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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2016 Texas Instruments
4 * Author: Jyri Sarha <jsarha@ti.com>
5 */
6
7#include <linux/gpio/consumer.h>
8#include <linux/i2c.h>
9#include <linux/media-bus-format.h>
10#include <linux/module.h>
11#include <linux/of_graph.h>
12#include <linux/platform_device.h>
13#include <linux/workqueue.h>
14
15#include <drm/drm_atomic_helper.h>
16#include <drm/drm_bridge.h>
17#include <drm/drm_crtc.h>
18#include <drm/drm_edid.h>
19#include <drm/drm_print.h>
20#include <drm/drm_probe_helper.h>
21
22#define HOTPLUG_DEBOUNCE_MS 1100
23
24struct tfp410 {
25 struct drm_bridge bridge;
26 struct drm_connector connector;
27
28 u32 bus_format;
29 struct delayed_work hpd_work;
30 struct gpio_desc *powerdown;
31
32 struct drm_bridge_timings timings;
33 struct drm_bridge *next_bridge;
34
35 struct device *dev;
36};
37
38static inline struct tfp410 *
39drm_bridge_to_tfp410(struct drm_bridge *bridge)
40{
41 return container_of(bridge, struct tfp410, bridge);
42}
43
44static inline struct tfp410 *
45drm_connector_to_tfp410(struct drm_connector *connector)
46{
47 return container_of(connector, struct tfp410, connector);
48}
49
50static int tfp410_get_modes(struct drm_connector *connector)
51{
52 struct tfp410 *dvi = drm_connector_to_tfp410(connector);
53 const struct drm_edid *drm_edid;
54 int ret;
55
56 if (dvi->next_bridge->ops & DRM_BRIDGE_OP_EDID) {
57 drm_edid = drm_bridge_edid_read(dvi->next_bridge, connector);
58 if (!drm_edid)
59 DRM_INFO("EDID read failed. Fallback to standard modes\n");
60 } else {
61 drm_edid = NULL;
62 }
63
64 drm_edid_connector_update(connector, drm_edid);
65
66 if (!drm_edid) {
67 /*
68 * No EDID, fallback on the XGA standard modes and prefer a mode
69 * pretty much anything can handle.
70 */
71 ret = drm_add_modes_noedid(connector, 1920, 1200);
72 drm_set_preferred_mode(connector, 1024, 768);
73 return ret;
74 }
75
76 ret = drm_edid_connector_add_modes(connector);
77
78 drm_edid_free(drm_edid);
79
80 return ret;
81}
82
83static const struct drm_connector_helper_funcs tfp410_con_helper_funcs = {
84 .get_modes = tfp410_get_modes,
85};
86
87static enum drm_connector_status
88tfp410_connector_detect(struct drm_connector *connector, bool force)
89{
90 struct tfp410 *dvi = drm_connector_to_tfp410(connector);
91
92 return drm_bridge_detect(dvi->next_bridge);
93}
94
95static const struct drm_connector_funcs tfp410_con_funcs = {
96 .detect = tfp410_connector_detect,
97 .fill_modes = drm_helper_probe_single_connector_modes,
98 .destroy = drm_connector_cleanup,
99 .reset = drm_atomic_helper_connector_reset,
100 .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
101 .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
102};
103
104static void tfp410_hpd_work_func(struct work_struct *work)
105{
106 struct tfp410 *dvi;
107
108 dvi = container_of(work, struct tfp410, hpd_work.work);
109
110 if (dvi->bridge.dev)
111 drm_helper_hpd_irq_event(dvi->bridge.dev);
112}
113
114static void tfp410_hpd_callback(void *arg, enum drm_connector_status status)
115{
116 struct tfp410 *dvi = arg;
117
118 mod_delayed_work(system_wq, &dvi->hpd_work,
119 msecs_to_jiffies(HOTPLUG_DEBOUNCE_MS));
120}
121
122static int tfp410_attach(struct drm_bridge *bridge,
123 enum drm_bridge_attach_flags flags)
124{
125 struct tfp410 *dvi = drm_bridge_to_tfp410(bridge);
126 int ret;
127
128 ret = drm_bridge_attach(bridge->encoder, dvi->next_bridge, bridge,
129 DRM_BRIDGE_ATTACH_NO_CONNECTOR);
130 if (ret < 0)
131 return ret;
132
133 if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)
134 return 0;
135
136 if (dvi->next_bridge->ops & DRM_BRIDGE_OP_DETECT)
137 dvi->connector.polled = DRM_CONNECTOR_POLL_HPD;
138 else
139 dvi->connector.polled = DRM_CONNECTOR_POLL_CONNECT | DRM_CONNECTOR_POLL_DISCONNECT;
140
141 if (dvi->next_bridge->ops & DRM_BRIDGE_OP_HPD) {
142 INIT_DELAYED_WORK(&dvi->hpd_work, tfp410_hpd_work_func);
143 drm_bridge_hpd_enable(dvi->next_bridge, tfp410_hpd_callback,
144 dvi);
145 }
146
147 drm_connector_helper_add(&dvi->connector,
148 &tfp410_con_helper_funcs);
149 ret = drm_connector_init_with_ddc(bridge->dev, &dvi->connector,
150 &tfp410_con_funcs,
151 dvi->next_bridge->type,
152 dvi->next_bridge->ddc);
153 if (ret) {
154 dev_err(dvi->dev, "drm_connector_init_with_ddc() failed: %d\n",
155 ret);
156 return ret;
157 }
158
159 drm_display_info_set_bus_formats(&dvi->connector.display_info,
160 &dvi->bus_format, 1);
161
162 drm_connector_attach_encoder(&dvi->connector, bridge->encoder);
163
164 return 0;
165}
166
167static void tfp410_detach(struct drm_bridge *bridge)
168{
169 struct tfp410 *dvi = drm_bridge_to_tfp410(bridge);
170
171 if (dvi->connector.dev && dvi->next_bridge->ops & DRM_BRIDGE_OP_HPD) {
172 drm_bridge_hpd_disable(dvi->next_bridge);
173 cancel_delayed_work_sync(&dvi->hpd_work);
174 }
175}
176
177static void tfp410_enable(struct drm_bridge *bridge)
178{
179 struct tfp410 *dvi = drm_bridge_to_tfp410(bridge);
180
181 gpiod_set_value_cansleep(dvi->powerdown, 0);
182}
183
184static void tfp410_disable(struct drm_bridge *bridge)
185{
186 struct tfp410 *dvi = drm_bridge_to_tfp410(bridge);
187
188 gpiod_set_value_cansleep(dvi->powerdown, 1);
189}
190
191static enum drm_mode_status tfp410_mode_valid(struct drm_bridge *bridge,
192 const struct drm_display_info *info,
193 const struct drm_display_mode *mode)
194{
195 if (mode->clock < 25000)
196 return MODE_CLOCK_LOW;
197
198 if (mode->clock > 165000)
199 return MODE_CLOCK_HIGH;
200
201 return MODE_OK;
202}
203
204static u32 *tfp410_get_input_bus_fmts(struct drm_bridge *bridge,
205 struct drm_bridge_state *bridge_state,
206 struct drm_crtc_state *crtc_state,
207 struct drm_connector_state *conn_state,
208 u32 output_fmt,
209 unsigned int *num_input_fmts)
210{
211 struct tfp410 *dvi = drm_bridge_to_tfp410(bridge);
212 u32 *input_fmts;
213
214 *num_input_fmts = 0;
215
216 input_fmts = kzalloc(sizeof(*input_fmts), GFP_KERNEL);
217 if (!input_fmts)
218 return NULL;
219
220 *num_input_fmts = 1;
221 input_fmts[0] = dvi->bus_format;
222
223 return input_fmts;
224}
225
226static int tfp410_atomic_check(struct drm_bridge *bridge,
227 struct drm_bridge_state *bridge_state,
228 struct drm_crtc_state *crtc_state,
229 struct drm_connector_state *conn_state)
230{
231 struct tfp410 *dvi = drm_bridge_to_tfp410(bridge);
232
233 /*
234 * There might be flags negotiation supported in future.
235 * Set the bus flags in atomic_check statically for now.
236 */
237 bridge_state->input_bus_cfg.flags = dvi->timings.input_bus_flags;
238
239 return 0;
240}
241
242static const struct drm_bridge_funcs tfp410_bridge_funcs = {
243 .attach = tfp410_attach,
244 .detach = tfp410_detach,
245 .enable = tfp410_enable,
246 .disable = tfp410_disable,
247 .mode_valid = tfp410_mode_valid,
248 .atomic_reset = drm_atomic_helper_bridge_reset,
249 .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
250 .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
251 .atomic_get_input_bus_fmts = tfp410_get_input_bus_fmts,
252 .atomic_check = tfp410_atomic_check,
253};
254
255static const struct drm_bridge_timings tfp410_default_timings = {
256 .input_bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE
257 | DRM_BUS_FLAG_DE_HIGH,
258 .setup_time_ps = 1200,
259 .hold_time_ps = 1300,
260};
261
262static int tfp410_parse_timings(struct tfp410 *dvi, bool i2c)
263{
264 struct drm_bridge_timings *timings = &dvi->timings;
265 struct device_node *ep;
266 u32 pclk_sample = 0;
267 u32 bus_width = 24;
268 u32 deskew = 0;
269
270 /* Start with defaults. */
271 *timings = tfp410_default_timings;
272
273 if (i2c)
274 /*
275 * In I2C mode timings are configured through the I2C interface.
276 * As the driver doesn't support I2C configuration yet, we just
277 * go with the defaults (BSEL=1, DSEL=1, DKEN=0, EDGE=1).
278 */
279 return 0;
280
281 /*
282 * In non-I2C mode, timings are configured through the BSEL, DSEL, DKEN
283 * and EDGE pins. They are specified in DT through endpoint properties
284 * and vendor-specific properties.
285 */
286 ep = of_graph_get_endpoint_by_regs(dvi->dev->of_node, 0, 0);
287 if (!ep)
288 return -EINVAL;
289
290 /* Get the sampling edge from the endpoint. */
291 of_property_read_u32(ep, "pclk-sample", &pclk_sample);
292 of_property_read_u32(ep, "bus-width", &bus_width);
293 of_node_put(ep);
294
295 timings->input_bus_flags = DRM_BUS_FLAG_DE_HIGH;
296
297 switch (pclk_sample) {
298 case 0:
299 timings->input_bus_flags |= DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE
300 | DRM_BUS_FLAG_SYNC_SAMPLE_NEGEDGE;
301 break;
302 case 1:
303 timings->input_bus_flags |= DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE
304 | DRM_BUS_FLAG_SYNC_SAMPLE_POSEDGE;
305 break;
306 default:
307 return -EINVAL;
308 }
309
310 switch (bus_width) {
311 case 12:
312 dvi->bus_format = MEDIA_BUS_FMT_RGB888_2X12_LE;
313 break;
314 case 24:
315 dvi->bus_format = MEDIA_BUS_FMT_RGB888_1X24;
316 break;
317 default:
318 return -EINVAL;
319 }
320
321 /* Get the setup and hold time from vendor-specific properties. */
322 of_property_read_u32(dvi->dev->of_node, "ti,deskew", &deskew);
323 if (deskew > 7)
324 return -EINVAL;
325
326 timings->setup_time_ps = 1200 - 350 * ((s32)deskew - 4);
327 timings->hold_time_ps = max(0, 1300 + 350 * ((s32)deskew - 4));
328
329 return 0;
330}
331
332static int tfp410_init(struct device *dev, bool i2c)
333{
334 struct device_node *node;
335 struct tfp410 *dvi;
336 int ret;
337
338 if (!dev->of_node) {
339 dev_err(dev, "device-tree data is missing\n");
340 return -ENXIO;
341 }
342
343 dvi = devm_kzalloc(dev, sizeof(*dvi), GFP_KERNEL);
344 if (!dvi)
345 return -ENOMEM;
346
347 dvi->dev = dev;
348 dev_set_drvdata(dev, dvi);
349
350 dvi->bridge.funcs = &tfp410_bridge_funcs;
351 dvi->bridge.of_node = dev->of_node;
352 dvi->bridge.timings = &dvi->timings;
353 dvi->bridge.type = DRM_MODE_CONNECTOR_DVID;
354
355 ret = tfp410_parse_timings(dvi, i2c);
356 if (ret)
357 return ret;
358
359 /* Get the next bridge, connected to port@1. */
360 node = of_graph_get_remote_node(dev->of_node, 1, -1);
361 if (!node)
362 return -ENODEV;
363
364 dvi->next_bridge = of_drm_find_bridge(node);
365 of_node_put(node);
366
367 if (!dvi->next_bridge)
368 return -EPROBE_DEFER;
369
370 /* Get the powerdown GPIO. */
371 dvi->powerdown = devm_gpiod_get_optional(dev, "powerdown",
372 GPIOD_OUT_HIGH);
373 if (IS_ERR(dvi->powerdown)) {
374 dev_err(dev, "failed to parse powerdown gpio\n");
375 return PTR_ERR(dvi->powerdown);
376 }
377
378 /* Register the DRM bridge. */
379 drm_bridge_add(&dvi->bridge);
380
381 return 0;
382}
383
384static void tfp410_fini(struct device *dev)
385{
386 struct tfp410 *dvi = dev_get_drvdata(dev);
387
388 drm_bridge_remove(&dvi->bridge);
389}
390
391static int tfp410_probe(struct platform_device *pdev)
392{
393 return tfp410_init(&pdev->dev, false);
394}
395
396static void tfp410_remove(struct platform_device *pdev)
397{
398 tfp410_fini(&pdev->dev);
399}
400
401static const struct of_device_id tfp410_match[] = {
402 { .compatible = "ti,tfp410" },
403 {},
404};
405MODULE_DEVICE_TABLE(of, tfp410_match);
406
407static struct platform_driver tfp410_platform_driver = {
408 .probe = tfp410_probe,
409 .remove = tfp410_remove,
410 .driver = {
411 .name = "tfp410-bridge",
412 .of_match_table = tfp410_match,
413 },
414};
415
416#if IS_ENABLED(CONFIG_I2C)
417/* There is currently no i2c functionality. */
418static int tfp410_i2c_probe(struct i2c_client *client)
419{
420 int reg;
421
422 if (!client->dev.of_node ||
423 of_property_read_u32(client->dev.of_node, "reg", ®)) {
424 dev_err(&client->dev,
425 "Can't get i2c reg property from device-tree\n");
426 return -ENXIO;
427 }
428
429 return tfp410_init(&client->dev, true);
430}
431
432static void tfp410_i2c_remove(struct i2c_client *client)
433{
434 tfp410_fini(&client->dev);
435}
436
437static const struct i2c_device_id tfp410_i2c_ids[] = {
438 { "tfp410", 0 },
439 { }
440};
441MODULE_DEVICE_TABLE(i2c, tfp410_i2c_ids);
442
443static struct i2c_driver tfp410_i2c_driver = {
444 .driver = {
445 .name = "tfp410",
446 .of_match_table = tfp410_match,
447 },
448 .id_table = tfp410_i2c_ids,
449 .probe = tfp410_i2c_probe,
450 .remove = tfp410_i2c_remove,
451};
452#endif /* IS_ENABLED(CONFIG_I2C) */
453
454static struct {
455 uint i2c:1;
456 uint platform:1;
457} tfp410_registered_driver;
458
459static int __init tfp410_module_init(void)
460{
461 int ret;
462
463#if IS_ENABLED(CONFIG_I2C)
464 ret = i2c_add_driver(&tfp410_i2c_driver);
465 if (ret)
466 pr_err("%s: registering i2c driver failed: %d",
467 __func__, ret);
468 else
469 tfp410_registered_driver.i2c = 1;
470#endif
471
472 ret = platform_driver_register(&tfp410_platform_driver);
473 if (ret)
474 pr_err("%s: registering platform driver failed: %d",
475 __func__, ret);
476 else
477 tfp410_registered_driver.platform = 1;
478
479 if (tfp410_registered_driver.i2c ||
480 tfp410_registered_driver.platform)
481 return 0;
482
483 return ret;
484}
485module_init(tfp410_module_init);
486
487static void __exit tfp410_module_exit(void)
488{
489#if IS_ENABLED(CONFIG_I2C)
490 if (tfp410_registered_driver.i2c)
491 i2c_del_driver(&tfp410_i2c_driver);
492#endif
493 if (tfp410_registered_driver.platform)
494 platform_driver_unregister(&tfp410_platform_driver);
495}
496module_exit(tfp410_module_exit);
497
498MODULE_AUTHOR("Jyri Sarha <jsarha@ti.com>");
499MODULE_DESCRIPTION("TI TFP410 DVI bridge driver");
500MODULE_LICENSE("GPL");