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From:   Daniel Mack <daniel@zonque.org>
To:     gregkh@linuxfoundation.org
Cc:     devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        Daniel Mack <daniel@zonque.org>
Subject: [PATCH v2 1/2] uio: uio_pdrv_genirq: Make UIO name controllable via DT node property
Date:   Thu, 15 Aug 2019 23:28:06 +0200
Message-Id: <20190815212807.25058-1-daniel@zonque.org>
MIME-Version: 1.0
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Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

When probed via DT, the uio_pdrv_genirq driver currently uses the name
of the node and exposes that as name of the UIO device to userspace.

This doesn't work for systems where multiple nodes with the same name
(but different unit addresses) are present, or for systems where the
node names are auto-generated by a third-party tool.

This patch adds the possibility to read the UIO name from the optional
"linux,uio-name" property.

Signed-off-by: Daniel Mack <daniel@zonque.org>
---
 drivers/uio/uio_pdrv_genirq.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/uio/uio_pdrv_genirq.c b/drivers/uio/uio_pdrv_genirq.c
index 6c759934bff3..24d60eb1bda5 100644
--- a/drivers/uio/uio_pdrv_genirq.c
+++ b/drivers/uio/uio_pdrv_genirq.c
@@ -105,12 +105,15 @@ static int uio_pdrv_genirq_irqcontrol(struct uio_info *dev_info, s32 irq_on)
 static int uio_pdrv_genirq_probe(struct platform_device *pdev)
 {
 	struct uio_info *uioinfo = dev_get_platdata(&pdev->dev);
+	struct device_node *node = pdev->dev.of_node;
 	struct uio_pdrv_genirq_platdata *priv;
 	struct uio_mem *uiomem;
 	int ret = -EINVAL;
 	int i;
 
-	if (pdev->dev.of_node) {
+	if (node) {
+		const char *name;
+
 		/* alloc uioinfo for one device */
 		uioinfo = devm_kzalloc(&pdev->dev, sizeof(*uioinfo),
 				       GFP_KERNEL);
@@ -118,8 +121,13 @@ static int uio_pdrv_genirq_probe(struct platform_device *pdev)
 			dev_err(&pdev->dev, "unable to kmalloc\n");
 			return -ENOMEM;
 		}
-		uioinfo->name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "%pOFn",
-					       pdev->dev.of_node);
+
+		if (!of_property_read_string(node, "linux,uio-name", &name))
+			uioinfo->name = devm_kstrdup(&pdev->dev, name, GFP_KERNEL);
+		else
+			uioinfo->name = devm_kasprintf(&pdev->dev, GFP_KERNEL,
+						       "%pOFn", node);
+
 		uioinfo->version = "devicetree";
 		/* Multiple IRQs are not supported */
 	}
-- 
2.21.0