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authorGeert Uytterhoeven <geert+renesas@glider.be>2018-11-13 13:47:44 +0100
committerPhilipp Zabel <p.zabel@pengutronix.de>2019-01-07 16:38:26 +0100
commiteaf91db0ab22dc2c664a9782f2f31dcbc410f3b5 (patch)
tree73558bd411854718af939759af7fb5a561abaf57
parent12c62b9d6ce57d37f3c03cc902c30498909fbc42 (diff)
downloadlinux-0-day-eaf91db0ab22dc2c664a9782f2f31dcbc410f3b5.tar.gz
reset: Add reset_control_get_count()
Currently the reset core has internal support for counting the number of resets for a device described in DT. Generalize this to devices using lookup resets, and export it for public use. This will be used by generic drivers that need to be sure a device is controlled by a single, dedicated reset line (e.g. vfio-platform). Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> [p.zabel@pengutronix.de: fixed a typo in reset_control_get_count comment] Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
-rw-r--r--drivers/reset/core.c41
-rw-r--r--include/linux/reset.h7
2 files changed, 48 insertions, 0 deletions
diff --git a/drivers/reset/core.c b/drivers/reset/core.c
index d1887c0..bce2d6a 100644
--- a/drivers/reset/core.c
+++ b/drivers/reset/core.c
@@ -795,3 +795,44 @@ devm_reset_control_array_get(struct device *dev, bool shared, bool optional)
return rstc;
}
EXPORT_SYMBOL_GPL(devm_reset_control_array_get);
+
+static int reset_control_get_count_from_lookup(struct device *dev)
+{
+ const struct reset_control_lookup *lookup;
+ const char *dev_id = dev_name(dev);
+ int count = 0;
+
+ if (!dev)
+ return -EINVAL;
+
+ mutex_lock(&reset_lookup_mutex);
+
+ list_for_each_entry(lookup, &reset_lookup_list, list) {
+ if (!strcmp(lookup->dev_id, dev_id))
+ count++;
+ }
+
+ mutex_unlock(&reset_lookup_mutex);
+
+ if (count == 0)
+ count = -ENOENT;
+
+ return count;
+}
+
+/**
+ * reset_control_get_count - Count number of resets available with a device
+ *
+ * @dev: device for which to return the number of resets
+ *
+ * Returns positive reset count on success, or error number on failure and
+ * on count being zero.
+ */
+int reset_control_get_count(struct device *dev)
+{
+ if (dev->of_node)
+ return of_reset_control_get_count(dev->of_node);
+
+ return reset_control_get_count_from_lookup(dev);
+}
+EXPORT_SYMBOL_GPL(reset_control_get_count);
diff --git a/include/linux/reset.h b/include/linux/reset.h
index 76690cf..c1901b6 100644
--- a/include/linux/reset.h
+++ b/include/linux/reset.h
@@ -32,6 +32,8 @@ struct reset_control *devm_reset_control_array_get(struct device *dev,
struct reset_control *of_reset_control_array_get(struct device_node *np,
bool shared, bool optional);
+int reset_control_get_count(struct device *dev);
+
#else
static inline int reset_control_reset(struct reset_control *rstc)
@@ -97,6 +99,11 @@ of_reset_control_array_get(struct device_node *np, bool shared, bool optional)
return optional ? NULL : ERR_PTR(-ENOTSUPP);
}
+static inline int reset_control_get_count(struct device *dev)
+{
+ return -ENOENT;
+}
+
#endif /* CONFIG_RESET_CONTROLLER */
static inline int __must_check device_reset(struct device *dev)