[PATCH v3 1/2] drivers: provide devm_platform_request_irq()

[Dejin Zheng <zhengdejin5@gmail.com>]

It will call devm_request_irq() after platform_get_irq() function
in many drivers, sometimes, it is not right for the error handling
of these two functions in some drivers. so provide this function
to simplify the driver.

Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Dejin Zheng <zhengdejin5@gmail.com>
---
v2 -> v3:
	- add devm_platform_request_irq() to devres.rst by Grygorii's
	  suggestion.
v1 -> v2:
	- The patch content has not changed. just resend it by this discussion:
	  https://patchwork.ozlabs.org/project/linux-i2c/patch/20200520144821.8069-1-zhengdejin5@gmail.com/

 .../driver-api/driver-model/devres.rst        |  1 +
 drivers/base/platform.c                       | 33 +++++++++++++++++++
 include/linux/platform_device.h               |  4 +++
 3 files changed, 38 insertions(+)

diff --git a/Documentation/driver-api/driver-model/devres.rst b/Documentation/driver-api/driver-model/devres.rst
index 644078332354..89681264ee2c 100644
--- a/Documentation/driver-api/driver-model/devres.rst
+++ b/Documentation/driver-api/driver-model/devres.rst
@@ -325,6 +325,7 @@ IRQ
   devm_request_any_context_irq()
   devm_request_irq()
   devm_request_threaded_irq()
+  devm_platform_request_irq()
   devm_irq_alloc_descs()
   devm_irq_alloc_desc()
   devm_irq_alloc_desc_at()
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index c0d0a5490ac6..1d2fd1ea3bc5 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -275,6 +275,39 @@ int platform_irq_count(struct platform_device *dev)
 }
 EXPORT_SYMBOL_GPL(platform_irq_count);
 
+/**
+ * devm_platform_request_irq - get an irq and allocate an interrupt
+ *				line for a managed device
+ * @pdev: platform device
+ * @num: IRQ number index
+ * @irq: get an IRQ for a device if irq != NULL
+ * @handler: function to be called when the IRQ occurs
+ * @irqflags: interrupt type flags
+ * @devname: an ascii name for the claiming device, dev_name(dev) if NULL
+ * @dev_id: a cookie passed back to the handler function
+ *
+ * Return: zero on success, negative error number on failure.
+ */
+int devm_platform_request_irq(struct platform_device *pdev, unsigned int num,
+		unsigned int *irq, irq_handler_t handler,
+		unsigned long irqflags, const char *devname, void *dev_id)
+{
+	int tmp_irq, ret;
+
+	tmp_irq = platform_get_irq(pdev, num);
+	if (tmp_irq < 0)
+		return tmp_irq;
+
+	ret = devm_request_irq(&pdev->dev, tmp_irq, handler, irqflags,
+				devname, dev_id);
+	if (ret < 0)
+		dev_err(&pdev->dev, "can't request IRQ\n");
+	else if (irq != NULL)
+		*irq = tmp_irq;
+	return ret;
+}
+EXPORT_SYMBOL_GPL(devm_platform_request_irq);
+
 /**
  * platform_get_resource_byname - get a resource for a device by name
  * @dev: platform device
diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h
index 77a2aada106d..d94652deea5c 100644
--- a/include/linux/platform_device.h
+++ b/include/linux/platform_device.h
@@ -11,6 +11,7 @@
 #define _PLATFORM_DEVICE_H_
 
 #include <linux/device.h>
+#include <linux/interrupt.h>
 
 #define PLATFORM_DEVID_NONE	(-1)
 #define PLATFORM_DEVID_AUTO	(-2)
@@ -70,6 +71,9 @@ devm_platform_ioremap_resource_byname(struct platform_device *pdev,
 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 int devm_platform_request_irq(struct platform_device *pdev,
+		unsigned int num, unsigned int *irq, irq_handler_t handler,
+		unsigned long irqflags, const char *devname, void *dev_id);
 extern struct resource *platform_get_resource_byname(struct platform_device *,
 						     unsigned int,
 						     const char *);
-- 
2.25.0