Message-Id: <E1bO2Tw-0006KI-Fo@debutante>
Date:	Fri, 15 Jul 2016 13:44:40 +0100
From:	Mark Brown <broonie@...nel.org>
To:	Philipp Zabel <p.zabel@...gutronix.de>
Cc:	Mark Brown <broonie@...nel.org>, Mark Brown <broonie@...nel.org>,
	linux-kernel@...r.kernel.org, kernel@...gutronix.de
Subject: Applied "regmap: add iopoll-like polling macro" to the regmap tree

The patch

   regmap: add iopoll-like polling macro

has been applied to the regmap tree at

   git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap.git 

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

>From 08188ba8822163922e6b9c600095d21ce02f6a84 Mon Sep 17 00:00:00 2001
From: Philipp Zabel <p.zabel@...gutronix.de>
Date: Wed, 6 Jul 2016 16:19:41 +0200
Subject: [PATCH] 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: Philipp Zabel <p.zabel@...gutronix.de>
Signed-off-by: Mark Brown <broonie@...nel.org>
---
 include/linux/regmap.h | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index 3dc08ce15426..26914dfcc9fc 100644
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -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 {
-- 
2.8.1

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