xref: /openbmc/linux/drivers/gpu/drm/bridge/ti-tfp410.c (revision 4f6cce39)
1 /*
2  * Copyright (C) 2016 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/module.h>
12 #include <linux/of_graph.h>
13 #include <linux/platform_device.h>
14 #include <linux/i2c.h>
15 
16 #include <drm/drmP.h>
17 #include <drm/drm_atomic_helper.h>
18 #include <drm/drm_crtc.h>
19 #include <drm/drm_crtc_helper.h>
20 
21 struct tfp410 {
22 	struct drm_bridge	bridge;
23 	struct drm_connector	connector;
24 
25 	struct i2c_adapter	*ddc;
26 
27 	struct device *dev;
28 };
29 
30 static inline struct tfp410 *
31 drm_bridge_to_tfp410(struct drm_bridge *bridge)
32 {
33 	return container_of(bridge, struct tfp410, bridge);
34 }
35 
36 static inline struct tfp410 *
37 drm_connector_to_tfp410(struct drm_connector *connector)
38 {
39 	return container_of(connector, struct tfp410, connector);
40 }
41 
42 static int tfp410_get_modes(struct drm_connector *connector)
43 {
44 	struct tfp410 *dvi = drm_connector_to_tfp410(connector);
45 	struct edid *edid;
46 	int ret;
47 
48 	if (!dvi->ddc)
49 		goto fallback;
50 
51 	edid = drm_get_edid(connector, dvi->ddc);
52 	if (!edid) {
53 		DRM_INFO("EDID read failed. Fallback to standard modes\n");
54 		goto fallback;
55 	}
56 
57 	drm_mode_connector_update_edid_property(connector, edid);
58 
59 	return drm_add_edid_modes(connector, edid);
60 fallback:
61 	/* No EDID, fallback on the XGA standard modes */
62 	ret = drm_add_modes_noedid(connector, 1920, 1200);
63 
64 	/* And prefer a mode pretty much anything can handle */
65 	drm_set_preferred_mode(connector, 1024, 768);
66 
67 	return ret;
68 }
69 
70 static const struct drm_connector_helper_funcs tfp410_con_helper_funcs = {
71 	.get_modes	= tfp410_get_modes,
72 };
73 
74 static enum drm_connector_status
75 tfp410_connector_detect(struct drm_connector *connector, bool force)
76 {
77 	struct tfp410 *dvi = drm_connector_to_tfp410(connector);
78 
79 	if (dvi->ddc) {
80 		if (drm_probe_ddc(dvi->ddc))
81 			return connector_status_connected;
82 		else
83 			return connector_status_disconnected;
84 	}
85 
86 	return connector_status_unknown;
87 }
88 
89 static const struct drm_connector_funcs tfp410_con_funcs = {
90 	.dpms			= drm_atomic_helper_connector_dpms,
91 	.detect			= tfp410_connector_detect,
92 	.fill_modes		= drm_helper_probe_single_connector_modes,
93 	.destroy		= drm_connector_cleanup,
94 	.reset			= drm_atomic_helper_connector_reset,
95 	.atomic_duplicate_state	= drm_atomic_helper_connector_duplicate_state,
96 	.atomic_destroy_state	= drm_atomic_helper_connector_destroy_state,
97 };
98 
99 static int tfp410_attach(struct drm_bridge *bridge)
100 {
101 	struct tfp410 *dvi = drm_bridge_to_tfp410(bridge);
102 	int ret;
103 
104 	if (!bridge->encoder) {
105 		dev_err(dvi->dev, "Missing encoder\n");
106 		return -ENODEV;
107 	}
108 
109 	drm_connector_helper_add(&dvi->connector,
110 				 &tfp410_con_helper_funcs);
111 	ret = drm_connector_init(bridge->dev, &dvi->connector,
112 				 &tfp410_con_funcs, DRM_MODE_CONNECTOR_HDMIA);
113 	if (ret) {
114 		dev_err(dvi->dev, "drm_connector_init() failed: %d\n", ret);
115 		return ret;
116 	}
117 
118 	drm_mode_connector_attach_encoder(&dvi->connector,
119 					  bridge->encoder);
120 
121 	return 0;
122 }
123 
124 static const struct drm_bridge_funcs tfp410_bridge_funcs = {
125 	.attach		= tfp410_attach,
126 };
127 
128 static int tfp410_get_connector_ddc(struct tfp410 *dvi)
129 {
130 	struct device_node *ep = NULL, *connector_node = NULL;
131 	struct device_node *ddc_phandle = NULL;
132 	int ret = 0;
133 
134 	/* port@1 is the connector node */
135 	ep = of_graph_get_endpoint_by_regs(dvi->dev->of_node, 1, -1);
136 	if (!ep)
137 		goto fail;
138 
139 	connector_node = of_graph_get_remote_port_parent(ep);
140 	if (!connector_node)
141 		goto fail;
142 
143 	ddc_phandle = of_parse_phandle(connector_node, "ddc-i2c-bus", 0);
144 	if (!ddc_phandle)
145 		goto fail;
146 
147 	dvi->ddc = of_get_i2c_adapter_by_node(ddc_phandle);
148 	if (dvi->ddc)
149 		dev_info(dvi->dev, "Connector's ddc i2c bus found\n");
150 	else
151 		ret = -EPROBE_DEFER;
152 
153 fail:
154 	of_node_put(ep);
155 	of_node_put(connector_node);
156 	of_node_put(ddc_phandle);
157 	return ret;
158 }
159 
160 static int tfp410_init(struct device *dev)
161 {
162 	struct tfp410 *dvi;
163 	int ret;
164 
165 	if (!dev->of_node) {
166 		dev_err(dev, "device-tree data is missing\n");
167 		return -ENXIO;
168 	}
169 
170 	dvi = devm_kzalloc(dev, sizeof(*dvi), GFP_KERNEL);
171 	if (!dvi)
172 		return -ENOMEM;
173 	dev_set_drvdata(dev, dvi);
174 
175 	dvi->bridge.funcs = &tfp410_bridge_funcs;
176 	dvi->bridge.of_node = dev->of_node;
177 	dvi->dev = dev;
178 
179 	ret = tfp410_get_connector_ddc(dvi);
180 	if (ret)
181 		goto fail;
182 
183 	ret = drm_bridge_add(&dvi->bridge);
184 	if (ret) {
185 		dev_err(dev, "drm_bridge_add() failed: %d\n", ret);
186 		goto fail;
187 	}
188 
189 	return 0;
190 fail:
191 	i2c_put_adapter(dvi->ddc);
192 	return ret;
193 }
194 
195 static int tfp410_fini(struct device *dev)
196 {
197 	struct tfp410 *dvi = dev_get_drvdata(dev);
198 
199 	drm_bridge_remove(&dvi->bridge);
200 
201 	if (dvi->ddc)
202 		i2c_put_adapter(dvi->ddc);
203 
204 	return 0;
205 }
206 
207 static int tfp410_probe(struct platform_device *pdev)
208 {
209 	return tfp410_init(&pdev->dev);
210 }
211 
212 static int tfp410_remove(struct platform_device *pdev)
213 {
214 	return tfp410_fini(&pdev->dev);
215 }
216 
217 static const struct of_device_id tfp410_match[] = {
218 	{ .compatible = "ti,tfp410" },
219 	{},
220 };
221 MODULE_DEVICE_TABLE(of, tfp410_match);
222 
223 struct platform_driver tfp410_platform_driver = {
224 	.probe	= tfp410_probe,
225 	.remove	= tfp410_remove,
226 	.driver	= {
227 		.name		= "tfp410-bridge",
228 		.of_match_table	= tfp410_match,
229 	},
230 };
231 
232 #if IS_ENABLED(CONFIG_I2C)
233 /* There is currently no i2c functionality. */
234 static int tfp410_i2c_probe(struct i2c_client *client,
235 			    const struct i2c_device_id *id)
236 {
237 	int reg;
238 
239 	if (!client->dev.of_node ||
240 	    of_property_read_u32(client->dev.of_node, "reg", &reg)) {
241 		dev_err(&client->dev,
242 			"Can't get i2c reg property from device-tree\n");
243 		return -ENXIO;
244 	}
245 
246 	return tfp410_init(&client->dev);
247 }
248 
249 static int tfp410_i2c_remove(struct i2c_client *client)
250 {
251 	return tfp410_fini(&client->dev);
252 }
253 
254 static const struct i2c_device_id tfp410_i2c_ids[] = {
255 	{ "tfp410", 0 },
256 	{ }
257 };
258 MODULE_DEVICE_TABLE(i2c, tfp410_i2c_ids);
259 
260 static struct i2c_driver tfp410_i2c_driver = {
261 	.driver = {
262 		.name	= "tfp410",
263 		.of_match_table = of_match_ptr(tfp410_match),
264 	},
265 	.id_table	= tfp410_i2c_ids,
266 	.probe		= tfp410_i2c_probe,
267 	.remove		= tfp410_i2c_remove,
268 };
269 #endif /* IS_ENABLED(CONFIG_I2C) */
270 
271 static struct {
272 	uint i2c:1;
273 	uint platform:1;
274 }  tfp410_registered_driver;
275 
276 static int __init tfp410_module_init(void)
277 {
278 	int ret;
279 
280 #if IS_ENABLED(CONFIG_I2C)
281 	ret = i2c_add_driver(&tfp410_i2c_driver);
282 	if (ret)
283 		pr_err("%s: registering i2c driver failed: %d",
284 		       __func__, ret);
285 	else
286 		tfp410_registered_driver.i2c = 1;
287 #endif
288 
289 	ret = platform_driver_register(&tfp410_platform_driver);
290 	if (ret)
291 		pr_err("%s: registering platform driver failed: %d",
292 		       __func__, ret);
293 	else
294 		tfp410_registered_driver.platform = 1;
295 
296 	if (tfp410_registered_driver.i2c ||
297 	    tfp410_registered_driver.platform)
298 		return 0;
299 
300 	return ret;
301 }
302 module_init(tfp410_module_init);
303 
304 static void __exit tfp410_module_exit(void)
305 {
306 #if IS_ENABLED(CONFIG_I2C)
307 	if (tfp410_registered_driver.i2c)
308 		i2c_del_driver(&tfp410_i2c_driver);
309 #endif
310 	if (tfp410_registered_driver.platform)
311 		platform_driver_unregister(&tfp410_platform_driver);
312 }
313 module_exit(tfp410_module_exit);
314 
315 MODULE_AUTHOR("Jyri Sarha <jsarha@ti.com>");
316 MODULE_DESCRIPTION("TI TFP410 DVI bridge driver");
317 MODULE_LICENSE("GPL");
318