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
 21struct tfp410 {
 22	struct drm_bridge	bridge;
 23	struct drm_connector	connector;
 24
 25	struct i2c_adapter	*ddc;
 26
 27	struct device *dev;
 28};
 29
 30static inline struct tfp410 *
 31drm_bridge_to_tfp410(struct drm_bridge *bridge)
 32{
 33	return container_of(bridge, struct tfp410, bridge);
 34}
 35
 36static inline struct tfp410 *
 37drm_connector_to_tfp410(struct drm_connector *connector)
 38{
 39	return container_of(connector, struct tfp410, connector);
 40}
 41
 42static 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);
 60fallback:
 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
 70static const struct drm_connector_helper_funcs tfp410_con_helper_funcs = {
 71	.get_modes	= tfp410_get_modes,
 72};
 73
 74static enum drm_connector_status
 75tfp410_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
 89static 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
 99static 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
124static const struct drm_bridge_funcs tfp410_bridge_funcs = {
125	.attach		= tfp410_attach,
126};
127
128static 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
153fail:
154	of_node_put(ep);
155	of_node_put(connector_node);
156	of_node_put(ddc_phandle);
157	return ret;
158}
159
160static 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;
190fail:
191	i2c_put_adapter(dvi->ddc);
192	return ret;
193}
194
195static 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
207static int tfp410_probe(struct platform_device *pdev)
208{
209	return tfp410_init(&pdev->dev);
210}
211
212static int tfp410_remove(struct platform_device *pdev)
213{
214	return tfp410_fini(&pdev->dev);
215}
216
217static const struct of_device_id tfp410_match[] = {
218	{ .compatible = "ti,tfp410" },
219	{},
220};
221MODULE_DEVICE_TABLE(of, tfp410_match);
222
223struct 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. */
234static 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
249static int tfp410_i2c_remove(struct i2c_client *client)
250{
251	return tfp410_fini(&client->dev);
252}
253
254static const struct i2c_device_id tfp410_i2c_ids[] = {
255	{ "tfp410", 0 },
256	{ }
257};
258MODULE_DEVICE_TABLE(i2c, tfp410_i2c_ids);
259
260static 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
271static struct {
272	uint i2c:1;
273	uint platform:1;
274}  tfp410_registered_driver;
275
276static 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}
302module_init(tfp410_module_init);
303
304static 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}
313module_exit(tfp410_module_exit);
314
315MODULE_AUTHOR("Jyri Sarha <jsarha@ti.com>");
316MODULE_DESCRIPTION("TI TFP410 DVI bridge driver");
317MODULE_LICENSE("GPL");