GitHub-Mirror/Star64_linux
2
0
Fork 0
mirror of https://github.com/Fishwaldo/Star64_linux.git synced 2025-07-23 23:32:14 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

coresight: Add support for CLAIM tag protocol

Browse source 
Coresight architecture defines CLAIM tags for a device to negotiate
control of the components (external agent vs self-hosted). Each device
has a pair of registers (CLAIMSET & CLAIMCLR) for managing the CLAIM
tags. However, the protocol for the CLAIM tags is IMPLEMENTATION DEFINED.
PSCI has recommendations for the use of the CLAIM tags to negotiate
controls for external agent vs self-hosted use. This patch implements
the recommended protocol by PSCI.

The claim/disclaim operations are performed from the device specific
drivers. The disadvantage is that the calls are sprinkled in each driver,
but this makes the operation much simpler.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Suzuki K Poulose 2018-09-20 13:18:11 -06:00 • committed by Greg Kroah-Hartman
parent 30af4fb619
commit 2478a6ae4a
3 changed files with 113 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

20
include/linux/coresight.h
View file

@ -257,6 +257,13 @@ extern int coresight_enable(struct coresight_device *csdev);
extern void coresight_disable(struct coresight_device *csdev);
extern int coresight_timeout(void __iomem *addr, u32 offset,
int position, int value);
extern int coresight_claim_device(void __iomem *base);
extern int coresight_claim_device_unlocked(void __iomem *base);
extern void coresight_disclaim_device(void __iomem *base);
extern void coresight_disclaim_device_unlocked(void __iomem *base);
#else
static inline struct coresight_device *
coresight_register(struct coresight_desc *desc) { return NULL; }
@ -266,6 +273,19 @@ coresight_enable(struct coresight_device *csdev) { return -ENOSYS; }
static inline void coresight_disable(struct coresight_device *csdev) {}
static inline int coresight_timeout(void __iomem *addr, u32 offset,
int position, int value) { return 1; }
static inline int coresight_claim_device_unlocked(void __iomem *base)
{
return -EINVAL;
}
static inline int coresight_claim_device(void __iomem *base)
{
return -EINVAL;
}
static inline void coresight_disclaim_device(void __iomem *base) {}
static inline void coresight_disclaim_device_unlocked(void __iomem *base) {}
#endif
#ifdef CONFIG_OF