[PATCH v2 4/6] iommu/sun50i: Support variants without an external reset

[Samuel Holland <samuel@sholland.org>]

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.

Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Samuel Holland <samuel@sholland.org>
---

(no changes since v1)

 drivers/iommu/sun50i-iommu.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/sun50i-iommu.c b/drivers/iommu/sun50i-iommu.c
index a3a462933c62..d19f6ce25f76 100644
--- 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;
 
@@ -995,9 +999,14 @@ static irqreturn_t sun50i_iommu_irq(int irq, void *dev_id)
 
 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;
@@ -1037,7 +1046,8 @@ static int sun50i_iommu_probe(struct platform_device *pdev)
 		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);
@@ -1075,8 +1085,12 @@ static int sun50i_iommu_probe(struct platform_device *pdev)
 	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);
-- 
2.37.4