drm/aspeed: Update INTR_STS handling

Add interrupt clear register define for further chip support.
Signed-off-by: Tommy Haung <tommy_huang@aspeedtech.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Link: https://patchwork.freedesktop.org/patch/msgid/20220302024930.18758-4-tommy_huang@aspeedtech.com

drivers/gpu/drm/aspeed/aspeed_gfx.h

@@ -12,6 +12,7 @@ struct aspeed_gfx {
 	struct regmap			*scu;
 
 	u32				dac_reg;
+	u32				int_clr_reg;
 	u32				vga_scratch_reg;
 	u32				throd_val;
 	u32				scan_line_max;

drivers/gpu/drm/aspeed/aspeed_gfx_drv.c

@@ -61,6 +61,7 @@
 
 struct aspeed_gfx_config {
 	u32 dac_reg;		/* DAC register in SCU */
+	u32 int_clear_reg;	/* Interrupt clear register */
 	u32 vga_scratch_reg;	/* VGA scratch register in SCU */
 	u32 throd_val;		/* Default Threshold Seting */
 	u32 scan_line_max;	/* Max memory size of one scan line */
@@ -68,6 +69,7 @@ struct aspeed_gfx_config {
 
 static const struct aspeed_gfx_config ast2400_config = {
 	.dac_reg = 0x2c,
+	.int_clear_reg = 0x60,
 	.vga_scratch_reg = 0x50,
 	.throd_val = CRT_THROD_LOW(0x1e) | CRT_THROD_HIGH(0x12),
 	.scan_line_max = 64,
@@ -75,6 +77,7 @@ static const struct aspeed_gfx_config ast2400_config = {
 
 static const struct aspeed_gfx_config ast2500_config = {
 	.dac_reg = 0x2c,
+	.int_clear_reg = 0x60,
 	.vga_scratch_reg = 0x50,
 	.throd_val = CRT_THROD_LOW(0x24) | CRT_THROD_HIGH(0x3c),
 	.scan_line_max = 128,
@@ -120,7 +123,7 @@ static irqreturn_t aspeed_gfx_irq_handler(int irq, void *data)
 
 	if (reg & CRT_CTRL_VERTICAL_INTR_STS) {
 		drm_crtc_handle_vblank(&priv->pipe.crtc);
-		writel(reg, priv->base + CRT_CTRL1);
+		writel(reg, priv->base + priv->int_clr_reg);
 		return IRQ_HANDLED;
 	}
 
@@ -148,6 +151,7 @@ static int aspeed_gfx_load(struct drm_device *drm)
 	config = match->data;
 
 	priv->dac_reg = config->dac_reg;
+	priv->int_clr_reg = config->int_clear_reg;
 	priv->vga_scratch_reg = config->vga_scratch_reg;
 	priv->throd_val = config->throd_val;
 	priv->scan_line_max = config->scan_line_max;