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reset: Add devres helpers to request pre-deasserted reset controls
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Add devres helpers

 - devm_reset_control_bulk_get_exclusive_deasserted
 - devm_reset_control_bulk_get_optional_exclusive_deasserted
 - devm_reset_control_bulk_get_optional_shared_deasserted
 - devm_reset_control_bulk_get_shared_deasserted
 - devm_reset_control_get_exclusive_deasserted
 - devm_reset_control_get_optional_exclusive_deasserted
 - devm_reset_control_get_optional_shared_deasserted
 - devm_reset_control_get_shared_deasserted

to request and immediately deassert reset controls. During cleanup,
reset_control_assert() will be called automatically on the returned
reset controls.

Acked-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://lore.kernel.org/r/20240925-reset-get-deasserted-v2-2-b3601bbd0458@pengutronix.de
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
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Philipp Zabel committed Oct 1, 2024
1 parent dad35f7 commit d872bed
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Showing 2 changed files with 159 additions and 2 deletions.
48 changes: 46 additions & 2 deletions drivers/reset/core.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1236,23 +1236,46 @@ static void devm_reset_control_release(struct device *dev, void *res)
reset_control_put(*(struct reset_control **)res);
}

static void devm_reset_control_release_deasserted(struct device *dev, void *res)
{
struct reset_control *rstc = *(struct reset_control **)res;

reset_control_assert(rstc);
reset_control_put(rstc);
}

struct reset_control *
__devm_reset_control_get(struct device *dev, const char *id, int index,
enum reset_control_flags flags)
{
struct reset_control **ptr, *rstc;
bool deasserted = flags & RESET_CONTROL_FLAGS_BIT_DEASSERTED;

ptr = devres_alloc(devm_reset_control_release, sizeof(*ptr),
ptr = devres_alloc(deasserted ? devm_reset_control_release_deasserted :
devm_reset_control_release, sizeof(*ptr),
GFP_KERNEL);
if (!ptr)
return ERR_PTR(-ENOMEM);

flags &= ~RESET_CONTROL_FLAGS_BIT_DEASSERTED;

rstc = __reset_control_get(dev, id, index, flags);
if (IS_ERR_OR_NULL(rstc)) {
devres_free(ptr);
return rstc;
}

if (deasserted) {
int ret;

ret = reset_control_deassert(rstc);
if (ret) {
reset_control_put(rstc);
devres_free(ptr);
return ERR_PTR(ret);
}
}

*ptr = rstc;
devres_add(dev, ptr);

Expand All @@ -1272,24 +1295,45 @@ static void devm_reset_control_bulk_release(struct device *dev, void *res)
reset_control_bulk_put(devres->num_rstcs, devres->rstcs);
}

static void devm_reset_control_bulk_release_deasserted(struct device *dev, void *res)
{
struct reset_control_bulk_devres *devres = res;

reset_control_bulk_assert(devres->num_rstcs, devres->rstcs);
reset_control_bulk_put(devres->num_rstcs, devres->rstcs);
}

int __devm_reset_control_bulk_get(struct device *dev, int num_rstcs,
struct reset_control_bulk_data *rstcs,
enum reset_control_flags flags)
{
struct reset_control_bulk_devres *ptr;
bool deasserted = flags & RESET_CONTROL_FLAGS_BIT_DEASSERTED;
int ret;

ptr = devres_alloc(devm_reset_control_bulk_release, sizeof(*ptr),
ptr = devres_alloc(deasserted ? devm_reset_control_bulk_release_deasserted :
devm_reset_control_bulk_release, sizeof(*ptr),
GFP_KERNEL);
if (!ptr)
return -ENOMEM;

flags &= ~RESET_CONTROL_FLAGS_BIT_DEASSERTED;

ret = __reset_control_bulk_get(dev, num_rstcs, rstcs, flags);
if (ret < 0) {
devres_free(ptr);
return ret;
}

if (deasserted) {
ret = reset_control_bulk_deassert(num_rstcs, rstcs);
if (ret) {
reset_control_bulk_put(num_rstcs, rstcs);
devres_free(ptr);
return ret;
}
}

ptr->num_rstcs = num_rstcs;
ptr->rstcs = rstcs;
devres_add(dev, ptr);
Expand Down
113 changes: 113 additions & 0 deletions include/linux/reset.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -28,28 +28,43 @@ struct reset_control_bulk_data {
#define RESET_CONTROL_FLAGS_BIT_SHARED BIT(0) /* not exclusive */
#define RESET_CONTROL_FLAGS_BIT_OPTIONAL BIT(1)
#define RESET_CONTROL_FLAGS_BIT_ACQUIRED BIT(2) /* iff exclusive, not released */
#define RESET_CONTROL_FLAGS_BIT_DEASSERTED BIT(3)

/**
* enum reset_control_flags - Flags that can be passed to the reset_control_get functions
* to determine the type of reset control.
* These values cannot be OR'd.
*
* @RESET_CONTROL_EXCLUSIVE: exclusive, acquired,
* @RESET_CONTROL_EXCLUSIVE_DEASSERTED: exclusive, acquired, deasserted
* @RESET_CONTROL_EXCLUSIVE_RELEASED: exclusive, released,
* @RESET_CONTROL_SHARED: shared
* @RESET_CONTROL_SHARED_DEASSERTED: shared, deasserted
* @RESET_CONTROL_OPTIONAL_EXCLUSIVE: optional, exclusive, acquired
* @RESET_CONTROL_OPTIONAL_EXCLUSIVE_DEASSERTED: optional, exclusive, acquired, deasserted
* @RESET_CONTROL_OPTIONAL_EXCLUSIVE_RELEASED: optional, exclusive, released
* @RESET_CONTROL_OPTIONAL_SHARED: optional, shared
* @RESET_CONTROL_OPTIONAL_SHARED_DEASSERTED: optional, shared, deasserted
*/
enum reset_control_flags {
RESET_CONTROL_EXCLUSIVE = RESET_CONTROL_FLAGS_BIT_ACQUIRED,
RESET_CONTROL_EXCLUSIVE_DEASSERTED = RESET_CONTROL_FLAGS_BIT_ACQUIRED |
RESET_CONTROL_FLAGS_BIT_DEASSERTED,
RESET_CONTROL_EXCLUSIVE_RELEASED = 0,
RESET_CONTROL_SHARED = RESET_CONTROL_FLAGS_BIT_SHARED,
RESET_CONTROL_SHARED_DEASSERTED = RESET_CONTROL_FLAGS_BIT_SHARED |
RESET_CONTROL_FLAGS_BIT_DEASSERTED,
RESET_CONTROL_OPTIONAL_EXCLUSIVE = RESET_CONTROL_FLAGS_BIT_OPTIONAL |
RESET_CONTROL_FLAGS_BIT_ACQUIRED,
RESET_CONTROL_OPTIONAL_EXCLUSIVE_DEASSERTED = RESET_CONTROL_FLAGS_BIT_OPTIONAL |
RESET_CONTROL_FLAGS_BIT_ACQUIRED |
RESET_CONTROL_FLAGS_BIT_DEASSERTED,
RESET_CONTROL_OPTIONAL_EXCLUSIVE_RELEASED = RESET_CONTROL_FLAGS_BIT_OPTIONAL,
RESET_CONTROL_OPTIONAL_SHARED = RESET_CONTROL_FLAGS_BIT_OPTIONAL |
RESET_CONTROL_FLAGS_BIT_SHARED,
RESET_CONTROL_OPTIONAL_SHARED_DEASSERTED = RESET_CONTROL_FLAGS_BIT_OPTIONAL |
RESET_CONTROL_FLAGS_BIT_SHARED |
RESET_CONTROL_FLAGS_BIT_DEASSERTED,
};

#ifdef CONFIG_RESET_CONTROLLER
Expand Down Expand Up @@ -596,6 +611,25 @@ __must_check devm_reset_control_get_exclusive(struct device *dev,
return __devm_reset_control_get(dev, id, 0, RESET_CONTROL_EXCLUSIVE);
}

/**
* devm_reset_control_get_exclusive_deasserted - resource managed
* reset_control_get_exclusive() +
* reset_control_deassert()
* @dev: device to be reset by the controller
* @id: reset line name
*
* Managed reset_control_get_exclusive() + reset_control_deassert(). For reset
* controllers returned from this function, reset_control_assert() +
* reset_control_put() is called automatically on driver detach.
*
* See reset_control_get_exclusive() for more information.
*/
static inline struct reset_control * __must_check
devm_reset_control_get_exclusive_deasserted(struct device *dev, const char *id)
{
return __devm_reset_control_get(dev, id, 0, RESET_CONTROL_EXCLUSIVE_DEASSERTED);
}

/**
* devm_reset_control_bulk_get_exclusive - resource managed
* reset_control_bulk_get_exclusive()
Expand Down Expand Up @@ -712,6 +746,25 @@ static inline struct reset_control *devm_reset_control_get_shared(
return __devm_reset_control_get(dev, id, 0, RESET_CONTROL_SHARED);
}

/**
* devm_reset_control_get_shared_deasserted - resource managed
* reset_control_get_shared() +
* reset_control_deassert()
* @dev: device to be reset by the controller
* @id: reset line name
*
* Managed reset_control_get_shared() + reset_control_deassert(). For reset
* controllers returned from this function, reset_control_assert() +
* reset_control_put() is called automatically on driver detach.
*
* See devm_reset_control_get_shared() for more information.
*/
static inline struct reset_control * __must_check
devm_reset_control_get_shared_deasserted(struct device *dev, const char *id)
{
return __devm_reset_control_get(dev, id, 0, RESET_CONTROL_SHARED_DEASSERTED);
}

/**
* devm_reset_control_bulk_get_shared - resource managed
* reset_control_bulk_get_shared()
Expand All @@ -732,6 +785,28 @@ devm_reset_control_bulk_get_shared(struct device *dev, int num_rstcs,
return __devm_reset_control_bulk_get(dev, num_rstcs, rstcs, RESET_CONTROL_SHARED);
}

/**
* devm_reset_control_bulk_get_shared_deasserted - resource managed
* reset_control_bulk_get_shared() +
* reset_control_bulk_deassert()
* @dev: device to be reset by the controller
* @num_rstcs: number of entries in rstcs array
* @rstcs: array of struct reset_control_bulk_data with reset line names set
*
* Managed reset_control_bulk_get_shared() + reset_control_bulk_deassert(). For
* reset controllers returned from this function, reset_control_bulk_assert() +
* reset_control_bulk_put() are called automatically on driver detach.
*
* See devm_reset_control_bulk_get_shared() for more information.
*/
static inline int __must_check
devm_reset_control_bulk_get_shared_deasserted(struct device *dev, int num_rstcs,
struct reset_control_bulk_data *rstcs)
{
return __devm_reset_control_bulk_get(dev, num_rstcs, rstcs,
RESET_CONTROL_SHARED_DEASSERTED);
}

/**
* devm_reset_control_get_optional_exclusive - resource managed
* reset_control_get_optional_exclusive()
Expand All @@ -750,6 +825,25 @@ static inline struct reset_control *devm_reset_control_get_optional_exclusive(
return __devm_reset_control_get(dev, id, 0, RESET_CONTROL_OPTIONAL_EXCLUSIVE);
}

/**
* devm_reset_control_get_optional_exclusive_deasserted - resource managed
* reset_control_get_optional_exclusive() +
* reset_control_deassert()
* @dev: device to be reset by the controller
* @id: reset line name
*
* Managed reset_control_get_optional_exclusive() + reset_control_deassert().
* For reset controllers returned from this function, reset_control_assert() +
* reset_control_put() is called automatically on driver detach.
*
* See devm_reset_control_get_optional_exclusive() for more information.
*/
static inline struct reset_control *
devm_reset_control_get_optional_exclusive_deasserted(struct device *dev, const char *id)
{
return __devm_reset_control_get(dev, id, 0, RESET_CONTROL_OPTIONAL_EXCLUSIVE_DEASSERTED);
}

/**
* devm_reset_control_bulk_get_optional_exclusive - resource managed
* reset_control_bulk_get_optional_exclusive()
Expand Down Expand Up @@ -789,6 +883,25 @@ static inline struct reset_control *devm_reset_control_get_optional_shared(
return __devm_reset_control_get(dev, id, 0, RESET_CONTROL_OPTIONAL_SHARED);
}

/**
* devm_reset_control_get_optional_shared_deasserted - resource managed
* reset_control_get_optional_shared() +
* reset_control_deassert()
* @dev: device to be reset by the controller
* @id: reset line name
*
* Managed reset_control_get_optional_shared() + reset_control_deassert(). For
* reset controllers returned from this function, reset_control_assert() +
* reset_control_put() is called automatically on driver detach.
*
* See devm_reset_control_get_optional_shared() for more information.
*/
static inline struct reset_control *
devm_reset_control_get_optional_shared_deasserted(struct device *dev, const char *id)
{
return __devm_reset_control_get(dev, id, 0, RESET_CONTROL_OPTIONAL_SHARED_DEASSERTED);
}

/**
* devm_reset_control_bulk_get_optional_shared - resource managed
* reset_control_bulk_get_optional_shared()
Expand Down

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