1 // SPDX-License-Identifier: GPL-2.0+
2 
3 #include <linux/dma-buf-map.h>
4 
5 #include <drm/drm_atomic.h>
6 #include <drm/drm_fourcc.h>
7 #include <drm/drm_writeback.h>
8 #include <drm/drm_probe_helper.h>
9 #include <drm/drm_atomic_helper.h>
10 #include <drm/drm_gem_framebuffer_helper.h>
11 #include <drm/drm_gem_shmem_helper.h>
12 
13 #include "vkms_drv.h"
14 
15 static const u32 vkms_wb_formats[] = {
16 	DRM_FORMAT_XRGB8888,
17 };
18 
19 static const struct drm_connector_funcs vkms_wb_connector_funcs = {
20 	.fill_modes = drm_helper_probe_single_connector_modes,
21 	.destroy = drm_connector_cleanup,
22 	.reset = drm_atomic_helper_connector_reset,
23 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
24 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
25 };
26 
27 static int vkms_wb_encoder_atomic_check(struct drm_encoder *encoder,
28 					struct drm_crtc_state *crtc_state,
29 					struct drm_connector_state *conn_state)
30 {
31 	struct drm_framebuffer *fb;
32 	const struct drm_display_mode *mode = &crtc_state->mode;
33 
34 	if (!conn_state->writeback_job || !conn_state->writeback_job->fb)
35 		return 0;
36 
37 	fb = conn_state->writeback_job->fb;
38 	if (fb->width != mode->hdisplay || fb->height != mode->vdisplay) {
39 		DRM_DEBUG_KMS("Invalid framebuffer size %ux%u\n",
40 			      fb->width, fb->height);
41 		return -EINVAL;
42 	}
43 
44 	if (fb->format->format != vkms_wb_formats[0]) {
45 		DRM_DEBUG_KMS("Invalid pixel format %p4cc\n",
46 			      &fb->format->format);
47 		return -EINVAL;
48 	}
49 
50 	return 0;
51 }
52 
53 static const struct drm_encoder_helper_funcs vkms_wb_encoder_helper_funcs = {
54 	.atomic_check = vkms_wb_encoder_atomic_check,
55 };
56 
57 static int vkms_wb_connector_get_modes(struct drm_connector *connector)
58 {
59 	struct drm_device *dev = connector->dev;
60 
61 	return drm_add_modes_noedid(connector, dev->mode_config.max_width,
62 				    dev->mode_config.max_height);
63 }
64 
65 static int vkms_wb_prepare_job(struct drm_writeback_connector *wb_connector,
66 			       struct drm_writeback_job *job)
67 {
68 	struct drm_gem_object *gem_obj;
69 	struct dma_buf_map map;
70 	int ret;
71 
72 	if (!job->fb)
73 		return 0;
74 
75 	gem_obj = drm_gem_fb_get_obj(job->fb, 0);
76 	ret = drm_gem_shmem_vmap(gem_obj, &map);
77 	if (ret) {
78 		DRM_ERROR("vmap failed: %d\n", ret);
79 		return ret;
80 	}
81 
82 	job->priv = map.vaddr;
83 
84 	return 0;
85 }
86 
87 static void vkms_wb_cleanup_job(struct drm_writeback_connector *connector,
88 				struct drm_writeback_job *job)
89 {
90 	struct drm_gem_object *gem_obj;
91 	struct vkms_device *vkmsdev;
92 	struct dma_buf_map map;
93 
94 	if (!job->fb)
95 		return;
96 
97 	gem_obj = drm_gem_fb_get_obj(job->fb, 0);
98 	dma_buf_map_set_vaddr(&map, job->priv);
99 	drm_gem_shmem_vunmap(gem_obj, &map);
100 
101 	vkmsdev = drm_device_to_vkms_device(gem_obj->dev);
102 	vkms_set_composer(&vkmsdev->output, false);
103 }
104 
105 static void vkms_wb_atomic_commit(struct drm_connector *conn,
106 				  struct drm_atomic_state *state)
107 {
108 	struct drm_connector_state *connector_state = drm_atomic_get_new_connector_state(state,
109 											 conn);
110 	struct vkms_device *vkmsdev = drm_device_to_vkms_device(conn->dev);
111 	struct vkms_output *output = &vkmsdev->output;
112 	struct drm_writeback_connector *wb_conn = &output->wb_connector;
113 	struct drm_connector_state *conn_state = wb_conn->base.state;
114 	struct vkms_crtc_state *crtc_state = output->composer_state;
115 
116 	if (!conn_state)
117 		return;
118 
119 	vkms_set_composer(&vkmsdev->output, true);
120 
121 	spin_lock_irq(&output->composer_lock);
122 	crtc_state->active_writeback = conn_state->writeback_job->priv;
123 	crtc_state->wb_pending = true;
124 	spin_unlock_irq(&output->composer_lock);
125 	drm_writeback_queue_job(wb_conn, connector_state);
126 }
127 
128 static const struct drm_connector_helper_funcs vkms_wb_conn_helper_funcs = {
129 	.get_modes = vkms_wb_connector_get_modes,
130 	.prepare_writeback_job = vkms_wb_prepare_job,
131 	.cleanup_writeback_job = vkms_wb_cleanup_job,
132 	.atomic_commit = vkms_wb_atomic_commit,
133 };
134 
135 int vkms_enable_writeback_connector(struct vkms_device *vkmsdev)
136 {
137 	struct drm_writeback_connector *wb = &vkmsdev->output.wb_connector;
138 
139 	vkmsdev->output.wb_connector.encoder.possible_crtcs = 1;
140 	drm_connector_helper_add(&wb->base, &vkms_wb_conn_helper_funcs);
141 
142 	return drm_writeback_connector_init(&vkmsdev->drm, wb,
143 					    &vkms_wb_connector_funcs,
144 					    &vkms_wb_encoder_helper_funcs,
145 					    vkms_wb_formats,
146 					    ARRAY_SIZE(vkms_wb_formats));
147 }
148