xref: /openbmc/linux/drivers/gpu/drm/bridge/ti-tfp410.c (revision b830f94f)
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(bridge->dev, &dvi->connector,
138 				 &tfp410_con_funcs, dvi->connector_type);
139 	if (ret) {
140 		dev_err(dvi->dev, "drm_connector_init() failed: %d\n", ret);
141 		return ret;
142 	}
143 
144 	drm_display_info_set_bus_formats(&dvi->connector.display_info,
145 					 &dvi->bus_format, 1);
146 
147 	drm_connector_attach_encoder(&dvi->connector,
148 					  bridge->encoder);
149 
150 	return 0;
151 }
152 
153 static void tfp410_enable(struct drm_bridge *bridge)
154 {
155 	struct tfp410 *dvi = drm_bridge_to_tfp410(bridge);
156 
157 	gpiod_set_value_cansleep(dvi->powerdown, 0);
158 }
159 
160 static void tfp410_disable(struct drm_bridge *bridge)
161 {
162 	struct tfp410 *dvi = drm_bridge_to_tfp410(bridge);
163 
164 	gpiod_set_value_cansleep(dvi->powerdown, 1);
165 }
166 
167 static const struct drm_bridge_funcs tfp410_bridge_funcs = {
168 	.attach		= tfp410_attach,
169 	.enable		= tfp410_enable,
170 	.disable	= tfp410_disable,
171 };
172 
173 static void tfp410_hpd_work_func(struct work_struct *work)
174 {
175 	struct tfp410 *dvi;
176 
177 	dvi = container_of(work, struct tfp410, hpd_work.work);
178 
179 	if (dvi->bridge.dev)
180 		drm_helper_hpd_irq_event(dvi->bridge.dev);
181 }
182 
183 static irqreturn_t tfp410_hpd_irq_thread(int irq, void *arg)
184 {
185 	struct tfp410 *dvi = arg;
186 
187 	mod_delayed_work(system_wq, &dvi->hpd_work,
188 			msecs_to_jiffies(HOTPLUG_DEBOUNCE_MS));
189 
190 	return IRQ_HANDLED;
191 }
192 
193 static const struct drm_bridge_timings tfp410_default_timings = {
194 	.input_bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE
195 			 | DRM_BUS_FLAG_DE_HIGH,
196 	.setup_time_ps = 1200,
197 	.hold_time_ps = 1300,
198 };
199 
200 static int tfp410_parse_timings(struct tfp410 *dvi, bool i2c)
201 {
202 	struct drm_bridge_timings *timings = &dvi->timings;
203 	struct device_node *ep;
204 	u32 pclk_sample = 0;
205 	u32 bus_width = 24;
206 	s32 deskew = 0;
207 
208 	/* Start with defaults. */
209 	*timings = tfp410_default_timings;
210 
211 	if (i2c)
212 		/*
213 		 * In I2C mode timings are configured through the I2C interface.
214 		 * As the driver doesn't support I2C configuration yet, we just
215 		 * go with the defaults (BSEL=1, DSEL=1, DKEN=0, EDGE=1).
216 		 */
217 		return 0;
218 
219 	/*
220 	 * In non-I2C mode, timings are configured through the BSEL, DSEL, DKEN
221 	 * and EDGE pins. They are specified in DT through endpoint properties
222 	 * and vendor-specific properties.
223 	 */
224 	ep = of_graph_get_endpoint_by_regs(dvi->dev->of_node, 0, 0);
225 	if (!ep)
226 		return -EINVAL;
227 
228 	/* Get the sampling edge from the endpoint. */
229 	of_property_read_u32(ep, "pclk-sample", &pclk_sample);
230 	of_property_read_u32(ep, "bus-width", &bus_width);
231 	of_node_put(ep);
232 
233 	timings->input_bus_flags = DRM_BUS_FLAG_DE_HIGH;
234 
235 	switch (pclk_sample) {
236 	case 0:
237 		timings->input_bus_flags |= DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE
238 					 |  DRM_BUS_FLAG_SYNC_SAMPLE_NEGEDGE;
239 		break;
240 	case 1:
241 		timings->input_bus_flags |= DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE
242 					 |  DRM_BUS_FLAG_SYNC_SAMPLE_POSEDGE;
243 		break;
244 	default:
245 		return -EINVAL;
246 	}
247 
248 	switch (bus_width) {
249 	case 12:
250 		dvi->bus_format = MEDIA_BUS_FMT_RGB888_2X12_LE;
251 		break;
252 	case 24:
253 		dvi->bus_format = MEDIA_BUS_FMT_RGB888_1X24;
254 		break;
255 	default:
256 		return -EINVAL;
257 	}
258 
259 	/* Get the setup and hold time from vendor-specific properties. */
260 	of_property_read_u32(dvi->dev->of_node, "ti,deskew", (u32 *)&deskew);
261 	if (deskew < -4 || deskew > 3)
262 		return -EINVAL;
263 
264 	timings->setup_time_ps = min(0, 1200 - 350 * deskew);
265 	timings->hold_time_ps = min(0, 1300 + 350 * deskew);
266 
267 	return 0;
268 }
269 
270 static int tfp410_get_connector_properties(struct tfp410 *dvi)
271 {
272 	struct device_node *connector_node, *ddc_phandle;
273 	int ret = 0;
274 
275 	/* port@1 is the connector node */
276 	connector_node = of_graph_get_remote_node(dvi->dev->of_node, 1, -1);
277 	if (!connector_node)
278 		return -ENODEV;
279 
280 	if (of_device_is_compatible(connector_node, "hdmi-connector"))
281 		dvi->connector_type = DRM_MODE_CONNECTOR_HDMIA;
282 	else
283 		dvi->connector_type = DRM_MODE_CONNECTOR_DVID;
284 
285 	dvi->hpd = fwnode_get_named_gpiod(&connector_node->fwnode,
286 					"hpd-gpios", 0, GPIOD_IN, "hpd");
287 	if (IS_ERR(dvi->hpd)) {
288 		ret = PTR_ERR(dvi->hpd);
289 		dvi->hpd = NULL;
290 		if (ret == -ENOENT)
291 			ret = 0;
292 		else
293 			goto fail;
294 	}
295 
296 	ddc_phandle = of_parse_phandle(connector_node, "ddc-i2c-bus", 0);
297 	if (!ddc_phandle)
298 		goto fail;
299 
300 	dvi->ddc = of_get_i2c_adapter_by_node(ddc_phandle);
301 	if (dvi->ddc)
302 		dev_info(dvi->dev, "Connector's ddc i2c bus found\n");
303 	else
304 		ret = -EPROBE_DEFER;
305 
306 	of_node_put(ddc_phandle);
307 
308 fail:
309 	of_node_put(connector_node);
310 	return ret;
311 }
312 
313 static int tfp410_init(struct device *dev, bool i2c)
314 {
315 	struct tfp410 *dvi;
316 	int ret;
317 
318 	if (!dev->of_node) {
319 		dev_err(dev, "device-tree data is missing\n");
320 		return -ENXIO;
321 	}
322 
323 	dvi = devm_kzalloc(dev, sizeof(*dvi), GFP_KERNEL);
324 	if (!dvi)
325 		return -ENOMEM;
326 	dev_set_drvdata(dev, dvi);
327 
328 	dvi->bridge.funcs = &tfp410_bridge_funcs;
329 	dvi->bridge.of_node = dev->of_node;
330 	dvi->bridge.timings = &dvi->timings;
331 	dvi->dev = dev;
332 
333 	ret = tfp410_parse_timings(dvi, i2c);
334 	if (ret)
335 		goto fail;
336 
337 	ret = tfp410_get_connector_properties(dvi);
338 	if (ret)
339 		goto fail;
340 
341 	dvi->powerdown = devm_gpiod_get_optional(dev, "powerdown",
342 						 GPIOD_OUT_HIGH);
343 	if (IS_ERR(dvi->powerdown)) {
344 		dev_err(dev, "failed to parse powerdown gpio\n");
345 		return PTR_ERR(dvi->powerdown);
346 	}
347 
348 	if (dvi->hpd)
349 		dvi->hpd_irq = gpiod_to_irq(dvi->hpd);
350 	else
351 		dvi->hpd_irq = -ENXIO;
352 
353 	if (dvi->hpd_irq >= 0) {
354 		INIT_DELAYED_WORK(&dvi->hpd_work, tfp410_hpd_work_func);
355 
356 		ret = devm_request_threaded_irq(dev, dvi->hpd_irq,
357 			NULL, tfp410_hpd_irq_thread, IRQF_TRIGGER_RISING |
358 			IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
359 			"hdmi-hpd", dvi);
360 		if (ret) {
361 			DRM_ERROR("failed to register hpd interrupt\n");
362 			goto fail;
363 		}
364 	}
365 
366 	drm_bridge_add(&dvi->bridge);
367 
368 	return 0;
369 fail:
370 	i2c_put_adapter(dvi->ddc);
371 	if (dvi->hpd)
372 		gpiod_put(dvi->hpd);
373 	return ret;
374 }
375 
376 static int tfp410_fini(struct device *dev)
377 {
378 	struct tfp410 *dvi = dev_get_drvdata(dev);
379 
380 	if (dvi->hpd_irq >= 0)
381 		cancel_delayed_work_sync(&dvi->hpd_work);
382 
383 	drm_bridge_remove(&dvi->bridge);
384 
385 	if (dvi->ddc)
386 		i2c_put_adapter(dvi->ddc);
387 	if (dvi->hpd)
388 		gpiod_put(dvi->hpd);
389 
390 	return 0;
391 }
392 
393 static int tfp410_probe(struct platform_device *pdev)
394 {
395 	return tfp410_init(&pdev->dev, false);
396 }
397 
398 static int tfp410_remove(struct platform_device *pdev)
399 {
400 	return tfp410_fini(&pdev->dev);
401 }
402 
403 static const struct of_device_id tfp410_match[] = {
404 	{ .compatible = "ti,tfp410" },
405 	{},
406 };
407 MODULE_DEVICE_TABLE(of, tfp410_match);
408 
409 static struct platform_driver tfp410_platform_driver = {
410 	.probe	= tfp410_probe,
411 	.remove	= tfp410_remove,
412 	.driver	= {
413 		.name		= "tfp410-bridge",
414 		.of_match_table	= tfp410_match,
415 	},
416 };
417 
418 #if IS_ENABLED(CONFIG_I2C)
419 /* There is currently no i2c functionality. */
420 static int tfp410_i2c_probe(struct i2c_client *client,
421 			    const struct i2c_device_id *id)
422 {
423 	int reg;
424 
425 	if (!client->dev.of_node ||
426 	    of_property_read_u32(client->dev.of_node, "reg", &reg)) {
427 		dev_err(&client->dev,
428 			"Can't get i2c reg property from device-tree\n");
429 		return -ENXIO;
430 	}
431 
432 	return tfp410_init(&client->dev, true);
433 }
434 
435 static int tfp410_i2c_remove(struct i2c_client *client)
436 {
437 	return tfp410_fini(&client->dev);
438 }
439 
440 static const struct i2c_device_id tfp410_i2c_ids[] = {
441 	{ "tfp410", 0 },
442 	{ }
443 };
444 MODULE_DEVICE_TABLE(i2c, tfp410_i2c_ids);
445 
446 static struct i2c_driver tfp410_i2c_driver = {
447 	.driver = {
448 		.name	= "tfp410",
449 		.of_match_table = of_match_ptr(tfp410_match),
450 	},
451 	.id_table	= tfp410_i2c_ids,
452 	.probe		= tfp410_i2c_probe,
453 	.remove		= tfp410_i2c_remove,
454 };
455 #endif /* IS_ENABLED(CONFIG_I2C) */
456 
457 static struct {
458 	uint i2c:1;
459 	uint platform:1;
460 }  tfp410_registered_driver;
461 
462 static int __init tfp410_module_init(void)
463 {
464 	int ret;
465 
466 #if IS_ENABLED(CONFIG_I2C)
467 	ret = i2c_add_driver(&tfp410_i2c_driver);
468 	if (ret)
469 		pr_err("%s: registering i2c driver failed: %d",
470 		       __func__, ret);
471 	else
472 		tfp410_registered_driver.i2c = 1;
473 #endif
474 
475 	ret = platform_driver_register(&tfp410_platform_driver);
476 	if (ret)
477 		pr_err("%s: registering platform driver failed: %d",
478 		       __func__, ret);
479 	else
480 		tfp410_registered_driver.platform = 1;
481 
482 	if (tfp410_registered_driver.i2c ||
483 	    tfp410_registered_driver.platform)
484 		return 0;
485 
486 	return ret;
487 }
488 module_init(tfp410_module_init);
489 
490 static void __exit tfp410_module_exit(void)
491 {
492 #if IS_ENABLED(CONFIG_I2C)
493 	if (tfp410_registered_driver.i2c)
494 		i2c_del_driver(&tfp410_i2c_driver);
495 #endif
496 	if (tfp410_registered_driver.platform)
497 		platform_driver_unregister(&tfp410_platform_driver);
498 }
499 module_exit(tfp410_module_exit);
500 
501 MODULE_AUTHOR("Jyri Sarha <jsarha@ti.com>");
502 MODULE_DESCRIPTION("TI TFP410 DVI bridge driver");
503 MODULE_LICENSE("GPL");
504