From c84b0326d5e4fe08d493f6fff245da2ad473f4ae Mon Sep 17 00:00:00 2001 From: Philipp Zabel Date: Thu, 21 Feb 2019 16:25:53 +0100 Subject: reset: add acquired/released state for exclusive reset controls There are cases where a driver needs explicit control over a reset line that is exclusively conneted to its device, but this control has to be temporarily handed over to the power domain controller to handle reset requirements during power transitions. Allow multiple exclusive reset controls to be requested in 'released' state for the same physical reset line, only one of which can be acquired at the same time. Signed-off-by: Philipp Zabel Signed-off-by: Thierry Reding --- include/linux/reset.h | 93 ++++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 73 insertions(+), 20 deletions(-) (limited to 'include') diff --git a/include/linux/reset.h b/include/linux/reset.h index c1901b61ca30..ea9a8a1ce4b1 100644 --- a/include/linux/reset.h +++ b/include/linux/reset.h @@ -14,18 +14,20 @@ 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); +int reset_control_acquire(struct reset_control *rstc); +void reset_control_release(struct reset_control *rstc); struct reset_control *__of_reset_control_get(struct device_node *node, const char *id, int index, bool shared, - bool optional); + bool optional, bool acquired); struct reset_control *__reset_control_get(struct device *dev, const char *id, int index, bool shared, - bool optional); + bool optional, bool acquired); void reset_control_put(struct reset_control *rstc); int __device_reset(struct device *dev, bool optional); struct reset_control *__devm_reset_control_get(struct device *dev, const char *id, int index, bool shared, - bool optional); + bool optional, bool acquired); struct reset_control *devm_reset_control_array_get(struct device *dev, bool shared, bool optional); @@ -56,6 +58,15 @@ static inline int reset_control_status(struct reset_control *rstc) return 0; } +static inline int reset_control_acquire(struct reset_control *rstc) +{ + return 0; +} + +static inline void reset_control_release(struct reset_control *rstc) +{ +} + static inline void reset_control_put(struct reset_control *rstc) { } @@ -68,21 +79,23 @@ static inline int __device_reset(struct device *dev, bool optional) static inline struct reset_control *__of_reset_control_get( struct device_node *node, const char *id, int index, bool shared, - bool optional) + bool optional, bool acquired) { return optional ? NULL : ERR_PTR(-ENOTSUPP); } static inline struct reset_control *__reset_control_get( struct device *dev, const char *id, - int index, bool shared, bool optional) + int index, bool shared, bool optional, + bool acquired) { return optional ? NULL : ERR_PTR(-ENOTSUPP); } static inline struct reset_control *__devm_reset_control_get( struct device *dev, const char *id, - int index, bool shared, bool optional) + int index, bool shared, bool optional, + bool acquired) { return optional ? NULL : ERR_PTR(-ENOTSUPP); } @@ -134,7 +147,28 @@ static inline int device_reset_optional(struct device *dev) static inline struct reset_control * __must_check reset_control_get_exclusive(struct device *dev, const char *id) { - return __reset_control_get(dev, id, 0, false, false); + return __reset_control_get(dev, id, 0, false, false, true); +} + +/** + * reset_control_get_exclusive_released - Lookup and obtain a temoprarily + * exclusive reference to a reset + * controller. + * @dev: device to be reset by the controller + * @id: reset line name + * + * Returns a struct reset_control or IS_ERR() condition containing errno. + * reset-controls returned by this function must be acquired via + * reset_control_acquire() before they can be used and should be released + * via reset_control_release() afterwards. + * + * Use of id names is optional. + */ +static inline struct reset_control * +__must_check reset_control_get_exclusive_released(struct device *dev, + const char *id) +{ + return __reset_control_get(dev, id, 0, false, false, false); } /** @@ -162,19 +196,19 @@ __must_check reset_control_get_exclusive(struct device *dev, const char *id) static inline struct reset_control *reset_control_get_shared( struct device *dev, const char *id) { - return __reset_control_get(dev, id, 0, true, false); + return __reset_control_get(dev, id, 0, true, false, false); } static inline struct reset_control *reset_control_get_optional_exclusive( struct device *dev, const char *id) { - return __reset_control_get(dev, id, 0, false, true); + return __reset_control_get(dev, id, 0, false, true, true); } static inline struct reset_control *reset_control_get_optional_shared( struct device *dev, const char *id) { - return __reset_control_get(dev, id, 0, true, true); + return __reset_control_get(dev, id, 0, true, true, false); } /** @@ -190,7 +224,7 @@ static inline struct reset_control *reset_control_get_optional_shared( static inline struct reset_control *of_reset_control_get_exclusive( struct device_node *node, const char *id) { - return __of_reset_control_get(node, id, 0, false, false); + return __of_reset_control_get(node, id, 0, false, false, true); } /** @@ -215,7 +249,7 @@ static inline struct reset_control *of_reset_control_get_exclusive( static inline struct reset_control *of_reset_control_get_shared( struct device_node *node, const char *id) { - return __of_reset_control_get(node, id, 0, true, false); + return __of_reset_control_get(node, id, 0, true, false, false); } /** @@ -232,7 +266,7 @@ static inline struct reset_control *of_reset_control_get_shared( static inline struct reset_control *of_reset_control_get_exclusive_by_index( struct device_node *node, int index) { - return __of_reset_control_get(node, NULL, index, false, false); + return __of_reset_control_get(node, NULL, index, false, false, true); } /** @@ -260,7 +294,7 @@ static inline struct reset_control *of_reset_control_get_exclusive_by_index( static inline struct reset_control *of_reset_control_get_shared_by_index( struct device_node *node, int index) { - return __of_reset_control_get(node, NULL, index, true, false); + return __of_reset_control_get(node, NULL, index, true, false, false); } /** @@ -279,7 +313,26 @@ static inline struct reset_control * __must_check devm_reset_control_get_exclusive(struct device *dev, const char *id) { - return __devm_reset_control_get(dev, id, 0, false, false); + return __devm_reset_control_get(dev, id, 0, false, false, true); +} + +/** + * devm_reset_control_get_exclusive_released - resource managed + * reset_control_get_exclusive_released() + * @dev: device to be reset by the controller + * @id: reset line name + * + * Managed reset_control_get_exclusive_released(). For reset controllers + * returned from this function, reset_control_put() is called automatically on + * driver detach. + * + * See reset_control_get_exclusive_released() for more information. + */ +static inline struct reset_control * +__must_check devm_reset_control_get_exclusive_released(struct device *dev, + const char *id) +{ + return __devm_reset_control_get(dev, id, 0, false, false, false); } /** @@ -294,19 +347,19 @@ __must_check devm_reset_control_get_exclusive(struct device *dev, static inline struct reset_control *devm_reset_control_get_shared( struct device *dev, const char *id) { - return __devm_reset_control_get(dev, id, 0, true, false); + return __devm_reset_control_get(dev, id, 0, true, false, false); } 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, false, true); + return __devm_reset_control_get(dev, id, 0, false, true, true); } 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, true, true); + return __devm_reset_control_get(dev, id, 0, true, true, false); } /** @@ -324,7 +377,7 @@ static inline struct reset_control *devm_reset_control_get_optional_shared( static inline struct reset_control * devm_reset_control_get_exclusive_by_index(struct device *dev, int index) { - return __devm_reset_control_get(dev, NULL, index, false, false); + return __devm_reset_control_get(dev, NULL, index, false, false, true); } /** @@ -340,7 +393,7 @@ devm_reset_control_get_exclusive_by_index(struct device *dev, int index) static inline struct reset_control * devm_reset_control_get_shared_by_index(struct device *dev, int index) { - return __devm_reset_control_get(dev, NULL, index, true, false); + return __devm_reset_control_get(dev, NULL, index, true, false, false); } /* -- cgit v1.2.3 From f31d5c24fb2ea6fcfa4d300886eb87b662fbc0da Mon Sep 17 00:00:00 2001 From: Thierry Reding Date: Thu, 21 Feb 2019 16:25:54 +0100 Subject: reset: Add acquired flag to of_reset_control_array_get() In order to be able to request an array of reset controls in acquired or released mode, add the acquired flag to of_reset_control_array_get() and pass the flag to subsequent calls of __of_reset_control_get(). Signed-off-by: Thierry Reding Acked-by: Felipe Balbi Signed-off-by: Philipp Zabel --- drivers/reset/core.c | 9 ++++++--- drivers/usb/dwc3/dwc3-of-simple.c | 3 ++- include/linux/reset.h | 14 ++++++++------ 3 files changed, 16 insertions(+), 10 deletions(-) (limited to 'include') diff --git a/drivers/reset/core.c b/drivers/reset/core.c index 1e8a42b16f23..f94da91c22af 100644 --- a/drivers/reset/core.c +++ b/drivers/reset/core.c @@ -830,12 +830,15 @@ static int of_reset_control_get_count(struct device_node *node) * @np: device node for the device that requests the reset controls array * @shared: whether reset controls are shared or not * @optional: whether it is optional to get the reset controls + * @acquired: only one reset control may be acquired for a given controller + * and ID * * Returns pointer to allocated reset_control_array on success or * error on failure */ struct reset_control * -of_reset_control_array_get(struct device_node *np, bool shared, bool optional) +of_reset_control_array_get(struct device_node *np, bool shared, bool optional, + bool acquired) { struct reset_control_array *resets; struct reset_control *rstc; @@ -851,7 +854,7 @@ of_reset_control_array_get(struct device_node *np, bool shared, bool optional) for (i = 0; i < num; i++) { rstc = __of_reset_control_get(np, NULL, i, shared, optional, - true); + acquired); if (IS_ERR(rstc)) goto err_rst; resets->rstc[i] = rstc; @@ -898,7 +901,7 @@ devm_reset_control_array_get(struct device *dev, bool shared, bool optional) if (!devres) return ERR_PTR(-ENOMEM); - rstc = of_reset_control_array_get(dev->of_node, shared, optional); + rstc = of_reset_control_array_get(dev->of_node, shared, optional, true); if (IS_ERR(rstc)) { devres_free(devres); return rstc; diff --git a/drivers/usb/dwc3/dwc3-of-simple.c b/drivers/usb/dwc3/dwc3-of-simple.c index 4c2771c5e727..67ce2037472d 100644 --- a/drivers/usb/dwc3/dwc3-of-simple.c +++ b/drivers/usb/dwc3/dwc3-of-simple.c @@ -107,7 +107,8 @@ static int dwc3_of_simple_probe(struct platform_device *pdev) simple->pulse_resets = true; } - simple->resets = of_reset_control_array_get(np, shared_resets, true); + simple->resets = of_reset_control_array_get(np, shared_resets, true, + true); if (IS_ERR(simple->resets)) { ret = PTR_ERR(simple->resets); dev_err(dev, "failed to get device resets, err=%d\n", ret); diff --git a/include/linux/reset.h b/include/linux/reset.h index ea9a8a1ce4b1..a01b32bf51d4 100644 --- a/include/linux/reset.h +++ b/include/linux/reset.h @@ -32,7 +32,8 @@ struct reset_control *__devm_reset_control_get(struct device *dev, struct reset_control *devm_reset_control_array_get(struct device *dev, bool shared, bool optional); struct reset_control *of_reset_control_array_get(struct device_node *np, - bool shared, bool optional); + bool shared, bool optional, + bool acquired); int reset_control_get_count(struct device *dev); @@ -107,7 +108,8 @@ devm_reset_control_array_get(struct device *dev, bool shared, bool optional) } static inline struct reset_control * -of_reset_control_array_get(struct device_node *np, bool shared, bool optional) +of_reset_control_array_get(struct device_node *np, bool shared, bool optional, + bool acquired) { return optional ? NULL : ERR_PTR(-ENOTSUPP); } @@ -465,24 +467,24 @@ devm_reset_control_array_get_optional_shared(struct device *dev) static inline struct reset_control * of_reset_control_array_get_exclusive(struct device_node *node) { - return of_reset_control_array_get(node, false, false); + return of_reset_control_array_get(node, false, false, true); } static inline struct reset_control * of_reset_control_array_get_shared(struct device_node *node) { - return of_reset_control_array_get(node, true, false); + return of_reset_control_array_get(node, true, false, true); } static inline struct reset_control * of_reset_control_array_get_optional_exclusive(struct device_node *node) { - return of_reset_control_array_get(node, false, true); + return of_reset_control_array_get(node, false, true, true); } static inline struct reset_control * of_reset_control_array_get_optional_shared(struct device_node *node) { - return of_reset_control_array_get(node, true, true); + return of_reset_control_array_get(node, true, true, true); } #endif -- cgit v1.2.3 From 22815f1825e4c50314e7084ca375f7368704fdd4 Mon Sep 17 00:00:00 2001 From: Thierry Reding Date: Thu, 21 Feb 2019 16:25:55 +0100 Subject: reset: Add acquire/release support for arrays Add implementations that apply acquire and release operations to all reset controls part of a reset control array. Signed-off-by: Thierry Reding Reviewed-by: Philipp Zabel Signed-off-by: Philipp Zabel --- drivers/reset/core.c | 36 +++++++++++++++++++++++++++++++++++- include/linux/reset.h | 6 ++++++ 2 files changed, 41 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/drivers/reset/core.c b/drivers/reset/core.c index f94da91c22af..81ea77cba123 100644 --- a/drivers/reset/core.c +++ b/drivers/reset/core.c @@ -245,6 +245,34 @@ err: return ret; } +static int reset_control_array_acquire(struct reset_control_array *resets) +{ + unsigned int i; + int err; + + for (i = 0; i < resets->num_rstcs; i++) { + err = reset_control_acquire(resets->rstc[i]); + if (err < 0) + goto release; + } + + return 0; + +release: + while (i--) + reset_control_release(resets->rstc[i]); + + return err; +} + +static void reset_control_array_release(struct reset_control_array *resets) +{ + unsigned int i; + + for (i = 0; i < resets->num_rstcs; i++) + reset_control_release(resets->rstc[i]); +} + static inline bool reset_control_is_array(struct reset_control *rstc) { return rstc->array; @@ -464,6 +492,9 @@ int reset_control_acquire(struct reset_control *rstc) if (WARN_ON(IS_ERR(rstc))) return -EINVAL; + if (reset_control_is_array(rstc)) + return reset_control_array_acquire(rstc_to_array(rstc)); + mutex_lock(&reset_list_mutex); if (rstc->acquired) { @@ -502,7 +533,10 @@ void reset_control_release(struct reset_control *rstc) if (!rstc || WARN_ON(IS_ERR(rstc))) return; - rstc->acquired = false; + if (reset_control_is_array(rstc)) + reset_control_array_release(rstc_to_array(rstc)); + else + rstc->acquired = false; } EXPORT_SYMBOL_GPL(reset_control_release); diff --git a/include/linux/reset.h b/include/linux/reset.h index a01b32bf51d4..95d555c2130a 100644 --- a/include/linux/reset.h +++ b/include/linux/reset.h @@ -470,6 +470,12 @@ of_reset_control_array_get_exclusive(struct device_node *node) return of_reset_control_array_get(node, false, false, true); } +static inline struct reset_control * +of_reset_control_array_get_exclusive_released(struct device_node *node) +{ + return of_reset_control_array_get(node, false, false, false); +} + static inline struct reset_control * of_reset_control_array_get_shared(struct device_node *node) { -- cgit v1.2.3