[PATCH v3 6/6] soc/tegra: pmc: Link children power domains to the parent domain

[Dmitry Osipenko <digetx@xxxxxxxxx>]

The Core domain is a parent of PMC power domains, hence PMC domains
should be set up as a sub-domains of the parent (Core) domain if
"power-domains" phandle presents in a device-tree node of PMC domain.

This allows to propagate GENPD performance changes to the parent Core
domain if performance change is applied to a PMC domain.

Tested-by: Peter Geis <pgwipeout@xxxxxxxxx> # Ouya T30
Tested-by: Paul Fertser <fercerpav@xxxxxxxxx> # PAZ00 T20
Tested-by: Nicolas Chauvet <kwizart@xxxxxxxxx> # PAZ00 T20 and TK1 T124
Tested-by: Matt Merhar <mattmerhar@xxxxxxxxxxxxxx> # Ouya T30
Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
---
 drivers/soc/tegra/pmc.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/soc/tegra/pmc.c b/drivers/soc/tegra/pmc.c
index 84ab27d85d92..ba8407819397 100644
--- a/drivers/soc/tegra/pmc.c
+++ b/drivers/soc/tegra/pmc.c
@@ -1283,6 +1283,7 @@ static int tegra_powergate_add(struct tegra_pmc *pmc, struct device_node *np)
 static int tegra_powergate_init(struct tegra_pmc *pmc,
 				struct device_node *parent)
 {
+	struct of_phandle_args child_args, parent_args;
 	struct device_node *np, *child;
 	int err = 0;
 
@@ -1296,6 +1297,21 @@ static int tegra_powergate_init(struct tegra_pmc *pmc,
 			of_node_put(child);
 			break;
 		}
+
+		if (of_parse_phandle_with_args(child, "power-domains",
+					       "#power-domain-cells",
+					       0, &parent_args))
+			continue;
+
+		child_args.np = child;
+		child_args.args_count = 0;
+
+		err = of_genpd_add_subdomain(&parent_args, &child_args);
+		of_node_put(parent_args.np);
+		if (err) {
+			of_node_put(child);
+			break;
+		}
 	}
 
 	of_node_put(np);
-- 
2.29.2