1/*
2 * Copyright (c) 2016 Intel Corporation
3 *
4 * Permission to use, copy, modify, distribute, and sell this software and its
5 * documentation for any purpose is hereby granted without fee, provided that
6 * the above copyright notice appear in all copies and that both that copyright
7 * notice and this permission notice appear in supporting documentation, and
8 * that the name of the copyright holders not be used in advertising or
9 * publicity pertaining to distribution of the software without specific,
10 * written prior permission.  The copyright holders make no representations
11 * about the suitability of this software for any purpose.  It is provided "as
12 * is" without express or implied warranty.
13 *
14 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
15 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
16 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
17 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
18 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
19 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
20 * OF THIS SOFTWARE.
21 */
22
23#include <linux/export.h>
24
25#include <drm/drm_bridge.h>
26#include <drm/drm_device.h>
27#include <drm/drm_drv.h>
28#include <drm/drm_encoder.h>
29#include <drm/drm_managed.h>
30#include <drm/drm_print.h>
31
32#include "drm_crtc_internal.h"
33
34/**
35 * DOC: overview
36 *
37 * Encoders represent the connecting element between the CRTC (as the overall
38 * pixel pipeline, represented by &struct drm_crtc) and the connectors (as the
39 * generic sink entity, represented by &struct drm_connector). An encoder takes
40 * pixel data from a CRTC and converts it to a format suitable for any attached
41 * connector. Encoders are objects exposed to userspace, originally to allow
42 * userspace to infer cloning and connector/CRTC restrictions. Unfortunately
43 * almost all drivers get this wrong, making the uabi pretty much useless. On
44 * top of that the exposed restrictions are too simple for today's hardware, and
45 * the recommended way to infer restrictions is by using the
46 * DRM_MODE_ATOMIC_TEST_ONLY flag for the atomic IOCTL.
47 *
48 * Otherwise encoders aren't used in the uapi at all (any modeset request from
49 * userspace directly connects a connector with a CRTC), drivers are therefore
50 * free to use them however they wish. Modeset helper libraries make strong use
51 * of encoders to facilitate code sharing. But for more complex settings it is
52 * usually better to move shared code into a separate &drm_bridge. Compared to
53 * encoders, bridges also have the benefit of being purely an internal
54 * abstraction since they are not exposed to userspace at all.
55 *
56 * Encoders are initialized with drm_encoder_init() and cleaned up using
57 * drm_encoder_cleanup().
58 */
59static const struct drm_prop_enum_list drm_encoder_enum_list[] = {
60	{ DRM_MODE_ENCODER_NONE, "None" },
61	{ DRM_MODE_ENCODER_DAC, "DAC" },
62	{ DRM_MODE_ENCODER_TMDS, "TMDS" },
63	{ DRM_MODE_ENCODER_LVDS, "LVDS" },
64	{ DRM_MODE_ENCODER_TVDAC, "TV" },
65	{ DRM_MODE_ENCODER_VIRTUAL, "Virtual" },
66	{ DRM_MODE_ENCODER_DSI, "DSI" },
67	{ DRM_MODE_ENCODER_DPMST, "DP MST" },
68	{ DRM_MODE_ENCODER_DPI, "DPI" },
69};
70
71int drm_encoder_register_all(struct drm_device *dev)
72{
73	struct drm_encoder *encoder;
74	int ret = 0;
75
76	drm_for_each_encoder(encoder, dev) {
77		if (encoder->funcs && encoder->funcs->late_register)
78			ret = encoder->funcs->late_register(encoder);
79		if (ret)
80			return ret;
81	}
82
83	return 0;
84}
85
86void drm_encoder_unregister_all(struct drm_device *dev)
87{
88	struct drm_encoder *encoder;
89
90	drm_for_each_encoder(encoder, dev) {
91		if (encoder->funcs && encoder->funcs->early_unregister)
92			encoder->funcs->early_unregister(encoder);
93	}
94}
95
96__printf(5, 0)
97static int __drm_encoder_init(struct drm_device *dev,
98			      struct drm_encoder *encoder,
99			      const struct drm_encoder_funcs *funcs,
100			      int encoder_type, const char *name, va_list ap)
101{
102	int ret;
103
104	/* encoder index is used with 32bit bitmasks */
105	if (WARN_ON(dev->mode_config.num_encoder >= 32))
106		return -EINVAL;
107
108	ret = drm_mode_object_add(dev, &encoder->base, DRM_MODE_OBJECT_ENCODER);
109	if (ret)
110		return ret;
111
112	encoder->dev = dev;
113	encoder->encoder_type = encoder_type;
114	encoder->funcs = funcs;
115	if (name) {
116		encoder->name = kvasprintf(GFP_KERNEL, name, ap);
117	} else {
118		encoder->name = kasprintf(GFP_KERNEL, "%s-%d",
119					  drm_encoder_enum_list[encoder_type].name,
120					  encoder->base.id);
121	}
122	if (!encoder->name) {
123		ret = -ENOMEM;
124		goto out_put;
125	}
126
127	INIT_LIST_HEAD(&encoder->bridge_chain);
128	list_add_tail(&encoder->head, &dev->mode_config.encoder_list);
129	encoder->index = dev->mode_config.num_encoder++;
130
131out_put:
132	if (ret)
133		drm_mode_object_unregister(dev, &encoder->base);
134
135	return ret;
136}
137
138/**
139 * drm_encoder_init - Init a preallocated encoder
140 * @dev: drm device
141 * @encoder: the encoder to init
142 * @funcs: callbacks for this encoder
143 * @encoder_type: user visible type of the encoder
144 * @name: printf style format string for the encoder name, or NULL for default name
145 *
146 * Initializes a preallocated encoder. Encoder should be subclassed as part of
147 * driver encoder objects. At driver unload time the driver's
148 * &drm_encoder_funcs.destroy hook should call drm_encoder_cleanup() and kfree()
149 * the encoder structure. The encoder structure should not be allocated with
150 * devm_kzalloc().
151 *
152 * Note: consider using drmm_encoder_alloc() or drmm_encoder_init()
153 * instead of drm_encoder_init() to let the DRM managed resource
154 * infrastructure take care of cleanup and deallocation.
155 *
156 * Returns:
157 * Zero on success, error code on failure.
158 */
159int drm_encoder_init(struct drm_device *dev,
160		     struct drm_encoder *encoder,
161		     const struct drm_encoder_funcs *funcs,
162		     int encoder_type, const char *name, ...)
163{
164	va_list ap;
165	int ret;
166
167	WARN_ON(!funcs->destroy);
168
169	va_start(ap, name);
170	ret = __drm_encoder_init(dev, encoder, funcs, encoder_type, name, ap);
171	va_end(ap);
172
173	return ret;
174}
175EXPORT_SYMBOL(drm_encoder_init);
176
177/**
178 * drm_encoder_cleanup - cleans up an initialised encoder
179 * @encoder: encoder to cleanup
180 *
181 * Cleans up the encoder but doesn't free the object.
182 */
183void drm_encoder_cleanup(struct drm_encoder *encoder)
184{
185	struct drm_device *dev = encoder->dev;
186	struct drm_bridge *bridge, *next;
187
188	/* Note that the encoder_list is considered to be static; should we
189	 * remove the drm_encoder at runtime we would have to decrement all
190	 * the indices on the drm_encoder after us in the encoder_list.
191	 */
192
193	list_for_each_entry_safe(bridge, next, &encoder->bridge_chain,
194				 chain_node)
195		drm_bridge_detach(bridge);
196
197	drm_mode_object_unregister(dev, &encoder->base);
198	kfree(encoder->name);
199	list_del(&encoder->head);
200	dev->mode_config.num_encoder--;
201
202	memset(encoder, 0, sizeof(*encoder));
203}
204EXPORT_SYMBOL(drm_encoder_cleanup);
205
206static void drmm_encoder_alloc_release(struct drm_device *dev, void *ptr)
207{
208	struct drm_encoder *encoder = ptr;
209
210	if (WARN_ON(!encoder->dev))
211		return;
212
213	drm_encoder_cleanup(encoder);
214}
215
216__printf(5, 0)
217static int __drmm_encoder_init(struct drm_device *dev,
218			       struct drm_encoder *encoder,
219			       const struct drm_encoder_funcs *funcs,
220			       int encoder_type,
221			       const char *name,
222			       va_list args)
223{
224	int ret;
225
226	if (drm_WARN_ON(dev, funcs && funcs->destroy))
227		return -EINVAL;
228
229	ret = __drm_encoder_init(dev, encoder, funcs, encoder_type, name, args);
230	if (ret)
231		return ret;
232
233	ret = drmm_add_action_or_reset(dev, drmm_encoder_alloc_release, encoder);
234	if (ret)
235		return ret;
236
237	return 0;
238}
239
240void *__drmm_encoder_alloc(struct drm_device *dev, size_t size, size_t offset,
241			   const struct drm_encoder_funcs *funcs,
242			   int encoder_type, const char *name, ...)
243{
244	void *container;
245	struct drm_encoder *encoder;
246	va_list ap;
247	int ret;
248
249	container = drmm_kzalloc(dev, size, GFP_KERNEL);
250	if (!container)
251		return ERR_PTR(-ENOMEM);
252
253	encoder = container + offset;
254
255	va_start(ap, name);
256	ret = __drmm_encoder_init(dev, encoder, funcs, encoder_type, name, ap);
257	va_end(ap);
258	if (ret)
259		return ERR_PTR(ret);
260
261	return container;
262}
263EXPORT_SYMBOL(__drmm_encoder_alloc);
264
265/**
266 * drmm_encoder_init - Initialize a preallocated encoder
267 * @dev: drm device
268 * @encoder: the encoder to init
269 * @funcs: callbacks for this encoder (optional)
270 * @encoder_type: user visible type of the encoder
271 * @name: printf style format string for the encoder name, or NULL for default name
272 *
273 * Initializes a preallocated encoder. Encoder should be subclassed as
274 * part of driver encoder objects. Cleanup is automatically handled
275 * through registering drm_encoder_cleanup() with drmm_add_action(). The
276 * encoder structure should be allocated with drmm_kzalloc().
277 *
278 * The @drm_encoder_funcs.destroy hook must be NULL.
279 *
280 * Returns:
281 * Zero on success, error code on failure.
282 */
283int drmm_encoder_init(struct drm_device *dev, struct drm_encoder *encoder,
284		      const struct drm_encoder_funcs *funcs,
285		      int encoder_type, const char *name, ...)
286{
287	va_list ap;
288	int ret;
289
290	va_start(ap, name);
291	ret = __drmm_encoder_init(dev, encoder, funcs, encoder_type, name, ap);
292	va_end(ap);
293	if (ret)
294		return ret;
295
296	return 0;
297}
298EXPORT_SYMBOL(drmm_encoder_init);
299
300static struct drm_crtc *drm_encoder_get_crtc(struct drm_encoder *encoder)
301{
302	struct drm_connector *connector;
303	struct drm_device *dev = encoder->dev;
304	bool uses_atomic = false;
305	struct drm_connector_list_iter conn_iter;
306
307	/* For atomic drivers only state objects are synchronously updated and
308	 * protected by modeset locks, so check those first. */
309	drm_connector_list_iter_begin(dev, &conn_iter);
310	drm_for_each_connector_iter(connector, &conn_iter) {
311		if (!connector->state)
312			continue;
313
314		uses_atomic = true;
315
316		if (connector->state->best_encoder != encoder)
317			continue;
318
319		drm_connector_list_iter_end(&conn_iter);
320		return connector->state->crtc;
321	}
322	drm_connector_list_iter_end(&conn_iter);
323
324	/* Don't return stale data (e.g. pending async disable). */
325	if (uses_atomic)
326		return NULL;
327
328	return encoder->crtc;
329}
330
331int drm_mode_getencoder(struct drm_device *dev, void *data,
332			struct drm_file *file_priv)
333{
334	struct drm_mode_get_encoder *enc_resp = data;
335	struct drm_encoder *encoder;
336	struct drm_crtc *crtc;
337
338	if (!drm_core_check_feature(dev, DRIVER_MODESET))
339		return -EOPNOTSUPP;
340
341	encoder = drm_encoder_find(dev, file_priv, enc_resp->encoder_id);
342	if (!encoder)
343		return -ENOENT;
344
345	drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
346	crtc = drm_encoder_get_crtc(encoder);
347	if (crtc && drm_lease_held(file_priv, crtc->base.id))
348		enc_resp->crtc_id = crtc->base.id;
349	else
350		enc_resp->crtc_id = 0;
351	drm_modeset_unlock(&dev->mode_config.connection_mutex);
352
353	enc_resp->encoder_type = encoder->encoder_type;
354	enc_resp->encoder_id = encoder->base.id;
355	enc_resp->possible_crtcs = drm_lease_filter_crtcs(file_priv,
356							  encoder->possible_crtcs);
357	enc_resp->possible_clones = encoder->possible_clones;
358
359	return 0;
360}
361