xref: /linux/drivers/gpu/drm/ast/ast_vga.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
1 // SPDX-License-Identifier: MIT
2 
3 #include <drm/drm_atomic_state_helper.h>
4 #include <drm/drm_edid.h>
5 #include <drm/drm_modeset_helper_vtables.h>
6 #include <drm/drm_print.h>
7 #include <drm/drm_probe_helper.h>
8 
9 #include "ast_ddc.h"
10 #include "ast_drv.h"
11 
12 /*
13  * Encoder
14  */
15 
16 static const struct drm_encoder_funcs ast_vga_encoder_funcs = {
17 	.destroy = drm_encoder_cleanup,
18 };
19 
20 /*
21  * Connector
22  */
23 
24 static int ast_vga_connector_helper_get_modes(struct drm_connector *connector)
25 {
26 	struct ast_connector *ast_connector = to_ast_connector(connector);
27 	int count;
28 
29 	if (ast_connector->physical_status == connector_status_connected) {
30 		count = drm_connector_helper_get_modes(connector);
31 	} else {
32 		drm_edid_connector_update(connector, NULL);
33 
34 		/*
35 		 * There's no EDID data without a connected monitor. Set BMC-
36 		 * compatible modes in this case. The XGA default resolution
37 		 * should work well for all BMCs.
38 		 */
39 		count = drm_add_modes_noedid(connector, 4096, 4096);
40 		if (count)
41 			drm_set_preferred_mode(connector, 1024, 768);
42 	}
43 
44 	return count;
45 }
46 
47 static int ast_vga_connector_helper_detect_ctx(struct drm_connector *connector,
48 					       struct drm_modeset_acquire_ctx *ctx,
49 					       bool force)
50 {
51 	struct ast_connector *ast_connector = to_ast_connector(connector);
52 	enum drm_connector_status status;
53 
54 	status = drm_connector_helper_detect_from_ddc(connector, ctx, force);
55 
56 	if (status != ast_connector->physical_status)
57 		++connector->epoch_counter;
58 	ast_connector->physical_status = status;
59 
60 	return connector_status_connected;
61 }
62 
63 static const struct drm_connector_helper_funcs ast_vga_connector_helper_funcs = {
64 	.get_modes = ast_vga_connector_helper_get_modes,
65 	.detect_ctx = ast_vga_connector_helper_detect_ctx,
66 };
67 
68 static const struct drm_connector_funcs ast_vga_connector_funcs = {
69 	.reset = drm_atomic_helper_connector_reset,
70 	.fill_modes = drm_helper_probe_single_connector_modes,
71 	.destroy = drm_connector_cleanup,
72 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
73 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
74 };
75 
76 static int ast_vga_connector_init(struct drm_device *dev, struct drm_connector *connector)
77 {
78 	struct ast_device *ast = to_ast_device(dev);
79 	struct i2c_adapter *ddc;
80 	int ret;
81 
82 	ddc = ast_ddc_create(ast);
83 	if (IS_ERR(ddc)) {
84 		ret = PTR_ERR(ddc);
85 		drm_err(dev, "failed to add DDC bus for connector; ret=%d\n", ret);
86 		return ret;
87 	}
88 
89 	ret = drm_connector_init_with_ddc(dev, connector, &ast_vga_connector_funcs,
90 					  DRM_MODE_CONNECTOR_VGA, ddc);
91 	if (ret)
92 		return ret;
93 
94 	drm_connector_helper_add(connector, &ast_vga_connector_helper_funcs);
95 
96 	connector->interlace_allowed = 0;
97 	connector->doublescan_allowed = 0;
98 
99 	connector->polled = DRM_CONNECTOR_POLL_CONNECT | DRM_CONNECTOR_POLL_DISCONNECT;
100 
101 	return 0;
102 }
103 
104 int ast_vga_output_init(struct ast_device *ast)
105 {
106 	struct drm_device *dev = &ast->base;
107 	struct drm_crtc *crtc = &ast->crtc;
108 	struct drm_encoder *encoder = &ast->output.vga.encoder;
109 	struct ast_connector *ast_connector = &ast->output.vga.connector;
110 	struct drm_connector *connector = &ast_connector->base;
111 	int ret;
112 
113 	ret = drm_encoder_init(dev, encoder, &ast_vga_encoder_funcs,
114 			       DRM_MODE_ENCODER_DAC, NULL);
115 	if (ret)
116 		return ret;
117 	encoder->possible_crtcs = drm_crtc_mask(crtc);
118 
119 	ret = ast_vga_connector_init(dev, connector);
120 	if (ret)
121 		return ret;
122 	ast_connector->physical_status = connector->status;
123 
124 	ret = drm_connector_attach_encoder(connector, encoder);
125 	if (ret)
126 		return ret;
127 
128 	return 0;
129 }
130