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
20irqreturn_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(dev: ddev, pipe: 0);
40
41 if (ldev->irq_status & INT_CRTC1_VSYNC)
42 drm_handle_vblank(dev: ddev, pipe: 1);
43
44 return IRQ_HANDLED;
45}
46
47/* For the DC in LS7A1000 and LS2K1000 */
48irqreturn_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(dev: ddev, pipe: 0);
69
70 if (ldev->irq_status & INT_CRTC1_VSYNC)
71 drm_handle_vblank(dev: ddev, pipe: 1);
72
73 return IRQ_HANDLED;
74}
75

source code of linux/drivers/gpu/drm/loongson/lsdc_irq.c