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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2019 Laurent Pinchart <laurent.pinchart@ideasonboard.com>
4 */
5
6#include <linux/gpio/consumer.h>
7#include <linux/i2c.h>
8#include <linux/interrupt.h>
9#include <linux/media-bus-format.h>
10#include <linux/module.h>
11#include <linux/mutex.h>
12#include <linux/of.h>
13#include <linux/of_device.h>
14#include <linux/platform_device.h>
15#include <linux/regulator/consumer.h>
16
17#include <drm/drm_atomic_helper.h>
18#include <drm/drm_bridge.h>
19#include <drm/drm_edid.h>
20
21struct display_connector {
22 struct drm_bridge bridge;
23
24 struct gpio_desc *hpd_gpio;
25 int hpd_irq;
26
27 struct regulator *dp_pwr;
28 struct gpio_desc *ddc_en;
29};
30
31static inline struct display_connector *
32to_display_connector(struct drm_bridge *bridge)
33{
34 return container_of(bridge, struct display_connector, bridge);
35}
36
37static int display_connector_attach(struct drm_bridge *bridge,
38 enum drm_bridge_attach_flags flags)
39{
40 return flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR ? 0 : -EINVAL;
41}
42
43static enum drm_connector_status
44display_connector_detect(struct drm_bridge *bridge)
45{
46 struct display_connector *conn = to_display_connector(bridge);
47
48 if (conn->hpd_gpio) {
49 if (gpiod_get_value_cansleep(conn->hpd_gpio))
50 return connector_status_connected;
51 else
52 return connector_status_disconnected;
53 }
54
55 if (conn->bridge.ddc && drm_probe_ddc(conn->bridge.ddc))
56 return connector_status_connected;
57
58 switch (conn->bridge.type) {
59 case DRM_MODE_CONNECTOR_DVIA:
60 case DRM_MODE_CONNECTOR_DVID:
61 case DRM_MODE_CONNECTOR_DVII:
62 case DRM_MODE_CONNECTOR_HDMIA:
63 case DRM_MODE_CONNECTOR_HDMIB:
64 /*
65 * For DVI and HDMI connectors a DDC probe failure indicates
66 * that no cable is connected.
67 */
68 return connector_status_disconnected;
69
70 case DRM_MODE_CONNECTOR_Composite:
71 case DRM_MODE_CONNECTOR_SVIDEO:
72 case DRM_MODE_CONNECTOR_VGA:
73 default:
74 /*
75 * Composite and S-Video connectors have no other detection
76 * mean than the HPD GPIO. For VGA connectors, even if we have
77 * an I2C bus, we can't assume that the cable is disconnected
78 * if drm_probe_ddc fails, as some cables don't wire the DDC
79 * pins.
80 */
81 return connector_status_unknown;
82 }
83}
84
85static struct edid *display_connector_get_edid(struct drm_bridge *bridge,
86 struct drm_connector *connector)
87{
88 struct display_connector *conn = to_display_connector(bridge);
89
90 return drm_get_edid(connector, conn->bridge.ddc);
91}
92
93/*
94 * Since this bridge is tied to the connector, it acts like a passthrough,
95 * so concerning the output bus formats, either pass the bus formats from the
96 * previous bridge or return fallback data like done in the bridge function:
97 * drm_atomic_bridge_chain_select_bus_fmts().
98 * This supports negotiation if the bridge chain has all bits in place.
99 */
100static u32 *display_connector_get_output_bus_fmts(struct drm_bridge *bridge,
101 struct drm_bridge_state *bridge_state,
102 struct drm_crtc_state *crtc_state,
103 struct drm_connector_state *conn_state,
104 unsigned int *num_output_fmts)
105{
106 struct drm_bridge *prev_bridge = drm_bridge_get_prev_bridge(bridge);
107 struct drm_bridge_state *prev_bridge_state;
108
109 if (!prev_bridge || !prev_bridge->funcs->atomic_get_output_bus_fmts) {
110 struct drm_connector *conn = conn_state->connector;
111 u32 *out_bus_fmts;
112
113 *num_output_fmts = 1;
114 out_bus_fmts = kmalloc(sizeof(*out_bus_fmts), GFP_KERNEL);
115 if (!out_bus_fmts)
116 return NULL;
117
118 if (conn->display_info.num_bus_formats &&
119 conn->display_info.bus_formats)
120 out_bus_fmts[0] = conn->display_info.bus_formats[0];
121 else
122 out_bus_fmts[0] = MEDIA_BUS_FMT_FIXED;
123
124 return out_bus_fmts;
125 }
126
127 prev_bridge_state = drm_atomic_get_new_bridge_state(crtc_state->state,
128 prev_bridge);
129
130 return prev_bridge->funcs->atomic_get_output_bus_fmts(prev_bridge, prev_bridge_state,
131 crtc_state, conn_state,
132 num_output_fmts);
133}
134
135/*
136 * Since this bridge is tied to the connector, it acts like a passthrough,
137 * so concerning the input bus formats, either pass the bus formats from the
138 * previous bridge or MEDIA_BUS_FMT_FIXED (like select_bus_fmt_recursive())
139 * when atomic_get_input_bus_fmts is not supported.
140 * This supports negotiation if the bridge chain has all bits in place.
141 */
142static u32 *display_connector_get_input_bus_fmts(struct drm_bridge *bridge,
143 struct drm_bridge_state *bridge_state,
144 struct drm_crtc_state *crtc_state,
145 struct drm_connector_state *conn_state,
146 u32 output_fmt,
147 unsigned int *num_input_fmts)
148{
149 struct drm_bridge *prev_bridge = drm_bridge_get_prev_bridge(bridge);
150 struct drm_bridge_state *prev_bridge_state;
151
152 if (!prev_bridge || !prev_bridge->funcs->atomic_get_input_bus_fmts) {
153 u32 *in_bus_fmts;
154
155 *num_input_fmts = 1;
156 in_bus_fmts = kmalloc(sizeof(*in_bus_fmts), GFP_KERNEL);
157 if (!in_bus_fmts)
158 return NULL;
159
160 in_bus_fmts[0] = MEDIA_BUS_FMT_FIXED;
161
162 return in_bus_fmts;
163 }
164
165 prev_bridge_state = drm_atomic_get_new_bridge_state(crtc_state->state,
166 prev_bridge);
167
168 return prev_bridge->funcs->atomic_get_input_bus_fmts(prev_bridge, prev_bridge_state,
169 crtc_state, conn_state, output_fmt,
170 num_input_fmts);
171}
172
173static const struct drm_bridge_funcs display_connector_bridge_funcs = {
174 .attach = display_connector_attach,
175 .detect = display_connector_detect,
176 .get_edid = display_connector_get_edid,
177 .atomic_get_output_bus_fmts = display_connector_get_output_bus_fmts,
178 .atomic_get_input_bus_fmts = display_connector_get_input_bus_fmts,
179 .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
180 .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
181 .atomic_reset = drm_atomic_helper_bridge_reset,
182};
183
184static irqreturn_t display_connector_hpd_irq(int irq, void *arg)
185{
186 struct display_connector *conn = arg;
187 struct drm_bridge *bridge = &conn->bridge;
188
189 drm_bridge_hpd_notify(bridge, display_connector_detect(bridge));
190
191 return IRQ_HANDLED;
192}
193
194static int display_connector_probe(struct platform_device *pdev)
195{
196 struct display_connector *conn;
197 unsigned int type;
198 const char *label = NULL;
199 int ret;
200
201 conn = devm_kzalloc(&pdev->dev, sizeof(*conn), GFP_KERNEL);
202 if (!conn)
203 return -ENOMEM;
204
205 platform_set_drvdata(pdev, conn);
206
207 type = (uintptr_t)of_device_get_match_data(&pdev->dev);
208
209 /* Get the exact connector type. */
210 switch (type) {
211 case DRM_MODE_CONNECTOR_DVII: {
212 bool analog, digital;
213
214 analog = of_property_read_bool(pdev->dev.of_node, "analog");
215 digital = of_property_read_bool(pdev->dev.of_node, "digital");
216 if (analog && !digital) {
217 conn->bridge.type = DRM_MODE_CONNECTOR_DVIA;
218 } else if (!analog && digital) {
219 conn->bridge.type = DRM_MODE_CONNECTOR_DVID;
220 } else if (analog && digital) {
221 conn->bridge.type = DRM_MODE_CONNECTOR_DVII;
222 } else {
223 dev_err(&pdev->dev, "DVI connector with no type\n");
224 return -EINVAL;
225 }
226 break;
227 }
228
229 case DRM_MODE_CONNECTOR_HDMIA: {
230 const char *hdmi_type;
231
232 ret = of_property_read_string(pdev->dev.of_node, "type",
233 &hdmi_type);
234 if (ret < 0) {
235 dev_err(&pdev->dev, "HDMI connector with no type\n");
236 return -EINVAL;
237 }
238
239 if (!strcmp(hdmi_type, "a") || !strcmp(hdmi_type, "c") ||
240 !strcmp(hdmi_type, "d") || !strcmp(hdmi_type, "e")) {
241 conn->bridge.type = DRM_MODE_CONNECTOR_HDMIA;
242 } else if (!strcmp(hdmi_type, "b")) {
243 conn->bridge.type = DRM_MODE_CONNECTOR_HDMIB;
244 } else {
245 dev_err(&pdev->dev,
246 "Unsupported HDMI connector type '%s'\n",
247 hdmi_type);
248 return -EINVAL;
249 }
250
251 break;
252 }
253
254 default:
255 conn->bridge.type = type;
256 break;
257 }
258
259 /* All the supported connector types support interlaced modes. */
260 conn->bridge.interlace_allowed = true;
261
262 /* Get the optional connector label. */
263 of_property_read_string(pdev->dev.of_node, "label", &label);
264
265 /*
266 * Get the HPD GPIO for DVI, HDMI and DP connectors. If the GPIO can provide
267 * edge interrupts, register an interrupt handler.
268 */
269 if (type == DRM_MODE_CONNECTOR_DVII ||
270 type == DRM_MODE_CONNECTOR_HDMIA ||
271 type == DRM_MODE_CONNECTOR_DisplayPort) {
272 conn->hpd_gpio = devm_gpiod_get_optional(&pdev->dev, "hpd",
273 GPIOD_IN);
274 if (IS_ERR(conn->hpd_gpio)) {
275 if (PTR_ERR(conn->hpd_gpio) != -EPROBE_DEFER)
276 dev_err(&pdev->dev,
277 "Unable to retrieve HPD GPIO\n");
278 return PTR_ERR(conn->hpd_gpio);
279 }
280
281 conn->hpd_irq = gpiod_to_irq(conn->hpd_gpio);
282 } else {
283 conn->hpd_irq = -EINVAL;
284 }
285
286 if (conn->hpd_irq >= 0) {
287 ret = devm_request_threaded_irq(&pdev->dev, conn->hpd_irq,
288 NULL, display_connector_hpd_irq,
289 IRQF_TRIGGER_RISING |
290 IRQF_TRIGGER_FALLING |
291 IRQF_ONESHOT,
292 "HPD", conn);
293 if (ret) {
294 dev_info(&pdev->dev,
295 "Failed to request HPD edge interrupt, falling back to polling\n");
296 conn->hpd_irq = -EINVAL;
297 }
298 }
299
300 /* Retrieve the DDC I2C adapter for DVI, HDMI and VGA connectors. */
301 if (type == DRM_MODE_CONNECTOR_DVII ||
302 type == DRM_MODE_CONNECTOR_HDMIA ||
303 type == DRM_MODE_CONNECTOR_VGA) {
304 struct device_node *phandle;
305
306 phandle = of_parse_phandle(pdev->dev.of_node, "ddc-i2c-bus", 0);
307 if (phandle) {
308 conn->bridge.ddc = of_get_i2c_adapter_by_node(phandle);
309 of_node_put(phandle);
310 if (!conn->bridge.ddc)
311 return -EPROBE_DEFER;
312 } else {
313 dev_dbg(&pdev->dev,
314 "No I2C bus specified, disabling EDID readout\n");
315 }
316 }
317
318 /* Get the DP PWR for DP connector. */
319 if (type == DRM_MODE_CONNECTOR_DisplayPort) {
320 int ret;
321
322 conn->dp_pwr = devm_regulator_get_optional(&pdev->dev, "dp-pwr");
323
324 if (IS_ERR(conn->dp_pwr)) {
325 ret = PTR_ERR(conn->dp_pwr);
326
327 switch (ret) {
328 case -ENODEV:
329 conn->dp_pwr = NULL;
330 break;
331
332 case -EPROBE_DEFER:
333 return -EPROBE_DEFER;
334
335 default:
336 dev_err(&pdev->dev, "failed to get DP PWR regulator: %d\n", ret);
337 return ret;
338 }
339 }
340
341 if (conn->dp_pwr) {
342 ret = regulator_enable(conn->dp_pwr);
343 if (ret) {
344 dev_err(&pdev->dev, "failed to enable DP PWR regulator: %d\n", ret);
345 return ret;
346 }
347 }
348 }
349
350 /* enable DDC */
351 if (type == DRM_MODE_CONNECTOR_HDMIA) {
352 conn->ddc_en = devm_gpiod_get_optional(&pdev->dev, "ddc-en",
353 GPIOD_OUT_HIGH);
354
355 if (IS_ERR(conn->ddc_en)) {
356 dev_err(&pdev->dev, "Couldn't get ddc-en gpio\n");
357 return PTR_ERR(conn->ddc_en);
358 }
359 }
360
361 conn->bridge.funcs = &display_connector_bridge_funcs;
362 conn->bridge.of_node = pdev->dev.of_node;
363
364 if (conn->bridge.ddc)
365 conn->bridge.ops |= DRM_BRIDGE_OP_EDID
366 | DRM_BRIDGE_OP_DETECT;
367 if (conn->hpd_gpio)
368 conn->bridge.ops |= DRM_BRIDGE_OP_DETECT;
369 if (conn->hpd_irq >= 0)
370 conn->bridge.ops |= DRM_BRIDGE_OP_HPD;
371
372 dev_dbg(&pdev->dev,
373 "Found %s display connector '%s' %s DDC bus and %s HPD GPIO (ops 0x%x)\n",
374 drm_get_connector_type_name(conn->bridge.type),
375 label ? label : "<unlabelled>",
376 conn->bridge.ddc ? "with" : "without",
377 conn->hpd_gpio ? "with" : "without",
378 conn->bridge.ops);
379
380 drm_bridge_add(&conn->bridge);
381
382 return 0;
383}
384
385static int display_connector_remove(struct platform_device *pdev)
386{
387 struct display_connector *conn = platform_get_drvdata(pdev);
388
389 if (conn->ddc_en)
390 gpiod_set_value(conn->ddc_en, 0);
391
392 if (conn->dp_pwr)
393 regulator_disable(conn->dp_pwr);
394
395 drm_bridge_remove(&conn->bridge);
396
397 if (!IS_ERR(conn->bridge.ddc))
398 i2c_put_adapter(conn->bridge.ddc);
399
400 return 0;
401}
402
403static const struct of_device_id display_connector_match[] = {
404 {
405 .compatible = "composite-video-connector",
406 .data = (void *)DRM_MODE_CONNECTOR_Composite,
407 }, {
408 .compatible = "dvi-connector",
409 .data = (void *)DRM_MODE_CONNECTOR_DVII,
410 }, {
411 .compatible = "hdmi-connector",
412 .data = (void *)DRM_MODE_CONNECTOR_HDMIA,
413 }, {
414 .compatible = "svideo-connector",
415 .data = (void *)DRM_MODE_CONNECTOR_SVIDEO,
416 }, {
417 .compatible = "vga-connector",
418 .data = (void *)DRM_MODE_CONNECTOR_VGA,
419 }, {
420 .compatible = "dp-connector",
421 .data = (void *)DRM_MODE_CONNECTOR_DisplayPort,
422 },
423 {},
424};
425MODULE_DEVICE_TABLE(of, display_connector_match);
426
427static struct platform_driver display_connector_driver = {
428 .probe = display_connector_probe,
429 .remove = display_connector_remove,
430 .driver = {
431 .name = "display-connector",
432 .of_match_table = display_connector_match,
433 },
434};
435module_platform_driver(display_connector_driver);
436
437MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
438MODULE_DESCRIPTION("Display connector driver");
439MODULE_LICENSE("GPL");