1/*
2 * Generic DVI Connector driver
3 *
4 * Copyright (C) 2013 Texas Instruments
5 * Author: Tomi Valkeinen <tomi.valkeinen@ti.com>
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License version 2 as published by
9 * the Free Software Foundation.
10 */
11
12#include <linux/i2c.h>
13#include <linux/module.h>
14#include <linux/platform_device.h>
15#include <linux/slab.h>
16
17#include <drm/drm_edid.h>
18
19#include <video/omapdss.h>
20#include <video/omap-panel-data.h>
21
22static const struct omap_video_timings dvic_default_timings = {
23	.x_res		= 640,
24	.y_res		= 480,
25
26	.pixelclock	= 23500000,
27
28	.hfp		= 48,
29	.hsw		= 32,
30	.hbp		= 80,
31
32	.vfp		= 3,
33	.vsw		= 4,
34	.vbp		= 7,
35
36	.vsync_level	= OMAPDSS_SIG_ACTIVE_HIGH,
37	.hsync_level	= OMAPDSS_SIG_ACTIVE_HIGH,
38	.data_pclk_edge	= OMAPDSS_DRIVE_SIG_RISING_EDGE,
39	.de_level	= OMAPDSS_SIG_ACTIVE_HIGH,
40	.sync_pclk_edge	= OMAPDSS_DRIVE_SIG_OPPOSITE_EDGES,
41};
42
43struct panel_drv_data {
44	struct omap_dss_device dssdev;
45	struct omap_dss_device *in;
46
47	struct omap_video_timings timings;
48
49	struct i2c_adapter *i2c_adapter;
50};
51
52#define to_panel_data(x) container_of(x, struct panel_drv_data, dssdev)
53
54static int dvic_connect(struct omap_dss_device *dssdev)
55{
56	struct panel_drv_data *ddata = to_panel_data(dssdev);
57	struct omap_dss_device *in = ddata->in;
58	int r;
59
60	if (omapdss_device_is_connected(dssdev))
61		return 0;
62
63	r = in->ops.dvi->connect(in, dssdev);
64	if (r)
65		return r;
66
67	return 0;
68}
69
70static void dvic_disconnect(struct omap_dss_device *dssdev)
71{
72	struct panel_drv_data *ddata = to_panel_data(dssdev);
73	struct omap_dss_device *in = ddata->in;
74
75	if (!omapdss_device_is_connected(dssdev))
76		return;
77
78	in->ops.dvi->disconnect(in, dssdev);
79}
80
81static int dvic_enable(struct omap_dss_device *dssdev)
82{
83	struct panel_drv_data *ddata = to_panel_data(dssdev);
84	struct omap_dss_device *in = ddata->in;
85	int r;
86
87	if (!omapdss_device_is_connected(dssdev))
88		return -ENODEV;
89
90	if (omapdss_device_is_enabled(dssdev))
91		return 0;
92
93	in->ops.dvi->set_timings(in, &ddata->timings);
94
95	r = in->ops.dvi->enable(in);
96	if (r)
97		return r;
98
99	dssdev->state = OMAP_DSS_DISPLAY_ACTIVE;
100
101	return 0;
102}
103
104static void dvic_disable(struct omap_dss_device *dssdev)
105{
106	struct panel_drv_data *ddata = to_panel_data(dssdev);
107	struct omap_dss_device *in = ddata->in;
108
109	if (!omapdss_device_is_enabled(dssdev))
110		return;
111
112	in->ops.dvi->disable(in);
113
114	dssdev->state = OMAP_DSS_DISPLAY_DISABLED;
115}
116
117static void dvic_set_timings(struct omap_dss_device *dssdev,
118		struct omap_video_timings *timings)
119{
120	struct panel_drv_data *ddata = to_panel_data(dssdev);
121	struct omap_dss_device *in = ddata->in;
122
123	ddata->timings = *timings;
124	dssdev->panel.timings = *timings;
125
126	in->ops.dvi->set_timings(in, timings);
127}
128
129static void dvic_get_timings(struct omap_dss_device *dssdev,
130		struct omap_video_timings *timings)
131{
132	struct panel_drv_data *ddata = to_panel_data(dssdev);
133
134	*timings = ddata->timings;
135}
136
137static int dvic_check_timings(struct omap_dss_device *dssdev,
138		struct omap_video_timings *timings)
139{
140	struct panel_drv_data *ddata = to_panel_data(dssdev);
141	struct omap_dss_device *in = ddata->in;
142
143	return in->ops.dvi->check_timings(in, timings);
144}
145
146static int dvic_ddc_read(struct i2c_adapter *adapter,
147		unsigned char *buf, u16 count, u8 offset)
148{
149	int r, retries;
150
151	for (retries = 3; retries > 0; retries--) {
152		struct i2c_msg msgs[] = {
153			{
154				.addr   = DDC_ADDR,
155				.flags  = 0,
156				.len    = 1,
157				.buf    = &offset,
158			}, {
159				.addr   = DDC_ADDR,
160				.flags  = I2C_M_RD,
161				.len    = count,
162				.buf    = buf,
163			}
164		};
165
166		r = i2c_transfer(adapter, msgs, 2);
167		if (r == 2)
168			return 0;
169
170		if (r != -EAGAIN)
171			break;
172	}
173
174	return r < 0 ? r : -EIO;
175}
176
177static int dvic_read_edid(struct omap_dss_device *dssdev,
178		u8 *edid, int len)
179{
180	struct panel_drv_data *ddata = to_panel_data(dssdev);
181	int r, l, bytes_read;
182
183	if (!ddata->i2c_adapter)
184		return -ENODEV;
185
186	l = min(EDID_LENGTH, len);
187	r = dvic_ddc_read(ddata->i2c_adapter, edid, l, 0);
188	if (r)
189		return r;
190
191	bytes_read = l;
192
193	/* if there are extensions, read second block */
194	if (len > EDID_LENGTH && edid[0x7e] > 0) {
195		l = min(EDID_LENGTH, len - EDID_LENGTH);
196
197		r = dvic_ddc_read(ddata->i2c_adapter, edid + EDID_LENGTH,
198				l, EDID_LENGTH);
199		if (r)
200			return r;
201
202		bytes_read += l;
203	}
204
205	return bytes_read;
206}
207
208static bool dvic_detect(struct omap_dss_device *dssdev)
209{
210	struct panel_drv_data *ddata = to_panel_data(dssdev);
211	unsigned char out;
212	int r;
213
214	if (!ddata->i2c_adapter)
215		return true;
216
217	r = dvic_ddc_read(ddata->i2c_adapter, &out, 1, 0);
218
219	return r == 0;
220}
221
222static struct omap_dss_driver dvic_driver = {
223	.connect	= dvic_connect,
224	.disconnect	= dvic_disconnect,
225
226	.enable		= dvic_enable,
227	.disable	= dvic_disable,
228
229	.set_timings	= dvic_set_timings,
230	.get_timings	= dvic_get_timings,
231	.check_timings	= dvic_check_timings,
232
233	.get_resolution	= omapdss_default_get_resolution,
234
235	.read_edid	= dvic_read_edid,
236	.detect		= dvic_detect,
237};
238
239static int dvic_probe_pdata(struct platform_device *pdev)
240{
241	struct panel_drv_data *ddata = platform_get_drvdata(pdev);
242	struct connector_dvi_platform_data *pdata;
243	struct omap_dss_device *in, *dssdev;
244	int i2c_bus_num;
245
246	pdata = dev_get_platdata(&pdev->dev);
247	i2c_bus_num = pdata->i2c_bus_num;
248
249	if (i2c_bus_num != -1) {
250		struct i2c_adapter *adapter;
251
252		adapter = i2c_get_adapter(i2c_bus_num);
253		if (!adapter) {
254			dev_err(&pdev->dev,
255					"Failed to get I2C adapter, bus %d\n",
256					i2c_bus_num);
257			return -EPROBE_DEFER;
258		}
259
260		ddata->i2c_adapter = adapter;
261	}
262
263	in = omap_dss_find_output(pdata->source);
264	if (in == NULL) {
265		if (ddata->i2c_adapter)
266			i2c_put_adapter(ddata->i2c_adapter);
267
268		dev_err(&pdev->dev, "Failed to find video source\n");
269		return -EPROBE_DEFER;
270	}
271
272	ddata->in = in;
273
274	dssdev = &ddata->dssdev;
275	dssdev->name = pdata->name;
276
277	return 0;
278}
279
280static int dvic_probe_of(struct platform_device *pdev)
281{
282	struct panel_drv_data *ddata = platform_get_drvdata(pdev);
283	struct device_node *node = pdev->dev.of_node;
284	struct omap_dss_device *in;
285	struct device_node *adapter_node;
286	struct i2c_adapter *adapter;
287
288	in = omapdss_of_find_source_for_first_ep(node);
289	if (IS_ERR(in)) {
290		dev_err(&pdev->dev, "failed to find video source\n");
291		return PTR_ERR(in);
292	}
293
294	ddata->in = in;
295
296	adapter_node = of_parse_phandle(node, "ddc-i2c-bus", 0);
297	if (adapter_node) {
298		adapter = of_find_i2c_adapter_by_node(adapter_node);
299		if (adapter == NULL) {
300			dev_err(&pdev->dev, "failed to parse ddc-i2c-bus\n");
301			omap_dss_put_device(ddata->in);
302			return -EPROBE_DEFER;
303		}
304
305		ddata->i2c_adapter = adapter;
306	}
307
308	return 0;
309}
310
311static int dvic_probe(struct platform_device *pdev)
312{
313	struct panel_drv_data *ddata;
314	struct omap_dss_device *dssdev;
315	int r;
316
317	ddata = devm_kzalloc(&pdev->dev, sizeof(*ddata), GFP_KERNEL);
318	if (!ddata)
319		return -ENOMEM;
320
321	platform_set_drvdata(pdev, ddata);
322
323	if (dev_get_platdata(&pdev->dev)) {
324		r = dvic_probe_pdata(pdev);
325		if (r)
326			return r;
327	} else if (pdev->dev.of_node) {
328		r = dvic_probe_of(pdev);
329		if (r)
330			return r;
331	} else {
332		return -ENODEV;
333	}
334
335	ddata->timings = dvic_default_timings;
336
337	dssdev = &ddata->dssdev;
338	dssdev->driver = &dvic_driver;
339	dssdev->dev = &pdev->dev;
340	dssdev->type = OMAP_DISPLAY_TYPE_DVI;
341	dssdev->owner = THIS_MODULE;
342	dssdev->panel.timings = dvic_default_timings;
343
344	r = omapdss_register_display(dssdev);
345	if (r) {
346		dev_err(&pdev->dev, "Failed to register panel\n");
347		goto err_reg;
348	}
349
350	return 0;
351
352err_reg:
353	omap_dss_put_device(ddata->in);
354
355	if (ddata->i2c_adapter)
356		i2c_put_adapter(ddata->i2c_adapter);
357
358	return r;
359}
360
361static int __exit dvic_remove(struct platform_device *pdev)
362{
363	struct panel_drv_data *ddata = platform_get_drvdata(pdev);
364	struct omap_dss_device *dssdev = &ddata->dssdev;
365	struct omap_dss_device *in = ddata->in;
366
367	omapdss_unregister_display(&ddata->dssdev);
368
369	dvic_disable(dssdev);
370	dvic_disconnect(dssdev);
371
372	omap_dss_put_device(in);
373
374	if (ddata->i2c_adapter)
375		i2c_put_adapter(ddata->i2c_adapter);
376
377	return 0;
378}
379
380static const struct of_device_id dvic_of_match[] = {
381	{ .compatible = "omapdss,dvi-connector", },
382	{},
383};
384
385MODULE_DEVICE_TABLE(of, dvic_of_match);
386
387static struct platform_driver dvi_connector_driver = {
388	.probe	= dvic_probe,
389	.remove	= __exit_p(dvic_remove),
390	.driver	= {
391		.name	= "connector-dvi",
392		.owner	= THIS_MODULE,
393		.of_match_table = dvic_of_match,
394		.suppress_bind_attrs = true,
395	},
396};
397
398module_platform_driver(dvi_connector_driver);
399
400MODULE_AUTHOR("Tomi Valkeinen <tomi.valkeinen@ti.com>");
401MODULE_DESCRIPTION("Generic DVI Connector driver");
402MODULE_LICENSE("GPL");
403