xref: /linux/drivers/gpu/drm/bridge/ti-tfp410.c (revision b8d312aa075f33282565467662c4628dae0a2aff)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2016 Texas Instruments
4  * Author: Jyri Sarha <jsarha@ti.com>
5  */
6 
7 #include <linux/delay.h>
8 #include <linux/fwnode.h>
9 #include <linux/gpio/consumer.h>
10 #include <linux/i2c.h>
11 #include <linux/irq.h>
12 #include <linux/module.h>
13 #include <linux/of_graph.h>
14 #include <linux/platform_device.h>
15 
16 #include <drm/drm_atomic_helper.h>
17 #include <drm/drm_crtc.h>
18 #include <drm/drm_print.h>
19 #include <drm/drm_probe_helper.h>
20 
21 #define HOTPLUG_DEBOUNCE_MS		1100
22 
23 struct tfp410 {
24 	struct drm_bridge	bridge;
25 	struct drm_connector	connector;
26 	unsigned int		connector_type;
27 
28 	u32			bus_format;
29 	struct i2c_adapter	*ddc;
30 	struct gpio_desc	*hpd;
31 	int			hpd_irq;
32 	struct delayed_work	hpd_work;
33 	struct gpio_desc	*powerdown;
34 
35 	struct drm_bridge_timings timings;
36 
37 	struct device *dev;
38 };
39 
40 static inline struct tfp410 *
41 drm_bridge_to_tfp410(struct drm_bridge *bridge)
42 {
43 	return container_of(bridge, struct tfp410, bridge);
44 }
45 
46 static inline struct tfp410 *
47 drm_connector_to_tfp410(struct drm_connector *connector)
48 {
49 	return container_of(connector, struct tfp410, connector);
50 }
51 
52 static int tfp410_get_modes(struct drm_connector *connector)
53 {
54 	struct tfp410 *dvi = drm_connector_to_tfp410(connector);
55 	struct edid *edid;
56 	int ret;
57 
58 	if (!dvi->ddc)
59 		goto fallback;
60 
61 	edid = drm_get_edid(connector, dvi->ddc);
62 	if (!edid) {
63 		DRM_INFO("EDID read failed. Fallback to standard modes\n");
64 		goto fallback;
65 	}
66 
67 	drm_connector_update_edid_property(connector, edid);
68 
69 	ret = drm_add_edid_modes(connector, edid);
70 
71 	kfree(edid);
72 
73 	return ret;
74 
75 fallback:
76 	/* No EDID, fallback on the XGA standard modes */
77 	ret = drm_add_modes_noedid(connector, 1920, 1200);
78 
79 	/* And prefer a mode pretty much anything can handle */
80 	drm_set_preferred_mode(connector, 1024, 768);
81 
82 	return ret;
83 }
84 
85 static const struct drm_connector_helper_funcs tfp410_con_helper_funcs = {
86 	.get_modes	= tfp410_get_modes,
87 };
88 
89 static enum drm_connector_status
90 tfp410_connector_detect(struct drm_connector *connector, bool force)
91 {
92 	struct tfp410 *dvi = drm_connector_to_tfp410(connector);
93 
94 	if (dvi->hpd) {
95 		if (gpiod_get_value_cansleep(dvi->hpd))
96 			return connector_status_connected;
97 		else
98 			return connector_status_disconnected;
99 	}
100 
101 	if (dvi->ddc) {
102 		if (drm_probe_ddc(dvi->ddc))
103 			return connector_status_connected;
104 		else
105 			return connector_status_disconnected;
106 	}
107 
108 	return connector_status_unknown;
109 }
110 
111 static const struct drm_connector_funcs tfp410_con_funcs = {
112 	.detect			= tfp410_connector_detect,
113 	.fill_modes		= drm_helper_probe_single_connector_modes,
114 	.destroy		= drm_connector_cleanup,
115 	.reset			= drm_atomic_helper_connector_reset,
116 	.atomic_duplicate_state	= drm_atomic_helper_connector_duplicate_state,
117 	.atomic_destroy_state	= drm_atomic_helper_connector_destroy_state,
118 };
119 
120 static int tfp410_attach(struct drm_bridge *bridge)
121 {
122 	struct tfp410 *dvi = drm_bridge_to_tfp410(bridge);
123 	int ret;
124 
125 	if (!bridge->encoder) {
126 		dev_err(dvi->dev, "Missing encoder\n");
127 		return -ENODEV;
128 	}
129 
130 	if (dvi->hpd_irq >= 0)
131 		dvi->connector.polled = DRM_CONNECTOR_POLL_HPD;
132 	else
133 		dvi->connector.polled = DRM_CONNECTOR_POLL_CONNECT | DRM_CONNECTOR_POLL_DISCONNECT;
134 
135 	drm_connector_helper_add(&dvi->connector,
136 				 &tfp410_con_helper_funcs);
137 	ret = drm_connector_init_with_ddc(bridge->dev, &dvi->connector,
138 					  &tfp410_con_funcs,
139 					  dvi->connector_type,
140 					  dvi->ddc);
141 	if (ret) {
142 		dev_err(dvi->dev, "drm_connector_init() failed: %d\n", ret);
143 		return ret;
144 	}
145 
146 	drm_display_info_set_bus_formats(&dvi->connector.display_info,
147 					 &dvi->bus_format, 1);
148 
149 	drm_connector_attach_encoder(&dvi->connector,
150 					  bridge->encoder);
151 
152 	return 0;
153 }
154 
155 static void tfp410_enable(struct drm_bridge *bridge)
156 {
157 	struct tfp410 *dvi = drm_bridge_to_tfp410(bridge);
158 
159 	gpiod_set_value_cansleep(dvi->powerdown, 0);
160 }
161 
162 static void tfp410_disable(struct drm_bridge *bridge)
163 {
164 	struct tfp410 *dvi = drm_bridge_to_tfp410(bridge);
165 
166 	gpiod_set_value_cansleep(dvi->powerdown, 1);
167 }
168 
169 static const struct drm_bridge_funcs tfp410_bridge_funcs = {
170 	.attach		= tfp410_attach,
171 	.enable		= tfp410_enable,
172 	.disable	= tfp410_disable,
173 };
174 
175 static void tfp410_hpd_work_func(struct work_struct *work)
176 {
177 	struct tfp410 *dvi;
178 
179 	dvi = container_of(work, struct tfp410, hpd_work.work);
180 
181 	if (dvi->bridge.dev)
182 		drm_helper_hpd_irq_event(dvi->bridge.dev);
183 }
184 
185 static irqreturn_t tfp410_hpd_irq_thread(int irq, void *arg)
186 {
187 	struct tfp410 *dvi = arg;
188 
189 	mod_delayed_work(system_wq, &dvi->hpd_work,
190 			msecs_to_jiffies(HOTPLUG_DEBOUNCE_MS));
191 
192 	return IRQ_HANDLED;
193 }
194 
195 static const struct drm_bridge_timings tfp410_default_timings = {
196 	.input_bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE
197 			 | DRM_BUS_FLAG_DE_HIGH,
198 	.setup_time_ps = 1200,
199 	.hold_time_ps = 1300,
200 };
201 
202 static int tfp410_parse_timings(struct tfp410 *dvi, bool i2c)
203 {
204 	struct drm_bridge_timings *timings = &dvi->timings;
205 	struct device_node *ep;
206 	u32 pclk_sample = 0;
207 	u32 bus_width = 24;
208 	s32 deskew = 0;
209 
210 	/* Start with defaults. */
211 	*timings = tfp410_default_timings;
212 
213 	if (i2c)
214 		/*
215 		 * In I2C mode timings are configured through the I2C interface.
216 		 * As the driver doesn't support I2C configuration yet, we just
217 		 * go with the defaults (BSEL=1, DSEL=1, DKEN=0, EDGE=1).
218 		 */
219 		return 0;
220 
221 	/*
222 	 * In non-I2C mode, timings are configured through the BSEL, DSEL, DKEN
223 	 * and EDGE pins. They are specified in DT through endpoint properties
224 	 * and vendor-specific properties.
225 	 */
226 	ep = of_graph_get_endpoint_by_regs(dvi->dev->of_node, 0, 0);
227 	if (!ep)
228 		return -EINVAL;
229 
230 	/* Get the sampling edge from the endpoint. */
231 	of_property_read_u32(ep, "pclk-sample", &pclk_sample);
232 	of_property_read_u32(ep, "bus-width", &bus_width);
233 	of_node_put(ep);
234 
235 	timings->input_bus_flags = DRM_BUS_FLAG_DE_HIGH;
236 
237 	switch (pclk_sample) {
238 	case 0:
239 		timings->input_bus_flags |= DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE
240 					 |  DRM_BUS_FLAG_SYNC_SAMPLE_NEGEDGE;
241 		break;
242 	case 1:
243 		timings->input_bus_flags |= DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE
244 					 |  DRM_BUS_FLAG_SYNC_SAMPLE_POSEDGE;
245 		break;
246 	default:
247 		return -EINVAL;
248 	}
249 
250 	switch (bus_width) {
251 	case 12:
252 		dvi->bus_format = MEDIA_BUS_FMT_RGB888_2X12_LE;
253 		break;
254 	case 24:
255 		dvi->bus_format = MEDIA_BUS_FMT_RGB888_1X24;
256 		break;
257 	default:
258 		return -EINVAL;
259 	}
260 
261 	/* Get the setup and hold time from vendor-specific properties. */
262 	of_property_read_u32(dvi->dev->of_node, "ti,deskew", (u32 *)&deskew);
263 	if (deskew < -4 || deskew > 3)
264 		return -EINVAL;
265 
266 	timings->setup_time_ps = min(0, 1200 - 350 * deskew);
267 	timings->hold_time_ps = min(0, 1300 + 350 * deskew);
268 
269 	return 0;
270 }
271 
272 static int tfp410_get_connector_properties(struct tfp410 *dvi)
273 {
274 	struct device_node *connector_node, *ddc_phandle;
275 	int ret = 0;
276 
277 	/* port@1 is the connector node */
278 	connector_node = of_graph_get_remote_node(dvi->dev->of_node, 1, -1);
279 	if (!connector_node)
280 		return -ENODEV;
281 
282 	if (of_device_is_compatible(connector_node, "hdmi-connector"))
283 		dvi->connector_type = DRM_MODE_CONNECTOR_HDMIA;
284 	else
285 		dvi->connector_type = DRM_MODE_CONNECTOR_DVID;
286 
287 	dvi->hpd = fwnode_get_named_gpiod(&connector_node->fwnode,
288 					"hpd-gpios", 0, GPIOD_IN, "hpd");
289 	if (IS_ERR(dvi->hpd)) {
290 		ret = PTR_ERR(dvi->hpd);
291 		dvi->hpd = NULL;
292 		if (ret == -ENOENT)
293 			ret = 0;
294 		else
295 			goto fail;
296 	}
297 
298 	ddc_phandle = of_parse_phandle(connector_node, "ddc-i2c-bus", 0);
299 	if (!ddc_phandle)
300 		goto fail;
301 
302 	dvi->ddc = of_get_i2c_adapter_by_node(ddc_phandle);
303 	if (dvi->ddc)
304 		dev_info(dvi->dev, "Connector's ddc i2c bus found\n");
305 	else
306 		ret = -EPROBE_DEFER;
307 
308 	of_node_put(ddc_phandle);
309 
310 fail:
311 	of_node_put(connector_node);
312 	return ret;
313 }
314 
315 static int tfp410_init(struct device *dev, bool i2c)
316 {
317 	struct tfp410 *dvi;
318 	int ret;
319 
320 	if (!dev->of_node) {
321 		dev_err(dev, "device-tree data is missing\n");
322 		return -ENXIO;
323 	}
324 
325 	dvi = devm_kzalloc(dev, sizeof(*dvi), GFP_KERNEL);
326 	if (!dvi)
327 		return -ENOMEM;
328 	dev_set_drvdata(dev, dvi);
329 
330 	dvi->bridge.funcs = &tfp410_bridge_funcs;
331 	dvi->bridge.of_node = dev->of_node;
332 	dvi->bridge.timings = &dvi->timings;
333 	dvi->dev = dev;
334 
335 	ret = tfp410_parse_timings(dvi, i2c);
336 	if (ret)
337 		goto fail;
338 
339 	ret = tfp410_get_connector_properties(dvi);
340 	if (ret)
341 		goto fail;
342 
343 	dvi->powerdown = devm_gpiod_get_optional(dev, "powerdown",
344 						 GPIOD_OUT_HIGH);
345 	if (IS_ERR(dvi->powerdown)) {
346 		dev_err(dev, "failed to parse powerdown gpio\n");
347 		return PTR_ERR(dvi->powerdown);
348 	}
349 
350 	if (dvi->hpd)
351 		dvi->hpd_irq = gpiod_to_irq(dvi->hpd);
352 	else
353 		dvi->hpd_irq = -ENXIO;
354 
355 	if (dvi->hpd_irq >= 0) {
356 		INIT_DELAYED_WORK(&dvi->hpd_work, tfp410_hpd_work_func);
357 
358 		ret = devm_request_threaded_irq(dev, dvi->hpd_irq,
359 			NULL, tfp410_hpd_irq_thread, IRQF_TRIGGER_RISING |
360 			IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
361 			"hdmi-hpd", dvi);
362 		if (ret) {
363 			DRM_ERROR("failed to register hpd interrupt\n");
364 			goto fail;
365 		}
366 	}
367 
368 	drm_bridge_add(&dvi->bridge);
369 
370 	return 0;
371 fail:
372 	i2c_put_adapter(dvi->ddc);
373 	if (dvi->hpd)
374 		gpiod_put(dvi->hpd);
375 	return ret;
376 }
377 
378 static int tfp410_fini(struct device *dev)
379 {
380 	struct tfp410 *dvi = dev_get_drvdata(dev);
381 
382 	if (dvi->hpd_irq >= 0)
383 		cancel_delayed_work_sync(&dvi->hpd_work);
384 
385 	drm_bridge_remove(&dvi->bridge);
386 
387 	if (dvi->ddc)
388 		i2c_put_adapter(dvi->ddc);
389 	if (dvi->hpd)
390 		gpiod_put(dvi->hpd);
391 
392 	return 0;
393 }
394 
395 static int tfp410_probe(struct platform_device *pdev)
396 {
397 	return tfp410_init(&pdev->dev, false);
398 }
399 
400 static int tfp410_remove(struct platform_device *pdev)
401 {
402 	return tfp410_fini(&pdev->dev);
403 }
404 
405 static const struct of_device_id tfp410_match[] = {
406 	{ .compatible = "ti,tfp410" },
407 	{},
408 };
409 MODULE_DEVICE_TABLE(of, tfp410_match);
410 
411 static struct platform_driver tfp410_platform_driver = {
412 	.probe	= tfp410_probe,
413 	.remove	= tfp410_remove,
414 	.driver	= {
415 		.name		= "tfp410-bridge",
416 		.of_match_table	= tfp410_match,
417 	},
418 };
419 
420 #if IS_ENABLED(CONFIG_I2C)
421 /* There is currently no i2c functionality. */
422 static int tfp410_i2c_probe(struct i2c_client *client,
423 			    const struct i2c_device_id *id)
424 {
425 	int reg;
426 
427 	if (!client->dev.of_node ||
428 	    of_property_read_u32(client->dev.of_node, "reg", &reg)) {
429 		dev_err(&client->dev,
430 			"Can't get i2c reg property from device-tree\n");
431 		return -ENXIO;
432 	}
433 
434 	return tfp410_init(&client->dev, true);
435 }
436 
437 static int tfp410_i2c_remove(struct i2c_client *client)
438 {
439 	return tfp410_fini(&client->dev);
440 }
441 
442 static const struct i2c_device_id tfp410_i2c_ids[] = {
443 	{ "tfp410", 0 },
444 	{ }
445 };
446 MODULE_DEVICE_TABLE(i2c, tfp410_i2c_ids);
447 
448 static struct i2c_driver tfp410_i2c_driver = {
449 	.driver = {
450 		.name	= "tfp410",
451 		.of_match_table = of_match_ptr(tfp410_match),
452 	},
453 	.id_table	= tfp410_i2c_ids,
454 	.probe		= tfp410_i2c_probe,
455 	.remove		= tfp410_i2c_remove,
456 };
457 #endif /* IS_ENABLED(CONFIG_I2C) */
458 
459 static struct {
460 	uint i2c:1;
461 	uint platform:1;
462 }  tfp410_registered_driver;
463 
464 static int __init tfp410_module_init(void)
465 {
466 	int ret;
467 
468 #if IS_ENABLED(CONFIG_I2C)
469 	ret = i2c_add_driver(&tfp410_i2c_driver);
470 	if (ret)
471 		pr_err("%s: registering i2c driver failed: %d",
472 		       __func__, ret);
473 	else
474 		tfp410_registered_driver.i2c = 1;
475 #endif
476 
477 	ret = platform_driver_register(&tfp410_platform_driver);
478 	if (ret)
479 		pr_err("%s: registering platform driver failed: %d",
480 		       __func__, ret);
481 	else
482 		tfp410_registered_driver.platform = 1;
483 
484 	if (tfp410_registered_driver.i2c ||
485 	    tfp410_registered_driver.platform)
486 		return 0;
487 
488 	return ret;
489 }
490 module_init(tfp410_module_init);
491 
492 static void __exit tfp410_module_exit(void)
493 {
494 #if IS_ENABLED(CONFIG_I2C)
495 	if (tfp410_registered_driver.i2c)
496 		i2c_del_driver(&tfp410_i2c_driver);
497 #endif
498 	if (tfp410_registered_driver.platform)
499 		platform_driver_unregister(&tfp410_platform_driver);
500 }
501 module_exit(tfp410_module_exit);
502 
503 MODULE_AUTHOR("Jyri Sarha <jsarha@ti.com>");
504 MODULE_DESCRIPTION("TI TFP410 DVI bridge driver");
505 MODULE_LICENSE("GPL");
506