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 
22 static 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_FALLING_EDGE,
41 };
42 
43 struct 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 
54 static 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 
70 static 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 
81 static 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 
104 static 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 
117 static 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 
129 static 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 
137 static 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 
146 static 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 
177 static 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 
208 static 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 
222 static 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 
239 static 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 		i2c_put_adapter(ddata->i2c_adapter);
266 
267 		dev_err(&pdev->dev, "Failed to find video source\n");
268 		return -EPROBE_DEFER;
269 	}
270 
271 	ddata->in = in;
272 
273 	dssdev = &ddata->dssdev;
274 	dssdev->name = pdata->name;
275 
276 	return 0;
277 }
278 
279 static int dvic_probe_of(struct platform_device *pdev)
280 {
281 	struct panel_drv_data *ddata = platform_get_drvdata(pdev);
282 	struct device_node *node = pdev->dev.of_node;
283 	struct omap_dss_device *in;
284 	struct device_node *adapter_node;
285 	struct i2c_adapter *adapter;
286 
287 	in = omapdss_of_find_source_for_first_ep(node);
288 	if (IS_ERR(in)) {
289 		dev_err(&pdev->dev, "failed to find video source\n");
290 		return PTR_ERR(in);
291 	}
292 
293 	ddata->in = in;
294 
295 	adapter_node = of_parse_phandle(node, "ddc-i2c-bus", 0);
296 	if (adapter_node) {
297 		adapter = of_get_i2c_adapter_by_node(adapter_node);
298 		if (adapter == NULL) {
299 			dev_err(&pdev->dev, "failed to parse ddc-i2c-bus\n");
300 			omap_dss_put_device(ddata->in);
301 			return -EPROBE_DEFER;
302 		}
303 
304 		ddata->i2c_adapter = adapter;
305 	}
306 
307 	return 0;
308 }
309 
310 static int dvic_probe(struct platform_device *pdev)
311 {
312 	struct panel_drv_data *ddata;
313 	struct omap_dss_device *dssdev;
314 	int r;
315 
316 	ddata = devm_kzalloc(&pdev->dev, sizeof(*ddata), GFP_KERNEL);
317 	if (!ddata)
318 		return -ENOMEM;
319 
320 	platform_set_drvdata(pdev, ddata);
321 
322 	if (dev_get_platdata(&pdev->dev)) {
323 		r = dvic_probe_pdata(pdev);
324 		if (r)
325 			return r;
326 	} else if (pdev->dev.of_node) {
327 		r = dvic_probe_of(pdev);
328 		if (r)
329 			return r;
330 	} else {
331 		return -ENODEV;
332 	}
333 
334 	ddata->timings = dvic_default_timings;
335 
336 	dssdev = &ddata->dssdev;
337 	dssdev->driver = &dvic_driver;
338 	dssdev->dev = &pdev->dev;
339 	dssdev->type = OMAP_DISPLAY_TYPE_DVI;
340 	dssdev->owner = THIS_MODULE;
341 	dssdev->panel.timings = dvic_default_timings;
342 
343 	r = omapdss_register_display(dssdev);
344 	if (r) {
345 		dev_err(&pdev->dev, "Failed to register panel\n");
346 		goto err_reg;
347 	}
348 
349 	return 0;
350 
351 err_reg:
352 	omap_dss_put_device(ddata->in);
353 
354 	i2c_put_adapter(ddata->i2c_adapter);
355 
356 	return r;
357 }
358 
359 static int __exit dvic_remove(struct platform_device *pdev)
360 {
361 	struct panel_drv_data *ddata = platform_get_drvdata(pdev);
362 	struct omap_dss_device *dssdev = &ddata->dssdev;
363 	struct omap_dss_device *in = ddata->in;
364 
365 	omapdss_unregister_display(&ddata->dssdev);
366 
367 	dvic_disable(dssdev);
368 	dvic_disconnect(dssdev);
369 
370 	omap_dss_put_device(in);
371 
372 	i2c_put_adapter(ddata->i2c_adapter);
373 
374 	return 0;
375 }
376 
377 static const struct of_device_id dvic_of_match[] = {
378 	{ .compatible = "omapdss,dvi-connector", },
379 	{},
380 };
381 
382 MODULE_DEVICE_TABLE(of, dvic_of_match);
383 
384 static struct platform_driver dvi_connector_driver = {
385 	.probe	= dvic_probe,
386 	.remove	= __exit_p(dvic_remove),
387 	.driver	= {
388 		.name	= "connector-dvi",
389 		.of_match_table = dvic_of_match,
390 		.suppress_bind_attrs = true,
391 	},
392 };
393 
394 module_platform_driver(dvi_connector_driver);
395 
396 MODULE_AUTHOR("Tomi Valkeinen <tomi.valkeinen@ti.com>");
397 MODULE_DESCRIPTION("Generic DVI Connector driver");
398 MODULE_LICENSE("GPL");
399