xref: /linux/drivers/gpu/drm/omapdrm/omap_encoder.c (revision 9be5bab3)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2011 Texas Instruments Incorporated - https://www.ti.com/
4  * Author: Rob Clark <rob@ti.com>
5  */
6 
7 #include <linux/list.h>
8 
9 #include <drm/drm_bridge.h>
10 #include <drm/drm_crtc.h>
11 #include <drm/drm_modeset_helper_vtables.h>
12 #include <drm/drm_edid.h>
13 
14 #include "omap_drv.h"
15 
16 /*
17  * encoder funcs
18  */
19 
20 #define to_omap_encoder(x) container_of(x, struct omap_encoder, base)
21 
22 /* The encoder and connector both map to same dssdev.. the encoder
23  * handles the 'active' parts, ie. anything the modifies the state
24  * of the hw, and the connector handles the 'read-only' parts, like
25  * detecting connection and reading edid.
26  */
27 struct omap_encoder {
28 	struct drm_encoder base;
29 	struct omap_dss_device *output;
30 };
31 
32 static void omap_encoder_destroy(struct drm_encoder *encoder)
33 {
34 	struct omap_encoder *omap_encoder = to_omap_encoder(encoder);
35 
36 	drm_encoder_cleanup(encoder);
37 	kfree(omap_encoder);
38 }
39 
40 static const struct drm_encoder_funcs omap_encoder_funcs = {
41 	.destroy = omap_encoder_destroy,
42 };
43 
44 static void omap_encoder_update_videomode_flags(struct videomode *vm,
45 						u32 bus_flags)
46 {
47 	if (!(vm->flags & (DISPLAY_FLAGS_DE_LOW |
48 			   DISPLAY_FLAGS_DE_HIGH))) {
49 		if (bus_flags & DRM_BUS_FLAG_DE_LOW)
50 			vm->flags |= DISPLAY_FLAGS_DE_LOW;
51 		else if (bus_flags & DRM_BUS_FLAG_DE_HIGH)
52 			vm->flags |= DISPLAY_FLAGS_DE_HIGH;
53 	}
54 
55 	if (!(vm->flags & (DISPLAY_FLAGS_PIXDATA_POSEDGE |
56 			   DISPLAY_FLAGS_PIXDATA_NEGEDGE))) {
57 		if (bus_flags & DRM_BUS_FLAG_PIXDATA_DRIVE_POSEDGE)
58 			vm->flags |= DISPLAY_FLAGS_PIXDATA_POSEDGE;
59 		else if (bus_flags & DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE)
60 			vm->flags |= DISPLAY_FLAGS_PIXDATA_NEGEDGE;
61 	}
62 
63 	if (!(vm->flags & (DISPLAY_FLAGS_SYNC_POSEDGE |
64 			   DISPLAY_FLAGS_SYNC_NEGEDGE))) {
65 		if (bus_flags & DRM_BUS_FLAG_SYNC_DRIVE_POSEDGE)
66 			vm->flags |= DISPLAY_FLAGS_SYNC_POSEDGE;
67 		else if (bus_flags & DRM_BUS_FLAG_SYNC_DRIVE_NEGEDGE)
68 			vm->flags |= DISPLAY_FLAGS_SYNC_NEGEDGE;
69 	}
70 }
71 
72 static void omap_encoder_mode_set(struct drm_encoder *encoder,
73 				  struct drm_display_mode *mode,
74 				  struct drm_display_mode *adjusted_mode)
75 {
76 	struct omap_encoder *omap_encoder = to_omap_encoder(encoder);
77 	struct omap_dss_device *output = omap_encoder->output;
78 	struct omap_dss_device *dssdev;
79 	struct drm_device *dev = encoder->dev;
80 	struct drm_connector *connector;
81 	struct drm_bridge *bridge;
82 	struct videomode vm = { 0 };
83 	u32 bus_flags;
84 
85 	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
86 		if (connector->encoder == encoder)
87 			break;
88 	}
89 
90 	drm_display_mode_to_videomode(adjusted_mode, &vm);
91 
92 	/*
93 	 * HACK: This fixes the vm flags.
94 	 * struct drm_display_mode does not contain the VSYNC/HSYNC/DE flags and
95 	 * they get lost when converting back and forth between struct
96 	 * drm_display_mode and struct videomode. The hack below goes and
97 	 * fetches the missing flags.
98 	 *
99 	 * A better solution is to use DRM's bus-flags through the whole driver.
100 	 */
101 	for (dssdev = output; dssdev; dssdev = dssdev->next)
102 		omap_encoder_update_videomode_flags(&vm, dssdev->bus_flags);
103 
104 	for (bridge = output->bridge; bridge;
105 	     bridge = drm_bridge_get_next_bridge(bridge)) {
106 		if (!bridge->timings)
107 			continue;
108 
109 		bus_flags = bridge->timings->input_bus_flags;
110 		omap_encoder_update_videomode_flags(&vm, bus_flags);
111 	}
112 
113 	bus_flags = connector->display_info.bus_flags;
114 	omap_encoder_update_videomode_flags(&vm, bus_flags);
115 
116 	/* Set timings for all devices in the display pipeline. */
117 	dss_mgr_set_timings(output, &vm);
118 }
119 
120 static int omap_encoder_atomic_check(struct drm_encoder *encoder,
121 				     struct drm_crtc_state *crtc_state,
122 				     struct drm_connector_state *conn_state)
123 {
124 	struct omap_encoder *omap_encoder = to_omap_encoder(encoder);
125 	enum drm_mode_status status;
126 
127 	status = omap_connector_mode_fixup(omap_encoder->output,
128 					   &crtc_state->mode,
129 					   &crtc_state->adjusted_mode);
130 	if (status != MODE_OK) {
131 		dev_err(encoder->dev->dev, "invalid timings: %d\n", status);
132 		return -EINVAL;
133 	}
134 
135 	return 0;
136 }
137 
138 static const struct drm_encoder_helper_funcs omap_encoder_helper_funcs = {
139 	.mode_set = omap_encoder_mode_set,
140 	.atomic_check = omap_encoder_atomic_check,
141 };
142 
143 /* initialize encoder */
144 struct drm_encoder *omap_encoder_init(struct drm_device *dev,
145 				      struct omap_dss_device *output)
146 {
147 	struct drm_encoder *encoder = NULL;
148 	struct omap_encoder *omap_encoder;
149 
150 	omap_encoder = kzalloc(sizeof(*omap_encoder), GFP_KERNEL);
151 	if (!omap_encoder)
152 		goto fail;
153 
154 	omap_encoder->output = output;
155 
156 	encoder = &omap_encoder->base;
157 
158 	drm_encoder_init(dev, encoder, &omap_encoder_funcs,
159 			 DRM_MODE_ENCODER_TMDS, NULL);
160 	drm_encoder_helper_add(encoder, &omap_encoder_helper_funcs);
161 
162 	return encoder;
163 
164 fail:
165 	if (encoder)
166 		omap_encoder_destroy(encoder);
167 
168 	return NULL;
169 }
170