From e6e1817a55ba50e0d68ce77e6008edcba97ba41a Mon Sep 17 00:00:00 2001
From: Alexandre Courbot <acourbot@nvidia.com>
Date: Wed, 29 Mar 2017 18:31:21 +0900
Subject: [PATCH] drm/nouveau/platform: make VDD regulator optional

GP10B's power is managed by generic PM domains, so it does not require a
VDD regulator. Add this option into the chip function structure.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
---
 .../gpu/drm/nouveau/include/nvkm/core/tegra.h |  4 +++
 drivers/gpu/drm/nouveau/nouveau_platform.c    |  2 ++
 .../drm/nouveau/nvkm/engine/device/tegra.c    | 31 +++++++++++++------
 3 files changed, 28 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/include/nvkm/core/tegra.h b/drivers/gpu/drm/nouveau/include/nvkm/core/tegra.h
index e5c9b6268dcc..7c7d91cad09a 100644
--- a/drivers/gpu/drm/nouveau/include/nvkm/core/tegra.h
+++ b/drivers/gpu/drm/nouveau/include/nvkm/core/tegra.h
@@ -42,6 +42,10 @@ struct nvkm_device_tegra_func {
 	 * Whether the chip requires a reference clock
 	 */
 	bool require_ref_clk;
+	/*
+	 * Whether the chip requires the VDD regulator
+	 */
+	bool require_vdd;
 };
 
 int nvkm_device_tegra_new(const struct nvkm_device_tegra_func *,
diff --git a/drivers/gpu/drm/nouveau/nouveau_platform.c b/drivers/gpu/drm/nouveau/nouveau_platform.c
index 4c4cc2260257..49d9ba0e3c51 100644
--- a/drivers/gpu/drm/nouveau/nouveau_platform.c
+++ b/drivers/gpu/drm/nouveau/nouveau_platform.c
@@ -53,10 +53,12 @@ static int nouveau_platform_remove(struct platform_device *pdev)
 #if IS_ENABLED(CONFIG_OF)
 static const struct nvkm_device_tegra_func gk20a_platform_data = {
 	.iommu_bit = 34,
+	.require_vdd = true,
 };
 
 static const struct nvkm_device_tegra_func gm20b_platform_data = {
 	.iommu_bit = 34,
+	.require_vdd = true,
 	.require_ref_clk = true,
 };
 
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c b/drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c
index f2bc0b7d9b93..6474bd2a6d07 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c
@@ -28,9 +28,11 @@ nvkm_device_tegra_power_up(struct nvkm_device_tegra *tdev)
 {
 	int ret;
 
-	ret = regulator_enable(tdev->vdd);
-	if (ret)
-		goto err_power;
+	if (tdev->vdd) {
+		ret = regulator_enable(tdev->vdd);
+		if (ret)
+			goto err_power;
+	}
 
 	ret = clk_prepare_enable(tdev->clk);
 	if (ret)
@@ -67,7 +69,8 @@ nvkm_device_tegra_power_up(struct nvkm_device_tegra *tdev)
 err_clk_ref:
 	clk_disable_unprepare(tdev->clk);
 err_clk:
-	regulator_disable(tdev->vdd);
+	if (tdev->vdd)
+		regulator_disable(tdev->vdd);
 err_power:
 	return ret;
 }
@@ -75,6 +78,8 @@ nvkm_device_tegra_power_up(struct nvkm_device_tegra *tdev)
 static int
 nvkm_device_tegra_power_down(struct nvkm_device_tegra *tdev)
 {
+	int ret;
+
 	reset_control_assert(tdev->rst);
 	udelay(10);
 
@@ -84,7 +89,13 @@ nvkm_device_tegra_power_down(struct nvkm_device_tegra *tdev)
 	clk_disable_unprepare(tdev->clk);
 	udelay(10);
 
-	return regulator_disable(tdev->vdd);
+	if (tdev->vdd) {
+		ret = regulator_disable(tdev->vdd);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
 }
 
 static void
@@ -264,10 +275,12 @@ nvkm_device_tegra_new(const struct nvkm_device_tegra_func *func,
 	tdev->func = func;
 	tdev->pdev = pdev;
 
-	tdev->vdd = devm_regulator_get(&pdev->dev, "vdd");
-	if (IS_ERR(tdev->vdd)) {
-		ret = PTR_ERR(tdev->vdd);
-		goto free;
+	if (func->require_vdd) {
+		tdev->vdd = devm_regulator_get(&pdev->dev, "vdd");
+		if (IS_ERR(tdev->vdd)) {
+			ret = PTR_ERR(tdev->vdd);
+			goto free;
+		}
 	}
 
 	tdev->rst = devm_reset_control_get(&pdev->dev, "gpu");
-- 
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