diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/devicetree/bindings/hwlock/omap-hwspinlock.txt | 25 | ||||
| -rw-r--r-- | Documentation/hwspinlock.txt | 81 |
2 files changed, 101 insertions, 5 deletions
diff --git a/Documentation/devicetree/bindings/hwlock/omap-hwspinlock.txt b/Documentation/devicetree/bindings/hwlock/omap-hwspinlock.txt index 2c9804f4f4ac..8d365f89694c 100644 --- a/Documentation/devicetree/bindings/hwlock/omap-hwspinlock.txt +++ b/Documentation/devicetree/bindings/hwlock/omap-hwspinlock.txt @@ -1,12 +1,16 @@ -OMAP4+ HwSpinlock Driver -======================== +TI HwSpinlock for OMAP and K3 based SoCs +========================================= Required properties: -- compatible: Should be "ti,omap4-hwspinlock" for - OMAP44xx, OMAP54xx, AM33xx, AM43xx, DRA7xx SoCs +- compatible: Should be one of the following, + "ti,omap4-hwspinlock" for + OMAP44xx, OMAP54xx, AM33xx, AM43xx, DRA7xx SoCs + "ti,am654-hwspinlock" for + K3 AM65x and J721E SoCs - reg: Contains the hwspinlock module register address space (base address and length) - ti,hwmods: Name of the hwmod associated with the hwspinlock device + (for OMAP architecture based SoCs only) - #hwlock-cells: Should be 1. The OMAP hwspinlock users will use a 0-indexed relative hwlock number as the argument specifier value for requesting a specific hwspinlock @@ -17,10 +21,21 @@ Please look at the generic hwlock binding for usage information for consumers, Example: -/* OMAP4 */ +1. OMAP4 SoCs hwspinlock: spinlock@4a0f6000 { compatible = "ti,omap4-hwspinlock"; reg = <0x4a0f6000 0x1000>; ti,hwmods = "spinlock"; #hwlock-cells = <1>; }; + +2. AM65x SoCs and J721E SoCs +&cbass_main { + cbass_main_navss: interconnect0 { + hwspinlock: spinlock@30e00000 { + compatible = "ti,am654-hwspinlock"; + reg = <0x00 0x30e00000 0x00 0x1000>; + #hwlock-cells = <1>; + }; + }; +}; diff --git a/Documentation/hwspinlock.txt b/Documentation/hwspinlock.txt index ed640a278185..6f03713b7003 100644 --- a/Documentation/hwspinlock.txt +++ b/Documentation/hwspinlock.txt @@ -136,6 +136,39 @@ The function will never sleep. :: + int hwspin_lock_timeout_raw(struct hwspinlock *hwlock, unsigned int timeout); + +Lock a previously-assigned hwspinlock with a timeout limit (specified in +msecs). If the hwspinlock is already taken, the function will busy loop +waiting for it to be released, but give up when the timeout elapses. + +Caution: User must protect the routine of getting hardware lock with mutex +or spinlock to avoid dead-lock, that will let user can do some time-consuming +or sleepable operations under the hardware lock. + +Returns 0 when successful and an appropriate error code otherwise (most +notably -ETIMEDOUT if the hwspinlock is still busy after timeout msecs). + +The function will never sleep. + +:: + + int hwspin_lock_timeout_in_atomic(struct hwspinlock *hwlock, unsigned int to); + +Lock a previously-assigned hwspinlock with a timeout limit (specified in +msecs). If the hwspinlock is already taken, the function will busy loop +waiting for it to be released, but give up when the timeout elapses. + +This function shall be called only from an atomic context and the timeout +value shall not exceed a few msecs. + +Returns 0 when successful and an appropriate error code otherwise (most +notably -ETIMEDOUT if the hwspinlock is still busy after timeout msecs). + +The function will never sleep. + +:: + int hwspin_trylock(struct hwspinlock *hwlock); @@ -186,6 +219,34 @@ The function will never sleep. :: + int hwspin_trylock_raw(struct hwspinlock *hwlock); + +Attempt to lock a previously-assigned hwspinlock, but immediately fail if +it is already taken. + +Caution: User must protect the routine of getting hardware lock with mutex +or spinlock to avoid dead-lock, that will let user can do some time-consuming +or sleepable operations under the hardware lock. + +Returns 0 on success and an appropriate error code otherwise (most +notably -EBUSY if the hwspinlock was already taken). +The function will never sleep. + +:: + + int hwspin_trylock_in_atomic(struct hwspinlock *hwlock); + +Attempt to lock a previously-assigned hwspinlock, but immediately fail if +it is already taken. + +This function shall be called only from an atomic context. + +Returns 0 on success and an appropriate error code otherwise (most +notably -EBUSY if the hwspinlock was already taken). +The function will never sleep. + +:: + void hwspin_unlock(struct hwspinlock *hwlock); Unlock a previously-locked hwspinlock. Always succeed, and can be called @@ -222,6 +283,26 @@ the given flags. This function will never sleep. :: + void hwspin_unlock_raw(struct hwspinlock *hwlock); + +Unlock a previously-locked hwspinlock. + +The caller should **never** unlock an hwspinlock which is already unlocked. +Doing so is considered a bug (there is no protection against this). +This function will never sleep. + +:: + + void hwspin_unlock_in_atomic(struct hwspinlock *hwlock); + +Unlock a previously-locked hwspinlock. + +The caller should **never** unlock an hwspinlock which is already unlocked. +Doing so is considered a bug (there is no protection against this). +This function will never sleep. + +:: + int hwspin_lock_get_id(struct hwspinlock *hwlock); Retrieve id number of a given hwspinlock. This is needed when an |