[PATCH v6 3/3] PM / devfreq: Add required OPPs support to passive governor

[Hsin-Yi Wang <hsinyi@chromium.org>]

From: Saravana Kannan <saravanak@google.com>

Look at the required OPPs of the "parent" device to determine the OPP that
is required from the slave device managed by the passive governor. This
allows having mappings between a parent device and a slave device even when
they don't have the same number of OPPs.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Acked-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
---
 drivers/devfreq/governor_passive.c | 25 ++++++++++++++++++-------
 1 file changed, 18 insertions(+), 7 deletions(-)

diff --git a/drivers/devfreq/governor_passive.c b/drivers/devfreq/governor_passive.c
index 63332e4a65ae8..8fd51cc9b991a 100644
--- a/drivers/devfreq/governor_passive.c
+++ b/drivers/devfreq/governor_passive.c
@@ -19,7 +19,7 @@ static int devfreq_passive_get_target_freq(struct devfreq *devfreq,
 			= (struct devfreq_passive_data *)devfreq->data;
 	struct devfreq *parent_devfreq = (struct devfreq *)p_data->parent;
 	unsigned long child_freq = ULONG_MAX;
-	struct dev_pm_opp *opp;
+	struct dev_pm_opp *opp, *p_opp = ERR_PTR(-ENODEV);
 	int i, count, ret = 0;
 
 	/*
@@ -29,7 +29,7 @@ static int devfreq_passive_get_target_freq(struct devfreq *devfreq,
 	 */
 	if (p_data->get_target_freq) {
 		ret = p_data->get_target_freq(devfreq, freq);
-		goto out;
+		return ret;
 	}
 
 	/*
@@ -56,13 +56,22 @@ static int devfreq_passive_get_target_freq(struct devfreq *devfreq,
 	 * list of parent device. Because in this case, *freq is temporary
 	 * value which is decided by ondemand governor.
 	 */
-	opp = devfreq_recommended_opp(parent_devfreq->dev.parent, freq, 0);
-	if (IS_ERR(opp)) {
-		ret = PTR_ERR(opp);
-		goto out;
+	p_opp = devfreq_recommended_opp(parent_devfreq->dev.parent, freq, 0);
+	if (IS_ERR(p_opp)) {
+		ret = PTR_ERR(p_opp);
+		return ret;
 	}
 
-	dev_pm_opp_put(opp);
+	if (devfreq->opp_table && parent_devfreq->opp_table) {
+		opp = dev_pm_opp_xlate_required_opp(parent_devfreq->opp_table,
+						    devfreq->opp_table, p_opp);
+		if (!IS_ERR(opp)) {
+			*freq = dev_pm_opp_get_freq(opp);
+			dev_pm_opp_put(opp);
+		} else
+			ret = PTR_ERR(opp);
+		goto out;
+	}
 
 	/*
 	 * Get the OPP table's index of decided freqeuncy by governor
@@ -89,6 +98,8 @@ static int devfreq_passive_get_target_freq(struct devfreq *devfreq,
 	*freq = child_freq;
 
 out:
+	dev_pm_opp_put(p_opp);
+
 	return ret;
 }
 
-- 
2.30.0.365.g02bc693789-goog