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
 27struct 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
 38static inline struct tfp410 *
 39drm_bridge_to_tfp410(struct drm_bridge *bridge)
 40{
 41	return container_of(bridge, struct tfp410, bridge);
 42}
 43
 44static inline struct tfp410 *
 45drm_connector_to_tfp410(struct drm_connector *connector)
 46{
 47	return container_of(connector, struct tfp410, connector);
 48}
 49
 50static 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);
 68fallback:
 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
 78static const struct drm_connector_helper_funcs tfp410_con_helper_funcs = {
 79	.get_modes	= tfp410_get_modes,
 80};
 81
 82static enum drm_connector_status
 83tfp410_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
104static 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
113static 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
141static const struct drm_bridge_funcs tfp410_bridge_funcs = {
142	.attach		= tfp410_attach,
143};
144
145static 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
155static 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
165static 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
198fail:
199	of_node_put(connector_node);
200	return ret;
201}
202
203static 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;
242fail:
243	i2c_put_adapter(dvi->ddc);
244	if (dvi->hpd)
245		gpiod_put(dvi->hpd);
246	return ret;
247}
248
249static 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
265static int tfp410_probe(struct platform_device *pdev)
266{
267	return tfp410_init(&pdev->dev);
268}
269
270static int tfp410_remove(struct platform_device *pdev)
271{
272	return tfp410_fini(&pdev->dev);
273}
274
275static const struct of_device_id tfp410_match[] = {
276	{ .compatible = "ti,tfp410" },
277	{},
278};
279MODULE_DEVICE_TABLE(of, tfp410_match);
280
281static 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. */
292static 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
307static int tfp410_i2c_remove(struct i2c_client *client)
308{
309	return tfp410_fini(&client->dev);
310}
311
312static const struct i2c_device_id tfp410_i2c_ids[] = {
313	{ "tfp410", 0 },
314	{ }
315};
316MODULE_DEVICE_TABLE(i2c, tfp410_i2c_ids);
317
318static 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
329static struct {
330	uint i2c:1;
331	uint platform:1;
332}  tfp410_registered_driver;
333
334static 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}
360module_init(tfp410_module_init);
361
362static 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}
371module_exit(tfp410_module_exit);
372
373MODULE_AUTHOR("Jyri Sarha <jsarha@ti.com>");
374MODULE_DESCRIPTION("TI TFP410 DVI bridge driver");
375MODULE_LICENSE("GPL");