linux-kernel - [PATCH V2 2/5] OPP: Make _generic_set_opp_regulator() a config

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Message-Id: <2d9786a0e2460d3c4ac94a147a8b7ff77d36f696.1656664183.git.viresh.kumar@linaro.org>
Date:   Fri,  1 Jul 2022 14:04:52 +0530
From:   Viresh Kumar <viresh.kumar@...aro.org>
To:     Viresh Kumar <vireshk@...nel.org>, Nishanth Menon <nm@...com>,
        Stephen Boyd <sboyd@...nel.org>
Cc:     Viresh Kumar <viresh.kumar@...aro.org>, linux-pm@...r.kernel.org,
        Vincent Guittot <vincent.guittot@...aro.org>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        Dmitry Osipenko <dmitry.osipenko@...labora.com>,
        linux-kernel@...r.kernel.org
Subject: [PATCH V2 2/5] OPP: Make _generic_set_opp_regulator() a config_regulators() interface

In order to reuse the same code path, i.e. clk_set_rate() from
_set_opp(), migrate _generic_set_opp_regulator() to implement a
config_regulators() interface.

It is renamed to _opp_config_regulator_single() and is set as the
preferred config_regulators() interface whenever we have a single
regulator available.

Note that this also drops code responsible for restoring the
voltage/freq in case of errors. We aren't handling that properly
currently, restoring only some of the resources while leaving others out
(like bandwidth and required OPPs). It is better to drop all of it
instead of partial restoration.

Tested-by: Dmitry Osipenko <dmitry.osipenko@...labora.com>
Signed-off-by: Viresh Kumar <viresh.kumar@...aro.org>
---
 drivers/opp/core.c | 51 +++++++++++-----------------------------------
 1 file changed, 12 insertions(+), 39 deletions(-)

diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index d5e1ae6f5ea1..df0135f2cfec 100644
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -896,62 +896,34 @@ static inline int _generic_set_opp_clk_only(struct device *dev, struct clk *clk,
 	return ret;
 }
 
-static int _generic_set_opp_regulator(struct opp_table *opp_table,
-				      struct device *dev,
-				      struct dev_pm_opp *opp,
-				      unsigned long freq,
-				      int scaling_down)
+static int _opp_config_regulator_single(struct device *dev,
+			struct dev_pm_opp *old_opp, struct dev_pm_opp *new_opp,
+			struct regulator **regulators, unsigned int count)
 {
-	struct regulator *reg = opp_table->regulators[0];
-	struct dev_pm_opp *old_opp = opp_table->current_opp;
+	struct regulator *reg = regulators[0];
 	int ret;
 
 	/* This function only supports single regulator per device */
-	if (WARN_ON(opp_table->regulator_count > 1)) {
+	if (WARN_ON(count > 1)) {
 		dev_err(dev, "multiple regulators are not supported\n");
 		return -EINVAL;
 	}
 
-	/* Scaling up? Scale voltage before frequency */
-	if (!scaling_down) {
-		ret = _set_opp_voltage(dev, reg, opp->supplies);
-		if (ret)
-			goto restore_voltage;
-	}
-
-	/* Change frequency */
-	ret = _generic_set_opp_clk_only(dev, opp_table->clk, freq);
+	ret = _set_opp_voltage(dev, reg, new_opp->supplies);
 	if (ret)
-		goto restore_voltage;
-
-	/* Scaling down? Scale voltage after frequency */
-	if (scaling_down) {
-		ret = _set_opp_voltage(dev, reg, opp->supplies);
-		if (ret)
-			goto restore_freq;
-	}
+		return ret;
 
 	/*
 	 * Enable the regulator after setting its voltages, otherwise it breaks
 	 * some boot-enabled regulators.
 	 */
-	if (unlikely(!opp_table->enabled)) {
+	if (unlikely(!new_opp->opp_table->enabled)) {
 		ret = regulator_enable(reg);
 		if (ret < 0)
 			dev_warn(dev, "Failed to enable regulator: %d", ret);
 	}
 
 	return 0;
-
-restore_freq:
-	if (_generic_set_opp_clk_only(dev, opp_table->clk, old_opp->rate))
-		dev_err(dev, "%s: failed to restore old-freq (%lu Hz)\n",
-			__func__, old_opp->rate);
-restore_voltage:
-	/* This shouldn't harm even if the voltages weren't updated earlier */
-	_set_opp_voltage(dev, reg, old_opp->supplies);
-
-	return ret;
 }
 
 static int _set_opp_bw(const struct opp_table *opp_table,
@@ -1200,9 +1172,6 @@ static int _set_opp(struct device *dev, struct opp_table *opp_table,
 
 	if (opp_table->set_opp) {
 		ret = _set_opp_custom(opp_table, dev, opp, freq);
-	} else if (opp_table->regulators) {
-		ret = _generic_set_opp_regulator(opp_table, dev, opp, freq,
-						 scaling_down);
 	} else {
 		/* Only frequency scaling */
 		ret = _generic_set_opp_clk_only(dev, opp_table->clk, freq);
@@ -2113,6 +2082,10 @@ static int _opp_set_regulators(struct opp_table *opp_table, struct device *dev,
 	}
 	mutex_unlock(&opp_table->lock);
 
+	/* Set generic config_regulators() for single regulators here */
+	if (count == 1)
+		opp_table->config_regulators = _opp_config_regulator_single;
+
 	return 0;
 
 free_regulators:
-- 
2.31.1.272.g89b43f80a514