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