[PATCH v1 3/3] PM / devfreq: Add required OPPs support to passive governor

[Saravana Kannan]

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@xxxxxxxxxx>
---
 drivers/devfreq/governor_passive.c | 25 +++++++++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)

diff --git a/drivers/devfreq/governor_passive.c b/drivers/devfreq/governor_passive.c
index 3bc29acbd54e..bd4a98bb15b1 100644
--- a/drivers/devfreq/governor_passive.c
+++ b/drivers/devfreq/governor_passive.c
@@ -21,8 +21,9 @@ static int devfreq_passive_get_target_freq(struct devfreq *devfreq,
 	struct devfreq_passive_data *p_data
 			= (struct devfreq_passive_data *)devfreq->data;
 	struct devfreq *parent_devfreq = (struct devfreq *)p_data->parent;
+	struct opp_table *opp_table = NULL, *c_opp_table = NULL;
 	unsigned long child_freq = ULONG_MAX;
-	struct dev_pm_opp *opp;
+	struct dev_pm_opp *opp = NULL, *c_opp = NULL;
 	int i, count, ret = 0;
 
 	/*
@@ -65,7 +66,20 @@ static int devfreq_passive_get_target_freq(struct devfreq *devfreq,
 		goto out;
 	}
 
-	dev_pm_opp_put(opp);
+	opp_table = dev_pm_opp_get_opp_table(parent_devfreq->dev.parent);
+	if (IS_ERR_OR_NULL(opp_table)) {
+		ret = PTR_ERR(opp_table);
+		goto out;
+	}
+
+	c_opp_table = dev_pm_opp_get_opp_table(devfreq->dev.parent);
+	if (!IS_ERR_OR_NULL(c_opp_table))
+		c_opp = dev_pm_opp_xlate_opp(opp_table, c_opp_table, opp);
+	if (c_opp) {
+		*freq = dev_pm_opp_get_freq(c_opp);
+		dev_pm_opp_put(c_opp);
+		goto out;
+	}
 
 	/*
 	 * Get the OPP table's index of decided freqeuncy by governor
@@ -92,6 +106,13 @@ static int devfreq_passive_get_target_freq(struct devfreq *devfreq,
 	*freq = child_freq;
 
 out:
+	if (!IS_ERR_OR_NULL(opp_table))
+		dev_pm_opp_put_opp_table(opp_table);
+	if (!IS_ERR_OR_NULL(c_opp_table))
+		dev_pm_opp_put_opp_table(c_opp_table);
+	if (!IS_ERR_OR_NULL(opp))
+		dev_pm_opp_put(opp);
+
 	return ret;
 }
 
-- 
2.22.0.410.gd8fdbe21b5-goog