[PATCH V4 8/9] PM / Domain: Add struct device to genpd

[Viresh Kumar]

The power-domain core would be using the OPP core going forward and the
OPP core has a basic requirement of a device structure for its working.

Add a struct device to the genpd structure and also add a genpd bus type
for the devices.

Note that the of_node field of the device is only set when separate DT
node is present for the power-domain, otherwise the of node is common
across multiple genpd devices and filling the of_node field with it
doesn't sound right.

Signed-off-by: Viresh Kumar <viresh.ku...@linaro.org>
---
 drivers/base/power/domain.c | 36 ++++++++++++++++++++++++++++++++++++
 include/linux/pm_domain.h   |  1 +
 2 files changed, 37 insertions(+)

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 03dd7a61f08a..51d3afc0476d 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -1536,6 +1536,10 @@ static void genpd_lock_init(struct generic_pm_domain 
*genpd)
        }
 }
 
+static struct bus_type genpd_bus_type = {
+       .name =         "genpd",
+};
+
 /**
  * pm_genpd_init - Initialize a generic I/O PM domain object.
  * @genpd: PM domain object to initialize.
@@ -1588,6 +1592,18 @@ int pm_genpd_init(struct generic_pm_domain *genpd,
                        return ret;
        }
 
+       genpd->dev.bus = &genpd_bus_type;
+       device_initialize(&genpd->dev);
+       dev_set_name(&genpd->dev, "%s", genpd->name);
+
+       ret = device_add(&genpd->dev);
+       if (ret) {
+               dev_err(&genpd->dev, "failed to add device: %d\n", ret);
+               put_device(&genpd->dev);
+               kfree(genpd->free);
+               return ret;
+       }
+
        mutex_lock(&gpd_list_lock);
        list_add(&genpd->gpd_list_node, &gpd_list);
        mutex_unlock(&gpd_list_lock);
@@ -1625,6 +1641,7 @@ static int genpd_remove(struct generic_pm_domain *genpd)
 
        list_del(&genpd->gpd_list_node);
        genpd_unlock(genpd);
+       device_del(&genpd->dev);
        cancel_work_sync(&genpd->power_off_work);
        kfree(genpd->free);
        pr_debug("%s: removed %s\n", __func__, genpd->name);
@@ -1794,6 +1811,7 @@ int of_genpd_add_provider_simple(struct device_node *np,
                if (!ret) {
                        genpd->provider = &np->fwnode;
                        genpd->has_provider = true;
+                       genpd->dev->of_node = np;
                }
        }
 
@@ -2407,3 +2425,21 @@ static void __exit pm_genpd_debug_exit(void)
 }
 __exitcall(pm_genpd_debug_exit);
 #endif /* CONFIG_DEBUG_FS */
+
+static int __init pm_genpd_core_init(void)
+{
+       int ret;
+
+       ret = bus_register(&genpd_bus_type);
+       if (ret)
+               pr_err("bus_register failed (%d)\n", ret);
+
+       return ret;
+}
+pure_initcall(pm_genpd_core_init);
+
+static void __exit pm_genpd_core_exit(void)
+{
+       bus_unregister(&genpd_bus_type);
+}
+__exitcall(pm_genpd_core_exit);
diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index 83795935709e..d55c0112dcde 100644
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h
@@ -47,6 +47,7 @@ struct genpd_power_state {
 struct genpd_lock_ops;
 
 struct generic_pm_domain {
+       struct device dev;
        struct dev_pm_domain domain;    /* PM domain operations */
        struct list_head gpd_list_node; /* Node in the global PM domains list */
        struct list_head master_links;  /* Links with PM domain as a master */
-- 
2.12.0.432.g71c3a4f4ba37