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authorLinus Torvalds <torvalds@linux-foundation.org>2019-07-17 11:53:53 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-07-17 11:53:53 -0700
commit57ab5f740202babe93c8796013c5cfdfd6d08d7d (patch)
tree77ad80291bdaa8e95f2a26956a2d7d8625f049fa /Documentation
parentfdcec00405fae0befdd7bbcbe738b7325e5746fb (diff)
parent360aa640a59f269b784848c0b2d6d462952750d9 (diff)
Merge tag 'hwlock-v5.3' of git://github.com/andersson/remoteproc
Pull hwspinlock updates from Bjorn Andersson: "This contains support for hardware spinlock TI K3 AM65x and J721E family of SoCs, support for using hwspinlocks from atomic context and better error reporting when dealing with hardware disabled in DeviceTree" * tag 'hwlock-v5.3' of git://github.com/andersson/remoteproc: hwspinlock: add the 'in_atomic' API hwspinlock: document the hwspinlock 'raw' API hwspinlock: stm32: implement the relax() ops hwspinlock: ignore disabled device hwspinlock/omap: Add a trace during probe hwspinlock/omap: Add support for TI K3 SoCs dt-bindings: hwlock: Update OMAP binding for TI K3 SoCs
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/devicetree/bindings/hwlock/omap-hwspinlock.txt25
-rw-r--r--Documentation/hwspinlock.txt81
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