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Commit 7c0f24a4 authored by Daniel Vetter's avatar Daniel Vetter
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Merge tag 'regmap-poll-field' of...

Merge tag 'regmap-poll-field' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap

 into drm-misc-next

regmap: Add field polling macro

Requested by Maxime Ripard to make sun4i compile again (next time
the other way round is better).

Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20171004104732.jkps4ufekfizcrkz@sirena.co.uk
parents 0c17151a 667063ac
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+39 −0
Original line number Diff line number Diff line
@@ -139,6 +139,45 @@ struct reg_sequence {
	pollret ?: ((cond) ? 0 : -ETIMEDOUT); \
})

/**
 * regmap_field_read_poll_timeout - Poll until a condition is met or timeout
 *
 * @field: Regmap field to read from
 * @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_field_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_field_read_poll_timeout(field, val, cond, sleep_us, timeout_us) \
({ \
	ktime_t timeout = ktime_add_us(ktime_get(), timeout_us); \
	int pollret; \
	might_sleep_if(sleep_us); \
	for (;;) { \
		pollret = regmap_field_read((field), &(val)); \
		if (pollret) \
			break; \
		if (cond) \
			break; \
		if (timeout_us && ktime_compare(ktime_get(), timeout) > 0) { \
			pollret = regmap_field_read((field), &(val)); \
			break; \
		} \
		if (sleep_us) \
			usleep_range((sleep_us >> 2) + 1, sleep_us); \
	} \
	pollret ?: ((cond) ? 0 : -ETIMEDOUT); \
})

#ifdef CONFIG_REGMAP

enum regmap_endian {