1/*
  2 * Generic DVI Connector driver
  3 *
  4 * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com/
  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/gpio/consumer.h>
 13#include <linux/i2c.h>
 14#include <linux/module.h>
 15#include <linux/platform_device.h>
 16#include <linux/slab.h>
 17
 18#include <drm/drm_edid.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	struct gpio_desc *hpd_gpio;
 50
 51	void (*hpd_cb)(void *cb_data, enum drm_connector_status status);
 52	void *hpd_cb_data;
 53	bool hpd_enabled;
 54	/* mutex for hpd fields above */
 55	struct mutex hpd_lock;
 56};
 57
 58#define to_panel_data(x) container_of(x, struct panel_drv_data, dssdev)
 59
 60static int dvic_connect(struct omap_dss_device *dssdev)
 61{
 62	struct panel_drv_data *ddata = to_panel_data(dssdev);
 63	struct omap_dss_device *in;
 64	int r;
 65
 66	if (omapdss_device_is_connected(dssdev))
 67		return 0;
 68
 69	in = omapdss_of_find_source_for_first_ep(dssdev->dev->of_node);
 70	if (IS_ERR(in)) {
 71		dev_err(dssdev->dev, "failed to find video source\n");
 72		return PTR_ERR(in);
 73	}
 74
 75	r = in->ops.dvi->connect(in, dssdev);
 76	if (r) {
 77		omap_dss_put_device(in);
 78		return r;
 79	}
 80
 81	ddata->in = in;
 82	return 0;
 83}
 84
 85static void dvic_disconnect(struct omap_dss_device *dssdev)
 86{
 87	struct panel_drv_data *ddata = to_panel_data(dssdev);
 88	struct omap_dss_device *in = ddata->in;
 89
 90	if (!omapdss_device_is_connected(dssdev))
 91		return;
 92
 93	in->ops.dvi->disconnect(in, dssdev);
 94
 95	omap_dss_put_device(in);
 96	ddata->in = NULL;
 97}
 98
 99static int dvic_enable(struct omap_dss_device *dssdev)
100{
101	struct panel_drv_data *ddata = to_panel_data(dssdev);
102	struct omap_dss_device *in = ddata->in;
103	int r;
104
105	if (!omapdss_device_is_connected(dssdev))
106		return -ENODEV;
107
108	if (omapdss_device_is_enabled(dssdev))
109		return 0;
110
111	in->ops.dvi->set_timings(in, &ddata->vm);
112
113	r = in->ops.dvi->enable(in);
114	if (r)
115		return r;
116
117	dssdev->state = OMAP_DSS_DISPLAY_ACTIVE;
118
119	return 0;
120}
121
122static void dvic_disable(struct omap_dss_device *dssdev)
123{
124	struct panel_drv_data *ddata = to_panel_data(dssdev);
125	struct omap_dss_device *in = ddata->in;
126
127	if (!omapdss_device_is_enabled(dssdev))
128		return;
129
130	in->ops.dvi->disable(in);
131
132	dssdev->state = OMAP_DSS_DISPLAY_DISABLED;
133}
134
135static void dvic_set_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	ddata->vm = *vm;
142	dssdev->panel.vm = *vm;
143
144	in->ops.dvi->set_timings(in, vm);
145}
146
147static void dvic_get_timings(struct omap_dss_device *dssdev,
148			     struct videomode *vm)
149{
150	struct panel_drv_data *ddata = to_panel_data(dssdev);
151
152	*vm = ddata->vm;
153}
154
155static int dvic_check_timings(struct omap_dss_device *dssdev,
156			      struct videomode *vm)
157{
158	struct panel_drv_data *ddata = to_panel_data(dssdev);
159	struct omap_dss_device *in = ddata->in;
160
161	return in->ops.dvi->check_timings(in, vm);
162}
163
164static int dvic_ddc_read(struct i2c_adapter *adapter,
165		unsigned char *buf, u16 count, u8 offset)
166{
167	int r, retries;
168
169	for (retries = 3; retries > 0; retries--) {
170		struct i2c_msg msgs[] = {
171			{
172				.addr   = DDC_ADDR,
173				.flags  = 0,
174				.len    = 1,
175				.buf    = &offset,
176			}, {
177				.addr   = DDC_ADDR,
178				.flags  = I2C_M_RD,
179				.len    = count,
180				.buf    = buf,
181			}
182		};
183
184		r = i2c_transfer(adapter, msgs, 2);
185		if (r == 2)
186			return 0;
187
188		if (r != -EAGAIN)
189			break;
190	}
191
192	return r < 0 ? r : -EIO;
193}
194
195static int dvic_read_edid(struct omap_dss_device *dssdev,
196		u8 *edid, int len)
197{
198	struct panel_drv_data *ddata = to_panel_data(dssdev);
199	int r, l, bytes_read;
200
201	if (ddata->hpd_gpio && !gpiod_get_value_cansleep(ddata->hpd_gpio))
202		return -ENODEV;
203
204	if (!ddata->i2c_adapter)
205		return -ENODEV;
206
207	l = min(EDID_LENGTH, len);
208	r = dvic_ddc_read(ddata->i2c_adapter, edid, l, 0);
209	if (r)
210		return r;
211
212	bytes_read = l;
213
214	/* if there are extensions, read second block */
215	if (len > EDID_LENGTH && edid[0x7e] > 0) {
216		l = min(EDID_LENGTH, len - EDID_LENGTH);
217
218		r = dvic_ddc_read(ddata->i2c_adapter, edid + EDID_LENGTH,
219				l, EDID_LENGTH);
220		if (r)
221			return r;
222
223		bytes_read += l;
224	}
225
226	return bytes_read;
227}
228
229static bool dvic_detect(struct omap_dss_device *dssdev)
230{
231	struct panel_drv_data *ddata = to_panel_data(dssdev);
232	unsigned char out;
233	int r;
234
235	if (ddata->hpd_gpio)
236		return gpiod_get_value_cansleep(ddata->hpd_gpio);
237
238	if (!ddata->i2c_adapter)
239		return true;
240
241	r = dvic_ddc_read(ddata->i2c_adapter, &out, 1, 0);
242
243	return r == 0;
244}
245
246static int dvic_register_hpd_cb(struct omap_dss_device *dssdev,
247				 void (*cb)(void *cb_data,
248					    enum drm_connector_status status),
249				 void *cb_data)
250{
251	struct panel_drv_data *ddata = to_panel_data(dssdev);
252
253	if (!ddata->hpd_gpio)
254		return -ENOTSUPP;
255
256	mutex_lock(&ddata->hpd_lock);
257	ddata->hpd_cb = cb;
258	ddata->hpd_cb_data = cb_data;
259	mutex_unlock(&ddata->hpd_lock);
260	return 0;
261}
262
263static void dvic_unregister_hpd_cb(struct omap_dss_device *dssdev)
264{
265	struct panel_drv_data *ddata = to_panel_data(dssdev);
266
267	if (!ddata->hpd_gpio)
268		return;
269
270	mutex_lock(&ddata->hpd_lock);
271	ddata->hpd_cb = NULL;
272	ddata->hpd_cb_data = NULL;
273	mutex_unlock(&ddata->hpd_lock);
274}
275
276static void dvic_enable_hpd(struct omap_dss_device *dssdev)
277{
278	struct panel_drv_data *ddata = to_panel_data(dssdev);
279
280	if (!ddata->hpd_gpio)
281		return;
282
283	mutex_lock(&ddata->hpd_lock);
284	ddata->hpd_enabled = true;
285	mutex_unlock(&ddata->hpd_lock);
286}
287
288static void dvic_disable_hpd(struct omap_dss_device *dssdev)
289{
290	struct panel_drv_data *ddata = to_panel_data(dssdev);
291
292	if (!ddata->hpd_gpio)
293		return;
294
295	mutex_lock(&ddata->hpd_lock);
296	ddata->hpd_enabled = false;
297	mutex_unlock(&ddata->hpd_lock);
298}
299
300static struct omap_dss_driver dvic_driver = {
301	.connect	= dvic_connect,
302	.disconnect	= dvic_disconnect,
303
304	.enable		= dvic_enable,
305	.disable	= dvic_disable,
306
307	.set_timings	= dvic_set_timings,
308	.get_timings	= dvic_get_timings,
309	.check_timings	= dvic_check_timings,
310
311	.read_edid	= dvic_read_edid,
312	.detect		= dvic_detect,
313
314	.register_hpd_cb	= dvic_register_hpd_cb,
315	.unregister_hpd_cb	= dvic_unregister_hpd_cb,
316	.enable_hpd		= dvic_enable_hpd,
317	.disable_hpd		= dvic_disable_hpd,
318};
319
320static irqreturn_t dvic_hpd_isr(int irq, void *data)
321{
322	struct panel_drv_data *ddata = data;
323
324	mutex_lock(&ddata->hpd_lock);
325	if (ddata->hpd_enabled && ddata->hpd_cb) {
326		enum drm_connector_status status;
327
328		if (dvic_detect(&ddata->dssdev))
329			status = connector_status_connected;
330		else
331			status = connector_status_disconnected;
332
333		ddata->hpd_cb(ddata->hpd_cb_data, status);
334	}
335	mutex_unlock(&ddata->hpd_lock);
336
337	return IRQ_HANDLED;
338}
339
340static int dvic_probe_of(struct platform_device *pdev)
341{
342	struct panel_drv_data *ddata = platform_get_drvdata(pdev);
343	struct device_node *node = pdev->dev.of_node;
344	struct device_node *adapter_node;
345	struct i2c_adapter *adapter;
346	struct gpio_desc *gpio;
347	int r;
348
349	gpio = devm_gpiod_get_optional(&pdev->dev, "hpd", GPIOD_IN);
350	if (IS_ERR(gpio)) {
351		dev_err(&pdev->dev, "failed to parse HPD gpio\n");
352		return PTR_ERR(gpio);
353	}
354
355	ddata->hpd_gpio = gpio;
356
357	mutex_init(&ddata->hpd_lock);
358
359	if (ddata->hpd_gpio) {
360		r = devm_request_threaded_irq(&pdev->dev,
361			gpiod_to_irq(ddata->hpd_gpio), NULL, dvic_hpd_isr,
362			IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
363			"DVI HPD", ddata);
364		if (r)
365			return r;
366	}
367
368	adapter_node = of_parse_phandle(node, "ddc-i2c-bus", 0);
369	if (adapter_node) {
370		adapter = of_get_i2c_adapter_by_node(adapter_node);
371		of_node_put(adapter_node);
372		if (adapter == NULL) {
373			dev_err(&pdev->dev, "failed to parse ddc-i2c-bus\n");
374			return -EPROBE_DEFER;
375		}
376
377		ddata->i2c_adapter = adapter;
378	}
379
380	return 0;
381}
382
383static int dvic_probe(struct platform_device *pdev)
384{
385	struct panel_drv_data *ddata;
386	struct omap_dss_device *dssdev;
387	int r;
388
389	ddata = devm_kzalloc(&pdev->dev, sizeof(*ddata), GFP_KERNEL);
390	if (!ddata)
391		return -ENOMEM;
392
393	platform_set_drvdata(pdev, ddata);
394
395	r = dvic_probe_of(pdev);
396	if (r)
397		return r;
398
399	ddata->vm = dvic_default_vm;
400
401	dssdev = &ddata->dssdev;
402	dssdev->driver = &dvic_driver;
403	dssdev->dev = &pdev->dev;
404	dssdev->type = OMAP_DISPLAY_TYPE_DVI;
405	dssdev->owner = THIS_MODULE;
406	dssdev->panel.vm = dvic_default_vm;
407
408	r = omapdss_register_display(dssdev);
409	if (r) {
410		dev_err(&pdev->dev, "Failed to register panel\n");
411		goto err_reg;
412	}
413
414	return 0;
415
416err_reg:
417	i2c_put_adapter(ddata->i2c_adapter);
418	mutex_destroy(&ddata->hpd_lock);
419
420	return r;
421}
422
423static int __exit dvic_remove(struct platform_device *pdev)
424{
425	struct panel_drv_data *ddata = platform_get_drvdata(pdev);
426	struct omap_dss_device *dssdev = &ddata->dssdev;
427
428	omapdss_unregister_display(&ddata->dssdev);
429
430	dvic_disable(dssdev);
431	dvic_disconnect(dssdev);
432
433	i2c_put_adapter(ddata->i2c_adapter);
434
435	mutex_destroy(&ddata->hpd_lock);
436
437	return 0;
438}
439
440static const struct of_device_id dvic_of_match[] = {
441	{ .compatible = "omapdss,dvi-connector", },
442	{},
443};
444
445MODULE_DEVICE_TABLE(of, dvic_of_match);
446
447static struct platform_driver dvi_connector_driver = {
448	.probe	= dvic_probe,
449	.remove	= __exit_p(dvic_remove),
450	.driver	= {
451		.name	= "connector-dvi",
452		.of_match_table = dvic_of_match,
453		.suppress_bind_attrs = true,
454	},
455};
456
457module_platform_driver(dvi_connector_driver);
458
459MODULE_AUTHOR("Tomi Valkeinen <tomi.valkeinen@ti.com>");
460MODULE_DESCRIPTION("Generic DVI Connector driver");
461MODULE_LICENSE("GPL");