drm/tegra: gr3d: Convert into devm_pm_domain_attach_list()

JIRA: https://issues.redhat.com/browse/RHEL-75956

commit 1ce91bf
Author: Ulf Hansson <ulf.hansson@linaro.org>
Date:   Wed Oct 2 14:22:29 2024 +0200

    drm/tegra: gr3d: Convert into devm_pm_domain_attach_list()

    Rather than hooking up the PM domains through devm_pm_opp_attach_genpd()
    and manage the device-link, let's avoid the boilerplate-code by converting
    into devm_pm_domain_attach_list().

    Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
    Acked-by: Thierry Reding <treding@nvidia.com>
    Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
    Link: https://lore.kernel.org/r/20241002122232.194245-9-ulf.hansson@linaro.org

Signed-off-by: José Expósito <jexposit@redhat.com>

Author: jexposit

drivers/gpu/drm/tegra/gr3d.c

@@ -46,6 +46,7 @@ struct gr3d {
 	unsigned int nclocks;
 	struct reset_control_bulk_data resets[RST_GR3D_MAX];
 	unsigned int nresets;
+	struct dev_pm_domain_list *pd_list;
 
 	DECLARE_BITMAP(addr_regs, GR3D_NUM_REGS);
 };
@@ -369,18 +370,13 @@ static int gr3d_power_up_legacy_domain(struct device *dev, const char *name,
 	return 0;
 }
 
-static void gr3d_del_link(void *link)
-{
-	device_link_del(link);
-}
-
 static int gr3d_init_power(struct device *dev, struct gr3d *gr3d)
 {
-	static const char * const opp_genpd_names[] = { "3d0", "3d1", NULL };
-	const u32 link_flags = DL_FLAG_STATELESS | DL_FLAG_PM_RUNTIME;
-	struct device **opp_virt_devs, *pd_dev;
-	struct device_link *link;
-	unsigned int i;
+	struct dev_pm_domain_attach_data pd_data = {
+		.pd_names = (const char *[]) { "3d0", "3d1" },
+		.num_pd_names = 2,
+		.pd_flags = PD_FLAG_REQUIRED_OPP,
+	};
 	int err;
 
 	err = of_count_phandle_with_args(dev->of_node, "power-domains",
@@ -414,29 +410,10 @@ static int gr3d_init_power(struct device *dev, struct gr3d *gr3d)
 	if (dev->pm_domain)
 		return 0;
 
-	err = devm_pm_opp_attach_genpd(dev, opp_genpd_names, &opp_virt_devs);
-	if (err)
+	err = devm_pm_domain_attach_list(dev, &pd_data, &gr3d->pd_list);
+	if (err < 0)
 		return err;
 
-	for (i = 0; opp_genpd_names[i]; i++) {
-		pd_dev = opp_virt_devs[i];
-		if (!pd_dev) {
-			dev_err(dev, "failed to get %s power domain\n",
-				opp_genpd_names[i]);
-			return -EINVAL;
-		}
-
-		link = device_link_add(dev, pd_dev, link_flags);
-		if (!link) {
-			dev_err(dev, "failed to link to %s\n", dev_name(pd_dev));
-			return -EINVAL;
-		}
-
-		err = devm_add_action_or_reset(dev, gr3d_del_link, link);
-		if (err)
-			return err;
-	}
-
 	return 0;
 }