[PATCH drm/hisilicon 1/2] drm/irq: Add the new api to enable pci msi

[Tian Tao <tiantao6@hisilicon.com>]

Add new api devm_drm_msi_install() to register interrupts,
no need to call pci_disable_msi() when the drm module is removed.

Signed-off-by: Tian Tao <tiantao6@hisilicon.com>
---
 drivers/gpu/drm/drm_irq.c | 33 +++++++++++++++++++++++++++++++++
 include/drm/drm_irq.h     |  1 +
 2 files changed, 34 insertions(+)

diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index 803af4b..da58b2c 100644
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -246,6 +246,39 @@ int devm_drm_irq_install(struct drm_device *dev, int irq)
 }
 EXPORT_SYMBOL(devm_drm_irq_install);
 
+static void devm_drm_msi_uninstall(void *data)
+{
+	struct drm_device *dev = (struct drm_device *)data;
+
+	pci_disable_msi(dev->pdev);
+}
+
+/**
+ * devm_drm_msi_install - install IRQ handler
+ * @dev: DRM device
+ *
+ * devm_drm_msi_install is a  help function of pci_enable_msi.
+ *
+ * if the driver uses devm_drm_msi_install, there is no need
+ * to call pci_disable_msi when the drm module get unloaded,
+ * as this will done automagically.
+ *
+ * Returns:
+ * Zero on success or a negative error code on failure.
+ */
+int devm_drm_msi_install(struct drm_device *dev)
+{
+	int ret;
+
+	ret = pci_enable_msi(dev->pdev);
+	if (ret)
+		return ret;
+
+	return devm_add_action_or_reset(dev->dev,
+					devm_drm_msi_uninstall, dev);
+}
+EXPORT_SYMBOL(devm_drm_msi_install);
+
 #if IS_ENABLED(CONFIG_DRM_LEGACY)
 int drm_legacy_irq_control(struct drm_device *dev, void *data,
 			   struct drm_file *file_priv)
diff --git a/include/drm/drm_irq.h b/include/drm/drm_irq.h
index 631b22f..c8dff45 100644
--- a/include/drm/drm_irq.h
+++ b/include/drm/drm_irq.h
@@ -29,4 +29,5 @@ struct drm_device;
 int drm_irq_install(struct drm_device *dev, int irq);
 int drm_irq_uninstall(struct drm_device *dev);
 int devm_drm_irq_install(struct drm_device *dev, int irq);
+int devm_drm_msi_install(struct drm_device *dev);
 #endif
-- 
2.7.4