From 2478a6ae4a6a4c8e3f7e9f6f849dffe92e5238e1 Mon Sep 17 00:00:00 2001 From: Suzuki K Poulose Date: Thu, 20 Sep 2018 13:18:11 -0600 Subject: coresight: Add support for CLAIM tag protocol 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 Signed-off-by: Suzuki K Poulose Signed-off-by: Mathieu Poirier Signed-off-by: Greg Kroah-Hartman --- include/linux/coresight.h | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'include/linux/coresight.h') diff --git a/include/linux/coresight.h b/include/linux/coresight.h index 53535821dc25..46c67a764877 100644 --- a/include/linux/coresight.h +++ b/include/linux/coresight.h @@ -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 -- cgit v1.2.3