On Sun, Feb 03, 2013 at 03:17:57PM +0100, Lars-Peter Clausen wrote: > On 02/03/2013 01:59 AM, Guenter Roeck wrote: > > Provide bindings and parse OF data during initialization. > > > > Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx> > > --- > > - 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. > > > > From my point of view this looks good in general now, Just a few comments. > > > .../devicetree/bindings/iio/iio-bindings.txt | 76 ++++++++ > > drivers/iio/inkern.c | 186 ++++++++++++++++++++ > > 2 files changed, 262 insertions(+) > > 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..58df5f6 > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/iio/iio-bindings.txt > > @@ -0,0 +1,76 @@ > > +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 clock provider node. > > + > > Is the extra space at the begining of each sentence on purpose? > Copied from clock code, and used throughout documentation here or there. Not my style, really, and I'll likely forget to do it if/when I add text myself, so I'll change it. [ ... ] > > + 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>; > > I'm not sure how much sense this example makes, since you can only request > those channels which have a name. > It does - of_iio_channel_get_all() returns all channels even if there are no names. > [...] > > + > > +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 = kzalloc(sizeof(*chans)*(nummaps + 1), GFP_KERNEL); > > I think using kcalloc makes sense here. > that would leave chan->data uninitialized, and I would have to initialize it explicitly. also, if additional fields are ever added, we would risk having uninitialized fields. Using kzalloc avoids a potential future error case, so I would prefer to keep it. > > + if (chans == NULL) { > > + ret = -ENOMEM; > > + goto error; > > + } > > + > > + /* Search for OF matches */ > > + for (mapind = 0; mapind < nummaps; mapind++) { > > + struct device *idev; > > + struct iio_dev *indio_dev; > > + int channel; > > + struct of_phandle_args iiospec; > > + > > + ret = of_parse_phandle_with_args(dev->of_node, > > + "io-channels", > > + "#io-channel-cells", > > + mapind, &iiospec); > > + if (ret) > > + goto error_free_chans; > > + > > + idev = bus_find_device(&iio_bus_type, NULL, iiospec.np, > > + iio_dev_node_match); > > + of_node_put(iiospec.np); > > + if (idev == NULL) { > > + ret = -EPROBE_DEFER; > > + goto error_free_chans; > > + } > > + indio_dev = dev_to_iio_dev(idev); > > + channel = iiospec.args_count ? iiospec.args[0] : 0; > > + if (channel >= indio_dev->num_channels) { > > + ret = -EINVAL; > > + goto error_free_chans; > > + } > > Hm, I wonder if we can share some code with of_iio_get_channel here, since it > is pretty much the same code. Maybe put the whole parse_phandle and device > lookup in a heler function. > Done; introduced __of_iio_get_channel to be called by both functions. > > + chans[mapind].indio_dev = indio_dev; > > + chans[mapind].channel = &indio_dev->channels[channel]; > > + } > > + return chans; > > + > > +error_free_chans: > > + for (i = 0; i < mapind; i++) > > + iio_device_put(chans[i].indio_dev); > > + kfree(chans); > > +error: > > + 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 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 +324,14 @@ 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 (!IS_ERR(channel)) > > Hm, I wonder if we should use the same semantics as for of_iio_channel_get_all > here. NULL means there is no channel use the map lookup and error code means > there is a channel, but there was an error requesting it. As it is right now > for probe deferral won't work, since EPROBE_DEFER is not passed on. > Yes, you are right. I'll try, and also write some test code to actually test it to make sure that it works as intended. -- 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