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 drm_device *dev = encoder->dev;
79 	struct drm_connector *connector;
80 	struct drm_bridge *bridge;
81 	struct videomode vm = { 0 };
82 	u32 bus_flags;
83 
84 	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
85 		if (connector->encoder == encoder)
86 			break;
87 	}
88 
89 	drm_display_mode_to_videomode(adjusted_mode, &vm);
90 
91 	/*
92 	 * HACK: This fixes the vm flags.
93 	 * struct drm_display_mode does not contain the VSYNC/HSYNC/DE flags and
94 	 * they get lost when converting back and forth between struct
95 	 * drm_display_mode and struct videomode. The hack below goes and
96 	 * fetches the missing flags.
97 	 *
98 	 * A better solution is to use DRM's bus-flags through the whole driver.
99 	 */
100 	for (bridge = output->bridge; bridge;
101 	     bridge = drm_bridge_get_next_bridge(bridge)) {
102 		if (!bridge->timings)
103 			continue;
104 
105 		bus_flags = bridge->timings->input_bus_flags;
106 		omap_encoder_update_videomode_flags(&vm, bus_flags);
107 	}
108 
109 	bus_flags = connector->display_info.bus_flags;
110 	omap_encoder_update_videomode_flags(&vm, bus_flags);
111 
112 	/* Set timings for all devices in the display pipeline. */
113 	dss_mgr_set_timings(output, &vm);
114 }
115 
116 static const struct drm_encoder_helper_funcs omap_encoder_helper_funcs = {
117 	.mode_set = omap_encoder_mode_set,
118 };
119 
120 /* initialize encoder */
121 struct drm_encoder *omap_encoder_init(struct drm_device *dev,
122 				      struct omap_dss_device *output)
123 {
124 	struct drm_encoder *encoder = NULL;
125 	struct omap_encoder *omap_encoder;
126 
127 	omap_encoder = kzalloc(sizeof(*omap_encoder), GFP_KERNEL);
128 	if (!omap_encoder)
129 		goto fail;
130 
131 	omap_encoder->output = output;
132 
133 	encoder = &omap_encoder->base;
134 
135 	drm_encoder_init(dev, encoder, &omap_encoder_funcs,
136 			 DRM_MODE_ENCODER_TMDS, NULL);
137 	drm_encoder_helper_add(encoder, &omap_encoder_helper_funcs);
138 
139 	return encoder;
140 
141 fail:
142 	if (encoder)
143 		omap_encoder_destroy(encoder);
144 
145 	return NULL;
146 }
147