From 15a0487680cf506bb4b9bfee2c41b2c3176d4efa Mon Sep 17 00:00:00 2001
From: Samuel Holland <samuel@sholland.org>
Date: Wed, 27 Apr 2022 19:01:57 -0500
Subject: [PATCH 050/117] iommu/sun50i: Support variants without an external
 reset

The IOMMU in the Allwinner D1 SoC does not have an external reset line.

Only attempt to get the reset on hardware variants which should have one
according to the binding. And switch from the deprecated function to the
explicit "exclusive" variant.

Signed-off-by: Samuel Holland <samuel@sholland.org>
---
 drivers/iommu/sun50i-iommu.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

--- a/drivers/iommu/sun50i-iommu.c
+++ b/drivers/iommu/sun50i-iommu.c
@@ -95,6 +95,10 @@
 
 #define SPAGE_SIZE			4096
 
+struct sun50i_iommu_variant {
+	bool has_reset;
+};
+
 struct sun50i_iommu {
 	struct iommu_device iommu;
 
@@ -979,9 +983,14 @@ static irqreturn_t sun50i_iommu_irq(int
 
 static int sun50i_iommu_probe(struct platform_device *pdev)
 {
+	const struct sun50i_iommu_variant *variant;
 	struct sun50i_iommu *iommu;
 	int ret, irq;
 
+	variant = of_device_get_match_data(&pdev->dev);
+	if (!variant)
+		return -EINVAL;
+
 	iommu = devm_kzalloc(&pdev->dev, sizeof(*iommu), GFP_KERNEL);
 	if (!iommu)
 		return -ENOMEM;
@@ -1021,7 +1030,8 @@ static int sun50i_iommu_probe(struct pla
 		goto err_free_group;
 	}
 
-	iommu->reset = devm_reset_control_get(&pdev->dev, NULL);
+	if (variant->has_reset)
+		iommu->reset = devm_reset_control_get_exclusive(&pdev->dev, NULL);
 	if (IS_ERR(iommu->reset)) {
 		dev_err(&pdev->dev, "Couldn't get our reset line.\n");
 		ret = PTR_ERR(iommu->reset);
@@ -1059,8 +1069,12 @@ err_free_cache:
 	return ret;
 }
 
+static const struct sun50i_iommu_variant sun50i_h6_iommu = {
+	.has_reset = true,
+};
+
 static const struct of_device_id sun50i_iommu_dt[] = {
-	{ .compatible = "allwinner,sun50i-h6-iommu", },
+	{ .compatible = "allwinner,sun50i-h6-iommu", .data = &sun50i_h6_iommu },
 	{ /* sentinel */ },
 };
 MODULE_DEVICE_TABLE(of, sun50i_iommu_dt);