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/omapfb_dss.h>
20 
21 static const struct omap_video_timings dvic_default_timings = {
22 	.x_res		= 640,
23 	.y_res		= 480,
24 
25 	.pixelclock	= 23500000,
26 
27 	.hfp		= 48,
28 	.hsw		= 32,
29 	.hbp		= 80,
30 
31 	.vfp		= 3,
32 	.vsw		= 4,
33 	.vbp		= 7,
34 
35 	.vsync_level	= OMAPDSS_SIG_ACTIVE_HIGH,
36 	.hsync_level	= OMAPDSS_SIG_ACTIVE_HIGH,
37 	.data_pclk_edge	= OMAPDSS_DRIVE_SIG_RISING_EDGE,
38 	.de_level	= OMAPDSS_SIG_ACTIVE_HIGH,
39 	.sync_pclk_edge	= OMAPDSS_DRIVE_SIG_FALLING_EDGE,
40 };
41 
42 struct panel_drv_data {
43 	struct omap_dss_device dssdev;
44 	struct omap_dss_device *in;
45 
46 	struct omap_video_timings timings;
47 
48 	struct i2c_adapter *i2c_adapter;
49 };
50 
51 #define to_panel_data(x) container_of(x, struct panel_drv_data, dssdev)
52 
53 static int dvic_connect(struct omap_dss_device *dssdev)
54 {
55 	struct panel_drv_data *ddata = to_panel_data(dssdev);
56 	struct omap_dss_device *in = ddata->in;
57 	int r;
58 
59 	if (omapdss_device_is_connected(dssdev))
60 		return 0;
61 
62 	r = in->ops.dvi->connect(in, dssdev);
63 	if (r)
64 		return r;
65 
66 	return 0;
67 }
68 
69 static void dvic_disconnect(struct omap_dss_device *dssdev)
70 {
71 	struct panel_drv_data *ddata = to_panel_data(dssdev);
72 	struct omap_dss_device *in = ddata->in;
73 
74 	if (!omapdss_device_is_connected(dssdev))
75 		return;
76 
77 	in->ops.dvi->disconnect(in, dssdev);
78 }
79 
80 static int dvic_enable(struct omap_dss_device *dssdev)
81 {
82 	struct panel_drv_data *ddata = to_panel_data(dssdev);
83 	struct omap_dss_device *in = ddata->in;
84 	int r;
85 
86 	if (!omapdss_device_is_connected(dssdev))
87 		return -ENODEV;
88 
89 	if (omapdss_device_is_enabled(dssdev))
90 		return 0;
91 
92 	in->ops.dvi->set_timings(in, &ddata->timings);
93 
94 	r = in->ops.dvi->enable(in);
95 	if (r)
96 		return r;
97 
98 	dssdev->state = OMAP_DSS_DISPLAY_ACTIVE;
99 
100 	return 0;
101 }
102 
103 static void dvic_disable(struct omap_dss_device *dssdev)
104 {
105 	struct panel_drv_data *ddata = to_panel_data(dssdev);
106 	struct omap_dss_device *in = ddata->in;
107 
108 	if (!omapdss_device_is_enabled(dssdev))
109 		return;
110 
111 	in->ops.dvi->disable(in);
112 
113 	dssdev->state = OMAP_DSS_DISPLAY_DISABLED;
114 }
115 
116 static void dvic_set_timings(struct omap_dss_device *dssdev,
117 		struct omap_video_timings *timings)
118 {
119 	struct panel_drv_data *ddata = to_panel_data(dssdev);
120 	struct omap_dss_device *in = ddata->in;
121 
122 	ddata->timings = *timings;
123 	dssdev->panel.timings = *timings;
124 
125 	in->ops.dvi->set_timings(in, timings);
126 }
127 
128 static void dvic_get_timings(struct omap_dss_device *dssdev,
129 		struct omap_video_timings *timings)
130 {
131 	struct panel_drv_data *ddata = to_panel_data(dssdev);
132 
133 	*timings = ddata->timings;
134 }
135 
136 static int dvic_check_timings(struct omap_dss_device *dssdev,
137 		struct omap_video_timings *timings)
138 {
139 	struct panel_drv_data *ddata = to_panel_data(dssdev);
140 	struct omap_dss_device *in = ddata->in;
141 
142 	return in->ops.dvi->check_timings(in, timings);
143 }
144 
145 static int dvic_ddc_read(struct i2c_adapter *adapter,
146 		unsigned char *buf, u16 count, u8 offset)
147 {
148 	int r, retries;
149 
150 	for (retries = 3; retries > 0; retries--) {
151 		struct i2c_msg msgs[] = {
152 			{
153 				.addr   = DDC_ADDR,
154 				.flags  = 0,
155 				.len    = 1,
156 				.buf    = &offset,
157 			}, {
158 				.addr   = DDC_ADDR,
159 				.flags  = I2C_M_RD,
160 				.len    = count,
161 				.buf    = buf,
162 			}
163 		};
164 
165 		r = i2c_transfer(adapter, msgs, 2);
166 		if (r == 2)
167 			return 0;
168 
169 		if (r != -EAGAIN)
170 			break;
171 	}
172 
173 	return r < 0 ? r : -EIO;
174 }
175 
176 static int dvic_read_edid(struct omap_dss_device *dssdev,
177 		u8 *edid, int len)
178 {
179 	struct panel_drv_data *ddata = to_panel_data(dssdev);
180 	int r, l, bytes_read;
181 
182 	if (!ddata->i2c_adapter)
183 		return -ENODEV;
184 
185 	l = min(EDID_LENGTH, len);
186 	r = dvic_ddc_read(ddata->i2c_adapter, edid, l, 0);
187 	if (r)
188 		return r;
189 
190 	bytes_read = l;
191 
192 	/* if there are extensions, read second block */
193 	if (len > EDID_LENGTH && edid[0x7e] > 0) {
194 		l = min(EDID_LENGTH, len - EDID_LENGTH);
195 
196 		r = dvic_ddc_read(ddata->i2c_adapter, edid + EDID_LENGTH,
197 				l, EDID_LENGTH);
198 		if (r)
199 			return r;
200 
201 		bytes_read += l;
202 	}
203 
204 	return bytes_read;
205 }
206 
207 static bool dvic_detect(struct omap_dss_device *dssdev)
208 {
209 	struct panel_drv_data *ddata = to_panel_data(dssdev);
210 	unsigned char out;
211 	int r;
212 
213 	if (!ddata->i2c_adapter)
214 		return true;
215 
216 	r = dvic_ddc_read(ddata->i2c_adapter, &out, 1, 0);
217 
218 	return r == 0;
219 }
220 
221 static struct omap_dss_driver dvic_driver = {
222 	.connect	= dvic_connect,
223 	.disconnect	= dvic_disconnect,
224 
225 	.enable		= dvic_enable,
226 	.disable	= dvic_disable,
227 
228 	.set_timings	= dvic_set_timings,
229 	.get_timings	= dvic_get_timings,
230 	.check_timings	= dvic_check_timings,
231 
232 	.get_resolution	= omapdss_default_get_resolution,
233 
234 	.read_edid	= dvic_read_edid,
235 	.detect		= dvic_detect,
236 };
237 
238 static int dvic_probe_of(struct platform_device *pdev)
239 {
240 	struct panel_drv_data *ddata = platform_get_drvdata(pdev);
241 	struct device_node *node = pdev->dev.of_node;
242 	struct omap_dss_device *in;
243 	struct device_node *adapter_node;
244 	struct i2c_adapter *adapter;
245 
246 	in = omapdss_of_find_source_for_first_ep(node);
247 	if (IS_ERR(in)) {
248 		dev_err(&pdev->dev, "failed to find video source\n");
249 		return PTR_ERR(in);
250 	}
251 
252 	ddata->in = in;
253 
254 	adapter_node = of_parse_phandle(node, "ddc-i2c-bus", 0);
255 	if (adapter_node) {
256 		adapter = of_get_i2c_adapter_by_node(adapter_node);
257 		if (adapter == NULL) {
258 			dev_err(&pdev->dev, "failed to parse ddc-i2c-bus\n");
259 			omap_dss_put_device(ddata->in);
260 			return -EPROBE_DEFER;
261 		}
262 
263 		ddata->i2c_adapter = adapter;
264 	}
265 
266 	return 0;
267 }
268 
269 static int dvic_probe(struct platform_device *pdev)
270 {
271 	struct panel_drv_data *ddata;
272 	struct omap_dss_device *dssdev;
273 	int r;
274 
275 	if (!pdev->dev.of_node)
276 		return -ENODEV;
277 
278 	ddata = devm_kzalloc(&pdev->dev, sizeof(*ddata), GFP_KERNEL);
279 	if (!ddata)
280 		return -ENOMEM;
281 
282 	platform_set_drvdata(pdev, ddata);
283 
284 	r = dvic_probe_of(pdev);
285 	if (r)
286 		return r;
287 
288 	ddata->timings = dvic_default_timings;
289 
290 	dssdev = &ddata->dssdev;
291 	dssdev->driver = &dvic_driver;
292 	dssdev->dev = &pdev->dev;
293 	dssdev->type = OMAP_DISPLAY_TYPE_DVI;
294 	dssdev->owner = THIS_MODULE;
295 	dssdev->panel.timings = dvic_default_timings;
296 
297 	r = omapdss_register_display(dssdev);
298 	if (r) {
299 		dev_err(&pdev->dev, "Failed to register panel\n");
300 		goto err_reg;
301 	}
302 
303 	return 0;
304 
305 err_reg:
306 	omap_dss_put_device(ddata->in);
307 
308 	i2c_put_adapter(ddata->i2c_adapter);
309 
310 	return r;
311 }
312 
313 static int __exit dvic_remove(struct platform_device *pdev)
314 {
315 	struct panel_drv_data *ddata = platform_get_drvdata(pdev);
316 	struct omap_dss_device *dssdev = &ddata->dssdev;
317 	struct omap_dss_device *in = ddata->in;
318 
319 	omapdss_unregister_display(&ddata->dssdev);
320 
321 	dvic_disable(dssdev);
322 	dvic_disconnect(dssdev);
323 
324 	omap_dss_put_device(in);
325 
326 	i2c_put_adapter(ddata->i2c_adapter);
327 
328 	return 0;
329 }
330 
331 static const struct of_device_id dvic_of_match[] = {
332 	{ .compatible = "omapdss,dvi-connector", },
333 	{},
334 };
335 
336 MODULE_DEVICE_TABLE(of, dvic_of_match);
337 
338 static struct platform_driver dvi_connector_driver = {
339 	.probe	= dvic_probe,
340 	.remove	= __exit_p(dvic_remove),
341 	.driver	= {
342 		.name	= "connector-dvi",
343 		.of_match_table = dvic_of_match,
344 		.suppress_bind_attrs = true,
345 	},
346 };
347 
348 module_platform_driver(dvi_connector_driver);
349 
350 MODULE_AUTHOR("Tomi Valkeinen <tomi.valkeinen@ti.com>");
351 MODULE_DESCRIPTION("Generic DVI Connector driver");
352 MODULE_LICENSE("GPL");
353