Commit 08188ba8 authored by Philipp Zabel's avatar Philipp Zabel Committed by Mark Brown

regmap: add iopoll-like polling macro

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: default avatarPhilipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 1a695a90
......@@ -95,6 +95,45 @@ struct reg_sequence {
#define regmap_fields_force_update_bits(field, id, mask, val) \
regmap_fields_update_bits_base(field, id, mask, val, NULL, false, true)
/**
* 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); \
})
#ifdef CONFIG_REGMAP
enum regmap_endian {
......
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