drm/atmel-hlcdc: Convert to Linux IRQ interfaces

Drop the DRM IRQ midlayer in favor of Linux IRQ interfaces. DRM's
IRQ helpers are mostly useful for UMS drivers. Modern KMS drivers
don't benefit from using it. DRM IRQ callbacks are now being called
directly or inlined.

v2:
	* use managed release via devm_request_irq() (Sam)
	* drop extra test for irq != IRQ_NOTCONNECTED (Sam)
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Tested-by: Dan Sneddon <Dan.Sneddon@microchip.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210803090704.32152-4-tzimmermann@suse.de

drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c

@@ -22,7 +22,6 @@
 #include <drm/drm_fb_helper.h>
 #include <drm/drm_gem_cma_helper.h>
 #include <drm/drm_gem_framebuffer_helper.h>
-#include <drm/drm_irq.h>
 #include <drm/drm_probe_helper.h>
 #include <drm/drm_vblank.h>
 
@@ -557,6 +556,51 @@ static irqreturn_t atmel_hlcdc_dc_irq_handler(int irq, void *data)
 	return IRQ_HANDLED;
 }
 
+static void atmel_hlcdc_dc_irq_postinstall(struct drm_device *dev)
+{
+	struct atmel_hlcdc_dc *dc = dev->dev_private;
+	unsigned int cfg = 0;
+	int i;
+
+	/* Enable interrupts on activated layers */
+	for (i = 0; i < ATMEL_HLCDC_MAX_LAYERS; i++) {
+		if (dc->layers[i])
+			cfg |= ATMEL_HLCDC_LAYER_STATUS(i);
+	}
+
+	regmap_write(dc->hlcdc->regmap, ATMEL_HLCDC_IER, cfg);
+}
+
+static void atmel_hlcdc_dc_irq_disable(struct drm_device *dev)
+{
+	struct atmel_hlcdc_dc *dc = dev->dev_private;
+	unsigned int isr;
+
+	regmap_write(dc->hlcdc->regmap, ATMEL_HLCDC_IDR, 0xffffffff);
+	regmap_read(dc->hlcdc->regmap, ATMEL_HLCDC_ISR, &isr);
+}
+
+static int atmel_hlcdc_dc_irq_install(struct drm_device *dev, unsigned int irq)
+{
+	int ret;
+
+	atmel_hlcdc_dc_irq_disable(dev);
+
+	ret = devm_request_irq(dev->dev, irq, atmel_hlcdc_dc_irq_handler, 0,
+			       dev->driver->name, dev);
+	if (ret)
+		return ret;
+
+	atmel_hlcdc_dc_irq_postinstall(dev);
+
+	return 0;
+}
+
+static void atmel_hlcdc_dc_irq_uninstall(struct drm_device *dev)
+{
+	atmel_hlcdc_dc_irq_disable(dev);
+}
+
 static const struct drm_mode_config_funcs mode_config_funcs = {
 	.fb_create = drm_gem_fb_create,
 	.atomic_check = drm_atomic_helper_check,
@@ -647,7 +691,7 @@ static int atmel_hlcdc_dc_load(struct drm_device *dev)
 	drm_mode_config_reset(dev);
 
 	pm_runtime_get_sync(dev->dev);
-	ret = drm_irq_install(dev, dc->hlcdc->irq);
+	ret = atmel_hlcdc_dc_irq_install(dev, dc->hlcdc->irq);
 	pm_runtime_put_sync(dev->dev);
 	if (ret < 0) {
 		dev_err(dev->dev, "failed to install IRQ handler\n");
@@ -676,7 +720,7 @@ static void atmel_hlcdc_dc_unload(struct drm_device *dev)
 	drm_mode_config_cleanup(dev);
 
 	pm_runtime_get_sync(dev->dev);
-	drm_irq_uninstall(dev);
+	atmel_hlcdc_dc_irq_uninstall(dev);
 	pm_runtime_put_sync(dev->dev);
 
 	dev->dev_private = NULL;
@@ -685,40 +729,10 @@ static void atmel_hlcdc_dc_unload(struct drm_device *dev)
 	clk_disable_unprepare(dc->hlcdc->periph_clk);
 }
 
-static int atmel_hlcdc_dc_irq_postinstall(struct drm_device *dev)
-{
-	struct atmel_hlcdc_dc *dc = dev->dev_private;
-	unsigned int cfg = 0;
-	int i;
-
-	/* Enable interrupts on activated layers */
-	for (i = 0; i < ATMEL_HLCDC_MAX_LAYERS; i++) {
-		if (dc->layers[i])
-			cfg |= ATMEL_HLCDC_LAYER_STATUS(i);
-	}
-
-	regmap_write(dc->hlcdc->regmap, ATMEL_HLCDC_IER, cfg);
-
-	return 0;
-}
-
-static void atmel_hlcdc_dc_irq_uninstall(struct drm_device *dev)
-{
-	struct atmel_hlcdc_dc *dc = dev->dev_private;
-	unsigned int isr;
-
-	regmap_write(dc->hlcdc->regmap, ATMEL_HLCDC_IDR, 0xffffffff);
-	regmap_read(dc->hlcdc->regmap, ATMEL_HLCDC_ISR, &isr);
-}
-
 DEFINE_DRM_GEM_CMA_FOPS(fops);
 
 static const struct drm_driver atmel_hlcdc_dc_driver = {
 	.driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
-	.irq_handler = atmel_hlcdc_dc_irq_handler,
-	.irq_preinstall = atmel_hlcdc_dc_irq_uninstall,
-	.irq_postinstall = atmel_hlcdc_dc_irq_postinstall,
-	.irq_uninstall = atmel_hlcdc_dc_irq_uninstall,
 	DRM_GEM_CMA_DRIVER_OPS,
 	.fops = &fops,
 	.name = "atmel-hlcdc",