drm/tegra: gr3d: Convert into dev_pm_domain_attach|detach_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 dev_pm_domain_attach|detach_list.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240723144610.564273-2-ulf.hansson@linaro.org

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 +370,12 @@ 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,
+	};
 	int err;
 
 	err = of_count_phandle_with_args(dev->of_node, "power-domains",
@@ -414,28 +409,9 @@ 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)
-		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)
+	err = dev_pm_domain_attach_list(dev, &pd_data, &gr3d->pd_list);
+	if (err < 0)
 		return err;
-	}
 
 	return 0;
 }
@@ -527,13 +503,13 @@ static int gr3d_probe(struct platform_device *pdev)
 
 	err = devm_tegra_core_dev_init_opp_table_common(&pdev->dev);
 	if (err)
-		return err;
+		goto err;
 
 	err = host1x_client_register(&gr3d->client.base);
 	if (err < 0) {
 		dev_err(&pdev->dev, "failed to register host1x client: %d\n",
 			err);
-		return err;
+		goto err;
 	}
 
 	/* initialize address register map */
@@ -541,6 +517,9 @@ static int gr3d_probe(struct platform_device *pdev)
 		set_bit(gr3d_addr_regs[i], gr3d->addr_regs);
 
 	return 0;
+err:
+	dev_pm_domain_detach_list(gr3d->pd_list);
+	return err;
 }
 
 static void gr3d_remove(struct platform_device *pdev)
@@ -549,6 +528,7 @@ static void gr3d_remove(struct platform_device *pdev)
 
 	pm_runtime_disable(&pdev->dev);
 	host1x_client_unregister(&gr3d->client.base);
+	dev_pm_domain_detach_list(gr3d->pd_list);
 }
 
 static int __maybe_unused gr3d_runtime_suspend(struct device *dev)