[PATCH 09/14] iio: inkern: triggers: create helpers for OF trigger retrieval

Eugen Hristev
2017-12-22T15:07:16Z

Create helper API to get trigger information from OF regarding
trigger producer/consumer for iio triggers.
The functions will search for matching trigger by name, similar
with channel retrieval

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
---
drivers/iio/inkern.c | 91 ++++++++++++++++++++++++++++++++++++
include/linux/iio/trigger_consumer.h | 1 +
2 files changed, 92 insertions(+)

diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c
index 069defc..58bd18d 100644
--- a/drivers/iio/inkern.c
+++ b/drivers/iio/inkern.c
@@ -14,9 +14,13 @@

#include <linux/iio/iio.h>
#include "iio_core.h"
+#include "iio_core_trigger.h"
#include <linux/iio/machine.h>
#include <linux/iio/driver.h>
#include <linux/iio/consumer.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+

struct iio_map_internal {
struct iio_dev *indio_dev;
@@ -262,6 +266,39 @@ static struct iio_channel *of_iio_channel_get_all(struct device *dev)
return ERR_PTR(ret);
}

+#ifdef CONFIG_IIO_TRIGGER
+
+static struct iio_trigger *of_iio_trigger_get(struct device_node *np, int index)
+{
+ struct device *idev;
+ struct iio_dev *indio_dev;
+ int err;
+ struct of_phandle_args iiospec;
+ struct iio_trigger *trig;
+
+ err = of_parse_phandle_with_args(np, "io-triggers",
+ "#io-trigger-cells",
+ index, &iiospec);
+ if (err)
+ return ERR_PTR(err);
+
+ idev = bus_find_device(&iio_bus_type, NULL, iiospec.np,
+ iio_dev_node_match);
+ of_node_put(iiospec.np);
+ if (!idev)
+ return ERR_PTR(-EPROBE_DEFER);
+
+ indio_dev = dev_to_iio_dev(idev);
+
+ trig = iio_trigger_find_from_device(indio_dev, iiospec.args[0]);
+
+ if (!trig)
+ return ERR_PTR(-ENODEV);
+
+ return trig;
+}
+#endif /* CONFIG_IIO_TRIGGER */
+
#else /* CONFIG_OF */

static inline struct iio_channel *
@@ -275,6 +312,12 @@ static inline struct iio_channel *of_iio_channel_get_all(struct device *dev)
return NULL;
}

+static inline struct iio_trigger *of_iio_trigger_get(struct device_node *np,
+ int index)
+{
+ return NULL;
+}
+
#endif /* CONFIG_OF */

static struct iio_channel *iio_channel_get_sys(const char *name,
@@ -927,3 +970,51 @@ ssize_t iio_write_channel_ext_info(struct iio_channel *chan, const char *attr,
chan->channel, buf, len);
}
EXPORT_SYMBOL_GPL(iio_write_channel_ext_info);
+
+#ifdef CONFIG_IIO_TRIGGER
+struct iio_trigger *iio_trigger_find(struct device *dev, char *name)
+{
+ struct device_node *np = dev->of_node;
+ struct iio_trigger *trig = NULL;
+
+ /* Walk up the tree of devices looking for a matching iio trigger */
+ while (np) {
+ int index = 0;
+
+ /*
+ * For named iio triggers, first look up the name in the
+ * "io-trigger-names" property. If it cannot be found, the
+ * index will be an error code, and of_iio_trigger_get()
+ * will fail.
+ */
+ if (name)
+ index = of_property_match_string(np, "io-trigger-names",
+ name);
+ trig = of_iio_trigger_get(np, index);
+ if (!IS_ERR(trig) || PTR_ERR(trig) == -EPROBE_DEFER) {
+ break;
+ } else if (name && index >= 0) {
+ pr_err("ERROR: could not get IIO trigger %pOF:%s(%i)\n",
+ np, name ? name : "", index);
+ return trig;
+ }
+
+ /*
+ * No matching IIO trigger found on this node.
+ * If the parent node has a "io-trigger-ranges" property,
+ * then we can try one of its channels.
+ */
+ np = np->parent;
+ if (np && !of_get_property(np, "io-trigger-ranges", NULL))
+ return trig;
+ }
+
+ if (!trig || (IS_ERR(trig) && PTR_ERR(trig) != -EPROBE_DEFER))
+ dev_dbg(dev, "error retrieving trigger information\n");
+ else
+ dev_dbg(dev, "trigger found: %s\n", name);
+
+ return trig;
+}
+EXPORT_SYMBOL_GPL(iio_trigger_find);
+#endif /* CONFIG_IIO_TRIGGER */
diff --git a/include/linux/iio/trigger_consumer.h b/include/linux/iio/trigger_consumer.h
index 13be595..b2fc485 100644
--- a/include/linux/iio/trigger_consumer.h
+++ b/include/linux/iio/trigger_consumer.h
@@ -62,6 +62,7 @@ irqreturn_t iio_pollfunc_store_time(int irq, void *p);

void iio_trigger_notify_done(struct iio_trigger *trig);

+struct iio_trigger *iio_trigger_find(struct device *dev, char *name);
/*
* Two functions for common case where all that happens is a pollfunc
* is attached and detached from a trigger
--
2.7.4