Current coresight_timeout function spins on a bit on a test register, till bit value achieved or timeout hit.
Add another function to return the full value of the register being tested.
Signed-off-by: Mike Leach mike.leach@linaro.org --- drivers/hwtracing/coresight/coresight-core.c | 50 +++++++++++++++----- include/linux/coresight.h | 10 +++- 2 files changed, 48 insertions(+), 12 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c index d3bf82c0de1d..c4db111ab32b 100644 --- a/drivers/hwtracing/coresight/coresight-core.c +++ b/drivers/hwtracing/coresight/coresight-core.c @@ -1456,32 +1456,37 @@ static void coresight_remove_conns(struct coresight_device *csdev) }
/** - * coresight_timeout - loop until a bit has changed to a specific register - * state. + * coresight_timeout_retval - loop until a bit has changed to a specific register + * state. Return final register value * @csa: coresight device access for the device * @offset: Offset of the register from the base of the device. * @position: the position of the bit of interest. * @value: the value the bit should have. + * @rval: the last read value of the register being tested. * * Return: 0 as soon as the bit has taken the desired state or -EAGAIN if * TIMEOUT_US has elapsed, which ever happens first. */ -int coresight_timeout(struct csdev_access *csa, u32 offset, - int position, int value) +int coresight_timeout_retval(struct csdev_access *csa, u32 offset, + int position, int value, u32 *rval) { - int i; - u32 val; + int i, rc = -EAGAIN; + u32 val = 0;
for (i = TIMEOUT_US; i > 0; i--) { val = csdev_access_read32(csa, offset); /* waiting on the bit to go from 0 to 1 */ if (value) { - if (val & BIT(position)) - return 0; + if (val & BIT(position)) { + rc = 0; + goto return_rval; + } /* waiting on the bit to go from 1 to 0 */ } else { - if (!(val & BIT(position))) - return 0; + if (!(val & BIT(position))) { + rc = 0; + goto return_rval; + } }
/* @@ -1493,7 +1498,30 @@ int coresight_timeout(struct csdev_access *csa, u32 offset, udelay(1); }
- return -EAGAIN; +return_rval: + *rval = val; + + return rc; +} +EXPORT_SYMBOL_GPL(coresight_timeout_retval); + +/** + * coresight_timeout - loop until a bit has changed to a specific register + * state + * @csa: coresight device access for the device + * @offset: Offset of the register from the base of the device. + * @position: the position of the bit of interest. + * @value: the value the bit should have. + * + * Return: 0 as soon as the bit has taken the desired state or -EAGAIN if + * TIMEOUT_US has elapsed, which ever happens first. + */ +int coresight_timeout(struct csdev_access *csa, u32 offset, + int position, int value) +{ + u32 rval = 0; + + return coresight_timeout_retval(csa, offset, position, value, &rval); } EXPORT_SYMBOL_GPL(coresight_timeout);
diff --git a/include/linux/coresight.h b/include/linux/coresight.h index f19a47b9bb5a..6b6b45ef6971 100644 --- a/include/linux/coresight.h +++ b/include/linux/coresight.h @@ -500,7 +500,8 @@ extern int coresight_enable(struct coresight_device *csdev); extern void coresight_disable(struct coresight_device *csdev); extern int coresight_timeout(struct csdev_access *csa, u32 offset, int position, int value); - +extern int coresight_timeout_retval(struct csdev_access *csa, u32 offset, + int position, int value, u32 *rval); extern int coresight_claim_device(struct coresight_device *csdev); extern int coresight_claim_device_unlocked(struct coresight_device *csdev);
@@ -536,6 +537,13 @@ static inline int coresight_timeout(struct csdev_access *csa, u32 offset, return 1; }
+static inline int coresight_timeout_retval(struct csdev_access *csa, u32 offset, + int position, int value, u32 *rval) +{ + *rval = 0; + return 1; +} + static inline int coresight_claim_device_unlocked(struct coresight_device *csdev) { return -EINVAL;