xref: /linux/drivers/gpu/drm/loongson/lsdc_irq.c (revision 8e07e0e3964ca4e23ce7b68e2096fe660a888942)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2023 Loongson Technology Corporation Limited
4  */
5 
6 #include <drm/drm_vblank.h>
7 
8 #include "lsdc_irq.h"
9 
10 /*
11  * For the DC in LS7A2000, clearing interrupt status is achieved by
12  * write "1" to LSDC_INT_REG.
13  *
14  * For the DC in LS7A1000, clear interrupt status is achieved by write "0"
15  * to LSDC_INT_REG.
16  *
17  * Two different hardware engineers modify it as their will.
18  */
19 
20 irqreturn_t ls7a2000_dc_irq_handler(int irq, void *arg)
21 {
22 	struct drm_device *ddev = arg;
23 	struct lsdc_device *ldev = to_lsdc(ddev);
24 	u32 val;
25 
26 	/* Read the interrupt status */
27 	val = lsdc_rreg32(ldev, LSDC_INT_REG);
28 	if ((val & INT_STATUS_MASK) == 0) {
29 		drm_warn(ddev, "no interrupt occurs\n");
30 		return IRQ_NONE;
31 	}
32 
33 	ldev->irq_status = val;
34 
35 	/* write "1" to clear the interrupt status */
36 	lsdc_wreg32(ldev, LSDC_INT_REG, val);
37 
38 	if (ldev->irq_status & INT_CRTC0_VSYNC)
39 		drm_handle_vblank(ddev, 0);
40 
41 	if (ldev->irq_status & INT_CRTC1_VSYNC)
42 		drm_handle_vblank(ddev, 1);
43 
44 	return IRQ_HANDLED;
45 }
46 
47 /* For the DC in LS7A1000 and LS2K1000 */
48 irqreturn_t ls7a1000_dc_irq_handler(int irq, void *arg)
49 {
50 	struct drm_device *ddev = arg;
51 	struct lsdc_device *ldev = to_lsdc(ddev);
52 	u32 val;
53 
54 	/* Read the interrupt status */
55 	val = lsdc_rreg32(ldev, LSDC_INT_REG);
56 	if ((val & INT_STATUS_MASK) == 0) {
57 		drm_warn(ddev, "no interrupt occurs\n");
58 		return IRQ_NONE;
59 	}
60 
61 	ldev->irq_status = val;
62 
63 	/* write "0" to clear the interrupt status */
64 	val &= ~(INT_CRTC0_VSYNC | INT_CRTC1_VSYNC);
65 	lsdc_wreg32(ldev, LSDC_INT_REG, val);
66 
67 	if (ldev->irq_status & INT_CRTC0_VSYNC)
68 		drm_handle_vblank(ddev, 0);
69 
70 	if (ldev->irq_status & INT_CRTC1_VSYNC)
71 		drm_handle_vblank(ddev, 1);
72 
73 	return IRQ_HANDLED;
74 }
75