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

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

include/linux/regmap.h

+39 −0
Original line number Diff line number Diff line
@@ -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 {