drm/arm/hdlcd: Simplify IRQ install/uninstall

Since we no longer need to conform to the structure of the various DRM
IRQ callbacks, we can streamline the code by consolidating the piecemeal
functions and passing around our private data structure directly. We're
also a platform device so should never see IRQ_NOTCONNECTED either.

Furthermore we can also get rid of all the unnecesary read-modify-write
operations, since on install we know we cleared the whole interrupt mask
before enabling the debug IRQs, and thus on uninstall we're always
clearing everything as well.
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Liviu Dudau <liviu.dudau@arm.com>
Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/65cf7818b23c1a8629dc851f1d058ecb8a14849e.1655309413.git.robin.murphy@arm.com

drivers/gpu/drm/arm/hdlcd_drv.c

@@ -41,8 +41,7 @@
 
 static irqreturn_t hdlcd_irq(int irq, void *arg)
 {
-	struct drm_device *drm = arg;
-	struct hdlcd_drm_private *hdlcd = drm->dev_private;
+	struct hdlcd_drm_private *hdlcd = arg;
 	unsigned long irq_status;
 
 	irq_status = hdlcd_read(hdlcd, HDLCD_REG_INT_STATUS);
@@ -70,61 +69,32 @@ static irqreturn_t hdlcd_irq(int irq, void *arg)
 	return IRQ_HANDLED;
 }
 
-static void hdlcd_irq_preinstall(struct drm_device *drm)
+static int hdlcd_irq_install(struct hdlcd_drm_private *hdlcd)
 {
-	struct hdlcd_drm_private *hdlcd = drm->dev_private;
+	int ret;
+
 	/* Ensure interrupts are disabled */
 	hdlcd_write(hdlcd, HDLCD_REG_INT_MASK, 0);
 	hdlcd_write(hdlcd, HDLCD_REG_INT_CLEAR, ~0);
-}
-
-static void hdlcd_irq_postinstall(struct drm_device *drm)
-{
-#ifdef CONFIG_DEBUG_FS
-	struct hdlcd_drm_private *hdlcd = drm->dev_private;
-	unsigned long irq_mask = hdlcd_read(hdlcd, HDLCD_REG_INT_MASK);
-
-	/* enable debug interrupts */
-	irq_mask |= HDLCD_DEBUG_INT_MASK;
-
-	hdlcd_write(hdlcd, HDLCD_REG_INT_MASK, irq_mask);
-#endif
-}
 
-static int hdlcd_irq_install(struct drm_device *drm, int irq)
-{
-	int ret;
-
-	if (irq == IRQ_NOTCONNECTED)
-		return -ENOTCONN;
-
-	hdlcd_irq_preinstall(drm);
-
-	ret = request_irq(irq, hdlcd_irq, 0, drm->driver->name, drm);
+	ret = request_irq(hdlcd->irq, hdlcd_irq, 0, "hdlcd", hdlcd);
 	if (ret)
 		return ret;
 
-	hdlcd_irq_postinstall(drm);
+#ifdef CONFIG_DEBUG_FS
+	/* enable debug interrupts */
+	hdlcd_write(hdlcd, HDLCD_REG_INT_MASK, HDLCD_DEBUG_INT_MASK);
+#endif
 
 	return 0;
 }
 
-static void hdlcd_irq_uninstall(struct drm_device *drm)
+static void hdlcd_irq_uninstall(struct hdlcd_drm_private *hdlcd)
 {
-	struct hdlcd_drm_private *hdlcd = drm->dev_private;
 	/* disable all the interrupts that we might have enabled */
-	unsigned long irq_mask = hdlcd_read(hdlcd, HDLCD_REG_INT_MASK);
-
-#ifdef CONFIG_DEBUG_FS
-	/* disable debug interrupts */
-	irq_mask &= ~HDLCD_DEBUG_INT_MASK;
-#endif
-
-	/* disable vsync interrupts */
-	irq_mask &= ~HDLCD_INTERRUPT_VSYNC;
-	hdlcd_write(hdlcd, HDLCD_REG_INT_MASK, irq_mask);
+	hdlcd_write(hdlcd, HDLCD_REG_INT_MASK, 0);
 
-	free_irq(hdlcd->irq, drm);
+	free_irq(hdlcd->irq, hdlcd);
 }
 
 static int hdlcd_load(struct drm_device *drm, unsigned long flags)
@@ -184,7 +154,7 @@ static int hdlcd_load(struct drm_device *drm, unsigned long flags)
 		goto irq_fail;
 	hdlcd->irq = ret;
 
-	ret = hdlcd_irq_install(drm, hdlcd->irq);
+	ret = hdlcd_irq_install(hdlcd);
 	if (ret < 0) {
 		DRM_ERROR("failed to install IRQ handler\n");
 		goto irq_fail;
@@ -345,7 +315,7 @@ static int hdlcd_drm_bind(struct device *dev)
 err_unload:
 	of_node_put(hdlcd->crtc.port);
 	hdlcd->crtc.port = NULL;
-	hdlcd_irq_uninstall(drm);
+	hdlcd_irq_uninstall(hdlcd);
 	of_reserved_mem_device_release(drm->dev);
 err_free:
 	drm_mode_config_cleanup(drm);
@@ -367,7 +337,7 @@ static void hdlcd_drm_unbind(struct device *dev)
 	hdlcd->crtc.port = NULL;
 	pm_runtime_get_sync(dev);
 	drm_atomic_helper_shutdown(drm);
-	hdlcd_irq_uninstall(drm);
+	hdlcd_irq_uninstall(hdlcd);
 	pm_runtime_put(dev);
 	if (pm_runtime_enabled(dev))
 		pm_runtime_disable(dev);