1 files changed, 74 insertions, 0 deletions
diff --git a/drivers/gpu/drm/loongson/lsdc_irq.c b/drivers/gpu/drm/loongson/lsdc_irq.c
new file mode 100644
index 000000000000..efdc4d10792d
--- /dev/null
+++ b/drivers/gpu/drm/loongson/lsdc_irq.c
@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2023 Loongson Technology Corporation Limited
+ */
+
+#include <drm/drm_vblank.h>
+
+#include "lsdc_irq.h"
+
+/*
+ * For the DC in LS7A2000, clearing interrupt status is achieved by
+ * write "1" to LSDC_INT_REG.
+ *
+ * For the DC in LS7A1000, clear interrupt status is achieved by write "0"
+ * to LSDC_INT_REG.
+ *
+ * Two different hardware engineers modify it as their will.
+ */
+
+irqreturn_t ls7a2000_dc_irq_handler(int irq, void *arg)
+{
+	struct drm_device *ddev = arg;
+	struct lsdc_device *ldev = to_lsdc(ddev);
+	u32 val;
+
+	/* Read the interrupt status */
+	val = lsdc_rreg32(ldev, LSDC_INT_REG);
+	if ((val & INT_STATUS_MASK) == 0) {
+		drm_warn(ddev, "no interrupt occurs\n");
+		return IRQ_NONE;
+	}
+
+	ldev->irq_status = val;
+
+	/* write "1" to clear the interrupt status */
+	lsdc_wreg32(ldev, LSDC_INT_REG, val);
+
+	if (ldev->irq_status & INT_CRTC0_VSYNC)
+		drm_handle_vblank(ddev, 0);
+
+	if (ldev->irq_status & INT_CRTC1_VSYNC)
+		drm_handle_vblank(ddev, 1);
+
+	return IRQ_HANDLED;
+}
+
+/* For the DC in LS7A1000 and LS2K1000 */
+irqreturn_t ls7a1000_dc_irq_handler(int irq, void *arg)
+{
+	struct drm_device *ddev = arg;
+	struct lsdc_device *ldev = to_lsdc(ddev);
+	u32 val;
+
+	/* Read the interrupt status */
+	val = lsdc_rreg32(ldev, LSDC_INT_REG);
+	if ((val & INT_STATUS_MASK) == 0) {
+		drm_warn(ddev, "no interrupt occurs\n");
+		return IRQ_NONE;
+	}
+
+	ldev->irq_status = val;
+
+	/* write "0" to clear the interrupt status */
+	val &= ~(INT_CRTC0_VSYNC | INT_CRTC1_VSYNC);
+	lsdc_wreg32(ldev, LSDC_INT_REG, val);
+
+	if (ldev->irq_status & INT_CRTC0_VSYNC)
+		drm_handle_vblank(ddev, 0);
+
+	if (ldev->irq_status & INT_CRTC1_VSYNC)
+		drm_handle_vblank(ddev, 1);
+
+	return IRQ_HANDLED;
+}