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. .../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. + +[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. + +For example: + + adc: adc@35 { + compatible = "maxim,max1139"; + reg = <0x35>; + #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 #clock-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/inkern.c b/drivers/iio/inkern.c index b289915..d48f2a8 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 +93,179 @@ static const struct iio_chan_spec return chan; } +#ifdef CONFIG_OF + +static int iio_dev_node_match(struct device *dev, void *data) +{ + return !strcmp(dev->type->name, "iio_device") && dev->of_node == data; +} + +static struct iio_channel *of_iio_channel_get(struct device_node *np, int index) +{ + struct iio_channel *channel; + struct device *idev; + struct iio_dev *indio_dev; + int err; + struct of_phandle_args iiospec; + + if (index < 0) + return ERR_PTR(-EINVAL); + + err = of_parse_phandle_with_args(np, "io-channels", + "#io-channel-cells", + index, &iiospec); + if (err) + return ERR_PTR(err); + + idev = bus_find_device(&iio_bus_type, NULL, iiospec.np, + iio_dev_node_match); + of_node_put(iiospec.np); + if (idev == NULL) + return ERR_PTR(-EPROBE_DEFER); + + indio_dev = dev_to_iio_dev(idev); + + channel = kzalloc(sizeof(*channel), GFP_KERNEL); + if (channel == NULL) { + err = -ENOMEM; + goto err_no_mem; + } + + channel->indio_dev = indio_dev; + index = iiospec.args_count ? iiospec.args[0] : 0; + if (index >= indio_dev->num_channels) { + err = -EINVAL; + goto err_no_channel; + } + channel->channel = &indio_dev->channels[index]; + + return channel; + +err_no_channel: + kfree(channel); +err_no_mem: + iio_device_put(indio_dev); + 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 = ERR_PTR(-ENOENT); + + /* 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 = kzalloc(sizeof(*chans)*(nummaps + 1), GFP_KERNEL); + 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; + } + 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)) + return channel; + } return iio_channel_get_sys(name, channel_name); } EXPORT_SYMBOL_GPL(iio_channel_get); @@ -173,6 +354,11 @@ 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
