Re: [PATCH v3 2/6] iio: trigger: add OF support

[Jonathan Cameron <jic23@kernel.org>]

On 28/02/17 16:51, Fabrice Gasnier wrote:
> Provide OF support. Device drivers can get IIO triggers from dt.
> Introduce IIO trigger specifiers, so there are:
> - IIO trigger providers, e.g. dt nodes designated with
>   #io-trigger-cells=<num of cells>
> - IIO trigger consumers, e.g. phandles listed in io-triggers = <...>.
>   Those can be identified by names by using 'io-trigger-names'.
> 
> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Subject to binding discussion this looks fine to me.

Jonathan
> ---
>  drivers/iio/industrialio-trigger.c | 100 +++++++++++++++++++++++++++++++++++++
>  include/linux/iio/trigger.h        |   4 ++
>  2 files changed, 104 insertions(+)
> 
> diff --git a/drivers/iio/industrialio-trigger.c b/drivers/iio/industrialio-trigger.c
> index 978e1592..00ee3a7 100644
> --- a/drivers/iio/industrialio-trigger.c
> +++ b/drivers/iio/industrialio-trigger.c
> @@ -768,3 +768,103 @@ int iio_triggered_buffer_predisable(struct iio_dev *indio_dev)
>  					     indio_dev->pollfunc);
>  }
>  EXPORT_SYMBOL(iio_triggered_buffer_predisable);
> +
> +#ifdef CONFIG_OF
> +static int iio_trig_node_match(struct device *dev, void *data)
> +{
> +	return dev->of_node == data && dev->type == &iio_trig_type;
> +}
> +
> +static struct iio_trigger *__of_iio_trig_get(struct device_node *np, int index)
> +{
> +	struct of_phandle_args trigspec;
> +	struct device *dev;
> +	int err;
> +
> +	err = of_parse_phandle_with_args(np, "io-triggers",
> +					 "#io-trigger-cells",
> +					 index, &trigspec);
> +	if (err)
> +		return ERR_PTR(err);
> +
> +	dev = bus_find_device(&iio_bus_type, NULL, trigspec.np,
> +			      iio_trig_node_match);
> +	of_node_put(trigspec.np);
> +	if (!dev)
> +		return ERR_PTR(-EPROBE_DEFER);
> +
> +	return to_iio_trigger(dev);
> +}
> +
> +static struct iio_trigger *__of_iio_trig_get_by_name(struct device_node *np,
> +						     const char *name)
> +{
> +	struct iio_trigger *trig;
> +	int index = 0;
> +
> +	if (!np)
> +		return ERR_PTR(-EINVAL);
> +	if (name)
> +		index = of_property_match_string(np, "io-trigger-names", name);
> +	if (index < 0)
> +		return ERR_PTR(index);
> +	trig = __of_iio_trig_get(np, index);
> +	if (!IS_ERR(trig) || PTR_ERR(trig) == -EPROBE_DEFER)
> +		return trig;
> +
> +	if (name && index >= 0)
> +		pr_err("ERROR: could not get IIO trigger %s:%s(%i)\n",
> +		       np->full_name, name ? name : "", index);
> +
> +	return ERR_PTR(-ENOENT);
> +}
> +#else /* CONFIG_OF */
> +static inline struct iio_trigger *
> +__of_iio_trig_get_by_name(struct device_node *np, const char *name)
> +{
> +	return ERR_PTR(-ENOENT);
> +}
> +#endif
> +
> +struct iio_trigger *iio_trigger_get_by_name(struct device *dev,
> +					    const char *name)
> +{
> +	struct iio_trigger *trig;
> +
> +	if (!dev)
> +		return ERR_PTR(-EINVAL);
> +
> +	trig = __of_iio_trig_get_by_name(dev->of_node, name);
> +	if (!IS_ERR(trig))
> +		return iio_trigger_get(trig);
> +
> +	return trig;
> +}
> +EXPORT_SYMBOL_GPL(iio_trigger_get_by_name);
> +
> +static void devm_iio_trigger_put(struct device *dev, void *res)
> +{
> +	iio_trigger_put(*(struct iio_trigger **)res);
> +}
> +
> +struct iio_trigger *devm_iio_trigger_get_by_name(struct device *dev,
> +						 const char *name)
> +{
> +	struct iio_trigger **ptr, *trig;
> +
> +	ptr = devres_alloc(devm_iio_trigger_put, sizeof(*ptr), GFP_KERNEL);
> +	if (!ptr)
> +		return ERR_PTR(-ENOMEM);
> +
> +	trig = iio_trigger_get_by_name(dev, name);
> +	if (IS_ERR(trig)) {
> +		devres_free(ptr);
> +		return trig;
> +	}
> +
> +	*ptr = trig;
> +	devres_add(dev, ptr);
> +
> +	return trig;
> +}
> +EXPORT_SYMBOL_GPL(devm_iio_trigger_get_by_name);
> diff --git a/include/linux/iio/trigger.h b/include/linux/iio/trigger.h
> index ea08302..1f1ec20 100644
> --- a/include/linux/iio/trigger.h
> +++ b/include/linux/iio/trigger.h
> @@ -173,6 +173,10 @@ void devm_iio_trigger_unregister(struct device *dev,
>  int iio_trigger_validate_own_device(struct iio_trigger *trig,
>  				     struct iio_dev *indio_dev);
>  
> +struct iio_trigger *iio_trigger_get_by_name(struct device *dev,
> +					    const char *name);
> +struct iio_trigger *devm_iio_trigger_get_by_name(struct device *dev,
> +						 const char *name);
>  #else
>  struct iio_trigger;
>  struct iio_trigger_ops;
>