Up until now optional functions in the reset API were similar to the non optional.
This patch corrects that, while maintaining compatibility with existing drivers. As suggested here: https://lkml.org/lkml/2016/12/14/502 Signed-off-by: Ramiro Oliveira <ramiro.olive...@synopsys.com> --- drivers/reset/core.c | 21 +++++++++++++++++++-- include/linux/reset.h | 46 ++++++++++++++++++++++++++++++++++++++++++---- 2 files changed, 61 insertions(+), 6 deletions(-) diff --git a/drivers/reset/core.c b/drivers/reset/core.c index 395dc9c..6150e7c 100644 --- a/drivers/reset/core.c +++ b/drivers/reset/core.c @@ -135,9 +135,14 @@ EXPORT_SYMBOL_GPL(devm_reset_controller_register); * @rstc: reset controller * * Calling this on a shared reset controller is an error. + * + * If it's an optional reset it will return 0. */ int reset_control_reset(struct reset_control *rstc) { + if (!rstc) + return 0; + if (WARN_ON(rstc->shared)) return -EINVAL; @@ -158,9 +163,14 @@ EXPORT_SYMBOL_GPL(reset_control_reset); * * For shared reset controls a driver cannot expect the hw's registers and * internal state to be reset, but must be prepared for this to happen. + * + * If it's an optional reset it will return 0. */ int reset_control_assert(struct reset_control *rstc) { + if (!rstc) + return 0; + if (!rstc->rcdev->ops->assert) return -ENOTSUPP; @@ -180,10 +190,14 @@ EXPORT_SYMBOL_GPL(reset_control_assert); * reset_control_deassert - deasserts the reset line * @rstc: reset controller * - * After calling this function, the reset is guaranteed to be deasserted. + * After calling this function, the reset is guaranteed to be deasserted, if + * it's not optional. */ int reset_control_deassert(struct reset_control *rstc) { + if (!rstc) + return 0; + if (!rstc->rcdev->ops->deassert) return -ENOTSUPP; @@ -199,11 +213,14 @@ EXPORT_SYMBOL_GPL(reset_control_deassert); /** * reset_control_status - returns a negative errno if not supported, a * positive value if the reset line is asserted, or zero if the reset - * line is not asserted. + * line is not asserted or if the desc is NULL (optional reset). * @rstc: reset controller */ int reset_control_status(struct reset_control *rstc) { + if (!rstc) + return 0; + if (rstc->rcdev->ops->status) return rstc->rcdev->ops->status(rstc->rcdev, rstc->id); diff --git a/include/linux/reset.h b/include/linux/reset.h index 5daff15..1af1e62 100644 --- a/include/linux/reset.h +++ b/include/linux/reset.h @@ -138,13 +138,33 @@ static inline struct reset_control *reset_control_get_shared( static inline struct reset_control *reset_control_get_optional_exclusive( struct device *dev, const char *id) { - return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, 0); + struct reset_control *desc; + + desc = __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, 0); + + if (IS_ERR(desc)) { + if (PTR_ERR(desc) == -ENOENT) + return NULL; + } + + return desc; + } static inline struct reset_control *reset_control_get_optional_shared( struct device *dev, const char *id) { - return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, 1); + + struct reset_control *desc; + + desc = __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, 1); + + if (IS_ERR(desc)) { + if (PTR_ERR(desc) == -ENOENT) + return NULL; + } + + return desc; } /** @@ -273,13 +293,31 @@ static inline struct reset_control *devm_reset_control_get_shared( static inline struct reset_control *devm_reset_control_get_optional_exclusive( struct device *dev, const char *id) { - return __devm_reset_control_get(dev, id, 0, 0); + struct reset_control *desc; + + desc = __devm_reset_control_get(dev, id, 0, 0); + + if (IS_ERR(desc)) { + if (PTR_ERR(desc) == -ENOENT) + return NULL; + } + + return desc; } static inline struct reset_control *devm_reset_control_get_optional_shared( struct device *dev, const char *id) { - return __devm_reset_control_get(dev, id, 0, 1); + struct reset_control *desc; + + desc = __devm_reset_control_get(dev, id, 0, 1); + + if (IS_ERR(desc)) { + if (PTR_ERR(desc) == -ENOENT) + return NULL; + } + + return desc; } /** -- 2.10.2
