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_FALLING_EDGE,
 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_of(struct platform_device *pdev)
240{
241	struct panel_drv_data *ddata = platform_get_drvdata(pdev);
242	struct device_node *node = pdev->dev.of_node;
243	struct omap_dss_device *in;
244	struct device_node *adapter_node;
245	struct i2c_adapter *adapter;
246
247	in = omapdss_of_find_source_for_first_ep(node);
248	if (IS_ERR(in)) {
249		dev_err(&pdev->dev, "failed to find video source\n");
250		return PTR_ERR(in);
251	}
252
253	ddata->in = in;
254
255	adapter_node = of_parse_phandle(node, "ddc-i2c-bus", 0);
256	if (adapter_node) {
257		adapter = of_get_i2c_adapter_by_node(adapter_node);
258		if (adapter == NULL) {
259			dev_err(&pdev->dev, "failed to parse ddc-i2c-bus\n");
260			omap_dss_put_device(ddata->in);
261			return -EPROBE_DEFER;
262		}
263
264		ddata->i2c_adapter = adapter;
265	}
266
267	return 0;
268}
269
270static int dvic_probe(struct platform_device *pdev)
271{
272	struct panel_drv_data *ddata;
273	struct omap_dss_device *dssdev;
274	int r;
275
276	ddata = devm_kzalloc(&pdev->dev, sizeof(*ddata), GFP_KERNEL);
277	if (!ddata)
278		return -ENOMEM;
279
280	platform_set_drvdata(pdev, ddata);
281
282	if (!pdev->dev.of_node)
283		return -ENODEV;
284
285	r = dvic_probe_of(pdev);
286	if (r)
287		return r;
288
289	ddata->timings = dvic_default_timings;
290
291	dssdev = &ddata->dssdev;
292	dssdev->driver = &dvic_driver;
293	dssdev->dev = &pdev->dev;
294	dssdev->type = OMAP_DISPLAY_TYPE_DVI;
295	dssdev->owner = THIS_MODULE;
296	dssdev->panel.timings = dvic_default_timings;
297
298	r = omapdss_register_display(dssdev);
299	if (r) {
300		dev_err(&pdev->dev, "Failed to register panel\n");
301		goto err_reg;
302	}
303
304	return 0;
305
306err_reg:
307	omap_dss_put_device(ddata->in);
308
309	i2c_put_adapter(ddata->i2c_adapter);
310
311	return r;
312}
313
314static int __exit dvic_remove(struct platform_device *pdev)
315{
316	struct panel_drv_data *ddata = platform_get_drvdata(pdev);
317	struct omap_dss_device *dssdev = &ddata->dssdev;
318	struct omap_dss_device *in = ddata->in;
319
320	omapdss_unregister_display(&ddata->dssdev);
321
322	dvic_disable(dssdev);
323	dvic_disconnect(dssdev);
324
325	omap_dss_put_device(in);
326
327	i2c_put_adapter(ddata->i2c_adapter);
328
329	return 0;
330}
331
332static const struct of_device_id dvic_of_match[] = {
333	{ .compatible = "omapdss,dvi-connector", },
334	{},
335};
336
337MODULE_DEVICE_TABLE(of, dvic_of_match);
338
339static struct platform_driver dvi_connector_driver = {
340	.probe	= dvic_probe,
341	.remove	= __exit_p(dvic_remove),
342	.driver	= {
343		.name	= "connector-dvi",
344		.of_match_table = dvic_of_match,
345		.suppress_bind_attrs = true,
346	},
347};
348
349module_platform_driver(dvi_connector_driver);
350
351MODULE_AUTHOR("Tomi Valkeinen <tomi.valkeinen@ti.com>");
352MODULE_DESCRIPTION("Generic DVI Connector driver");
353MODULE_LICENSE("GPL");