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 #include <drm/drm_atomic_helper.h>
14 #include <drm/drm_of.h>
15 
16 #include "tilcdc_drv.h"
17 #include "tilcdc_external.h"
18 
19 static const struct tilcdc_panel_info panel_info_tda998x = {
20 		.ac_bias                = 255,
21 		.ac_bias_intrpt         = 0,
22 		.dma_burst_sz           = 16,
23 		.bpp                    = 16,
24 		.fdd                    = 0x80,
25 		.tft_alt_mode           = 0,
26 		.invert_pxl_clk		= 1,
27 		.sync_edge              = 1,
28 		.sync_ctrl              = 1,
29 		.raster_order           = 0,
30 };
31 
32 static const struct tilcdc_panel_info panel_info_default = {
33 		.ac_bias                = 255,
34 		.ac_bias_intrpt         = 0,
35 		.dma_burst_sz           = 16,
36 		.bpp                    = 16,
37 		.fdd                    = 0x80,
38 		.tft_alt_mode           = 0,
39 		.sync_edge              = 0,
40 		.sync_ctrl              = 1,
41 		.raster_order           = 0,
42 };
43 
44 static int tilcdc_external_mode_valid(struct drm_connector *connector,
45 				      struct drm_display_mode *mode)
46 {
47 	struct tilcdc_drm_private *priv = connector->dev->dev_private;
48 	int ret;
49 
50 	ret = tilcdc_crtc_mode_valid(priv->crtc, mode);
51 	if (ret != MODE_OK)
52 		return ret;
53 
54 	BUG_ON(priv->external_connector != connector);
55 	BUG_ON(!priv->connector_funcs);
56 
57 	/* If the connector has its own mode_valid call it. */
58 	if (!IS_ERR(priv->connector_funcs) &&
59 	    priv->connector_funcs->mode_valid)
60 		return priv->connector_funcs->mode_valid(connector, mode);
61 
62 	return MODE_OK;
63 }
64 
65 static int tilcdc_add_external_connector(struct drm_device *dev,
66 					 struct drm_connector *connector)
67 {
68 	struct tilcdc_drm_private *priv = dev->dev_private;
69 	struct drm_connector_helper_funcs *connector_funcs;
70 
71 	/* There should never be more than one connector */
72 	if (WARN_ON(priv->external_connector))
73 		return -EINVAL;
74 
75 	priv->external_connector = connector;
76 	connector_funcs = devm_kzalloc(dev->dev, sizeof(*connector_funcs),
77 				       GFP_KERNEL);
78 	if (!connector_funcs)
79 		return -ENOMEM;
80 
81 	/* connector->helper_private contains always struct
82 	 * connector_helper_funcs pointer. For tilcdc crtc to have a
83 	 * say if a specific mode is Ok, we need to install our own
84 	 * helper functions. In our helper functions we copy
85 	 * everything else but use our own mode_valid() (above).
86 	 */
87 	if (connector->helper_private) {
88 		priv->connector_funcs =	connector->helper_private;
89 		*connector_funcs = *priv->connector_funcs;
90 	} else {
91 		priv->connector_funcs = ERR_PTR(-ENOENT);
92 	}
93 	connector_funcs->mode_valid = tilcdc_external_mode_valid;
94 	drm_connector_helper_add(connector, connector_funcs);
95 
96 	dev_dbg(dev->dev, "External connector '%s' connected\n",
97 		connector->name);
98 
99 	return 0;
100 }
101 
102 static
103 struct drm_connector *tilcdc_encoder_find_connector(struct drm_device *ddev,
104 						    struct drm_encoder *encoder)
105 {
106 	struct drm_connector *connector;
107 
108 	list_for_each_entry(connector, &ddev->mode_config.connector_list, head) {
109 		if (drm_connector_has_possible_encoder(connector, encoder))
110 			return connector;
111 	}
112 
113 	dev_err(ddev->dev, "No connector found for %s encoder (id %d)\n",
114 		encoder->name, encoder->base.id);
115 
116 	return NULL;
117 }
118 
119 int tilcdc_add_component_encoder(struct drm_device *ddev)
120 {
121 	struct tilcdc_drm_private *priv = ddev->dev_private;
122 	struct drm_connector *connector;
123 	struct drm_encoder *encoder;
124 
125 	list_for_each_entry(encoder, &ddev->mode_config.encoder_list, head)
126 		if (encoder->possible_crtcs & (1 << priv->crtc->index))
127 			break;
128 
129 	if (!encoder) {
130 		dev_err(ddev->dev, "%s: No suitable encoder found\n", __func__);
131 		return -ENODEV;
132 	}
133 
134 	connector = tilcdc_encoder_find_connector(ddev, encoder);
135 
136 	if (!connector)
137 		return -ENODEV;
138 
139 	/* Only tda998x is supported at the moment. */
140 	tilcdc_crtc_set_simulate_vesa_sync(priv->crtc, true);
141 	tilcdc_crtc_set_panel_info(priv->crtc, &panel_info_tda998x);
142 
143 	return tilcdc_add_external_connector(ddev, connector);
144 }
145 
146 void tilcdc_remove_external_device(struct drm_device *dev)
147 {
148 	struct tilcdc_drm_private *priv = dev->dev_private;
149 
150 	/* Restore the original helper functions, if any. */
151 	if (IS_ERR(priv->connector_funcs))
152 		drm_connector_helper_add(priv->external_connector, NULL);
153 	else if (priv->connector_funcs)
154 		drm_connector_helper_add(priv->external_connector,
155 					 priv->connector_funcs);
156 }
157 
158 static const struct drm_encoder_funcs tilcdc_external_encoder_funcs = {
159 	.destroy	= drm_encoder_cleanup,
160 };
161 
162 static
163 int tilcdc_attach_bridge(struct drm_device *ddev, struct drm_bridge *bridge)
164 {
165 	struct tilcdc_drm_private *priv = ddev->dev_private;
166 	struct drm_connector *connector;
167 	int ret;
168 
169 	priv->external_encoder->possible_crtcs = BIT(0);
170 
171 	ret = drm_bridge_attach(priv->external_encoder, bridge, NULL);
172 	if (ret) {
173 		dev_err(ddev->dev, "drm_bridge_attach() failed %d\n", ret);
174 		return ret;
175 	}
176 
177 	tilcdc_crtc_set_panel_info(priv->crtc, &panel_info_default);
178 
179 	connector = tilcdc_encoder_find_connector(ddev, priv->external_encoder);
180 	if (!connector)
181 		return -ENODEV;
182 
183 	ret = tilcdc_add_external_connector(ddev, connector);
184 
185 	return ret;
186 }
187 
188 int tilcdc_attach_external_device(struct drm_device *ddev)
189 {
190 	struct tilcdc_drm_private *priv = ddev->dev_private;
191 	struct drm_bridge *bridge;
192 	struct drm_panel *panel;
193 	int ret;
194 
195 	ret = drm_of_find_panel_or_bridge(ddev->dev->of_node, 0, 0,
196 					  &panel, &bridge);
197 	if (ret == -ENODEV)
198 		return 0;
199 	else if (ret)
200 		return ret;
201 
202 	priv->external_encoder = devm_kzalloc(ddev->dev,
203 					      sizeof(*priv->external_encoder),
204 					      GFP_KERNEL);
205 	if (!priv->external_encoder)
206 		return -ENOMEM;
207 
208 	ret = drm_encoder_init(ddev, priv->external_encoder,
209 			       &tilcdc_external_encoder_funcs,
210 			       DRM_MODE_ENCODER_NONE, NULL);
211 	if (ret) {
212 		dev_err(ddev->dev, "drm_encoder_init() failed %d\n", ret);
213 		return ret;
214 	}
215 
216 	if (panel) {
217 		bridge = devm_drm_panel_bridge_add(ddev->dev, panel,
218 						   DRM_MODE_CONNECTOR_DPI);
219 		if (IS_ERR(bridge)) {
220 			ret = PTR_ERR(bridge);
221 			goto err_encoder_cleanup;
222 		}
223 	}
224 
225 	ret = tilcdc_attach_bridge(ddev, bridge);
226 	if (ret)
227 		goto err_encoder_cleanup;
228 
229 	return 0;
230 
231 err_encoder_cleanup:
232 	drm_encoder_cleanup(priv->external_encoder);
233 	return ret;
234 }
235 
236 static int dev_match_of(struct device *dev, void *data)
237 {
238 	return dev->of_node == data;
239 }
240 
241 int tilcdc_get_external_components(struct device *dev,
242 				   struct component_match **match)
243 {
244 	struct device_node *node;
245 
246 	node = of_graph_get_remote_node(dev->of_node, 0, 0);
247 
248 	if (!of_device_is_compatible(node, "nxp,tda998x")) {
249 		of_node_put(node);
250 		return 0;
251 	}
252 
253 	if (match)
254 		drm_of_component_match_add(dev, match, dev_match_of, node);
255 	of_node_put(node);
256 	return 1;
257 }
258