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