blob: 465bfef9a42493f8a6b50c2b024ca11d1e31a26f [file] [log] [blame]
From 4c30379282d8ef78632ef19ee9d2bbac050b0e9f Mon Sep 17 00:00:00 2001
From: Thierry Reding <treding@nvidia.com>
Date: Wed, 28 Aug 2019 10:34:10 +0200
Subject: [PATCH] driver core: platform: Introduce platform_get_irq_optional()
commit 8973ea47901c81a1912bd05f1577bed9b5b52506 upstream.
In some cases the interrupt line of a device is optional. Introduce a
new platform_get_irq_optional() that works much like platform_get_irq()
but does not output an error on failure to find the interrupt.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20190828083411.2496-1-thierry.reding@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index 8550d63754b5..53fdc3b1e6f9 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -172,6 +172,28 @@ int platform_get_irq(struct platform_device *dev, unsigned int num)
EXPORT_SYMBOL_GPL(platform_get_irq);
/**
+ * platform_get_irq_optional - get an optional IRQ for a device
+ * @dev: platform device
+ * @num: IRQ number index
+ *
+ * Gets an IRQ for a platform device. Device drivers should check the return
+ * value for errors so as to not pass a negative integer value to the
+ * request_irq() APIs. This is the same as platform_get_irq(), except that it
+ * does not print an error message if an IRQ can not be obtained.
+ *
+ * Example:
+ * int irq = platform_get_irq_optional(pdev, 0);
+ * if (irq < 0)
+ * return irq;
+ *
+ * Return: IRQ number on success, negative error number on failure.
+ */
+int platform_get_irq_optional(struct platform_device *dev, unsigned int num)
+{
+ return __platform_get_irq(dev, num);
+}
+
+/**
* platform_irq_count - Count the number of IRQs a platform device uses
* @dev: platform device
*
diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h
index beb25f277889..0f3db1b2e723 100644
--- a/include/linux/platform_device.h
+++ b/include/linux/platform_device.h
@@ -55,6 +55,7 @@ extern void __iomem *
devm_platform_ioremap_resource(struct platform_device *pdev,
unsigned int index);
extern int platform_get_irq(struct platform_device *, unsigned int);
+extern int platform_get_irq_optional(struct platform_device *, unsigned int);
extern int platform_irq_count(struct platform_device *);
extern struct resource *platform_get_resource_byname(struct platform_device *,
unsigned int,
--
2.7.4