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v5.9
  1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 * Copyright (C) 2019 Laurent Pinchart <laurent.pinchart@ideasonboard.com>
  4 */
  5
  6#include <linux/kernel.h>
  7#include <linux/module.h>
  8#include <linux/slab.h>
  9
 10#include <drm/drm_atomic_state_helper.h>
 11#include <drm/drm_bridge.h>
 12#include <drm/drm_bridge_connector.h>
 13#include <drm/drm_connector.h>
 14#include <drm/drm_device.h>
 15#include <drm/drm_edid.h>
 16#include <drm/drm_modeset_helper_vtables.h>
 17#include <drm/drm_probe_helper.h>
 18
 19/**
 20 * DOC: overview
 21 *
 22 * The DRM bridge connector helper object provides a DRM connector
 23 * implementation that wraps a chain of &struct drm_bridge. The connector
 24 * operations are fully implemented based on the operations of the bridges in
 25 * the chain, and don't require any intervention from the display controller
 26 * driver at runtime.
 27 *
 28 * To use the helper, display controller drivers create a bridge connector with
 29 * a call to drm_bridge_connector_init(). This associates the newly created
 30 * connector with the chain of bridges passed to the function and registers it
 31 * with the DRM device. At that point the connector becomes fully usable, no
 32 * further operation is needed.
 33 *
 34 * The DRM bridge connector operations are implemented based on the operations
 35 * provided by the bridges in the chain. Each connector operation is delegated
 36 * to the bridge closest to the connector (at the end of the chain) that
 37 * provides the relevant functionality.
 38 *
 39 * To make use of this helper, all bridges in the chain shall report bridge
 40 * operation flags (&drm_bridge->ops) and bridge output type
 41 * (&drm_bridge->type), as well as the DRM_BRIDGE_ATTACH_NO_CONNECTOR attach
 42 * flag (none of the bridges shall create a DRM connector directly).
 43 */
 44
 45/**
 46 * struct drm_bridge_connector - A connector backed by a chain of bridges
 47 */
 48struct drm_bridge_connector {
 49	/**
 50	 * @base: The base DRM connector
 51	 */
 52	struct drm_connector base;
 53	/**
 54	 * @encoder:
 55	 *
 56	 * The encoder at the start of the bridges chain.
 57	 */
 58	struct drm_encoder *encoder;
 59	/**
 60	 * @bridge_edid:
 61	 *
 62	 * The last bridge in the chain (closest to the connector) that provides
 63	 * EDID read support, if any (see &DRM_BRIDGE_OP_EDID).
 64	 */
 65	struct drm_bridge *bridge_edid;
 66	/**
 67	 * @bridge_hpd:
 68	 *
 69	 * The last bridge in the chain (closest to the connector) that provides
 70	 * hot-plug detection notification, if any (see &DRM_BRIDGE_OP_HPD).
 71	 */
 72	struct drm_bridge *bridge_hpd;
 73	/**
 74	 * @bridge_detect:
 75	 *
 76	 * The last bridge in the chain (closest to the connector) that provides
 77	 * connector detection, if any (see &DRM_BRIDGE_OP_DETECT).
 78	 */
 79	struct drm_bridge *bridge_detect;
 80	/**
 81	 * @bridge_modes:
 82	 *
 83	 * The last bridge in the chain (closest to the connector) that provides
 84	 * connector modes detection, if any (see &DRM_BRIDGE_OP_MODES).
 85	 */
 86	struct drm_bridge *bridge_modes;
 87};
 88
 89#define to_drm_bridge_connector(x) \
 90	container_of(x, struct drm_bridge_connector, base)
 91
 92/* -----------------------------------------------------------------------------
 93 * Bridge Connector Hot-Plug Handling
 94 */
 95
 96static void drm_bridge_connector_hpd_notify(struct drm_connector *connector,
 97					    enum drm_connector_status status)
 98{
 99	struct drm_bridge_connector *bridge_connector =
100		to_drm_bridge_connector(connector);
101	struct drm_bridge *bridge;
102
103	/* Notify all bridges in the pipeline of hotplug events. */
104	drm_for_each_bridge_in_chain(bridge_connector->encoder, bridge) {
105		if (bridge->funcs->hpd_notify)
106			bridge->funcs->hpd_notify(bridge, status);
107	}
108}
109
110static void drm_bridge_connector_hpd_cb(void *cb_data,
111					enum drm_connector_status status)
112{
113	struct drm_bridge_connector *drm_bridge_connector = cb_data;
114	struct drm_connector *connector = &drm_bridge_connector->base;
115	struct drm_device *dev = connector->dev;
116	enum drm_connector_status old_status;
117
118	mutex_lock(&dev->mode_config.mutex);
119	old_status = connector->status;
120	connector->status = status;
121	mutex_unlock(&dev->mode_config.mutex);
122
123	if (old_status == status)
124		return;
125
126	drm_bridge_connector_hpd_notify(connector, status);
127
128	drm_kms_helper_hotplug_event(dev);
129}
130
131/**
132 * drm_bridge_connector_enable_hpd - Enable hot-plug detection for the connector
133 * @connector: The DRM bridge connector
134 *
135 * This function enables hot-plug detection for the given bridge connector.
136 * This is typically used by display drivers in their resume handler.
137 */
138void drm_bridge_connector_enable_hpd(struct drm_connector *connector)
139{
140	struct drm_bridge_connector *bridge_connector =
141		to_drm_bridge_connector(connector);
142	struct drm_bridge *hpd = bridge_connector->bridge_hpd;
143
144	if (hpd)
145		drm_bridge_hpd_enable(hpd, drm_bridge_connector_hpd_cb,
146				      bridge_connector);
147}
148EXPORT_SYMBOL_GPL(drm_bridge_connector_enable_hpd);
149
150/**
151 * drm_bridge_connector_disable_hpd - Disable hot-plug detection for the
152 * connector
153 * @connector: The DRM bridge connector
154 *
155 * This function disables hot-plug detection for the given bridge connector.
156 * This is typically used by display drivers in their suspend handler.
157 */
158void drm_bridge_connector_disable_hpd(struct drm_connector *connector)
159{
160	struct drm_bridge_connector *bridge_connector =
161		to_drm_bridge_connector(connector);
162	struct drm_bridge *hpd = bridge_connector->bridge_hpd;
163
164	if (hpd)
165		drm_bridge_hpd_disable(hpd);
166}
167EXPORT_SYMBOL_GPL(drm_bridge_connector_disable_hpd);
168
169/* -----------------------------------------------------------------------------
170 * Bridge Connector Functions
171 */
172
173static enum drm_connector_status
174drm_bridge_connector_detect(struct drm_connector *connector, bool force)
175{
176	struct drm_bridge_connector *bridge_connector =
177		to_drm_bridge_connector(connector);
178	struct drm_bridge *detect = bridge_connector->bridge_detect;
179	enum drm_connector_status status;
180
181	if (detect) {
182		status = detect->funcs->detect(detect);
183
184		drm_bridge_connector_hpd_notify(connector, status);
185	} else {
186		switch (connector->connector_type) {
187		case DRM_MODE_CONNECTOR_DPI:
188		case DRM_MODE_CONNECTOR_LVDS:
189		case DRM_MODE_CONNECTOR_DSI:
 
190			status = connector_status_connected;
191			break;
192		default:
193			status = connector_status_unknown;
194			break;
195		}
196	}
197
198	return status;
199}
200
201static void drm_bridge_connector_destroy(struct drm_connector *connector)
202{
203	struct drm_bridge_connector *bridge_connector =
204		to_drm_bridge_connector(connector);
205
206	if (bridge_connector->bridge_hpd) {
207		struct drm_bridge *hpd = bridge_connector->bridge_hpd;
208
209		drm_bridge_hpd_disable(hpd);
210	}
211
212	drm_connector_unregister(connector);
213	drm_connector_cleanup(connector);
214
215	kfree(bridge_connector);
216}
217
 
 
 
 
 
 
 
 
 
 
 
 
 
 
218static const struct drm_connector_funcs drm_bridge_connector_funcs = {
219	.reset = drm_atomic_helper_connector_reset,
220	.detect = drm_bridge_connector_detect,
221	.fill_modes = drm_helper_probe_single_connector_modes,
222	.destroy = drm_bridge_connector_destroy,
223	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
224	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
 
225};
226
227/* -----------------------------------------------------------------------------
228 * Bridge Connector Helper Functions
229 */
230
231static int drm_bridge_connector_get_modes_edid(struct drm_connector *connector,
232					       struct drm_bridge *bridge)
233{
234	enum drm_connector_status status;
235	struct edid *edid;
236	int n;
237
238	status = drm_bridge_connector_detect(connector, false);
239	if (status != connector_status_connected)
240		goto no_edid;
241
242	edid = bridge->funcs->get_edid(bridge, connector);
243	if (!edid || !drm_edid_is_valid(edid)) {
244		kfree(edid);
245		goto no_edid;
246	}
247
248	drm_connector_update_edid_property(connector, edid);
249	n = drm_add_edid_modes(connector, edid);
250
251	kfree(edid);
252	return n;
253
254no_edid:
255	drm_connector_update_edid_property(connector, NULL);
256	return 0;
257}
258
259static int drm_bridge_connector_get_modes(struct drm_connector *connector)
260{
261	struct drm_bridge_connector *bridge_connector =
262		to_drm_bridge_connector(connector);
263	struct drm_bridge *bridge;
264
265	/*
266	 * If display exposes EDID, then we parse that in the normal way to
267	 * build table of supported modes.
268	 */
269	bridge = bridge_connector->bridge_edid;
270	if (bridge)
271		return drm_bridge_connector_get_modes_edid(connector, bridge);
272
273	/*
274	 * Otherwise if the display pipeline reports modes (e.g. with a fixed
275	 * resolution panel or an analog TV output), query it.
276	 */
277	bridge = bridge_connector->bridge_modes;
278	if (bridge)
279		return bridge->funcs->get_modes(bridge, connector);
280
281	/*
282	 * We can't retrieve modes, which can happen for instance for a DVI or
283	 * VGA output with the DDC bus unconnected. The KMS core will add the
284	 * default modes.
285	 */
286	return 0;
287}
288
289static const struct drm_connector_helper_funcs drm_bridge_connector_helper_funcs = {
290	.get_modes = drm_bridge_connector_get_modes,
291	/* No need for .mode_valid(), the bridges are checked by the core. */
292};
293
294/* -----------------------------------------------------------------------------
295 * Bridge Connector Initialisation
296 */
297
298/**
299 * drm_bridge_connector_init - Initialise a connector for a chain of bridges
300 * @drm: the DRM device
301 * @encoder: the encoder where the bridge chain starts
302 *
303 * Allocate, initialise and register a &drm_bridge_connector with the @drm
304 * device. The connector is associated with a chain of bridges that starts at
305 * the @encoder. All bridges in the chain shall report bridge operation flags
306 * (&drm_bridge->ops) and bridge output type (&drm_bridge->type), and none of
307 * them may create a DRM connector directly.
308 *
309 * Returns a pointer to the new connector on success, or a negative error
310 * pointer otherwise.
311 */
312struct drm_connector *drm_bridge_connector_init(struct drm_device *drm,
313						struct drm_encoder *encoder)
314{
315	struct drm_bridge_connector *bridge_connector;
316	struct drm_connector *connector;
317	struct i2c_adapter *ddc = NULL;
318	struct drm_bridge *bridge;
319	int connector_type;
320
321	bridge_connector = kzalloc(sizeof(*bridge_connector), GFP_KERNEL);
322	if (!bridge_connector)
323		return ERR_PTR(-ENOMEM);
324
325	bridge_connector->encoder = encoder;
326
327	/*
328	 * TODO: Handle doublescan_allowed, stereo_allowed and
329	 * ycbcr_420_allowed.
330	 */
331	connector = &bridge_connector->base;
332	connector->interlace_allowed = true;
333
334	/*
335	 * Initialise connector status handling. First locate the furthest
336	 * bridges in the pipeline that support HPD and output detection. Then
337	 * initialise the connector polling mode, using HPD if available and
338	 * falling back to polling if supported. If neither HPD nor output
339	 * detection are available, we don't support hotplug detection at all.
340	 */
341	connector_type = DRM_MODE_CONNECTOR_Unknown;
342	drm_for_each_bridge_in_chain(encoder, bridge) {
343		if (!bridge->interlace_allowed)
344			connector->interlace_allowed = false;
345
346		if (bridge->ops & DRM_BRIDGE_OP_EDID)
347			bridge_connector->bridge_edid = bridge;
348		if (bridge->ops & DRM_BRIDGE_OP_HPD)
349			bridge_connector->bridge_hpd = bridge;
350		if (bridge->ops & DRM_BRIDGE_OP_DETECT)
351			bridge_connector->bridge_detect = bridge;
352		if (bridge->ops & DRM_BRIDGE_OP_MODES)
353			bridge_connector->bridge_modes = bridge;
354
355		if (!drm_bridge_get_next_bridge(bridge))
356			connector_type = bridge->type;
357
358		if (bridge->ddc)
359			ddc = bridge->ddc;
 
 
 
360	}
361
362	if (connector_type == DRM_MODE_CONNECTOR_Unknown) {
363		kfree(bridge_connector);
364		return ERR_PTR(-EINVAL);
365	}
366
367	drm_connector_init_with_ddc(drm, connector, &drm_bridge_connector_funcs,
368				    connector_type, ddc);
369	drm_connector_helper_add(connector, &drm_bridge_connector_helper_funcs);
370
371	if (bridge_connector->bridge_hpd)
372		connector->polled = DRM_CONNECTOR_POLL_HPD;
 
 
373	else if (bridge_connector->bridge_detect)
374		connector->polled = DRM_CONNECTOR_POLL_CONNECT
375				  | DRM_CONNECTOR_POLL_DISCONNECT;
 
 
 
376
377	return connector;
378}
379EXPORT_SYMBOL_GPL(drm_bridge_connector_init);
v6.2
  1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 * Copyright (C) 2019 Laurent Pinchart <laurent.pinchart@ideasonboard.com>
  4 */
  5
  6#include <linux/kernel.h>
  7#include <linux/module.h>
  8#include <linux/slab.h>
  9
 10#include <drm/drm_atomic_state_helper.h>
 11#include <drm/drm_bridge.h>
 12#include <drm/drm_bridge_connector.h>
 13#include <drm/drm_connector.h>
 14#include <drm/drm_device.h>
 15#include <drm/drm_edid.h>
 16#include <drm/drm_modeset_helper_vtables.h>
 17#include <drm/drm_probe_helper.h>
 18
 19/**
 20 * DOC: overview
 21 *
 22 * The DRM bridge connector helper object provides a DRM connector
 23 * implementation that wraps a chain of &struct drm_bridge. The connector
 24 * operations are fully implemented based on the operations of the bridges in
 25 * the chain, and don't require any intervention from the display controller
 26 * driver at runtime.
 27 *
 28 * To use the helper, display controller drivers create a bridge connector with
 29 * a call to drm_bridge_connector_init(). This associates the newly created
 30 * connector with the chain of bridges passed to the function and registers it
 31 * with the DRM device. At that point the connector becomes fully usable, no
 32 * further operation is needed.
 33 *
 34 * The DRM bridge connector operations are implemented based on the operations
 35 * provided by the bridges in the chain. Each connector operation is delegated
 36 * to the bridge closest to the connector (at the end of the chain) that
 37 * provides the relevant functionality.
 38 *
 39 * To make use of this helper, all bridges in the chain shall report bridge
 40 * operation flags (&drm_bridge->ops) and bridge output type
 41 * (&drm_bridge->type), as well as the DRM_BRIDGE_ATTACH_NO_CONNECTOR attach
 42 * flag (none of the bridges shall create a DRM connector directly).
 43 */
 44
 45/**
 46 * struct drm_bridge_connector - A connector backed by a chain of bridges
 47 */
 48struct drm_bridge_connector {
 49	/**
 50	 * @base: The base DRM connector
 51	 */
 52	struct drm_connector base;
 53	/**
 54	 * @encoder:
 55	 *
 56	 * The encoder at the start of the bridges chain.
 57	 */
 58	struct drm_encoder *encoder;
 59	/**
 60	 * @bridge_edid:
 61	 *
 62	 * The last bridge in the chain (closest to the connector) that provides
 63	 * EDID read support, if any (see &DRM_BRIDGE_OP_EDID).
 64	 */
 65	struct drm_bridge *bridge_edid;
 66	/**
 67	 * @bridge_hpd:
 68	 *
 69	 * The last bridge in the chain (closest to the connector) that provides
 70	 * hot-plug detection notification, if any (see &DRM_BRIDGE_OP_HPD).
 71	 */
 72	struct drm_bridge *bridge_hpd;
 73	/**
 74	 * @bridge_detect:
 75	 *
 76	 * The last bridge in the chain (closest to the connector) that provides
 77	 * connector detection, if any (see &DRM_BRIDGE_OP_DETECT).
 78	 */
 79	struct drm_bridge *bridge_detect;
 80	/**
 81	 * @bridge_modes:
 82	 *
 83	 * The last bridge in the chain (closest to the connector) that provides
 84	 * connector modes detection, if any (see &DRM_BRIDGE_OP_MODES).
 85	 */
 86	struct drm_bridge *bridge_modes;
 87};
 88
 89#define to_drm_bridge_connector(x) \
 90	container_of(x, struct drm_bridge_connector, base)
 91
 92/* -----------------------------------------------------------------------------
 93 * Bridge Connector Hot-Plug Handling
 94 */
 95
 96static void drm_bridge_connector_hpd_notify(struct drm_connector *connector,
 97					    enum drm_connector_status status)
 98{
 99	struct drm_bridge_connector *bridge_connector =
100		to_drm_bridge_connector(connector);
101	struct drm_bridge *bridge;
102
103	/* Notify all bridges in the pipeline of hotplug events. */
104	drm_for_each_bridge_in_chain(bridge_connector->encoder, bridge) {
105		if (bridge->funcs->hpd_notify)
106			bridge->funcs->hpd_notify(bridge, status);
107	}
108}
109
110static void drm_bridge_connector_hpd_cb(void *cb_data,
111					enum drm_connector_status status)
112{
113	struct drm_bridge_connector *drm_bridge_connector = cb_data;
114	struct drm_connector *connector = &drm_bridge_connector->base;
115	struct drm_device *dev = connector->dev;
116	enum drm_connector_status old_status;
117
118	mutex_lock(&dev->mode_config.mutex);
119	old_status = connector->status;
120	connector->status = status;
121	mutex_unlock(&dev->mode_config.mutex);
122
123	if (old_status == status)
124		return;
125
126	drm_bridge_connector_hpd_notify(connector, status);
127
128	drm_kms_helper_hotplug_event(dev);
129}
130
131/**
132 * drm_bridge_connector_enable_hpd - Enable hot-plug detection for the connector
133 * @connector: The DRM bridge connector
134 *
135 * This function enables hot-plug detection for the given bridge connector.
136 * This is typically used by display drivers in their resume handler.
137 */
138void drm_bridge_connector_enable_hpd(struct drm_connector *connector)
139{
140	struct drm_bridge_connector *bridge_connector =
141		to_drm_bridge_connector(connector);
142	struct drm_bridge *hpd = bridge_connector->bridge_hpd;
143
144	if (hpd)
145		drm_bridge_hpd_enable(hpd, drm_bridge_connector_hpd_cb,
146				      bridge_connector);
147}
148EXPORT_SYMBOL_GPL(drm_bridge_connector_enable_hpd);
149
150/**
151 * drm_bridge_connector_disable_hpd - Disable hot-plug detection for the
152 * connector
153 * @connector: The DRM bridge connector
154 *
155 * This function disables hot-plug detection for the given bridge connector.
156 * This is typically used by display drivers in their suspend handler.
157 */
158void drm_bridge_connector_disable_hpd(struct drm_connector *connector)
159{
160	struct drm_bridge_connector *bridge_connector =
161		to_drm_bridge_connector(connector);
162	struct drm_bridge *hpd = bridge_connector->bridge_hpd;
163
164	if (hpd)
165		drm_bridge_hpd_disable(hpd);
166}
167EXPORT_SYMBOL_GPL(drm_bridge_connector_disable_hpd);
168
169/* -----------------------------------------------------------------------------
170 * Bridge Connector Functions
171 */
172
173static enum drm_connector_status
174drm_bridge_connector_detect(struct drm_connector *connector, bool force)
175{
176	struct drm_bridge_connector *bridge_connector =
177		to_drm_bridge_connector(connector);
178	struct drm_bridge *detect = bridge_connector->bridge_detect;
179	enum drm_connector_status status;
180
181	if (detect) {
182		status = detect->funcs->detect(detect);
183
184		drm_bridge_connector_hpd_notify(connector, status);
185	} else {
186		switch (connector->connector_type) {
187		case DRM_MODE_CONNECTOR_DPI:
188		case DRM_MODE_CONNECTOR_LVDS:
189		case DRM_MODE_CONNECTOR_DSI:
190		case DRM_MODE_CONNECTOR_eDP:
191			status = connector_status_connected;
192			break;
193		default:
194			status = connector_status_unknown;
195			break;
196		}
197	}
198
199	return status;
200}
201
202static void drm_bridge_connector_destroy(struct drm_connector *connector)
203{
204	struct drm_bridge_connector *bridge_connector =
205		to_drm_bridge_connector(connector);
206
207	if (bridge_connector->bridge_hpd) {
208		struct drm_bridge *hpd = bridge_connector->bridge_hpd;
209
210		drm_bridge_hpd_disable(hpd);
211	}
212
213	drm_connector_unregister(connector);
214	drm_connector_cleanup(connector);
215
216	kfree(bridge_connector);
217}
218
219static void drm_bridge_connector_debugfs_init(struct drm_connector *connector,
220					      struct dentry *root)
221{
222	struct drm_bridge_connector *bridge_connector =
223		to_drm_bridge_connector(connector);
224	struct drm_encoder *encoder = bridge_connector->encoder;
225	struct drm_bridge *bridge;
226
227	list_for_each_entry(bridge, &encoder->bridge_chain, chain_node) {
228		if (bridge->funcs->debugfs_init)
229			bridge->funcs->debugfs_init(bridge, root);
230	}
231}
232
233static const struct drm_connector_funcs drm_bridge_connector_funcs = {
234	.reset = drm_atomic_helper_connector_reset,
235	.detect = drm_bridge_connector_detect,
236	.fill_modes = drm_helper_probe_single_connector_modes,
237	.destroy = drm_bridge_connector_destroy,
238	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
239	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
240	.debugfs_init = drm_bridge_connector_debugfs_init,
241};
242
243/* -----------------------------------------------------------------------------
244 * Bridge Connector Helper Functions
245 */
246
247static int drm_bridge_connector_get_modes_edid(struct drm_connector *connector,
248					       struct drm_bridge *bridge)
249{
250	enum drm_connector_status status;
251	struct edid *edid;
252	int n;
253
254	status = drm_bridge_connector_detect(connector, false);
255	if (status != connector_status_connected)
256		goto no_edid;
257
258	edid = bridge->funcs->get_edid(bridge, connector);
259	if (!drm_edid_is_valid(edid)) {
260		kfree(edid);
261		goto no_edid;
262	}
263
264	drm_connector_update_edid_property(connector, edid);
265	n = drm_add_edid_modes(connector, edid);
266
267	kfree(edid);
268	return n;
269
270no_edid:
271	drm_connector_update_edid_property(connector, NULL);
272	return 0;
273}
274
275static int drm_bridge_connector_get_modes(struct drm_connector *connector)
276{
277	struct drm_bridge_connector *bridge_connector =
278		to_drm_bridge_connector(connector);
279	struct drm_bridge *bridge;
280
281	/*
282	 * If display exposes EDID, then we parse that in the normal way to
283	 * build table of supported modes.
284	 */
285	bridge = bridge_connector->bridge_edid;
286	if (bridge)
287		return drm_bridge_connector_get_modes_edid(connector, bridge);
288
289	/*
290	 * Otherwise if the display pipeline reports modes (e.g. with a fixed
291	 * resolution panel or an analog TV output), query it.
292	 */
293	bridge = bridge_connector->bridge_modes;
294	if (bridge)
295		return bridge->funcs->get_modes(bridge, connector);
296
297	/*
298	 * We can't retrieve modes, which can happen for instance for a DVI or
299	 * VGA output with the DDC bus unconnected. The KMS core will add the
300	 * default modes.
301	 */
302	return 0;
303}
304
305static const struct drm_connector_helper_funcs drm_bridge_connector_helper_funcs = {
306	.get_modes = drm_bridge_connector_get_modes,
307	/* No need for .mode_valid(), the bridges are checked by the core. */
308};
309
310/* -----------------------------------------------------------------------------
311 * Bridge Connector Initialisation
312 */
313
314/**
315 * drm_bridge_connector_init - Initialise a connector for a chain of bridges
316 * @drm: the DRM device
317 * @encoder: the encoder where the bridge chain starts
318 *
319 * Allocate, initialise and register a &drm_bridge_connector with the @drm
320 * device. The connector is associated with a chain of bridges that starts at
321 * the @encoder. All bridges in the chain shall report bridge operation flags
322 * (&drm_bridge->ops) and bridge output type (&drm_bridge->type), and none of
323 * them may create a DRM connector directly.
324 *
325 * Returns a pointer to the new connector on success, or a negative error
326 * pointer otherwise.
327 */
328struct drm_connector *drm_bridge_connector_init(struct drm_device *drm,
329						struct drm_encoder *encoder)
330{
331	struct drm_bridge_connector *bridge_connector;
332	struct drm_connector *connector;
333	struct i2c_adapter *ddc = NULL;
334	struct drm_bridge *bridge, *panel_bridge = NULL;
335	int connector_type;
336
337	bridge_connector = kzalloc(sizeof(*bridge_connector), GFP_KERNEL);
338	if (!bridge_connector)
339		return ERR_PTR(-ENOMEM);
340
341	bridge_connector->encoder = encoder;
342
343	/*
344	 * TODO: Handle doublescan_allowed, stereo_allowed and
345	 * ycbcr_420_allowed.
346	 */
347	connector = &bridge_connector->base;
348	connector->interlace_allowed = true;
349
350	/*
351	 * Initialise connector status handling. First locate the furthest
352	 * bridges in the pipeline that support HPD and output detection. Then
353	 * initialise the connector polling mode, using HPD if available and
354	 * falling back to polling if supported. If neither HPD nor output
355	 * detection are available, we don't support hotplug detection at all.
356	 */
357	connector_type = DRM_MODE_CONNECTOR_Unknown;
358	drm_for_each_bridge_in_chain(encoder, bridge) {
359		if (!bridge->interlace_allowed)
360			connector->interlace_allowed = false;
361
362		if (bridge->ops & DRM_BRIDGE_OP_EDID)
363			bridge_connector->bridge_edid = bridge;
364		if (bridge->ops & DRM_BRIDGE_OP_HPD)
365			bridge_connector->bridge_hpd = bridge;
366		if (bridge->ops & DRM_BRIDGE_OP_DETECT)
367			bridge_connector->bridge_detect = bridge;
368		if (bridge->ops & DRM_BRIDGE_OP_MODES)
369			bridge_connector->bridge_modes = bridge;
370
371		if (!drm_bridge_get_next_bridge(bridge))
372			connector_type = bridge->type;
373
374		if (bridge->ddc)
375			ddc = bridge->ddc;
376
377		if (drm_bridge_is_panel(bridge))
378			panel_bridge = bridge;
379	}
380
381	if (connector_type == DRM_MODE_CONNECTOR_Unknown) {
382		kfree(bridge_connector);
383		return ERR_PTR(-EINVAL);
384	}
385
386	drm_connector_init_with_ddc(drm, connector, &drm_bridge_connector_funcs,
387				    connector_type, ddc);
388	drm_connector_helper_add(connector, &drm_bridge_connector_helper_funcs);
389
390	if (bridge_connector->bridge_hpd) {
391		connector->polled = DRM_CONNECTOR_POLL_HPD;
392		drm_bridge_connector_enable_hpd(connector);
393	}
394	else if (bridge_connector->bridge_detect)
395		connector->polled = DRM_CONNECTOR_POLL_CONNECT
396				  | DRM_CONNECTOR_POLL_DISCONNECT;
397
398	if (panel_bridge)
399		drm_panel_bridge_set_orientation(connector, panel_bridge);
400
401	return connector;
402}
403EXPORT_SYMBOL_GPL(drm_bridge_connector_init);