1 /*
2  * Copyright (C) 2015 Texas Instruments
3  * Author: Jyri Sarha <jsarha@ti.com>
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms of the GNU General Public License version 2 as published by
7  * the Free Software Foundation.
8  *
9  */
10 
11 #include <linux/component.h>
12 #include <linux/of_graph.h>
13 
14 #include "tilcdc_drv.h"
15 #include "tilcdc_external.h"
16 
17 static const struct tilcdc_panel_info panel_info_tda998x = {
18 		.ac_bias                = 255,
19 		.ac_bias_intrpt         = 0,
20 		.dma_burst_sz           = 16,
21 		.bpp                    = 16,
22 		.fdd                    = 0x80,
23 		.tft_alt_mode           = 0,
24 		.invert_pxl_clk		= 1,
25 		.sync_edge              = 1,
26 		.sync_ctrl              = 1,
27 		.raster_order           = 0,
28 };
29 
30 static int tilcdc_external_mode_valid(struct drm_connector *connector,
31 				      struct drm_display_mode *mode)
32 {
33 	struct tilcdc_drm_private *priv = connector->dev->dev_private;
34 	int ret, i;
35 
36 	ret = tilcdc_crtc_mode_valid(priv->crtc, mode);
37 	if (ret != MODE_OK)
38 		return ret;
39 
40 	for (i = 0; i < priv->num_connectors &&
41 		     priv->connectors[i] != connector; i++)
42 		;
43 
44 	BUG_ON(priv->connectors[i] != connector);
45 	BUG_ON(!priv->connector_funcs[i]);
46 
47 	/* If the connector has its own mode_valid call it. */
48 	if (!IS_ERR(priv->connector_funcs[i]) &&
49 	    priv->connector_funcs[i]->mode_valid)
50 		return priv->connector_funcs[i]->mode_valid(connector, mode);
51 
52 	return MODE_OK;
53 }
54 
55 static int tilcdc_add_external_encoder(struct drm_device *dev, int *bpp,
56 				       struct drm_connector *connector)
57 {
58 	struct tilcdc_drm_private *priv = dev->dev_private;
59 	struct drm_connector_helper_funcs *connector_funcs;
60 
61 	priv->connectors[priv->num_connectors] = connector;
62 	priv->encoders[priv->num_encoders++] = connector->encoder;
63 
64 	/* Only tda998x is supported at the moment. */
65 	tilcdc_crtc_set_simulate_vesa_sync(priv->crtc, true);
66 	tilcdc_crtc_set_panel_info(priv->crtc, &panel_info_tda998x);
67 	*bpp = panel_info_tda998x.bpp;
68 
69 	connector_funcs = devm_kzalloc(dev->dev, sizeof(*connector_funcs),
70 				       GFP_KERNEL);
71 	if (!connector_funcs)
72 		return -ENOMEM;
73 
74 	/* connector->helper_private contains always struct
75 	 * connector_helper_funcs pointer. For tilcdc crtc to have a
76 	 * say if a specific mode is Ok, we need to install our own
77 	 * helper functions. In our helper functions we copy
78 	 * everything else but use our own mode_valid() (above).
79 	 */
80 	if (connector->helper_private) {
81 		priv->connector_funcs[priv->num_connectors] =
82 			connector->helper_private;
83 		*connector_funcs = *priv->connector_funcs[priv->num_connectors];
84 	} else {
85 		priv->connector_funcs[priv->num_connectors] = ERR_PTR(-ENOENT);
86 	}
87 	connector_funcs->mode_valid = tilcdc_external_mode_valid;
88 	drm_connector_helper_add(connector, connector_funcs);
89 	priv->num_connectors++;
90 
91 	dev_dbg(dev->dev, "External encoder '%s' connected\n",
92 		connector->encoder->name);
93 
94 	return 0;
95 }
96 
97 int tilcdc_add_external_encoders(struct drm_device *dev, int *bpp)
98 {
99 	struct tilcdc_drm_private *priv = dev->dev_private;
100 	struct drm_connector *connector;
101 	int num_internal_connectors = priv->num_connectors;
102 
103 	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
104 		bool found = false;
105 		int i, ret;
106 
107 		for (i = 0; i < num_internal_connectors; i++)
108 			if (connector == priv->connectors[i])
109 				found = true;
110 		if (!found) {
111 			ret = tilcdc_add_external_encoder(dev, bpp, connector);
112 			if (ret)
113 				return ret;
114 		}
115 	}
116 	return 0;
117 }
118 
119 void tilcdc_remove_external_encoders(struct drm_device *dev)
120 {
121 	struct tilcdc_drm_private *priv = dev->dev_private;
122 	int i;
123 
124 	/* Restore the original helper functions, if any. */
125 	for (i = 0; i < priv->num_connectors; i++)
126 		if (IS_ERR(priv->connector_funcs[i]))
127 			drm_connector_helper_add(priv->connectors[i], NULL);
128 		else if (priv->connector_funcs[i])
129 			drm_connector_helper_add(priv->connectors[i],
130 						 priv->connector_funcs[i]);
131 }
132 
133 static int dev_match_of(struct device *dev, void *data)
134 {
135 	return dev->of_node == data;
136 }
137 
138 int tilcdc_get_external_components(struct device *dev,
139 				   struct component_match **match)
140 {
141 	struct device_node *ep = NULL;
142 	int count = 0;
143 
144 	while ((ep = of_graph_get_next_endpoint(dev->of_node, ep))) {
145 		struct device_node *node;
146 
147 		node = of_graph_get_remote_port_parent(ep);
148 		if (!node && !of_device_is_available(node)) {
149 			of_node_put(node);
150 			continue;
151 		}
152 
153 		dev_dbg(dev, "Subdevice node '%s' found\n", node->name);
154 		if (match)
155 			component_match_add(dev, match, dev_match_of, node);
156 		of_node_put(node);
157 		count++;
158 	}
159 
160 	if (count > 1) {
161 		dev_err(dev, "Only one external encoder is supported\n");
162 		return -EINVAL;
163 	}
164 
165 	return count;
166 }
167