1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2015 Texas Instruments
4  * Author: Jyri Sarha <jsarha@ti.com>
5  */
6 
7 #include <linux/component.h>
8 #include <linux/of_graph.h>
9 
10 #include <drm/drm_atomic_helper.h>
11 #include <drm/drm_of.h>
12 
13 #include "tilcdc_drv.h"
14 #include "tilcdc_external.h"
15 
16 static const struct tilcdc_panel_info panel_info_tda998x = {
17 		.ac_bias                = 255,
18 		.ac_bias_intrpt         = 0,
19 		.dma_burst_sz           = 16,
20 		.bpp                    = 16,
21 		.fdd                    = 0x80,
22 		.tft_alt_mode           = 0,
23 		.invert_pxl_clk		= 1,
24 		.sync_edge              = 1,
25 		.sync_ctrl              = 1,
26 		.raster_order           = 0,
27 };
28 
29 static const struct tilcdc_panel_info panel_info_default = {
30 		.ac_bias                = 255,
31 		.ac_bias_intrpt         = 0,
32 		.dma_burst_sz           = 16,
33 		.bpp                    = 16,
34 		.fdd                    = 0x80,
35 		.tft_alt_mode           = 0,
36 		.sync_edge              = 0,
37 		.sync_ctrl              = 1,
38 		.raster_order           = 0,
39 };
40 
41 static int tilcdc_external_mode_valid(struct drm_connector *connector,
42 				      struct drm_display_mode *mode)
43 {
44 	struct tilcdc_drm_private *priv = connector->dev->dev_private;
45 	int ret;
46 
47 	ret = tilcdc_crtc_mode_valid(priv->crtc, mode);
48 	if (ret != MODE_OK)
49 		return ret;
50 
51 	BUG_ON(priv->external_connector != connector);
52 	BUG_ON(!priv->connector_funcs);
53 
54 	/* If the connector has its own mode_valid call it. */
55 	if (!IS_ERR(priv->connector_funcs) &&
56 	    priv->connector_funcs->mode_valid)
57 		return priv->connector_funcs->mode_valid(connector, mode);
58 
59 	return MODE_OK;
60 }
61 
62 static int tilcdc_add_external_connector(struct drm_device *dev,
63 					 struct drm_connector *connector)
64 {
65 	struct tilcdc_drm_private *priv = dev->dev_private;
66 	struct drm_connector_helper_funcs *connector_funcs;
67 
68 	/* There should never be more than one connector */
69 	if (WARN_ON(priv->external_connector))
70 		return -EINVAL;
71 
72 	priv->external_connector = connector;
73 	connector_funcs = devm_kzalloc(dev->dev, sizeof(*connector_funcs),
74 				       GFP_KERNEL);
75 	if (!connector_funcs)
76 		return -ENOMEM;
77 
78 	/* connector->helper_private contains always struct
79 	 * connector_helper_funcs pointer. For tilcdc crtc to have a
80 	 * say if a specific mode is Ok, we need to install our own
81 	 * helper functions. In our helper functions we copy
82 	 * everything else but use our own mode_valid() (above).
83 	 */
84 	if (connector->helper_private) {
85 		priv->connector_funcs =	connector->helper_private;
86 		*connector_funcs = *priv->connector_funcs;
87 	} else {
88 		priv->connector_funcs = ERR_PTR(-ENOENT);
89 	}
90 	connector_funcs->mode_valid = tilcdc_external_mode_valid;
91 	drm_connector_helper_add(connector, connector_funcs);
92 
93 	dev_dbg(dev->dev, "External connector '%s' connected\n",
94 		connector->name);
95 
96 	return 0;
97 }
98 
99 static
100 struct drm_connector *tilcdc_encoder_find_connector(struct drm_device *ddev,
101 						    struct drm_encoder *encoder)
102 {
103 	struct drm_connector *connector;
104 
105 	list_for_each_entry(connector, &ddev->mode_config.connector_list, head) {
106 		if (drm_connector_has_possible_encoder(connector, encoder))
107 			return connector;
108 	}
109 
110 	dev_err(ddev->dev, "No connector found for %s encoder (id %d)\n",
111 		encoder->name, encoder->base.id);
112 
113 	return NULL;
114 }
115 
116 int tilcdc_add_component_encoder(struct drm_device *ddev)
117 {
118 	struct tilcdc_drm_private *priv = ddev->dev_private;
119 	struct drm_connector *connector;
120 	struct drm_encoder *encoder;
121 
122 	list_for_each_entry(encoder, &ddev->mode_config.encoder_list, head)
123 		if (encoder->possible_crtcs & (1 << priv->crtc->index))
124 			break;
125 
126 	if (!encoder) {
127 		dev_err(ddev->dev, "%s: No suitable encoder found\n", __func__);
128 		return -ENODEV;
129 	}
130 
131 	connector = tilcdc_encoder_find_connector(ddev, encoder);
132 
133 	if (!connector)
134 		return -ENODEV;
135 
136 	/* Only tda998x is supported at the moment. */
137 	tilcdc_crtc_set_simulate_vesa_sync(priv->crtc, true);
138 	tilcdc_crtc_set_panel_info(priv->crtc, &panel_info_tda998x);
139 
140 	return tilcdc_add_external_connector(ddev, connector);
141 }
142 
143 void tilcdc_remove_external_device(struct drm_device *dev)
144 {
145 	struct tilcdc_drm_private *priv = dev->dev_private;
146 
147 	/* Restore the original helper functions, if any. */
148 	if (IS_ERR(priv->connector_funcs))
149 		drm_connector_helper_add(priv->external_connector, NULL);
150 	else if (priv->connector_funcs)
151 		drm_connector_helper_add(priv->external_connector,
152 					 priv->connector_funcs);
153 }
154 
155 static const struct drm_encoder_funcs tilcdc_external_encoder_funcs = {
156 	.destroy	= drm_encoder_cleanup,
157 };
158 
159 static
160 int tilcdc_attach_bridge(struct drm_device *ddev, struct drm_bridge *bridge)
161 {
162 	struct tilcdc_drm_private *priv = ddev->dev_private;
163 	struct drm_connector *connector;
164 	int ret;
165 
166 	priv->external_encoder->possible_crtcs = BIT(0);
167 
168 	ret = drm_bridge_attach(priv->external_encoder, bridge, NULL);
169 	if (ret) {
170 		dev_err(ddev->dev, "drm_bridge_attach() failed %d\n", ret);
171 		return ret;
172 	}
173 
174 	tilcdc_crtc_set_panel_info(priv->crtc, &panel_info_default);
175 
176 	connector = tilcdc_encoder_find_connector(ddev, priv->external_encoder);
177 	if (!connector)
178 		return -ENODEV;
179 
180 	ret = tilcdc_add_external_connector(ddev, connector);
181 
182 	return ret;
183 }
184 
185 int tilcdc_attach_external_device(struct drm_device *ddev)
186 {
187 	struct tilcdc_drm_private *priv = ddev->dev_private;
188 	struct drm_bridge *bridge;
189 	struct drm_panel *panel;
190 	int ret;
191 
192 	ret = drm_of_find_panel_or_bridge(ddev->dev->of_node, 0, 0,
193 					  &panel, &bridge);
194 	if (ret == -ENODEV)
195 		return 0;
196 	else if (ret)
197 		return ret;
198 
199 	priv->external_encoder = devm_kzalloc(ddev->dev,
200 					      sizeof(*priv->external_encoder),
201 					      GFP_KERNEL);
202 	if (!priv->external_encoder)
203 		return -ENOMEM;
204 
205 	ret = drm_encoder_init(ddev, priv->external_encoder,
206 			       &tilcdc_external_encoder_funcs,
207 			       DRM_MODE_ENCODER_NONE, NULL);
208 	if (ret) {
209 		dev_err(ddev->dev, "drm_encoder_init() failed %d\n", ret);
210 		return ret;
211 	}
212 
213 	if (panel) {
214 		bridge = devm_drm_panel_bridge_add(ddev->dev, panel,
215 						   DRM_MODE_CONNECTOR_DPI);
216 		if (IS_ERR(bridge)) {
217 			ret = PTR_ERR(bridge);
218 			goto err_encoder_cleanup;
219 		}
220 	}
221 
222 	ret = tilcdc_attach_bridge(ddev, bridge);
223 	if (ret)
224 		goto err_encoder_cleanup;
225 
226 	return 0;
227 
228 err_encoder_cleanup:
229 	drm_encoder_cleanup(priv->external_encoder);
230 	return ret;
231 }
232 
233 static int dev_match_of(struct device *dev, void *data)
234 {
235 	return dev->of_node == data;
236 }
237 
238 int tilcdc_get_external_components(struct device *dev,
239 				   struct component_match **match)
240 {
241 	struct device_node *node;
242 
243 	node = of_graph_get_remote_node(dev->of_node, 0, 0);
244 
245 	if (!of_device_is_compatible(node, "nxp,tda998x")) {
246 		of_node_put(node);
247 		return 0;
248 	}
249 
250 	if (match)
251 		drm_of_component_match_add(dev, match, dev_match_of, node);
252 	of_node_put(node);
253 	return 1;
254 }
255