* Re: [PATCH v3 2/2] iio: Add OF support
2013-02-04 20:26 ` Guenter Roeck
@ 2013-02-05 5:20 ` Guenter Roeck
-1 siblings, 0 replies; 28+ messages in thread
From: Guenter Roeck @ 2013-02-05 5:20 UTC (permalink / raw)
To: linux-iio-u79uwXL29TY76Z2rM5mHXA, Jonathan Cameron
Cc: devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ,
Naveen Krishna Chatradhi, Lars-Peter Clausen, Doug Anderson,
Tomasz Figa, Grant Likely, Rob Herring, MyungJoo Ham,
Chanwoo Choi, Anton Vorontsov, David Woodhouse
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-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org>
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
>
>
^ permalink raw reply [flat|nested] 28+ messages in thread* Re: [PATCH v3 2/2] iio: Add OF support
@ 2013-02-05 5:20 ` Guenter Roeck
0 siblings, 0 replies; 28+ messages in thread
From: Guenter Roeck @ 2013-02-05 5:20 UTC (permalink / raw)
To: linux-iio, Jonathan Cameron
Cc: devicetree-discuss, Naveen Krishna Chatradhi, Lars-Peter Clausen,
Doug Anderson, Tomasz Figa, Grant Likely, Rob Herring,
MyungJoo Ham, Chanwoo Choi, Anton Vorontsov, David Woodhouse
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@roeck-us.net>
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
>
>
^ permalink raw reply [flat|nested] 28+ messages in thread
* Re: [PATCH v3 2/2] iio: Add OF support
2013-02-04 20:26 ` Guenter Roeck
@ 2013-02-05 15:22 ` Guenter Roeck
-1 siblings, 0 replies; 28+ messages in thread
From: Guenter Roeck @ 2013-02-05 15:22 UTC (permalink / raw)
To: linux-iio-u79uwXL29TY76Z2rM5mHXA, Jonathan Cameron
Cc: devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ,
Naveen Krishna Chatradhi, Lars-Peter Clausen, Doug Anderson,
Tomasz Figa, Grant Likely, Rob Herring, MyungJoo Ham,
Chanwoo Choi, Anton Vorontsov, David Woodhouse
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-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org>
> ---
> 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;
>
[ ... ]
> +
> +#else /* CONFIG_OF */
> +
> +static inline struct iio_channel *
> +of_iio_channel_get_by_name(struct device *dev, const char *name)
> +{
> + return ERR_PTR(-ENOENT);
> +}
> +
The above should be
static inline struct iio_channel *
of_iio_channel_get_by_name(struct device_node *np, const char *name)
{
return NULL;
}
Will be fixed in the next version.
Guenter
^ permalink raw reply [flat|nested] 28+ messages in thread* Re: [PATCH v3 2/2] iio: Add OF support
@ 2013-02-05 15:22 ` Guenter Roeck
0 siblings, 0 replies; 28+ messages in thread
From: Guenter Roeck @ 2013-02-05 15:22 UTC (permalink / raw)
To: linux-iio, Jonathan Cameron
Cc: devicetree-discuss, Naveen Krishna Chatradhi, Lars-Peter Clausen,
Doug Anderson, Tomasz Figa, Grant Likely, Rob Herring,
MyungJoo Ham, Chanwoo Choi, Anton Vorontsov, David Woodhouse
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@roeck-us.net>
> ---
> 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;
>
[ ... ]
> +
> +#else /* CONFIG_OF */
> +
> +static inline struct iio_channel *
> +of_iio_channel_get_by_name(struct device *dev, const char *name)
> +{
> + return ERR_PTR(-ENOENT);
> +}
> +
The above should be
static inline struct iio_channel *
of_iio_channel_get_by_name(struct device_node *np, const char *name)
{
return NULL;
}
Will be fixed in the next version.
Guenter
^ permalink raw reply [flat|nested] 28+ messages in thread
* [PATCH v4 2/2] iio: Add OF support
2013-02-04 20:26 ` Guenter Roeck
@ 2013-02-06 18:29 ` Guenter Roeck
-1 siblings, 0 replies; 28+ messages in thread
From: Guenter Roeck @ 2013-02-06 18:29 UTC (permalink / raw)
To: linux-iio-u79uwXL29TY76Z2rM5mHXA, Jonathan Cameron
Cc: devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ,
Naveen Krishna Chatradhi, Lars-Peter Clausen, Doug Anderson,
Tomasz Figa, Grant Likely, Rob Herring, MyungJoo Ham,
Chanwoo Choi, Anton Vorontsov, David Woodhouse
Provide bindings and parse OF data during initialization.
Signed-off-by: Guenter Roeck <linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org>
---
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.
drivers/iio/iio_core.h | 1 +
drivers/iio/industrialio-core.c | 8 +-
drivers/iio/inkern.c | 171 ++++++++++++++++++++
4 files changed, 268 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..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);
--
1.7.9.7
^ permalink raw reply related [flat|nested] 28+ messages in thread* [PATCH v4 2/2] iio: Add OF support
@ 2013-02-06 18:29 ` Guenter Roeck
0 siblings, 0 replies; 28+ messages in thread
From: Guenter Roeck @ 2013-02-06 18:29 UTC (permalink / raw)
To: linux-iio, Jonathan Cameron
Cc: devicetree-discuss, Naveen Krishna Chatradhi, Lars-Peter Clausen,
Doug Anderson, Tomasz Figa, Grant Likely, Rob Herring,
MyungJoo Ham, Chanwoo Choi, Anton Vorontsov, David Woodhouse
Provide bindings and parse OF data during initialization.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
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.
drivers/iio/iio_core.h | 1 +
drivers/iio/industrialio-core.c | 8 +-
drivers/iio/inkern.c | 171 ++++++++++++++++++++
4 files changed, 268 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..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);
--
1.7.9.7
^ permalink raw reply related [flat|nested] 28+ messages in thread[parent not found: <20130206182923.GA14417-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org>]
* Re: [PATCH v4 2/2] iio: Add OF support
2013-02-06 18:29 ` Guenter Roeck
@ 2013-02-06 19:37 ` Jonathan Cameron
-1 siblings, 0 replies; 28+ messages in thread
From: Jonathan Cameron @ 2013-02-06 19:37 UTC (permalink / raw)
To: Guenter Roeck
Cc: linux-iio-u79uwXL29TY76Z2rM5mHXA,
devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ,
Naveen Krishna Chatradhi, Lars-Peter Clausen, Doug Anderson,
Tomasz Figa, Grant Likely, Rob Herring, MyungJoo Ham,
Chanwoo Choi, Anton Vorontsov, David Woodhouse
On 02/06/2013 06:29 PM, Guenter Roeck wrote:
> Provide bindings and parse OF data during initialization.
>
> Signed-off-by: Guenter Roeck <linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org>
looks good to me. Couple of little queries inline.
> ---
> 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.
>
> drivers/iio/iio_core.h | 1 +
> drivers/iio/industrialio-core.c | 8 +-
> drivers/iio/inkern.c | 171 ++++++++++++++++++++
> 4 files changed, 268 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>;
Why would the trigger have channel-cells?
So far we don't have any device tree stuff for the triggers.
> + };
> + };
> +
> +==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";
This example still seems a little odd. Why give one where there are
more channels than names?
> + };
> 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;
> +
I guess that's sensible, though I'd be inclined to check it and throw a wobbly
if it isn't defined. That way we have one 'right' place to do it.
> /* 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);
>
^ permalink raw reply [flat|nested] 28+ messages in thread* Re: [PATCH v4 2/2] iio: Add OF support
@ 2013-02-06 19:37 ` Jonathan Cameron
0 siblings, 0 replies; 28+ messages in thread
From: Jonathan Cameron @ 2013-02-06 19:37 UTC (permalink / raw)
To: Guenter Roeck
Cc: linux-iio, devicetree-discuss, Naveen Krishna Chatradhi,
Lars-Peter Clausen, Doug Anderson, Tomasz Figa, Grant Likely,
Rob Herring, MyungJoo Ham, Chanwoo Choi, Anton Vorontsov,
David Woodhouse
On 02/06/2013 06:29 PM, Guenter Roeck wrote:
> Provide bindings and parse OF data during initialization.
>
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
looks good to me. Couple of little queries inline.
> ---
> 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.
>
> drivers/iio/iio_core.h | 1 +
> drivers/iio/industrialio-core.c | 8 +-
> drivers/iio/inkern.c | 171 ++++++++++++++++++++
> 4 files changed, 268 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>;
Why would the trigger have channel-cells?
So far we don't have any device tree stuff for the triggers.
> + };
> + };
> +
> +==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";
This example still seems a little odd. Why give one where there are
more channels than names?
> + };
> 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;
> +
I guess that's sensible, though I'd be inclined to check it and throw a wobbly
if it isn't defined. That way we have one 'right' place to do it.
> /* 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);
>
^ permalink raw reply [flat|nested] 28+ messages in thread[parent not found: <5112B101.7040709-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>]
* Re: [PATCH v4 2/2] iio: Add OF support
2013-02-06 19:37 ` Jonathan Cameron
@ 2013-02-06 20:05 ` Guenter Roeck
-1 siblings, 0 replies; 28+ messages in thread
From: Guenter Roeck @ 2013-02-06 20:05 UTC (permalink / raw)
To: Jonathan Cameron
Cc: linux-iio-u79uwXL29TY76Z2rM5mHXA,
devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ,
Naveen Krishna Chatradhi, Lars-Peter Clausen, Doug Anderson,
Tomasz Figa, Grant Likely, Rob Herring, MyungJoo Ham,
Chanwoo Choi, Anton Vorontsov, David Woodhouse
On Wed, Feb 06, 2013 at 07:37:37PM +0000, Jonathan Cameron wrote:
> On 02/06/2013 06:29 PM, Guenter Roeck wrote:
> > Provide bindings and parse OF data during initialization.
> >
> > Signed-off-by: Guenter Roeck <linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org>
> looks good to me. Couple of little queries inline.
>
> > ---
> > 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.
> >
> > drivers/iio/iio_core.h | 1 +
> > drivers/iio/industrialio-core.c | 8 +-
> > drivers/iio/inkern.c | 171 ++++++++++++++++++++
> > 4 files changed, 268 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>;
> Why would the trigger have channel-cells?
> So far we don't have any device tree stuff for the triggers.
This comes from one of the examples passed around earlier.
Presumably, when triggers are supported through devicetree, you would have more
than one per device, meaning you need the same logic as for devices.
Though on the other side that isn't supported yet - I don't have hardware to
test, so I can not implement - or, rather, test - devicetree based trigger support.
I can take the entire thing out if you prefer - I don't really have a strong
opinion.
> > + };
> > + };
> > +
> > +==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";
> This example still seems a little odd. Why give one where there are
> more channels than names?
I just didn't have a better idea. Do you know of another iio consumer I could
use as example, one which doesn't use the get_all API ?
> > + };
> > 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;
> > +
> I guess that's sensible, though I'd be inclined to check it and throw a wobbly
> if it isn't defined. That way we have one 'right' place to do it.
>
I had to look that one up :). "throw a wobbly" = "reached the end of rational thought and action"
or "to become suddenly very agitated or angry". Is that about right ?
I assume you mean the case where indio_dev->dev.of_node is NULL ? Problem is
that this can hapen anytime (and always if CONFIG_OF is undefined).
I'd be more concerned if indio_dev->dev.parent is NULL, which happens with
a couple of drivers if I interpret the code correctly. Otherwise it only matters
if the node should really point to a sub-node and not to the parent's node
itself - but presumably programmers should detect that while writing the driver.
Alternative would be to set of_node in all calling drivers. Unfortunately, there
are about one hundred callers, so that would be a substantial effort.
Not sure myself what the right approach is here - that is why I asked for
feedback about it in v3. I am open to suggestions.
Thanks,
Guenter
^ permalink raw reply [flat|nested] 28+ messages in thread* Re: [PATCH v4 2/2] iio: Add OF support
@ 2013-02-06 20:05 ` Guenter Roeck
0 siblings, 0 replies; 28+ messages in thread
From: Guenter Roeck @ 2013-02-06 20:05 UTC (permalink / raw)
To: Jonathan Cameron
Cc: linux-iio, devicetree-discuss, Naveen Krishna Chatradhi,
Lars-Peter Clausen, Doug Anderson, Tomasz Figa, Grant Likely,
Rob Herring, MyungJoo Ham, Chanwoo Choi, Anton Vorontsov,
David Woodhouse
On Wed, Feb 06, 2013 at 07:37:37PM +0000, Jonathan Cameron wrote:
> On 02/06/2013 06:29 PM, Guenter Roeck wrote:
> > Provide bindings and parse OF data during initialization.
> >
> > Signed-off-by: Guenter Roeck <linux@roeck-us.net>
> looks good to me. Couple of little queries inline.
>
> > ---
> > 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.
> >
> > drivers/iio/iio_core.h | 1 +
> > drivers/iio/industrialio-core.c | 8 +-
> > drivers/iio/inkern.c | 171 ++++++++++++++++++++
> > 4 files changed, 268 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>;
> Why would the trigger have channel-cells?
> So far we don't have any device tree stuff for the triggers.
This comes from one of the examples passed around earlier.
Presumably, when triggers are supported through devicetree, you would have more
than one per device, meaning you need the same logic as for devices.
Though on the other side that isn't supported yet - I don't have hardware to
test, so I can not implement - or, rather, test - devicetree based trigger support.
I can take the entire thing out if you prefer - I don't really have a strong
opinion.
> > + };
> > + };
> > +
> > +==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";
> This example still seems a little odd. Why give one where there are
> more channels than names?
I just didn't have a better idea. Do you know of another iio consumer I could
use as example, one which doesn't use the get_all API ?
> > + };
> > 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;
> > +
> I guess that's sensible, though I'd be inclined to check it and throw a wobbly
> if it isn't defined. That way we have one 'right' place to do it.
>
I had to look that one up :). "throw a wobbly" = "reached the end of rational thought and action"
or "to become suddenly very agitated or angry". Is that about right ?
I assume you mean the case where indio_dev->dev.of_node is NULL ? Problem is
that this can hapen anytime (and always if CONFIG_OF is undefined).
I'd be more concerned if indio_dev->dev.parent is NULL, which happens with
a couple of drivers if I interpret the code correctly. Otherwise it only matters
if the node should really point to a sub-node and not to the parent's node
itself - but presumably programmers should detect that while writing the driver.
Alternative would be to set of_node in all calling drivers. Unfortunately, there
are about one hundred callers, so that would be a substantial effort.
Not sure myself what the right approach is here - that is why I asked for
feedback about it in v3. I am open to suggestions.
Thanks,
Guenter
^ permalink raw reply [flat|nested] 28+ messages in thread[parent not found: <20130206200513.GA18135-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org>]
* Re: [PATCH v4 2/2] iio: Add OF support
2013-02-06 20:05 ` Guenter Roeck
@ 2013-02-06 20:12 ` Tomasz Figa
-1 siblings, 0 replies; 28+ messages in thread
From: Tomasz Figa @ 2013-02-06 20:12 UTC (permalink / raw)
To: Guenter Roeck
Cc: Lars-Peter Clausen, Anton Vorontsov,
linux-iio-u79uwXL29TY76Z2rM5mHXA, David Woodhouse,
devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ, Rob Herring,
Chanwoo Choi, MyungJoo Ham, Naveen Krishna Chatradhi,
Jonathan Cameron
On Wednesday 06 of February 2013 12:05:13 Guenter Roeck wrote:
> On Wed, Feb 06, 2013 at 07:37:37PM +0000, Jonathan Cameron wrote:
> > On 02/06/2013 06:29 PM, Guenter Roeck wrote:
> > > Provide bindings and parse OF data during initialization.
> > >
> > > Signed-off-by: Guenter Roeck <linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org>
> >
> > looks good to me. Couple of little queries inline.
> >
> > > ---
> > > 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.
> > >
> > > drivers/iio/iio_core.h | 1 +
> > > drivers/iio/industrialio-core.c | 8 +-
> > > drivers/iio/inkern.c | 171
> > > ++++++++++++++++++++ 4 files changed, 268 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>;
> >
> > Why would the trigger have channel-cells?
> > So far we don't have any device tree stuff for the triggers.
>
> This comes from one of the examples passed around earlier.
>
> Presumably, when triggers are supported through devicetree, you would
> have more than one per device, meaning you need the same logic as for
> devices.
>
> Though on the other side that isn't supported yet - I don't have
> hardware to test, so I can not implement - or, rather, test -
> devicetree based trigger support. I can take the entire thing out if
> you prefer - I don't really have a strong opinion.
>
> > > + };
> > > + };
> > > +
> > > +==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";
> >
> > This example still seems a little odd. Why give one where there are
> > more channels than names?
>
> I just didn't have a better idea. Do you know of another iio consumer I
> could use as example, one which doesn't use the get_all API ?
>
> > > + };
> > > 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;
> > > +
> >
> > I guess that's sensible, though I'd be inclined to check it and throw
> > a wobbly if it isn't defined. That way we have one 'right' place to
> > do it.
> I had to look that one up :). "throw a wobbly" = "reached the end of
> rational thought and action" or "to become suddenly very agitated or
> angry". Is that about right ?
>
> I assume you mean the case where indio_dev->dev.of_node is NULL ?
> Problem is that this can hapen anytime (and always if CONFIG_OF is
> undefined). I'd be more concerned if indio_dev->dev.parent is NULL,
> which happens with a couple of drivers if I interpret the code
> correctly. Otherwise it only matters if the node should really point to
> a sub-node and not to the parent's node itself - but presumably
> programmers should detect that while writing the driver.
>
> Alternative would be to set of_node in all calling drivers.
> Unfortunately, there are about one hundred callers, so that would be a
> substantial effort.
>
> Not sure myself what the right approach is here - that is why I asked
> for feedback about it in v3. I am open to suggestions.
I'm not sure if I understand the point, so following might be just some
random thoughts:
There is no need to check for of_node. Case where there is no of_node
attached to the device is fine, as lots of systems are being booted
without device tree support.
Getting of_node from parent device seems reasonable to me, as this will
automatically handle all the simple cases where iio_device node would be
equal to physical device node.
Best regards,
Tomasz
^ permalink raw reply [flat|nested] 28+ messages in thread* Re: [PATCH v4 2/2] iio: Add OF support
@ 2013-02-06 20:12 ` Tomasz Figa
0 siblings, 0 replies; 28+ messages in thread
From: Tomasz Figa @ 2013-02-06 20:12 UTC (permalink / raw)
To: Guenter Roeck
Cc: Jonathan Cameron, linux-iio, devicetree-discuss,
Naveen Krishna Chatradhi, Lars-Peter Clausen, Doug Anderson,
Grant Likely, Rob Herring, MyungJoo Ham, Chanwoo Choi,
Anton Vorontsov, David Woodhouse
On Wednesday 06 of February 2013 12:05:13 Guenter Roeck wrote:
> On Wed, Feb 06, 2013 at 07:37:37PM +0000, Jonathan Cameron wrote:
> > On 02/06/2013 06:29 PM, Guenter Roeck wrote:
> > > Provide bindings and parse OF data during initialization.
> > >
> > > Signed-off-by: Guenter Roeck <linux@roeck-us.net>
> >
> > looks good to me. Couple of little queries inline.
> >
> > > ---
> > > 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.
> > >
> > > drivers/iio/iio_core.h | 1 +
> > > drivers/iio/industrialio-core.c | 8 +-
> > > drivers/iio/inkern.c | 171
> > > ++++++++++++++++++++ 4 files changed, 268 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>;
> >
> > Why would the trigger have channel-cells?
> > So far we don't have any device tree stuff for the triggers.
>
> This comes from one of the examples passed around earlier.
>
> Presumably, when triggers are supported through devicetree, you would
> have more than one per device, meaning you need the same logic as for
> devices.
>
> Though on the other side that isn't supported yet - I don't have
> hardware to test, so I can not implement - or, rather, test -
> devicetree based trigger support. I can take the entire thing out if
> you prefer - I don't really have a strong opinion.
>
> > > + };
> > > + };
> > > +
> > > +==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";
> >
> > This example still seems a little odd. Why give one where there are
> > more channels than names?
>
> I just didn't have a better idea. Do you know of another iio consumer I
> could use as example, one which doesn't use the get_all API ?
>
> > > + };
> > > 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;
> > > +
> >
> > I guess that's sensible, though I'd be inclined to check it and throw
> > a wobbly if it isn't defined. That way we have one 'right' place to
> > do it.
> I had to look that one up :). "throw a wobbly" = "reached the end of
> rational thought and action" or "to become suddenly very agitated or
> angry". Is that about right ?
>
> I assume you mean the case where indio_dev->dev.of_node is NULL ?
> Problem is that this can hapen anytime (and always if CONFIG_OF is
> undefined). I'd be more concerned if indio_dev->dev.parent is NULL,
> which happens with a couple of drivers if I interpret the code
> correctly. Otherwise it only matters if the node should really point to
> a sub-node and not to the parent's node itself - but presumably
> programmers should detect that while writing the driver.
>
> Alternative would be to set of_node in all calling drivers.
> Unfortunately, there are about one hundred callers, so that would be a
> substantial effort.
>
> Not sure myself what the right approach is here - that is why I asked
> for feedback about it in v3. I am open to suggestions.
I'm not sure if I understand the point, so following might be just some
random thoughts:
There is no need to check for of_node. Case where there is no of_node
attached to the device is fine, as lots of systems are being booted
without device tree support.
Getting of_node from parent device seems reasonable to me, as this will
automatically handle all the simple cases where iio_device node would be
equal to physical device node.
Best regards,
Tomasz
^ permalink raw reply [flat|nested] 28+ messages in thread
* Re: [PATCH v4 2/2] iio: Add OF support
2013-02-06 19:37 ` Jonathan Cameron
@ 2013-02-07 1:53 ` Guenter Roeck
-1 siblings, 0 replies; 28+ messages in thread
From: Guenter Roeck @ 2013-02-07 1:53 UTC (permalink / raw)
To: Jonathan Cameron
Cc: linux-iio-u79uwXL29TY76Z2rM5mHXA,
devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ,
Naveen Krishna Chatradhi, Lars-Peter Clausen, Doug Anderson,
Tomasz Figa, Grant Likely, Rob Herring, MyungJoo Ham,
Chanwoo Choi, Anton Vorontsov, David Woodhouse
On Wed, Feb 06, 2013 at 07:37:37PM +0000, Jonathan Cameron wrote:
> On 02/06/2013 06:29 PM, Guenter Roeck wrote:
> > Provide bindings and parse OF data during initialization.
> >
> > Signed-off-by: Guenter Roeck <linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org>
> looks good to me. Couple of little queries inline.
>
[ ... ]
> > +
> > +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>;
> Why would the trigger have channel-cells?
> So far we don't have any device tree stuff for the triggers.
I thought about keeping the example and adding a note that trigger support is
not currently implemented, but a better idea is to replace it with a second iio
device. I'll do that unless someone objects.
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 */
};
};
> > +
> > +==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";
> This example still seems a little odd. Why give one where there are
> more channels than names?
I replaced the example with
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";
};
Guenter
^ permalink raw reply [flat|nested] 28+ messages in thread* Re: [PATCH v4 2/2] iio: Add OF support
@ 2013-02-07 1:53 ` Guenter Roeck
0 siblings, 0 replies; 28+ messages in thread
From: Guenter Roeck @ 2013-02-07 1:53 UTC (permalink / raw)
To: Jonathan Cameron
Cc: linux-iio, devicetree-discuss, Naveen Krishna Chatradhi,
Lars-Peter Clausen, Doug Anderson, Tomasz Figa, Grant Likely,
Rob Herring, MyungJoo Ham, Chanwoo Choi, Anton Vorontsov,
David Woodhouse
On Wed, Feb 06, 2013 at 07:37:37PM +0000, Jonathan Cameron wrote:
> On 02/06/2013 06:29 PM, Guenter Roeck wrote:
> > Provide bindings and parse OF data during initialization.
> >
> > Signed-off-by: Guenter Roeck <linux@roeck-us.net>
> looks good to me. Couple of little queries inline.
>
[ ... ]
> > +
> > +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>;
> Why would the trigger have channel-cells?
> So far we don't have any device tree stuff for the triggers.
I thought about keeping the example and adding a note that trigger support is
not currently implemented, but a better idea is to replace it with a second iio
device. I'll do that unless someone objects.
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 */
};
};
> > +
> > +==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";
> This example still seems a little odd. Why give one where there are
> more channels than names?
I replaced the example with
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";
};
Guenter
^ permalink raw reply [flat|nested] 28+ messages in thread[parent not found: <20130207015346.GA15240-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org>]
* Re: [PATCH v4 2/2] iio: Add OF support
2013-02-07 1:53 ` Guenter Roeck
@ 2013-02-07 9:00 ` Jonathan Cameron
-1 siblings, 0 replies; 28+ messages in thread
From: Jonathan Cameron @ 2013-02-07 9:00 UTC (permalink / raw)
To: Guenter Roeck
Cc: Jonathan Cameron, linux-iio-u79uwXL29TY76Z2rM5mHXA,
devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ,
Naveen Krishna Chatradhi, Lars-Peter Clausen, Doug Anderson,
Tomasz Figa, Grant Likely, Rob Herring, MyungJoo Ham,
Chanwoo Choi, Anton Vorontsov, David Woodhouse
On 07/02/13 01:53, Guenter Roeck wrote:
> On Wed, Feb 06, 2013 at 07:37:37PM +0000, Jonathan Cameron wrote:
>> On 02/06/2013 06:29 PM, Guenter Roeck wrote:
>>> Provide bindings and parse OF data during initialization.
>>>
>>> Signed-off-by: Guenter Roeck <linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org>
>> looks good to me. Couple of little queries inline.
>>
> [ ... ]
>
>>> +
>>> +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>;
>> Why would the trigger have channel-cells?
>> So far we don't have any device tree stuff for the triggers.
>
> I thought about keeping the example and adding a note that trigger support is
> not currently implemented, but a better idea is to replace it with a second iio
> device. I'll do that unless someone objects.
>
> 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 */
> };
> };
Agreed.
>
>>> +
>>> +==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";
>> This example still seems a little odd. Why give one where there are
>> more channels than names?
>
> I replaced the example with
>
> 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";
> };
Good as well. Much happier with these examples as they
won't cause any confusion.
>
> Guenter
> --
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^ permalink raw reply [flat|nested] 28+ messages in thread* Re: [PATCH v4 2/2] iio: Add OF support
@ 2013-02-07 9:00 ` Jonathan Cameron
0 siblings, 0 replies; 28+ messages in thread
From: Jonathan Cameron @ 2013-02-07 9:00 UTC (permalink / raw)
To: Guenter Roeck
Cc: Jonathan Cameron, linux-iio, devicetree-discuss,
Naveen Krishna Chatradhi, Lars-Peter Clausen, Doug Anderson,
Tomasz Figa, Grant Likely, Rob Herring, MyungJoo Ham,
Chanwoo Choi, Anton Vorontsov, David Woodhouse
On 07/02/13 01:53, Guenter Roeck wrote:
> On Wed, Feb 06, 2013 at 07:37:37PM +0000, Jonathan Cameron wrote:
>> On 02/06/2013 06:29 PM, Guenter Roeck wrote:
>>> Provide bindings and parse OF data during initialization.
>>>
>>> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
>> looks good to me. Couple of little queries inline.
>>
> [ ... ]
>
>>> +
>>> +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>;
>> Why would the trigger have channel-cells?
>> So far we don't have any device tree stuff for the triggers.
>
> I thought about keeping the example and adding a note that trigger support is
> not currently implemented, but a better idea is to replace it with a second iio
> device. I'll do that unless someone objects.
>
> 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 */
> };
> };
Agreed.
>
>>> +
>>> +==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";
>> This example still seems a little odd. Why give one where there are
>> more channels than names?
>
> I replaced the example with
>
> 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";
> };
Good as well. Much happier with these examples as they
won't cause any confusion.
>
> Guenter
> --
> To unsubscribe from this list: send the line "unsubscribe linux-iio" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
^ permalink raw reply [flat|nested] 28+ messages in thread