github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-06-08 14:42:37 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

UPSTREAM: regmap: add iopoll-like polling macro

Browse Source 
This patch adds a macro regmap_read_poll_timeout that works similar
to the readx_poll_timeout defined in linux/iopoll.h, except that this
can also return the error value returned by a failed regmap_read.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
(cherry picked from commit 08188ba882)

Change-Id: I6f358e2b324591b311590e1b421cd7fb69f20cd7
Signed-off-by: Wyon Bi <bivvy.bi@rock-chips.com>
This commit is contained in:
Philipp Zabel 2016-07-06 16:19:41 +02:00 committed by Tao Huang
parent 94329df8b2
commit 14607484a2
1 changed files with 39 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

39
include/linux/regmap.h
View File

@ -783,6 +783,45 @@ int regmap_fields_read(struct regmap_field *field, unsigned int id,
int regmap_fields_update_bits(struct regmap_field *field, unsigned int id,
unsigned int mask, unsigned int val);
/**
* regmap_read_poll_timeout - Poll until a condition is met or a timeout occurs
* @map: Regmap to read from
* @addr: Address to poll
* @val: Unsigned integer variable to read the value into
* @cond: Break condition (usually involving @val)
* @sleep_us: Maximum time to sleep between reads in us (0
* tight-loops). Should be less than ~20ms since usleep_range
* is used (see Documentation/timers/timers-howto.txt).
* @timeout_us: Timeout in us, 0 means never timeout
*
* Returns 0 on success and -ETIMEDOUT upon a timeout or the regmap_read
* error return value in case of a error read. In the two former cases,
* the last read value at @addr is stored in @val. Must not be called
* from atomic context if sleep_us or timeout_us are used.
*
* This is modelled after the readx_poll_timeout macros in linux/iopoll.h.
*/
#define regmap_read_poll_timeout(map, addr, val, cond, sleep_us, timeout_us) \
({ \
ktime_t timeout = ktime_add_us(ktime_get(), timeout_us); \
int ret; \
might_sleep_if(sleep_us); \
for (;;) { \
ret = regmap_read((map), (addr), &(val)); \
if (ret) \
break; \
if (cond) \
break; \
if (timeout_us && ktime_compare(ktime_get(), timeout) > 0) { \
ret = regmap_read((map), (addr), &(val)); \
break; \
} \
if (sleep_us) \
usleep_range((sleep_us >> 2) + 1, sleep_us); \
} \
ret ?: ((cond) ? 0 : -ETIMEDOUT); \
})
/**
* Description of an IRQ for the generic regmap irq_chip.
*