1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Generic DVI Connector driver
4  *
5  * Copyright (C) 2013 Texas Instruments
6  * Author: Tomi Valkeinen <tomi.valkeinen@ti.com>
7  */
8 
9 #include <linux/i2c.h>
10 #include <linux/module.h>
11 #include <linux/platform_device.h>
12 #include <linux/slab.h>
13 
14 #include <drm/drm_edid.h>
15 
16 #include <video/omapfb_dss.h>
17 
18 static const struct omap_video_timings dvic_default_timings = {
19 	.x_res		= 640,
20 	.y_res		= 480,
21 
22 	.pixelclock	= 23500000,
23 
24 	.hfp		= 48,
25 	.hsw		= 32,
26 	.hbp		= 80,
27 
28 	.vfp		= 3,
29 	.vsw		= 4,
30 	.vbp		= 7,
31 
32 	.vsync_level	= OMAPDSS_SIG_ACTIVE_HIGH,
33 	.hsync_level	= OMAPDSS_SIG_ACTIVE_HIGH,
34 	.data_pclk_edge	= OMAPDSS_DRIVE_SIG_RISING_EDGE,
35 	.de_level	= OMAPDSS_SIG_ACTIVE_HIGH,
36 	.sync_pclk_edge	= OMAPDSS_DRIVE_SIG_FALLING_EDGE,
37 };
38 
39 struct panel_drv_data {
40 	struct omap_dss_device dssdev;
41 	struct omap_dss_device *in;
42 
43 	struct omap_video_timings timings;
44 
45 	struct i2c_adapter *i2c_adapter;
46 };
47 
48 #define to_panel_data(x) container_of(x, struct panel_drv_data, dssdev)
49 
50 static int dvic_connect(struct omap_dss_device *dssdev)
51 {
52 	struct panel_drv_data *ddata = to_panel_data(dssdev);
53 	struct omap_dss_device *in = ddata->in;
54 
55 	if (omapdss_device_is_connected(dssdev))
56 		return 0;
57 
58 	return in->ops.dvi->connect(in, dssdev);
59 }
60 
61 static void dvic_disconnect(struct omap_dss_device *dssdev)
62 {
63 	struct panel_drv_data *ddata = to_panel_data(dssdev);
64 	struct omap_dss_device *in = ddata->in;
65 
66 	if (!omapdss_device_is_connected(dssdev))
67 		return;
68 
69 	in->ops.dvi->disconnect(in, dssdev);
70 }
71 
72 static int dvic_enable(struct omap_dss_device *dssdev)
73 {
74 	struct panel_drv_data *ddata = to_panel_data(dssdev);
75 	struct omap_dss_device *in = ddata->in;
76 	int r;
77 
78 	if (!omapdss_device_is_connected(dssdev))
79 		return -ENODEV;
80 
81 	if (omapdss_device_is_enabled(dssdev))
82 		return 0;
83 
84 	in->ops.dvi->set_timings(in, &ddata->timings);
85 
86 	r = in->ops.dvi->enable(in);
87 	if (r)
88 		return r;
89 
90 	dssdev->state = OMAP_DSS_DISPLAY_ACTIVE;
91 
92 	return 0;
93 }
94 
95 static void dvic_disable(struct omap_dss_device *dssdev)
96 {
97 	struct panel_drv_data *ddata = to_panel_data(dssdev);
98 	struct omap_dss_device *in = ddata->in;
99 
100 	if (!omapdss_device_is_enabled(dssdev))
101 		return;
102 
103 	in->ops.dvi->disable(in);
104 
105 	dssdev->state = OMAP_DSS_DISPLAY_DISABLED;
106 }
107 
108 static void dvic_set_timings(struct omap_dss_device *dssdev,
109 		struct omap_video_timings *timings)
110 {
111 	struct panel_drv_data *ddata = to_panel_data(dssdev);
112 	struct omap_dss_device *in = ddata->in;
113 
114 	ddata->timings = *timings;
115 	dssdev->panel.timings = *timings;
116 
117 	in->ops.dvi->set_timings(in, timings);
118 }
119 
120 static void dvic_get_timings(struct omap_dss_device *dssdev,
121 		struct omap_video_timings *timings)
122 {
123 	struct panel_drv_data *ddata = to_panel_data(dssdev);
124 
125 	*timings = ddata->timings;
126 }
127 
128 static int dvic_check_timings(struct omap_dss_device *dssdev,
129 		struct omap_video_timings *timings)
130 {
131 	struct panel_drv_data *ddata = to_panel_data(dssdev);
132 	struct omap_dss_device *in = ddata->in;
133 
134 	return in->ops.dvi->check_timings(in, timings);
135 }
136 
137 static int dvic_ddc_read(struct i2c_adapter *adapter,
138 		unsigned char *buf, u16 count, u8 offset)
139 {
140 	int r, retries;
141 
142 	for (retries = 3; retries > 0; retries--) {
143 		struct i2c_msg msgs[] = {
144 			{
145 				.addr   = DDC_ADDR,
146 				.flags  = 0,
147 				.len    = 1,
148 				.buf    = &offset,
149 			}, {
150 				.addr   = DDC_ADDR,
151 				.flags  = I2C_M_RD,
152 				.len    = count,
153 				.buf    = buf,
154 			}
155 		};
156 
157 		r = i2c_transfer(adapter, msgs, 2);
158 		if (r == 2)
159 			return 0;
160 
161 		if (r != -EAGAIN)
162 			break;
163 	}
164 
165 	return r < 0 ? r : -EIO;
166 }
167 
168 static int dvic_read_edid(struct omap_dss_device *dssdev,
169 		u8 *edid, int len)
170 {
171 	struct panel_drv_data *ddata = to_panel_data(dssdev);
172 	int r, l, bytes_read;
173 
174 	if (!ddata->i2c_adapter)
175 		return -ENODEV;
176 
177 	l = min(EDID_LENGTH, len);
178 	r = dvic_ddc_read(ddata->i2c_adapter, edid, l, 0);
179 	if (r)
180 		return r;
181 
182 	bytes_read = l;
183 
184 	/* if there are extensions, read second block */
185 	if (len > EDID_LENGTH && edid[0x7e] > 0) {
186 		l = min(EDID_LENGTH, len - EDID_LENGTH);
187 
188 		r = dvic_ddc_read(ddata->i2c_adapter, edid + EDID_LENGTH,
189 				l, EDID_LENGTH);
190 		if (r)
191 			return r;
192 
193 		bytes_read += l;
194 	}
195 
196 	return bytes_read;
197 }
198 
199 static bool dvic_detect(struct omap_dss_device *dssdev)
200 {
201 	struct panel_drv_data *ddata = to_panel_data(dssdev);
202 	unsigned char out;
203 	int r;
204 
205 	if (!ddata->i2c_adapter)
206 		return true;
207 
208 	r = dvic_ddc_read(ddata->i2c_adapter, &out, 1, 0);
209 
210 	return r == 0;
211 }
212 
213 static struct omap_dss_driver dvic_driver = {
214 	.connect	= dvic_connect,
215 	.disconnect	= dvic_disconnect,
216 
217 	.enable		= dvic_enable,
218 	.disable	= dvic_disable,
219 
220 	.set_timings	= dvic_set_timings,
221 	.get_timings	= dvic_get_timings,
222 	.check_timings	= dvic_check_timings,
223 
224 	.get_resolution	= omapdss_default_get_resolution,
225 
226 	.read_edid	= dvic_read_edid,
227 	.detect		= dvic_detect,
228 };
229 
230 static int dvic_probe_of(struct platform_device *pdev)
231 {
232 	struct panel_drv_data *ddata = platform_get_drvdata(pdev);
233 	struct device_node *node = pdev->dev.of_node;
234 	struct omap_dss_device *in;
235 	struct device_node *adapter_node;
236 	struct i2c_adapter *adapter;
237 
238 	in = omapdss_of_find_source_for_first_ep(node);
239 	if (IS_ERR(in)) {
240 		dev_err(&pdev->dev, "failed to find video source\n");
241 		return PTR_ERR(in);
242 	}
243 
244 	ddata->in = in;
245 
246 	adapter_node = of_parse_phandle(node, "ddc-i2c-bus", 0);
247 	if (adapter_node) {
248 		adapter = of_get_i2c_adapter_by_node(adapter_node);
249 		of_node_put(adapter_node);
250 		if (adapter == NULL) {
251 			dev_err(&pdev->dev, "failed to parse ddc-i2c-bus\n");
252 			omap_dss_put_device(ddata->in);
253 			return -EPROBE_DEFER;
254 		}
255 
256 		ddata->i2c_adapter = adapter;
257 	}
258 
259 	return 0;
260 }
261 
262 static int dvic_probe(struct platform_device *pdev)
263 {
264 	struct panel_drv_data *ddata;
265 	struct omap_dss_device *dssdev;
266 	int r;
267 
268 	if (!pdev->dev.of_node)
269 		return -ENODEV;
270 
271 	ddata = devm_kzalloc(&pdev->dev, sizeof(*ddata), GFP_KERNEL);
272 	if (!ddata)
273 		return -ENOMEM;
274 
275 	platform_set_drvdata(pdev, ddata);
276 
277 	r = dvic_probe_of(pdev);
278 	if (r)
279 		return r;
280 
281 	ddata->timings = dvic_default_timings;
282 
283 	dssdev = &ddata->dssdev;
284 	dssdev->driver = &dvic_driver;
285 	dssdev->dev = &pdev->dev;
286 	dssdev->type = OMAP_DISPLAY_TYPE_DVI;
287 	dssdev->owner = THIS_MODULE;
288 	dssdev->panel.timings = dvic_default_timings;
289 
290 	r = omapdss_register_display(dssdev);
291 	if (r) {
292 		dev_err(&pdev->dev, "Failed to register panel\n");
293 		goto err_reg;
294 	}
295 
296 	return 0;
297 
298 err_reg:
299 	omap_dss_put_device(ddata->in);
300 
301 	i2c_put_adapter(ddata->i2c_adapter);
302 
303 	return r;
304 }
305 
306 static int __exit dvic_remove(struct platform_device *pdev)
307 {
308 	struct panel_drv_data *ddata = platform_get_drvdata(pdev);
309 	struct omap_dss_device *dssdev = &ddata->dssdev;
310 	struct omap_dss_device *in = ddata->in;
311 
312 	omapdss_unregister_display(&ddata->dssdev);
313 
314 	dvic_disable(dssdev);
315 	dvic_disconnect(dssdev);
316 
317 	omap_dss_put_device(in);
318 
319 	i2c_put_adapter(ddata->i2c_adapter);
320 
321 	return 0;
322 }
323 
324 static const struct of_device_id dvic_of_match[] = {
325 	{ .compatible = "omapdss,dvi-connector", },
326 	{},
327 };
328 
329 MODULE_DEVICE_TABLE(of, dvic_of_match);
330 
331 static struct platform_driver dvi_connector_driver = {
332 	.probe	= dvic_probe,
333 	.remove	= __exit_p(dvic_remove),
334 	.driver	= {
335 		.name	= "connector-dvi",
336 		.of_match_table = dvic_of_match,
337 		.suppress_bind_attrs = true,
338 	},
339 };
340 
341 module_platform_driver(dvi_connector_driver);
342 
343 MODULE_AUTHOR("Tomi Valkeinen <tomi.valkeinen@ti.com>");
344 MODULE_DESCRIPTION("Generic DVI Connector driver");
345 MODULE_LICENSE("GPL");
346