From 729de41baf63e2172b9d61de61bbd53f231095ca Mon Sep 17 00:00:00 2001 From: Dinh Nguyen Date: Fri, 10 Oct 2014 10:21:14 -0500 Subject: reset: add reset_control_status helper function There are cases where a system will want to read a reset status bit before doing any other toggling. Add a reset_control_status helper function to the reset controller API. Signed-off-by: Dinh Nguyen Signed-off-by: Philipp Zabel --- drivers/reset/core.c | 15 +++++++++++++++ include/linux/reset-controller.h | 2 ++ include/linux/reset.h | 7 +++++++ 3 files changed, 24 insertions(+) diff --git a/drivers/reset/core.c b/drivers/reset/core.c index baeaf82d40d9..7955e00d04d4 100644 --- a/drivers/reset/core.c +++ b/drivers/reset/core.c @@ -125,6 +125,21 @@ int reset_control_deassert(struct reset_control *rstc) } 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. + * @rstc: reset controller + */ +int reset_control_status(struct reset_control *rstc) +{ + if (rstc->rcdev->ops->status) + return rstc->rcdev->ops->status(rstc->rcdev, rstc->id); + + return -ENOSYS; +} +EXPORT_SYMBOL_GPL(reset_control_status); + /** * of_reset_control_get - Lookup and obtain a reference to a reset controller. * @node: device to be reset by the controller diff --git a/include/linux/reset-controller.h b/include/linux/reset-controller.h index 41a4695fde08..ce6b962ffed4 100644 --- a/include/linux/reset-controller.h +++ b/include/linux/reset-controller.h @@ -12,11 +12,13 @@ struct reset_controller_dev; * things to reset the device * @assert: manually assert the reset line, if supported * @deassert: manually deassert the reset line, if supported + * @status: return the status of the reset line, if supported */ struct reset_control_ops { int (*reset)(struct reset_controller_dev *rcdev, unsigned long id); int (*assert)(struct reset_controller_dev *rcdev, unsigned long id); int (*deassert)(struct reset_controller_dev *rcdev, unsigned long id); + int (*status)(struct reset_controller_dev *rcdev, unsigned long id); }; struct module; diff --git a/include/linux/reset.h b/include/linux/reset.h index 349f150ae12c..da5602bd77d7 100644 --- a/include/linux/reset.h +++ b/include/linux/reset.h @@ -10,6 +10,7 @@ struct reset_control; int reset_control_reset(struct reset_control *rstc); int reset_control_assert(struct reset_control *rstc); int reset_control_deassert(struct reset_control *rstc); +int reset_control_status(struct reset_control *rstc); struct reset_control *reset_control_get(struct device *dev, const char *id); void reset_control_put(struct reset_control *rstc); @@ -57,6 +58,12 @@ static inline int reset_control_deassert(struct reset_control *rstc) return 0; } +static inline int reset_control_status(struct reset_control *rstc) +{ + WARN_ON(1); + return 0; +} + static inline void reset_control_put(struct reset_control *rstc) { WARN_ON(1); -- cgit v1.2.3