Guenter Roeck <li...@roeck-us.net> wrote:
>On Wed, Feb 20, 2013 at 11:38:22AM -0600, Rob Herring wrote: >> On 02/07/2013 11:09 AM, Guenter Roeck wrote: >> > Provide bindings and parse OF data during initialization. >> > >> > Signed-off-by: Guenter Roeck <li...@roeck-us.net> >> > --- >> > v5: >> > - Updated examples in bindings. >> > v4: >> > - Fixed wrong parameter to dummy of_iio_channel_get_by_name if >CONFIG_OF is >> > undefined, and wrong return value. >> > - Initialize indio_dev->of_node in iio_device_register if the >calling driver >> > neglected to do it. >> > 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 | 97 >+++++++++++ >> > drivers/iio/iio_core.h | 1 + >> > drivers/iio/industrialio-core.c | 8 +- >> > drivers/iio/inkern.c | 171 >++++++++++++++++++++ >> > 4 files changed, 275 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..1182845 >> > --- /dev/null >> > +++ b/Documentation/devicetree/bindings/iio/iio-bindings.txt >> > @@ -0,0 +1,97 @@ >> > +This binding is a work-in-progress. It is derived from clock >bindings, >> > +and based on suggestions from Lars-Peter Clausen [1]. >> >> Bindings are an ABI. It should not be a WIP. What part is a WIP? >> >The text is copied from clock bindings. I do not claim to be better >than the clock subsystem is doing in respect to its bindings. > >I'll be more than happy to take this text out if it is a source of >contention, >even more so if that is what is holding up the patch. Jonathan ? I don't really care about the wording though can see why Rob asked! We will probably have other stuff to add anyway. Jonathan > >Thanks, >Guenter > >> Knowing nothing about IIO, the binding seems sane. >> >> Rob >> >> > +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 = "some-vendor,some-adc"; >> > + reg = <0x35>; >> > + >> > + adc1: iio-device@0 { >> > + #io-channel-cells = <1>; >> > + /* other properties */ >> > + }; >> > + adc2: iio-device@1 { >> > + #io-channel-cells = <1>; >> > + /* other properties */ >> > + }; >> > + }; >> > + >> > +==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>; >> > + }; >> > + >> > + some_consumer { >> > + compatible = "some-consumer"; >> > + io-channels = <&adc 10>, <&adc 11>; >> > + io-channel-names = "adc1", "adc2"; >> > + }; >> > 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..6d8b027 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); >> > @@ -960,6 +960,10 @@ int iio_device_register(struct iio_dev >*indio_dev) >> > { >> > int ret; >> > >> > + /* If the calling driver did not initialize of_node, do it here >*/ >> > + if (!indio_dev->dev.of_node && indio_dev->dev.parent) >> > + indio_dev->dev.of_node = indio_dev->dev.parent->of_node; >> > + >> > /* configure elements for the chrdev */ >> > indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id); >> > >> > diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c >> > index b289915..795d100 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_node *np, const char >*name) >> > +{ >> > + return NULL; >> > +} >> > + >> > +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); >> > >> >> -- Sent from my Android phone with K-9 Mail. Please excuse my brevity. _______________________________________________ devicetree-discuss mailing list devicetree-discuss@lists.ozlabs.org https://lists.ozlabs.org/listinfo/devicetree-discuss
