History

drm: Add writeback connector type

Writeback connectors represent writeback engines which can write the CRTC output to a memory framebuffer. Add a writeback connector type and related support functions. Drivers should initialize a writeback connector with drm_writeback_connector_init() which takes care of setting up all the writeback-specific details on top of the normal functionality of drm_connector_init(). Writeback connectors have a WRITEBACK_FB_ID property, used to set the output framebuffer, and a WRITEBACK_PIXEL_FORMATS blob used to expose the supported writeback formats to userspace. When a framebuffer is attached to a writeback connector with the WRITEBACK_FB_ID property, it is used only once (for the commit in which it was included), and userspace can never read back the value of WRITEBACK_FB_ID. WRITEBACK_FB_ID can only be set if the connector is attached to a CRTC. Changes since v1: - Added drm_writeback.c + documentation - Added helper to initialize writeback connector in one go - Added core checks - Squashed into a single commit - Dropped the client cap - Writeback framebuffers are no longer persistent Changes since v2: Daniel Vetter: - Subclass drm_connector to drm_writeback_connector - Relax check to allow CRTC to be set without an FB - Add some writeback_ prefixes - Drop PIXEL_FORMATS_SIZE property, as it was unnecessary Gustavo Padovan: - Add drm_writeback_job to handle writeback signalling centrally Changes since v3: - Rebased - Rename PIXEL_FORMATS -> WRITEBACK_PIXEL_FORMATS Chances since v4: - Embed a drm_encoder inside the drm_writeback_connector to reduce the amount of boilerplate code required from the drivers that are using it. Changes since v5: - Added Rob Clark's atomic_commit() vfunc to connector helper funcs, so that writeback jobs are committed from atomic helpers - Updated create_writeback_properties() signature to return an error code rather than a boolean false for failure. - Free writeback job with the connector state rather than when doing the cleanup_work() Changes since v7: - fix extraneous use of out_fence that is only introduced in a subsequent patch. Changes since v8: - whitespace changes pull from subsequent patch Changes since v9: - Revert the v6 changes that free the writeback job in the connector state cleanup and return to doing it in the cleanup_work() function

Brian Starkey committed 9 years ago

Commit 935774c1 parent f664a5212 files · +541 −2Browse files

Unified · Split

12 files
  1. Documentation/gpu/drm-kms.rst +9 −0
  2. drivers/gpu/drm/Makefile +1 −1
  3. drivers/gpu/drm/drm_atomic.c +124 −0
  4. drivers/gpu/drm/drm_atomic_helper.c +25 −0
  5. drivers/gpu/drm/drm_connector.c +3 −1
  6. drivers/gpu/drm/drm_writeback.c +245 −0
  7. include/drm/drm_atomic.h +3 −0
  8. include/drm/drm_connector.h +13 −0
  9. include/drm/drm_mode_config.h +15 −0
  10. include/drm/drm_modeset_helper_vtables.h +11 −0
  11. include/drm/drm_writeback.h +91 −0
  12. include/uapi/drm/drm_mode.h +1 −0
Documentation/gpu/drm-kms.rst+9−0
@@ -373,6 +373,15 @@ Connector Functions Reference · 372 unmodified lines
373.. kernel-doc:: drivers/gpu/drm/drm_connector.c373.. kernel-doc:: drivers/gpu/drm/drm_connector.c
374 :export:374 :export:
375 375
376Writeback Connectors
377--------------------
378
379.. kernel-doc:: drivers/gpu/drm/drm_writeback.c
380 :doc: overview
381
382.. kernel-doc:: drivers/gpu/drm/drm_writeback.c
383 :export:
384
376Encoder Abstraction385Encoder Abstraction
377===================386===================
378 387
drivers/gpu/drm/Makefile+1−1
@@ -18,7 +18,7 @@ drm-y := drm_auth.o drm_bufs.o drm_cache.o \ · 17 unmodified lines
18 drm_encoder.o drm_mode_object.o drm_property.o \18 drm_encoder.o drm_mode_object.o drm_property.o \
19 drm_plane.o drm_color_mgmt.o drm_print.o \19 drm_plane.o drm_color_mgmt.o drm_print.o \
20 drm_dumb_buffers.o drm_mode_config.o drm_vblank.o \20 drm_dumb_buffers.o drm_mode_config.o drm_vblank.o \
21 drm_syncobj.o drm_lease.o21 drm_syncobj.o drm_lease.o drm_writeback.o
22 22
23drm-$(CONFIG_DRM_LIB_RANDOM) += lib/drm_random.o23drm-$(CONFIG_DRM_LIB_RANDOM) += lib/drm_random.o
24drm-$(CONFIG_DRM_VM) += drm_vm.o24drm-$(CONFIG_DRM_VM) += drm_vm.o
drivers/gpu/drm/drm_atomic.c+124−0
@@ -30,6 +30,7 @@ · 29 unmodified lines
30#include <drm/drm_atomic.h>30#include <drm/drm_atomic.h>
31#include <drm/drm_mode.h>31#include <drm/drm_mode.h>
32#include <drm/drm_print.h>32#include <drm/drm_print.h>
33#include <drm/drm_writeback.h>
33#include <linux/sync_file.h>34#include <linux/sync_file.h>
34 35
35#include "drm_crtc_internal.h"36#include "drm_crtc_internal.h"
@@ -690,6 +691,45 @@ static void drm_atomic_crtc_print_state(struct drm_printer *p, · 654 unmodified lines
690 crtc->funcs->atomic_print_state(p, state);691 crtc->funcs->atomic_print_state(p, state);
691}692}
692 693
694/**
695 * drm_atomic_connector_check - check connector state
696 * @connector: connector to check
697 * @state: connector state to check
698 *
699 * Provides core sanity checks for connector state.
700 *
701 * RETURNS:
702 * Zero on success, error code on failure
703 */
704static int drm_atomic_connector_check(struct drm_connector *connector,
705 struct drm_connector_state *state)
706{
707 struct drm_crtc_state *crtc_state;
708 struct drm_writeback_job *writeback_job = state->writeback_job;
709
710 if ((connector->connector_type != DRM_MODE_CONNECTOR_WRITEBACK) || !writeback_job)
711 return 0;
712
713 if (writeback_job->fb && !state->crtc) {
714 DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] framebuffer without CRTC\n",
715 connector->base.id, connector->name);
716 return -EINVAL;
717 }
718
719 if (state->crtc)
720 crtc_state = drm_atomic_get_existing_crtc_state(state->state,
721 state->crtc);
722
723 if (writeback_job->fb && !crtc_state->active) {
724 DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] has framebuffer, but [CRTC:%d] is off\n",
725 connector->base.id, connector->name,
726 state->crtc->base.id);
727 return -EINVAL;
728 }
729
730 return 0;
731}
732
693/**733/**
694 * drm_atomic_get_plane_state - get plane state734 * drm_atomic_get_plane_state - get plane state
695 * @state: global atomic state object735 * @state: global atomic state object
@@ -1321,6 +1361,12 @@ static int drm_atomic_connector_set_property(struct drm_connector *connector, · 625 unmodified lines
1321 return -EINVAL;1361 return -EINVAL;
1322 }1362 }
1323 state->content_protection = val;1363 state->content_protection = val;
1364 } else if (property == config->writeback_fb_id_property) {
1365 struct drm_framebuffer *fb = drm_framebuffer_lookup(dev, NULL, val);
1366 int ret = drm_atomic_set_writeback_fb_for_connector(state, fb);
1367 if (fb)
1368 drm_framebuffer_put(fb);
1369 return ret;
1324 } else if (connector->funcs->atomic_set_property) {1370 } else if (connector->funcs->atomic_set_property) {
1325 return connector->funcs->atomic_set_property(connector,1371 return connector->funcs->atomic_set_property(connector,
1326 state, property, val);1372 state, property, val);
@@ -1407,6 +1453,9 @@ drm_atomic_connector_get_property(struct drm_connector *connector, · 80 unmodified lines
1407 *val = state->scaling_mode;1453 *val = state->scaling_mode;
1408 } else if (property == connector->content_protection_property) {1454 } else if (property == connector->content_protection_property) {
1409 *val = state->content_protection;1455 *val = state->content_protection;
1456 } else if (property == config->writeback_fb_id_property) {
1457 /* Writeback framebuffer is one-shot, write and forget */
1458 *val = 0;
1410 } else if (connector->funcs->atomic_get_property) {1459 } else if (connector->funcs->atomic_get_property) {
1411 return connector->funcs->atomic_get_property(connector,1460 return connector->funcs->atomic_get_property(connector,
1412 state, property, val);1461 state, property, val);
@@ -1631,6 +1680,70 @@ drm_atomic_set_crtc_for_connector(struct drm_connector_state *conn_state, · 218 unmodified lines
1631}1680}
1632EXPORT_SYMBOL(drm_atomic_set_crtc_for_connector);1681EXPORT_SYMBOL(drm_atomic_set_crtc_for_connector);
1633 1682
1683/*
1684 * drm_atomic_get_writeback_job - return or allocate a writeback job
1685 * @conn_state: Connector state to get the job for
1686 *
1687 * Writeback jobs have a different lifetime to the atomic state they are
1688 * associated with. This convenience function takes care of allocating a job
1689 * if there isn't yet one associated with the connector state, otherwise
1690 * it just returns the existing job.
1691 *
1692 * Returns: The writeback job for the given connector state
1693 */
1694static struct drm_writeback_job *
1695drm_atomic_get_writeback_job(struct drm_connector_state *conn_state)
1696{
1697 WARN_ON(conn_state->connector->connector_type != DRM_MODE_CONNECTOR_WRITEBACK);
1698
1699 if (!conn_state->writeback_job)
1700 conn_state->writeback_job =
1701 kzalloc(sizeof(*conn_state->writeback_job), GFP_KERNEL);
1702
1703 return conn_state->writeback_job;
1704}
1705
1706/**
1707 * drm_atomic_set_writeback_fb_for_connector - set writeback framebuffer
1708 * @conn_state: atomic state object for the connector
1709 * @fb: fb to use for the connector
1710 *
1711 * This is used to set the framebuffer for a writeback connector, which outputs
1712 * to a buffer instead of an actual physical connector.
1713 * Changing the assigned framebuffer requires us to grab a reference to the new
1714 * fb and drop the reference to the old fb, if there is one. This function
1715 * takes care of all these details besides updating the pointer in the
1716 * state object itself.
1717 *
1718 * Note: The only way conn_state can already have an fb set is if the commit
1719 * sets the property more than once.
1720 *
1721 * See also: drm_writeback_connector_init()
1722 *
1723 * Returns: 0 on success
1724 */
1725int drm_atomic_set_writeback_fb_for_connector(
1726 struct drm_connector_state *conn_state,
1727 struct drm_framebuffer *fb)
1728{
1729 struct drm_writeback_job *job =
1730 drm_atomic_get_writeback_job(conn_state);
1731 if (!job)
1732 return -ENOMEM;
1733
1734 drm_framebuffer_assign(&job->fb, fb);
1735
1736 if (fb)
1737 DRM_DEBUG_ATOMIC("Set [FB:%d] for connector state %p\n",
1738 fb->base.id, conn_state);
1739 else
1740 DRM_DEBUG_ATOMIC("Set [NOFB] for connector state %p\n",
1741 conn_state);
1742
1743 return 0;
1744}
1745EXPORT_SYMBOL(drm_atomic_set_writeback_fb_for_connector);
1746
1634/**1747/**
1635 * drm_atomic_add_affected_connectors - add connectors for crtc1748 * drm_atomic_add_affected_connectors - add connectors for crtc
1636 * @state: atomic state1749 * @state: atomic state
@@ -1752,6 +1865,8 @@ int drm_atomic_check_only(struct drm_atomic_state *state) · 115 unmodified lines
1752 struct drm_plane_state *plane_state;1865 struct drm_plane_state *plane_state;
1753 struct drm_crtc *crtc;1866 struct drm_crtc *crtc;
1754 struct drm_crtc_state *crtc_state;1867 struct drm_crtc_state *crtc_state;
1868 struct drm_connector *conn;
1869 struct drm_connector_state *conn_state;
1755 int i, ret = 0;1870 int i, ret = 0;
1756 1871
1757 DRM_DEBUG_ATOMIC("checking %p\n", state);1872 DRM_DEBUG_ATOMIC("checking %p\n", state);
@@ -1774,6 +1889,15 @@ int drm_atomic_check_only(struct drm_atomic_state *state) · 16 unmodified lines
1774 }1889 }
1775 }1890 }
1776 1891
1892 for_each_new_connector_in_state(state, conn, conn_state, i) {
1893 ret = drm_atomic_connector_check(conn, conn_state);
1894 if (ret) {
1895 DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] atomic core check failed\n",
1896 conn->base.id, conn->name);
1897 return ret;
1898 }
1899 }
1900
1777 if (config->funcs->atomic_check)1901 if (config->funcs->atomic_check)
1778 ret = config->funcs->atomic_check(state->dev, state);1902 ret = config->funcs->atomic_check(state->dev, state);
1779 1903
drivers/gpu/drm/drm_atomic_helper.c+25−0
@@ -30,6 +30,7 @@ · 29 unmodified lines
30#include <drm/drm_plane_helper.h>30#include <drm/drm_plane_helper.h>
31#include <drm/drm_crtc_helper.h>31#include <drm/drm_crtc_helper.h>
32#include <drm/drm_atomic_helper.h>32#include <drm/drm_atomic_helper.h>
33#include <drm/drm_writeback.h>
33#include <linux/dma-fence.h>34#include <linux/dma-fence.h>
34 35
35#include "drm_crtc_helper_internal.h"36#include "drm_crtc_helper_internal.h"
@@ -1172,6 +1173,25 @@ void drm_atomic_helper_commit_modeset_disables(struct drm_device *dev, · 1136 unmodified lines
1172}1173}
1173EXPORT_SYMBOL(drm_atomic_helper_commit_modeset_disables);1174EXPORT_SYMBOL(drm_atomic_helper_commit_modeset_disables);
1174 1175
1176static void drm_atomic_helper_commit_writebacks(struct drm_device *dev,
1177 struct drm_atomic_state *old_state)
1178{
1179 struct drm_connector *connector;
1180 struct drm_connector_state *new_conn_state;
1181 int i;
1182
1183 for_each_new_connector_in_state(old_state, connector, new_conn_state, i) {
1184 const struct drm_connector_helper_funcs *funcs;
1185
1186 funcs = connector->helper_private;
1187
1188 if (new_conn_state->writeback_job && new_conn_state->writeback_job->fb) {
1189 WARN_ON(connector->connector_type != DRM_MODE_CONNECTOR_WRITEBACK);
1190 funcs->atomic_commit(connector, new_conn_state->writeback_job);
1191 }
1192 }
1193}
1194
1175/**1195/**
1176 * drm_atomic_helper_commit_modeset_enables - modeset commit to enable outputs1196 * drm_atomic_helper_commit_modeset_enables - modeset commit to enable outputs
1177 * @dev: DRM device1197 * @dev: DRM device
@@ -1251,6 +1271,8 @@ void drm_atomic_helper_commit_modeset_enables(struct drm_device *dev, · 73 unmodified lines
1251 1271
1252 drm_bridge_enable(encoder->bridge);1272 drm_bridge_enable(encoder->bridge);
1253 }1273 }
1274
1275 drm_atomic_helper_commit_writebacks(dev, old_state);
1254}1276}
1255EXPORT_SYMBOL(drm_atomic_helper_commit_modeset_enables);1277EXPORT_SYMBOL(drm_atomic_helper_commit_modeset_enables);
1256 1278
@@ -3647,6 +3669,9 @@ __drm_atomic_helper_connector_duplicate_state(struct drm_connector *connector, · 2390 unmodified lines
3647 if (state->crtc)3669 if (state->crtc)
3648 drm_connector_get(connector);3670 drm_connector_get(connector);
3649 state->commit = NULL;3671 state->commit = NULL;
3672
3673 /* Don't copy over a writeback job, they are used only once */
3674 state->writeback_job = NULL;
3650}3675}
3651EXPORT_SYMBOL(__drm_atomic_helper_connector_duplicate_state);3676EXPORT_SYMBOL(__drm_atomic_helper_connector_duplicate_state);
3652 3677
drivers/gpu/drm/drm_connector.c+3−1
@@ -87,6 +87,7 @@ static struct drm_conn_prop_enum_list drm_connector_enum_list[] = { · 86 unmodified lines
87 { DRM_MODE_CONNECTOR_VIRTUAL, "Virtual" },87 { DRM_MODE_CONNECTOR_VIRTUAL, "Virtual" },
88 { DRM_MODE_CONNECTOR_DSI, "DSI" },88 { DRM_MODE_CONNECTOR_DSI, "DSI" },
89 { DRM_MODE_CONNECTOR_DPI, "DPI" },89 { DRM_MODE_CONNECTOR_DPI, "DPI" },
90 { DRM_MODE_CONNECTOR_WRITEBACK, "Writeback" },
90};91};
91 92
92void drm_connector_ida_init(void)93void drm_connector_ida_init(void)
@@ -253,7 +254,8 @@ int drm_connector_init(struct drm_device *dev, · 160 unmodified lines
253 config->num_connector++;254 config->num_connector++;
254 spin_unlock_irq(&config->connector_list_lock);255 spin_unlock_irq(&config->connector_list_lock);
255 256
256 if (connector_type != DRM_MODE_CONNECTOR_VIRTUAL)257 if (connector_type != DRM_MODE_CONNECTOR_VIRTUAL &&
258 connector_type != DRM_MODE_CONNECTOR_WRITEBACK)
257 drm_object_attach_property(&connector->base,259 drm_object_attach_property(&connector->base,
258 config->edid_property,260 config->edid_property,
259 0);261 0);
drivers/gpu/drm/drm_writeback.c+245−0
@@ -0,0 +1,245 @@
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * (C) COPYRIGHT 2016 ARM Limited. All rights reserved.
4 * Author: Brian Starkey <brian.starkey@arm.com>
5 *
6 * This program is free software and is provided to you under the terms of the
7 * GNU General Public License version 2 as published by the Free Software
8 * Foundation, and any use by you of this program is subject to the terms
9 * of such GNU licence.
10 */
11
12#include <drm/drm_crtc.h>
13#include <drm/drm_modeset_helper_vtables.h>
14#include <drm/drm_property.h>
15#include <drm/drm_writeback.h>
16#include <drm/drmP.h>
17
18/**
19 * DOC: overview
20 *
21 * Writeback connectors are used to expose hardware which can write the output
22 * from a CRTC to a memory buffer. They are used and act similarly to other
23 * types of connectors, with some important differences:
24 * - Writeback connectors don't provide a way to output visually to the user.
25 * - Writeback connectors should always report as "disconnected" (so that
26 * clients which don't understand them will ignore them).
27 * - Writeback connectors don't have EDID.
28 *
29 * A framebuffer may only be attached to a writeback connector when the
30 * connector is attached to a CRTC. The WRITEBACK_FB_ID property which sets the
31 * framebuffer applies only to a single commit (see below). A framebuffer may
32 * not be attached while the CRTC is off.
33 *
34 * Writeback connectors have some additional properties, which userspace
35 * can use to query and control them:
36 *
37 * "WRITEBACK_FB_ID":
38 * Write-only object property storing a DRM_MODE_OBJECT_FB: it stores the
39 * framebuffer to be written by the writeback connector. This property is
40 * similar to the FB_ID property on planes, but will always read as zero
41 * and is not preserved across commits.
42 * Userspace must set this property to an output buffer every time it
43 * wishes the buffer to get filled.
44 *
45 * "WRITEBACK_PIXEL_FORMATS":
46 * Immutable blob property to store the supported pixel formats table. The
47 * data is an array of u32 DRM_FORMAT_* fourcc values.
48 * Userspace can use this blob to find out what pixel formats are supported
49 * by the connector's writeback engine.
50 */
51
52static int create_writeback_properties(struct drm_device *dev)
53{
54 struct drm_property *prop;
55
56 if (!dev->mode_config.writeback_fb_id_property) {
57 prop = drm_property_create_object(dev, DRM_MODE_PROP_ATOMIC,
58 "WRITEBACK_FB_ID",
59 DRM_MODE_OBJECT_FB);
60 if (!prop)
61 return -ENOMEM;
62 dev->mode_config.writeback_fb_id_property = prop;
63 }
64
65 if (!dev->mode_config.writeback_pixel_formats_property) {
66 prop = drm_property_create(dev, DRM_MODE_PROP_BLOB |
67 DRM_MODE_PROP_ATOMIC |
68 DRM_MODE_PROP_IMMUTABLE,
69 "WRITEBACK_PIXEL_FORMATS", 0);
70 if (!prop)
71 return -ENOMEM;
72 dev->mode_config.writeback_pixel_formats_property = prop;
73 }
74
75 return 0;
76}
77
78static const struct drm_encoder_funcs drm_writeback_encoder_funcs = {
79 .destroy = drm_encoder_cleanup,
80};
81
82/**
83 * drm_writeback_connector_init - Initialize a writeback connector and its properties
84 * @dev: DRM device
85 * @wb_connector: Writeback connector to initialize
86 * @con_funcs: Connector funcs vtable
87 * @enc_helper_funcs: Encoder helper funcs vtable to be used by the internal encoder
88 * @formats: Array of supported pixel formats for the writeback engine
89 * @n_formats: Length of the formats array
90 *
91 * This function creates the writeback-connector-specific properties if they
92 * have not been already created, initializes the connector as
93 * type DRM_MODE_CONNECTOR_WRITEBACK, and correctly initializes the property
94 * values. It will also create an internal encoder associated with the
95 * drm_writeback_connector and set it to use the @enc_helper_funcs vtable for
96 * the encoder helper.
97 *
98 * Drivers should always use this function instead of drm_connector_init() to
99 * set up writeback connectors.
100 *
101 * Returns: 0 on success, or a negative error code
102 */
103int drm_writeback_connector_init(struct drm_device *dev,
104 struct drm_writeback_connector *wb_connector,
105 const struct drm_connector_funcs *con_funcs,
106 const struct drm_encoder_helper_funcs *enc_helper_funcs,
107 const u32 *formats, int n_formats)
108{
109 struct drm_property_blob *blob;
110 struct drm_connector *connector = &wb_connector->base;
111 struct drm_mode_config *config = &dev->mode_config;
112 int ret = create_writeback_properties(dev);
113
114 if (ret != 0)
115 return ret;
116
117 blob = drm_property_create_blob(dev, n_formats * sizeof(*formats),
118 formats);
119 if (IS_ERR(blob))
120 return PTR_ERR(blob);
121
122 drm_encoder_helper_add(&wb_connector->encoder, enc_helper_funcs);
123 ret = drm_encoder_init(dev, &wb_connector->encoder,
124 &drm_writeback_encoder_funcs,
125 DRM_MODE_ENCODER_VIRTUAL, NULL);
126 if (ret)
127 goto fail;
128
129 connector->interlace_allowed = 0;
130
131 ret = drm_connector_init(dev, connector, con_funcs,
132 DRM_MODE_CONNECTOR_WRITEBACK);
133 if (ret)
134 goto connector_fail;
135
136 ret = drm_mode_connector_attach_encoder(connector,
137 &wb_connector->encoder);
138 if (ret)
139 goto attach_fail;
140
141 INIT_LIST_HEAD(&wb_connector->job_queue);
142 spin_lock_init(&wb_connector->job_lock);
143
144 drm_object_attach_property(&connector->base,
145 config->writeback_fb_id_property, 0);
146
147 drm_object_attach_property(&connector->base,
148 config->writeback_pixel_formats_property,
149 blob->base.id);
150 wb_connector->pixel_formats_blob_ptr = blob;
151
152 return 0;
153
154attach_fail:
155 drm_connector_cleanup(connector);
156connector_fail:
157 drm_encoder_cleanup(&wb_connector->encoder);
158fail:
159 drm_property_blob_put(blob);
160 return ret;
161}
162EXPORT_SYMBOL(drm_writeback_connector_init);
163
164/**
165 * drm_writeback_queue_job - Queue a writeback job for later signalling
166 * @wb_connector: The writeback connector to queue a job on
167 * @job: The job to queue
168 *
169 * This function adds a job to the job_queue for a writeback connector. It
170 * should be considered to take ownership of the writeback job, and so any other
171 * references to the job must be cleared after calling this function.
172 *
173 * Drivers must ensure that for a given writeback connector, jobs are queued in
174 * exactly the same order as they will be completed by the hardware (and
175 * signaled via drm_writeback_signal_completion).
176 *
177 * For every call to drm_writeback_queue_job() there must be exactly one call to
178 * drm_writeback_signal_completion()
179 *
180 * See also: drm_writeback_signal_completion()
181 */
182void drm_writeback_queue_job(struct drm_writeback_connector *wb_connector,
183 struct drm_writeback_job *job)
184{
185 unsigned long flags;
186
187 spin_lock_irqsave(&wb_connector->job_lock, flags);
188 list_add_tail(&job->list_entry, &wb_connector->job_queue);
189 spin_unlock_irqrestore(&wb_connector->job_lock, flags);
190}
191EXPORT_SYMBOL(drm_writeback_queue_job);
192
193/*
194 * @cleanup_work: deferred cleanup of a writeback job
195 *
196 * The job cannot be cleaned up directly in drm_writeback_signal_completion,
197 * because it may be called in interrupt context. Dropping the framebuffer
198 * reference can sleep, and so the cleanup is deferred to a workqueue.
199 */
200static void cleanup_work(struct work_struct *work)
201{
202 struct drm_writeback_job *job = container_of(work,
203 struct drm_writeback_job,
204 cleanup_work);
205 drm_framebuffer_put(job->fb);
206 kfree(job);
207}
208
209
210/**
211 * drm_writeback_signal_completion - Signal the completion of a writeback job
212 * @wb_connector: The writeback connector whose job is complete
213 *
214 * Drivers should call this to signal the completion of a previously queued
215 * writeback job. It should be called as soon as possible after the hardware
216 * has finished writing, and may be called from interrupt context.
217 * It is the driver's responsibility to ensure that for a given connector, the
218 * hardware completes writeback jobs in the same order as they are queued.
219 *
220 * Unless the driver is holding its own reference to the framebuffer, it must
221 * not be accessed after calling this function.
222 *
223 * See also: drm_writeback_queue_job()
224 */
225void
226drm_writeback_signal_completion(struct drm_writeback_connector *wb_connector)
227{
228 unsigned long flags;
229 struct drm_writeback_job *job;
230
231 spin_lock_irqsave(&wb_connector->job_lock, flags);
232 job = list_first_entry_or_null(&wb_connector->job_queue,
233 struct drm_writeback_job,
234 list_entry);
235 if (job)
236 list_del(&job->list_entry);
237 spin_unlock_irqrestore(&wb_connector->job_lock, flags);
238
239 if (WARN_ON(!job))
240 return;
241
242 INIT_WORK(&job->cleanup_work, cleanup_work);
243 queue_work(system_long_wq, &job->cleanup_work);
244}
245EXPORT_SYMBOL(drm_writeback_signal_completion);
include/drm/drm_atomic.h+3−0
@@ -594,6 +594,9 @@ void drm_atomic_set_fence_for_plane(struct drm_plane_state *plane_state, · 593 unmodified lines
594int __must_check594int __must_check
595drm_atomic_set_crtc_for_connector(struct drm_connector_state *conn_state,595drm_atomic_set_crtc_for_connector(struct drm_connector_state *conn_state,
596 struct drm_crtc *crtc);596 struct drm_crtc *crtc);
597int drm_atomic_set_writeback_fb_for_connector(
598 struct drm_connector_state *conn_state,
599 struct drm_framebuffer *fb);
597int __must_check600int __must_check
598drm_atomic_add_affected_connectors(struct drm_atomic_state *state,601drm_atomic_add_affected_connectors(struct drm_atomic_state *state,
599 struct drm_crtc *crtc);602 struct drm_crtc *crtc);
include/drm/drm_connector.h+13−0
@@ -437,6 +437,19 @@ struct drm_connector_state { · 436 unmodified lines
437 * protection. This is most commonly used for HDCP.437 * protection. This is most commonly used for HDCP.
438 */438 */
439 unsigned int content_protection;439 unsigned int content_protection;
440
441 /**
442 * @writeback_job: Writeback job for writeback connectors
443 *
444 * Holds the framebuffer for a writeback connector. As the writeback
445 * completion may be asynchronous to the normal commit cycle, the
446 * writeback job lifetime is managed separately from the normal atomic
447 * state by this object.
448 *
449 * See also: drm_writeback_queue_job() and
450 * drm_writeback_signal_completion()
451 */
452 struct drm_writeback_job *writeback_job;
440};453};
441 454
442/**455/**
include/drm/drm_mode_config.h+15−0
@@ -784,6 +784,21 @@ struct drm_mode_config { · 783 unmodified lines
784 */784 */
785 struct drm_property *panel_orientation_property;785 struct drm_property *panel_orientation_property;
786 786
787 /**
788 * @writeback_fb_id_property: Property for writeback connectors, storing
789 * the ID of the output framebuffer.
790 * See also: drm_writeback_connector_init()
791 */
792 struct drm_property *writeback_fb_id_property;
793
794 /**
795 * @writeback_pixel_formats_property: Property for writeback connectors,
796 * storing an array of the supported pixel formats for the writeback
797 * engine (read-only).
798 * See also: drm_writeback_connector_init()
799 */
800 struct drm_property *writeback_pixel_formats_property;
801
787 /* dumb ioctl parameters */802 /* dumb ioctl parameters */
788 uint32_t preferred_depth, prefer_shadow;803 uint32_t preferred_depth, prefer_shadow;
789 804
include/drm/drm_modeset_helper_vtables.h+11−0
@@ -974,6 +974,17 @@ struct drm_connector_helper_funcs { · 973 unmodified lines
974 */974 */
975 int (*atomic_check)(struct drm_connector *connector,975 int (*atomic_check)(struct drm_connector *connector,
976 struct drm_connector_state *state);976 struct drm_connector_state *state);
977
978 /**
979 * @atomic_commit:
980 *
981 * This hook is to be used by drivers implementing writeback connectors
982 * that need a point when to commit the writeback job to the hardware.
983 *
984 * This callback is used by the atomic modeset helpers.
985 */
986 void (*atomic_commit)(struct drm_connector *connector,
987 struct drm_writeback_job *writeback_job);
977};988};
978 989
979/**990/**
include/drm/drm_writeback.h+91−0
@@ -0,0 +1,91 @@
1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * (C) COPYRIGHT 2016 ARM Limited. All rights reserved.
4 * Author: Brian Starkey <brian.starkey@arm.com>
5 *
6 * This program is free software and is provided to you under the terms of the
7 * GNU General Public License version 2 as published by the Free Software
8 * Foundation, and any use by you of this program is subject to the terms
9 * of such GNU licence.
10 */
11
12#ifndef __DRM_WRITEBACK_H__
13#define __DRM_WRITEBACK_H__
14#include <drm/drm_connector.h>
15#include <drm/drm_encoder.h>
16#include <linux/workqueue.h>
17
18struct drm_writeback_connector {
19 struct drm_connector base;
20
21 /**
22 * @encoder: Internal encoder used by the connector to fulfill
23 * the DRM framework requirements. The users of the
24 * @drm_writeback_connector control the behaviour of the @encoder
25 * by passing the @enc_funcs parameter to drm_writeback_connector_init()
26 * function.
27 */
28 struct drm_encoder encoder;
29
30 /**
31 * @pixel_formats_blob_ptr:
32 *
33 * DRM blob property data for the pixel formats list on writeback
34 * connectors
35 * See also drm_writeback_connector_init()
36 */
37 struct drm_property_blob *pixel_formats_blob_ptr;
38
39 /** @job_lock: Protects job_queue */
40 spinlock_t job_lock;
41
42 /**
43 * @job_queue:
44 *
45 * Holds a list of a connector's writeback jobs; the last item is the
46 * most recent. The first item may be either waiting for the hardware
47 * to begin writing, or currently being written.
48 *
49 * See also: drm_writeback_queue_job() and
50 * drm_writeback_signal_completion()
51 */
52 struct list_head job_queue;
53};
54
55struct drm_writeback_job {
56 /**
57 * @cleanup_work:
58 *
59 * Used to allow drm_writeback_signal_completion to defer dropping the
60 * framebuffer reference to a workqueue
61 */
62 struct work_struct cleanup_work;
63
64 /**
65 * @list_entry:
66 *
67 * List item for the writeback connector's @job_queue
68 */
69 struct list_head list_entry;
70
71 /**
72 * @fb:
73 *
74 * Framebuffer to be written to by the writeback connector. Do not set
75 * directly, use drm_atomic_set_writeback_fb_for_connector()
76 */
77 struct drm_framebuffer *fb;
78};
79
80int drm_writeback_connector_init(struct drm_device *dev,
81 struct drm_writeback_connector *wb_connector,
82 const struct drm_connector_funcs *con_funcs,
83 const struct drm_encoder_helper_funcs *enc_helper_funcs,
84 const u32 *formats, int n_formats);
85
86void drm_writeback_queue_job(struct drm_writeback_connector *wb_connector,
87 struct drm_writeback_job *job);
88
89void drm_writeback_cleanup_job(struct drm_writeback_job *job);
90void drm_writeback_signal_completion(struct drm_writeback_connector *wb_connector);
91#endif
include/uapi/drm/drm_mode.h+1−0
@@ -351,6 +351,7 @@ enum drm_mode_subconnector { · 350 unmodified lines
351#define DRM_MODE_CONNECTOR_VIRTUAL 15351#define DRM_MODE_CONNECTOR_VIRTUAL 15
352#define DRM_MODE_CONNECTOR_DSI 16352#define DRM_MODE_CONNECTOR_DSI 16
353#define DRM_MODE_CONNECTOR_DPI 17353#define DRM_MODE_CONNECTOR_DPI 17
354#define DRM_MODE_CONNECTOR_WRITEBACK 18
354 355
355struct drm_mode_get_connector {356struct drm_mode_get_connector {
356 357