[PATCH v4 6/6] soc/tegra: pmc: Link children power domains to the parent domain

[Dmitry Osipenko]

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 <pgwipe...@gmail.com> # Ouya T30
Tested-by: Paul Fertser <fercer...@gmail.com> # PAZ00 T20
Tested-by: Nicolas Chauvet <kwiz...@gmail.com> # PAZ00 T20 and TK1 T124
Tested-by: Matt Merhar <mattmer...@protonmail.com> # Ouya T30
Signed-off-by: Dmitry Osipenko <dig...@gmail.com>
---
 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);
-- 
2.30.2