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#include <video/omap-panel-data.h>
 19
 20#include "../dss/omapdss.h"
 21
 22static const struct videomode dvic_default_vm = {
 23	.hactive	= 640,
 24	.vactive	= 480,
 25
 26	.pixelclock	= 23500000,
 27
 28	.hfront_porch	= 48,
 29	.hsync_len	= 32,
 30	.hback_porch	= 80,
 31
 32	.vfront_porch	= 3,
 33	.vsync_len	= 4,
 34	.vback_porch	= 7,
 35
 36	.flags		= DISPLAY_FLAGS_HSYNC_HIGH | DISPLAY_FLAGS_VSYNC_HIGH |
 37			  DISPLAY_FLAGS_SYNC_NEGEDGE | DISPLAY_FLAGS_DE_HIGH |
 38			  DISPLAY_FLAGS_PIXDATA_POSEDGE,
 39};
 40
 41struct panel_drv_data {
 42	struct omap_dss_device dssdev;
 43	struct omap_dss_device *in;
 44
 45	struct videomode vm;
 46
 47	struct i2c_adapter *i2c_adapter;
 48};
 49
 50#define to_panel_data(x) container_of(x, struct panel_drv_data, dssdev)
 51
 52static int dvic_connect(struct omap_dss_device *dssdev)
 53{
 54	struct panel_drv_data *ddata = to_panel_data(dssdev);
 55	struct omap_dss_device *in = ddata->in;
 56	int r;
 57
 58	if (omapdss_device_is_connected(dssdev))
 59		return 0;
 60
 61	r = in->ops.dvi->connect(in, dssdev);
 62	if (r)
 63		return r;
 64
 65	return 0;
 66}
 67
 68static void dvic_disconnect(struct omap_dss_device *dssdev)
 69{
 70	struct panel_drv_data *ddata = to_panel_data(dssdev);
 71	struct omap_dss_device *in = ddata->in;
 72
 73	if (!omapdss_device_is_connected(dssdev))
 74		return;
 75
 76	in->ops.dvi->disconnect(in, dssdev);
 77}
 78
 79static int dvic_enable(struct omap_dss_device *dssdev)
 80{
 81	struct panel_drv_data *ddata = to_panel_data(dssdev);
 82	struct omap_dss_device *in = ddata->in;
 83	int r;
 84
 85	if (!omapdss_device_is_connected(dssdev))
 86		return -ENODEV;
 87
 88	if (omapdss_device_is_enabled(dssdev))
 89		return 0;
 90
 91	in->ops.dvi->set_timings(in, &ddata->vm);
 92
 93	r = in->ops.dvi->enable(in);
 94	if (r)
 95		return r;
 96
 97	dssdev->state = OMAP_DSS_DISPLAY_ACTIVE;
 98
 99	return 0;
100}
101
102static void dvic_disable(struct omap_dss_device *dssdev)
103{
104	struct panel_drv_data *ddata = to_panel_data(dssdev);
105	struct omap_dss_device *in = ddata->in;
106
107	if (!omapdss_device_is_enabled(dssdev))
108		return;
109
110	in->ops.dvi->disable(in);
111
112	dssdev->state = OMAP_DSS_DISPLAY_DISABLED;
113}
114
115static void dvic_set_timings(struct omap_dss_device *dssdev,
116			     struct videomode *vm)
117{
118	struct panel_drv_data *ddata = to_panel_data(dssdev);
119	struct omap_dss_device *in = ddata->in;
120
121	ddata->vm = *vm;
122	dssdev->panel.vm = *vm;
123
124	in->ops.dvi->set_timings(in, vm);
125}
126
127static void dvic_get_timings(struct omap_dss_device *dssdev,
128			     struct videomode *vm)
129{
130	struct panel_drv_data *ddata = to_panel_data(dssdev);
131
132	*vm = ddata->vm;
133}
134
135static int dvic_check_timings(struct omap_dss_device *dssdev,
136			      struct videomode *vm)
137{
138	struct panel_drv_data *ddata = to_panel_data(dssdev);
139	struct omap_dss_device *in = ddata->in;
140
141	return in->ops.dvi->check_timings(in, vm);
142}
143
144static int dvic_ddc_read(struct i2c_adapter *adapter,
145		unsigned char *buf, u16 count, u8 offset)
146{
147	int r, retries;
148
149	for (retries = 3; retries > 0; retries--) {
150		struct i2c_msg msgs[] = {
151			{
152				.addr   = DDC_ADDR,
153				.flags  = 0,
154				.len    = 1,
155				.buf    = &offset,
156			}, {
157				.addr   = DDC_ADDR,
158				.flags  = I2C_M_RD,
159				.len    = count,
160				.buf    = buf,
161			}
162		};
163
164		r = i2c_transfer(adapter, msgs, 2);
165		if (r == 2)
166			return 0;
167
168		if (r != -EAGAIN)
169			break;
170	}
171
172	return r < 0 ? r : -EIO;
173}
174
175static int dvic_read_edid(struct omap_dss_device *dssdev,
176		u8 *edid, int len)
177{
178	struct panel_drv_data *ddata = to_panel_data(dssdev);
179	int r, l, bytes_read;
180
181	if (!ddata->i2c_adapter)
182		return -ENODEV;
183
184	l = min(EDID_LENGTH, len);
185	r = dvic_ddc_read(ddata->i2c_adapter, edid, l, 0);
186	if (r)
187		return r;
188
189	bytes_read = l;
190
191	/* if there are extensions, read second block */
192	if (len > EDID_LENGTH && edid[0x7e] > 0) {
193		l = min(EDID_LENGTH, len - EDID_LENGTH);
194
195		r = dvic_ddc_read(ddata->i2c_adapter, edid + EDID_LENGTH,
196				l, EDID_LENGTH);
197		if (r)
198			return r;
199
200		bytes_read += l;
201	}
202
203	return bytes_read;
204}
205
206static bool dvic_detect(struct omap_dss_device *dssdev)
207{
208	struct panel_drv_data *ddata = to_panel_data(dssdev);
209	unsigned char out;
210	int r;
211
212	if (!ddata->i2c_adapter)
213		return true;
214
215	r = dvic_ddc_read(ddata->i2c_adapter, &out, 1, 0);
216
217	return r == 0;
218}
219
220static struct omap_dss_driver dvic_driver = {
221	.connect	= dvic_connect,
222	.disconnect	= dvic_disconnect,
223
224	.enable		= dvic_enable,
225	.disable	= dvic_disable,
226
227	.set_timings	= dvic_set_timings,
228	.get_timings	= dvic_get_timings,
229	.check_timings	= dvic_check_timings,
230
231	.get_resolution	= omapdss_default_get_resolution,
232
233	.read_edid	= dvic_read_edid,
234	.detect		= dvic_detect,
235};
236
237static int dvic_probe_of(struct platform_device *pdev)
238{
239	struct panel_drv_data *ddata = platform_get_drvdata(pdev);
240	struct device_node *node = pdev->dev.of_node;
241	struct omap_dss_device *in;
242	struct device_node *adapter_node;
243	struct i2c_adapter *adapter;
244
245	in = omapdss_of_find_source_for_first_ep(node);
246	if (IS_ERR(in)) {
247		dev_err(&pdev->dev, "failed to find video source\n");
248		return PTR_ERR(in);
249	}
250
251	ddata->in = in;
252
253	adapter_node = of_parse_phandle(node, "ddc-i2c-bus", 0);
254	if (adapter_node) {
255		adapter = of_get_i2c_adapter_by_node(adapter_node);
256		of_node_put(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
269static 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	ddata = devm_kzalloc(&pdev->dev, sizeof(*ddata), GFP_KERNEL);
276	if (!ddata)
277		return -ENOMEM;
278
279	platform_set_drvdata(pdev, ddata);
280
281	if (!pdev->dev.of_node)
282		return -ENODEV;
283
284	r = dvic_probe_of(pdev);
285	if (r)
286		return r;
287
288	ddata->vm = dvic_default_vm;
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.vm = dvic_default_vm;
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
305err_reg:
306	omap_dss_put_device(ddata->in);
307
308	i2c_put_adapter(ddata->i2c_adapter);
309
310	return r;
311}
312
313static 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
331static const struct of_device_id dvic_of_match[] = {
332	{ .compatible = "omapdss,dvi-connector", },
333	{},
334};
335
336MODULE_DEVICE_TABLE(of, dvic_of_match);
337
338static 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
348module_platform_driver(dvi_connector_driver);
349
350MODULE_AUTHOR("Tomi Valkeinen <tomi.valkeinen@ti.com>");
351MODULE_DESCRIPTION("Generic DVI Connector driver");
352MODULE_LICENSE("GPL");