xref: /openbmc/linux/drivers/gpu/drm/bridge/ti-tfp410.c (revision 68198dca)
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/delay.h>
12 #include <linux/fwnode.h>
13 #include <linux/gpio/consumer.h>
14 #include <linux/irq.h>
15 #include <linux/module.h>
16 #include <linux/of_graph.h>
17 #include <linux/platform_device.h>
18 #include <linux/i2c.h>
19 
20 #include <drm/drmP.h>
21 #include <drm/drm_atomic_helper.h>
22 #include <drm/drm_crtc.h>
23 #include <drm/drm_crtc_helper.h>
24 
25 #define HOTPLUG_DEBOUNCE_MS		1100
26 
27 struct tfp410 {
28 	struct drm_bridge	bridge;
29 	struct drm_connector	connector;
30 
31 	struct i2c_adapter	*ddc;
32 	struct gpio_desc	*hpd;
33 	struct delayed_work	hpd_work;
34 
35 	struct device *dev;
36 };
37 
38 static inline struct tfp410 *
39 drm_bridge_to_tfp410(struct drm_bridge *bridge)
40 {
41 	return container_of(bridge, struct tfp410, bridge);
42 }
43 
44 static inline struct tfp410 *
45 drm_connector_to_tfp410(struct drm_connector *connector)
46 {
47 	return container_of(connector, struct tfp410, connector);
48 }
49 
50 static int tfp410_get_modes(struct drm_connector *connector)
51 {
52 	struct tfp410 *dvi = drm_connector_to_tfp410(connector);
53 	struct edid *edid;
54 	int ret;
55 
56 	if (!dvi->ddc)
57 		goto fallback;
58 
59 	edid = drm_get_edid(connector, dvi->ddc);
60 	if (!edid) {
61 		DRM_INFO("EDID read failed. Fallback to standard modes\n");
62 		goto fallback;
63 	}
64 
65 	drm_mode_connector_update_edid_property(connector, edid);
66 
67 	return drm_add_edid_modes(connector, edid);
68 fallback:
69 	/* No EDID, fallback on the XGA standard modes */
70 	ret = drm_add_modes_noedid(connector, 1920, 1200);
71 
72 	/* And prefer a mode pretty much anything can handle */
73 	drm_set_preferred_mode(connector, 1024, 768);
74 
75 	return ret;
76 }
77 
78 static const struct drm_connector_helper_funcs tfp410_con_helper_funcs = {
79 	.get_modes	= tfp410_get_modes,
80 };
81 
82 static enum drm_connector_status
83 tfp410_connector_detect(struct drm_connector *connector, bool force)
84 {
85 	struct tfp410 *dvi = drm_connector_to_tfp410(connector);
86 
87 	if (dvi->hpd) {
88 		if (gpiod_get_value_cansleep(dvi->hpd))
89 			return connector_status_connected;
90 		else
91 			return connector_status_disconnected;
92 	}
93 
94 	if (dvi->ddc) {
95 		if (drm_probe_ddc(dvi->ddc))
96 			return connector_status_connected;
97 		else
98 			return connector_status_disconnected;
99 	}
100 
101 	return connector_status_unknown;
102 }
103 
104 static const struct drm_connector_funcs tfp410_con_funcs = {
105 	.detect			= tfp410_connector_detect,
106 	.fill_modes		= drm_helper_probe_single_connector_modes,
107 	.destroy		= drm_connector_cleanup,
108 	.reset			= drm_atomic_helper_connector_reset,
109 	.atomic_duplicate_state	= drm_atomic_helper_connector_duplicate_state,
110 	.atomic_destroy_state	= drm_atomic_helper_connector_destroy_state,
111 };
112 
113 static int tfp410_attach(struct drm_bridge *bridge)
114 {
115 	struct tfp410 *dvi = drm_bridge_to_tfp410(bridge);
116 	int ret;
117 
118 	if (!bridge->encoder) {
119 		dev_err(dvi->dev, "Missing encoder\n");
120 		return -ENODEV;
121 	}
122 
123 	if (dvi->hpd)
124 		dvi->connector.polled = DRM_CONNECTOR_POLL_HPD;
125 
126 	drm_connector_helper_add(&dvi->connector,
127 				 &tfp410_con_helper_funcs);
128 	ret = drm_connector_init(bridge->dev, &dvi->connector,
129 				 &tfp410_con_funcs, DRM_MODE_CONNECTOR_HDMIA);
130 	if (ret) {
131 		dev_err(dvi->dev, "drm_connector_init() failed: %d\n", ret);
132 		return ret;
133 	}
134 
135 	drm_mode_connector_attach_encoder(&dvi->connector,
136 					  bridge->encoder);
137 
138 	return 0;
139 }
140 
141 static const struct drm_bridge_funcs tfp410_bridge_funcs = {
142 	.attach		= tfp410_attach,
143 };
144 
145 static void tfp410_hpd_work_func(struct work_struct *work)
146 {
147 	struct tfp410 *dvi;
148 
149 	dvi = container_of(work, struct tfp410, hpd_work.work);
150 
151 	if (dvi->bridge.dev)
152 		drm_helper_hpd_irq_event(dvi->bridge.dev);
153 }
154 
155 static irqreturn_t tfp410_hpd_irq_thread(int irq, void *arg)
156 {
157 	struct tfp410 *dvi = arg;
158 
159 	mod_delayed_work(system_wq, &dvi->hpd_work,
160 			msecs_to_jiffies(HOTPLUG_DEBOUNCE_MS));
161 
162 	return IRQ_HANDLED;
163 }
164 
165 static int tfp410_get_connector_properties(struct tfp410 *dvi)
166 {
167 	struct device_node *connector_node, *ddc_phandle;
168 	int ret = 0;
169 
170 	/* port@1 is the connector node */
171 	connector_node = of_graph_get_remote_node(dvi->dev->of_node, 1, -1);
172 	if (!connector_node)
173 		return -ENODEV;
174 
175 	dvi->hpd = fwnode_get_named_gpiod(&connector_node->fwnode,
176 					"hpd-gpios", 0, GPIOD_IN, "hpd");
177 	if (IS_ERR(dvi->hpd)) {
178 		ret = PTR_ERR(dvi->hpd);
179 		dvi->hpd = NULL;
180 		if (ret == -ENOENT)
181 			ret = 0;
182 		else
183 			goto fail;
184 	}
185 
186 	ddc_phandle = of_parse_phandle(connector_node, "ddc-i2c-bus", 0);
187 	if (!ddc_phandle)
188 		goto fail;
189 
190 	dvi->ddc = of_get_i2c_adapter_by_node(ddc_phandle);
191 	if (dvi->ddc)
192 		dev_info(dvi->dev, "Connector's ddc i2c bus found\n");
193 	else
194 		ret = -EPROBE_DEFER;
195 
196 	of_node_put(ddc_phandle);
197 
198 fail:
199 	of_node_put(connector_node);
200 	return ret;
201 }
202 
203 static int tfp410_init(struct device *dev)
204 {
205 	struct tfp410 *dvi;
206 	int ret;
207 
208 	if (!dev->of_node) {
209 		dev_err(dev, "device-tree data is missing\n");
210 		return -ENXIO;
211 	}
212 
213 	dvi = devm_kzalloc(dev, sizeof(*dvi), GFP_KERNEL);
214 	if (!dvi)
215 		return -ENOMEM;
216 	dev_set_drvdata(dev, dvi);
217 
218 	dvi->bridge.funcs = &tfp410_bridge_funcs;
219 	dvi->bridge.of_node = dev->of_node;
220 	dvi->dev = dev;
221 
222 	ret = tfp410_get_connector_properties(dvi);
223 	if (ret)
224 		goto fail;
225 
226 	if (dvi->hpd) {
227 		INIT_DELAYED_WORK(&dvi->hpd_work, tfp410_hpd_work_func);
228 
229 		ret = devm_request_threaded_irq(dev, gpiod_to_irq(dvi->hpd),
230 			NULL, tfp410_hpd_irq_thread, IRQF_TRIGGER_RISING |
231 			IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
232 			"hdmi-hpd", dvi);
233 		if (ret) {
234 			DRM_ERROR("failed to register hpd interrupt\n");
235 			goto fail;
236 		}
237 	}
238 
239 	drm_bridge_add(&dvi->bridge);
240 
241 	return 0;
242 fail:
243 	i2c_put_adapter(dvi->ddc);
244 	if (dvi->hpd)
245 		gpiod_put(dvi->hpd);
246 	return ret;
247 }
248 
249 static int tfp410_fini(struct device *dev)
250 {
251 	struct tfp410 *dvi = dev_get_drvdata(dev);
252 
253 	cancel_delayed_work_sync(&dvi->hpd_work);
254 
255 	drm_bridge_remove(&dvi->bridge);
256 
257 	if (dvi->ddc)
258 		i2c_put_adapter(dvi->ddc);
259 	if (dvi->hpd)
260 		gpiod_put(dvi->hpd);
261 
262 	return 0;
263 }
264 
265 static int tfp410_probe(struct platform_device *pdev)
266 {
267 	return tfp410_init(&pdev->dev);
268 }
269 
270 static int tfp410_remove(struct platform_device *pdev)
271 {
272 	return tfp410_fini(&pdev->dev);
273 }
274 
275 static const struct of_device_id tfp410_match[] = {
276 	{ .compatible = "ti,tfp410" },
277 	{},
278 };
279 MODULE_DEVICE_TABLE(of, tfp410_match);
280 
281 static struct platform_driver tfp410_platform_driver = {
282 	.probe	= tfp410_probe,
283 	.remove	= tfp410_remove,
284 	.driver	= {
285 		.name		= "tfp410-bridge",
286 		.of_match_table	= tfp410_match,
287 	},
288 };
289 
290 #if IS_ENABLED(CONFIG_I2C)
291 /* There is currently no i2c functionality. */
292 static int tfp410_i2c_probe(struct i2c_client *client,
293 			    const struct i2c_device_id *id)
294 {
295 	int reg;
296 
297 	if (!client->dev.of_node ||
298 	    of_property_read_u32(client->dev.of_node, "reg", &reg)) {
299 		dev_err(&client->dev,
300 			"Can't get i2c reg property from device-tree\n");
301 		return -ENXIO;
302 	}
303 
304 	return tfp410_init(&client->dev);
305 }
306 
307 static int tfp410_i2c_remove(struct i2c_client *client)
308 {
309 	return tfp410_fini(&client->dev);
310 }
311 
312 static const struct i2c_device_id tfp410_i2c_ids[] = {
313 	{ "tfp410", 0 },
314 	{ }
315 };
316 MODULE_DEVICE_TABLE(i2c, tfp410_i2c_ids);
317 
318 static struct i2c_driver tfp410_i2c_driver = {
319 	.driver = {
320 		.name	= "tfp410",
321 		.of_match_table = of_match_ptr(tfp410_match),
322 	},
323 	.id_table	= tfp410_i2c_ids,
324 	.probe		= tfp410_i2c_probe,
325 	.remove		= tfp410_i2c_remove,
326 };
327 #endif /* IS_ENABLED(CONFIG_I2C) */
328 
329 static struct {
330 	uint i2c:1;
331 	uint platform:1;
332 }  tfp410_registered_driver;
333 
334 static int __init tfp410_module_init(void)
335 {
336 	int ret;
337 
338 #if IS_ENABLED(CONFIG_I2C)
339 	ret = i2c_add_driver(&tfp410_i2c_driver);
340 	if (ret)
341 		pr_err("%s: registering i2c driver failed: %d",
342 		       __func__, ret);
343 	else
344 		tfp410_registered_driver.i2c = 1;
345 #endif
346 
347 	ret = platform_driver_register(&tfp410_platform_driver);
348 	if (ret)
349 		pr_err("%s: registering platform driver failed: %d",
350 		       __func__, ret);
351 	else
352 		tfp410_registered_driver.platform = 1;
353 
354 	if (tfp410_registered_driver.i2c ||
355 	    tfp410_registered_driver.platform)
356 		return 0;
357 
358 	return ret;
359 }
360 module_init(tfp410_module_init);
361 
362 static void __exit tfp410_module_exit(void)
363 {
364 #if IS_ENABLED(CONFIG_I2C)
365 	if (tfp410_registered_driver.i2c)
366 		i2c_del_driver(&tfp410_i2c_driver);
367 #endif
368 	if (tfp410_registered_driver.platform)
369 		platform_driver_unregister(&tfp410_platform_driver);
370 }
371 module_exit(tfp410_module_exit);
372 
373 MODULE_AUTHOR("Jyri Sarha <jsarha@ti.com>");
374 MODULE_DESCRIPTION("TI TFP410 DVI bridge driver");
375 MODULE_LICENSE("GPL");
376