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| author | Geert Uytterhoeven <geert+renesas@glider.be> | 2018-11-13 13:47:44 +0100 |
|---|---|---|
| committer | Philipp Zabel <p.zabel@pengutronix.de> | 2019-01-07 16:38:26 +0100 |
| commit | eaf91db0ab22dc2c664a9782f2f31dcbc410f3b5 (patch) | |
| tree | 73558bd411854718af939759af7fb5a561abaf57 | |
| parent | 12c62b9d6ce57d37f3c03cc902c30498909fbc42 (diff) | |
| download | linux-0-day-eaf91db0ab22dc2c664a9782f2f31dcbc410f3b5.tar.gz linux-0-day-eaf91db0ab22dc2c664a9782f2f31dcbc410f3b5.tar.xz | |
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.c | 41 | ||||
| -rw-r--r-- | include/linux/reset.h | 7 |
2 files changed, 48 insertions, 0 deletions
diff --git a/drivers/reset/core.c b/drivers/reset/core.c index d1887c0ed5d3f..bce2d6aefef98 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 76690cf2e3e02..c1901b61ca300 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) |