diff options
Diffstat (limited to 'drivers/pinctrl/core.c')
| -rw-r--r-- | drivers/pinctrl/core.c | 30 |
1 files changed, 26 insertions, 4 deletions
diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c index e6373f30aeeb..5a2fe9aae20f 100644 --- a/drivers/pinctrl/core.c +++ b/drivers/pinctrl/core.c @@ -14,6 +14,7 @@ #define pr_fmt(fmt) "pinctrl core: " fmt #include <linux/kernel.h> +#include <linux/kref.h> #include <linux/export.h> #include <linux/init.h> #include <linux/device.h> @@ -727,6 +728,8 @@ static struct pinctrl *create_pinctrl(struct device *dev) return ERR_PTR(ret); } + kref_init(&p->users); + /* Add the pinctrl handle to the global list */ list_add_tail(&p->node, &pinctrl_list); @@ -740,9 +743,17 @@ static struct pinctrl *pinctrl_get_locked(struct device *dev) if (WARN_ON(!dev)) return ERR_PTR(-EINVAL); + /* + * See if somebody else (such as the device core) has already + * obtained a handle to the pinctrl for this device. In that case, + * return another pointer to it. + */ p = find_pinctrl(dev); - if (p != NULL) - return ERR_PTR(-EBUSY); + if (p != NULL) { + dev_dbg(dev, "obtain a copy of previously claimed pinctrl\n"); + kref_get(&p->users); + return p; + } return create_pinctrl(dev); } @@ -798,13 +809,24 @@ static void pinctrl_put_locked(struct pinctrl *p, bool inlist) } /** - * pinctrl_put() - release a previously claimed pinctrl handle + * pinctrl_release() - release the pinctrl handle + * @kref: the kref in the pinctrl being released + */ +void pinctrl_release(struct kref *kref) +{ + struct pinctrl *p = container_of(kref, struct pinctrl, users); + + pinctrl_put_locked(p, true); +} + +/** + * pinctrl_put() - decrease use count on a previously claimed pinctrl handle * @p: the pinctrl handle to release */ void pinctrl_put(struct pinctrl *p) { mutex_lock(&pinctrl_mutex); - pinctrl_put_locked(p, true); + kref_put(&p->users, pinctrl_release); mutex_unlock(&pinctrl_mutex); } EXPORT_SYMBOL_GPL(pinctrl_put); |