linux-kernel - [PATCH 2/2] regulator: core: Replace _regulator_enable

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Date:   Mon, 18 Apr 2022 14:12:40 -0700
From:   Brian Norris <briannorris@...omium.org>
To:     Liam Girdwood <lgirdwood@...il.com>,
        Mark Brown <broonie@...nel.org>
Cc:     Matthias Kaehlcke <mka@...omium.org>, linux-kernel@...r.kernel.org,
        Brian Norris <briannorris@...omium.org>
Subject: [PATCH 2/2] regulator: core: Replace _regulator_enable_delay() with fsleep()

fsleep() was designed to handle exactly the same thing as
_regulator_enable_delay(): flexible sleep lengths, according to the
guidelines at Documentation/timers/timers-howto.rst. Let's use it,
instead of duplicating it.

One notable difference: fsleep() allows a usleep range of twice the
requested amount instead of a fixed +100us.

Signed-off-by: Brian Norris <briannorris@...omium.org>
---

 drivers/regulator/core.c | 45 +++-------------------------------------
 1 file changed, 3 insertions(+), 42 deletions(-)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 223c6d71a2b2..d0bac80206d8 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -2510,45 +2510,6 @@ static int regulator_ena_gpio_ctrl(struct regulator_dev *rdev, bool enable)
 	return 0;
 }
 
-/**
- * _regulator_enable_delay - a delay helper function
- * @delay: time to delay in microseconds
- *
- * Delay for the requested amount of time as per the guidelines in:
- *
- *     Documentation/timers/timers-howto.rst
- *
- * The assumption here is that regulators will never be enabled in
- * atomic context and therefore sleeping functions can be used.
- */
-static void _regulator_enable_delay(unsigned int delay)
-{
-	unsigned int ms = delay / 1000;
-	unsigned int us = delay % 1000;
-
-	if (ms > 0) {
-		/*
-		 * For small enough values, handle super-millisecond
-		 * delays in the usleep_range() call below.
-		 */
-		if (ms < 20)
-			us += ms * 1000;
-		else
-			msleep(ms);
-	}
-
-	/*
-	 * Give the scheduler some room to coalesce with any other
-	 * wakeup sources. For delays shorter than 10 us, don't even
-	 * bother setting up high-resolution timers and just busy-
-	 * loop.
-	 */
-	if (us >= 10)
-		usleep_range(us, us + 100);
-	else
-		udelay(us);
-}
-
 /**
  * _regulator_check_status_enabled
  *
@@ -2603,7 +2564,7 @@ static int _regulator_do_enable(struct regulator_dev *rdev)
 		s64 remaining = ktime_us_delta(end, ktime_get());
 
 		if (remaining > 0)
-			_regulator_enable_delay(remaining);
+			fsleep(remaining);
 	}
 
 	if (rdev->ena_pin) {
@@ -2637,7 +2598,7 @@ static int _regulator_do_enable(struct regulator_dev *rdev)
 		unsigned int time_remaining = delay;
 
 		while (time_remaining > 0) {
-			_regulator_enable_delay(rdev->desc->poll_enabled_time);
+			fsleep(rdev->desc->poll_enabled_time);
 
 			if (rdev->desc->ops->get_status) {
 				ret = _regulator_check_status_enabled(rdev);
@@ -2656,7 +2617,7 @@ static int _regulator_do_enable(struct regulator_dev *rdev)
 			return -ETIMEDOUT;
 		}
 	} else {
-		_regulator_enable_delay(delay);
+		fsleep(delay);
 	}
 
 	trace_regulator_enable_complete(rdev_get_name(rdev));
-- 
2.36.0.rc0.470.gd361397f0d-goog