continue otherwise. > v2: > - Rebased to iio/togreg > - Documentation update per feedback > - Dropped io-channel-output-names from the bindings document. The property is > not used in the code, and it is not entirely clear what it would be used for. > If there is a need for it, we can add it back in later on. > - Don't export OF specific API calls > - For OF support, no longer depend on iio_map > - Add #ifdef CONFIG_OF where appropriate, and ensure that the code still builds > if it is not selected. > - Change iio_channel_get to take device pointer as argument instead of device > name. Retain old API as of_iio_channel_get_sys. > - iio_channel_get now works for both OF and non-OF configurations > - Use regulator to get vref for max1363 driver. > > .../devicetree/bindings/iio/iio-bindings.txt | 90 +++++++++++ > drivers/iio/iio_core.h | 1 + > drivers/iio/industrialio-core.c | 4 +- > drivers/iio/inkern.c | 171 ++++++++++++++++++++ > 4 files changed, 264 insertions(+), 2 deletions(-) > create mode 100644 Documentation/devicetree/bindings/iio/iio-bindings.txt > > diff --git a/Documentation/devicetree/bindings/iio/iio-bindings.txt b/Documentation/devicetree/bindings/iio/iio-bindings.txt > new file mode 100644 > index 0000000..2475c2e > --- /dev/null > +++ b/Documentation/devicetree/bindings/iio/iio-bindings.txt > @@ -0,0 +1,90 @@ > +This binding is a work-in-progress. It is derived from clock bindings, > +and based on suggestions from Lars-Peter Clausen [1]. > + > +Sources of IIO channels can be represented by any node in the device > +tree. Those nodes are designated as IIO providers. IIO consumer > +nodes use a phandle and IIO specifier pair to connect IIO provider > +outputs to IIO inputs. Similar to the gpio specifiers, an IIO > +specifier is an array of one or more cells identifying the IIO > +output on a device. The length of an IIO specifier is defined by the > +value of a #io-channel-cells property in the IIO provider node. > + > +[1] http://marc.info/?l=linux-iio&m=135902119507483&w=2 > + > +==IIO providers== > + > +Required properties: > +#io-channel-cells: Number of cells in an IIO specifier; Typically 0 for nodes > + with a single IIO output and 1 for nodes with multiple > + IIO outputs. > + > +Example for a simple configuration with no trigger: > + > + adc: voltage-sensor@35 { > + compatible = "maxim,max1139"; > + reg = <0x35>; > + #io-channel-cells = <1>; > + }; > + > +Example for a configuration with trigger: > + > + adc@35 { > + compatible = "maxim,max1139"; > + reg = <0x35>; > + > + adc: iio-device { > + #io-channel-cells = <1>; > + }; > + trigger: iio-trigger { > + #io-channel-cells = <1>; > + }; > + }; > + > +==IIO consumers== > + > +Required properties: > +io-channels: List of phandle and IIO specifier pairs, one pair > + for each IIO input to the device. Note: if the > + IIO provider specifies '0' for #io-channel-cells, > + then only the phandle portion of the pair will appear. > + > +Optional properties: > +io-channel-names: > + List of IIO input name strings sorted in the same > + order as the io-channels property. Consumers drivers > + will use io-channel-names to match IIO input names > + with IIO specifiers. > +io-channel-ranges: > + Empty property indicating that child nodes can inherit named > + IIO channels from this node. Useful for bus nodes to provide > + and IIO channel to their children. > + > +For example: > + > + device { > + io-channels = <&adc 1>, <&ref 0>; > + io-channel-names = "vcc", "vdd"; > + }; > + > +This represents a device with two IIO inputs, named "vcc" and "vdd". > +The vcc channel is connected to output 1 of the &adc device, and the > +vdd channel is connected to output 0 of the &ref device. > + > +==Example== > + > + adc: max1139@35 { > + compatible = "maxim,max1139"; > + reg = <0x35>; > + #io-channel-cells = <1>; > + }; > + > + ... > + > + iio_hwmon { > + compatible = "iio-hwmon"; > + io-channels = <&adc 0>, <&adc 1>, <&adc 2>, > + <&adc 3>, <&adc 4>, <&adc 5>, > + <&adc 6>, <&adc 7>, <&adc 8>, > + <&adc 9>, <&adc 10>, <&adc 11>; > + io-channel-names = "vcc", "vdd", "vref", "1.2V"; > + }; > diff --git a/drivers/iio/iio_core.h b/drivers/iio/iio_core.h > index f652e6a..05c1b74 100644 > --- a/drivers/iio/iio_core.h > +++ b/drivers/iio/iio_core.h > @@ -18,6 +18,7 @@ > struct iio_chan_spec; > struct iio_dev; > > +extern struct device_type iio_device_type; > > int __iio_add_chan_devattr(const char *postfix, > struct iio_chan_spec const *chan, > diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c > index 8848f16..81e3594 100644 > --- a/drivers/iio/industrialio-core.c > +++ b/drivers/iio/industrialio-core.c > @@ -847,7 +847,7 @@ static void iio_dev_release(struct device *device) > kfree(indio_dev); > } > > -static struct device_type iio_dev_type = { > +struct device_type iio_device_type = { > .name = "iio_device", > .release = iio_dev_release, > }; > @@ -869,7 +869,7 @@ struct iio_dev *iio_device_alloc(int sizeof_priv) > > if (dev) { > dev->dev.groups = dev->groups; > - dev->dev.type = &iio_dev_type; > + dev->dev.type = &iio_device_type; > dev->dev.bus = &iio_bus_type; > device_initialize(&dev->dev); > dev_set_drvdata(&dev->dev, (void *)dev); > diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c > index b289915..913428e 100644 > --- a/drivers/iio/inkern.c > +++ b/drivers/iio/inkern.c > @@ -10,6 +10,7 @@ > #include <linux/export.h> > #include <linux/slab.h> > #include <linux/mutex.h> > +#include <linux/of.h> > > #include <linux/iio/iio.h> > #include "iio_core.h" > @@ -92,6 +93,164 @@ static const struct iio_chan_spec > return chan; > } > > +#ifdef CONFIG_OF > + > +static int iio_dev_node_match(struct device *dev, void *data) > +{ > + return dev->of_node == data && dev->type == &iio_device_type; > +} > + > +static int __of_iio_channel_get(struct iio_channel *channel, > + struct device_node *np, int index) > +{ > + struct device *idev; > + struct iio_dev *indio_dev; > + int err; > + struct of_phandle_args iiospec; > + > + err = of_parse_phandle_with_args(np, "io-channels", > + "#io-channel-cells", > + index, &iiospec); > + if (err) > + return err; > + > + idev = bus_find_device(&iio_bus_type, NULL, iiospec.np, > + iio_dev_node_match); > + of_node_put(iiospec.np); > + if (idev == NULL) > + return -EPROBE_DEFER; > + > + indio_dev = dev_to_iio_dev(idev); > + channel->indio_dev = indio_dev; > + index = iiospec.args_count ? iiospec.args[0] : 0; > + if (index >= indio_dev->num_channels) { > + return -EINVAL; > + goto err_put; > + } > + channel->channel = &indio_dev->channels[index]; > + > + return 0; > + > +err_put: > + iio_device_put(indio_dev); > + return err; > +} > + > +static struct iio_channel *of_iio_channel_get(struct device_node *np, int index) > +{ > + struct iio_channel *channel; > + int err; > + > + if (index < 0) > + return ERR_PTR(-EINVAL); > + > + channel = kzalloc(sizeof(*channel), GFP_KERNEL); > + if (channel == NULL) > + return ERR_PTR(-ENOMEM); > + > + err = __of_iio_channel_get(channel, np, index); > + if (err) > + goto err_free_channel; > + > + return channel; > + > +err_free_channel: > + kfree(channel); > + return ERR_PTR(err); > +} > + > +static struct iio_channel *of_iio_channel_get_by_name(struct device_node *np, > + const char *name) > +{ > + struct iio_channel *chan = NULL; > + > + /* Walk up the tree of devices looking for a matching iio channel */ > + while (np) { > + int index = 0; > + > + /* > + * For named iio channels, first look up the name in the > + * "io-channel-names" property. If it cannot be found, the > + * index will be an error code, and of_iio_channel_get() > + * will fail. > + */ > + if (name) > + index = of_property_match_string(np, "io-channel-names", > + name); > + chan = of_iio_channel_get(np, index); > + if (!IS_ERR(chan)) > + break; > + else if (name && index >= 0) { > + pr_err("ERROR: could not get IIO channel %s:%s(%i)\n", > + np->full_name, name ? name : "", index); > + return chan; > + } > + > + /* > + * No matching IIO channel found on this node. > + * If the parent node has a "io-channel-ranges" property, > + * then we can try one of its channels. > + */ > + np = np->parent; > + if (np && !of_get_property(np, "io-channel-ranges", NULL)) > + break; > + } > + return chan; > +} > + > +static struct iio_channel *of_iio_channel_get_all(struct device *dev) > +{ > + struct iio_channel *chans; > + int i, mapind, nummaps = 0; > + int ret; > + > + do { > + ret = of_parse_phandle_with_args(dev->of_node, > + "io-channels", > + "#io-channel-cells", > + nummaps, NULL); > + if (ret < 0) > + break; > + } while (++nummaps); > + > + if (nummaps == 0) /* no error, return NULL to search map table */ > + return NULL; > + > + /* NULL terminated array to save passing size */ > + chans = kcalloc(nummaps + 1, sizeof(*chans), GFP_KERNEL); > + if (chans == NULL) > + return ERR_PTR(-ENOMEM); > + > + /* Search for OF matches */ > + for (mapind = 0; mapind < nummaps; mapind++) { > + ret = __of_iio_channel_get(&chans[mapind], dev->of_node, > + mapind); > + if (ret) > + goto error_free_chans; > + } > + return chans; > + > +error_free_chans: > + for (i = 0; i < mapind; i++) > + iio_device_put(chans[i].indio_dev); > + kfree(chans); > + return ERR_PTR(ret); > +} > + > +#else /* CONFIG_OF */ > + > +static inline struct iio_channel * > +of_iio_channel_get_by_name(struct device *dev, const char *name) > +{ > + return ERR_PTR(-ENOENT); > +} > + > +static inline struct iio_channel *of_iio_channel_get_all(struct device *dev) > +{ > + return NULL; > +} > + > +#endif /* CONFIG_OF */ > > static struct iio_channel *iio_channel_get_sys(const char *name, > const char *channel_name) > @@ -150,7 +309,14 @@ struct iio_channel *iio_channel_get(struct device *dev, > const char *channel_name) > { > const char *name = dev ? dev_name(dev) : NULL; > + struct iio_channel *channel; > > + if (dev) { > + channel = of_iio_channel_get_by_name(dev->of_node, > + channel_name); > + if (channel != NULL) > + return channel; > + } > return iio_channel_get_sys(name, channel_name); > } > EXPORT_SYMBOL_GPL(iio_channel_get); > @@ -173,6 +339,11 @@ struct iio_channel *iio_channel_get_all(struct device *dev) > > if (dev == NULL) > return ERR_PTR(-EINVAL); > + > + chans = of_iio_channel_get_all(dev); > + if (chans) > + return chans; > + > name = dev_name(dev); > > mutex_lock(&iio_map_list_lock); > -- > 1.7.9.7 > > -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
