drivers/gpu/drm/drm_simple_kms_helper.c

   1 /*
   2  * Copyright (C) 2016 Noralf Trønnes
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  */
   9
  10 #include <drm/drmP.h>
  11 #include <drm/drm_atomic.h>
  12 #include <drm/drm_atomic_helper.h>
  13 #include <drm/drm_crtc_helper.h>
  14 #include <drm/drm_plane_helper.h>
  15 #include <drm/drm_simple_kms_helper.h>
  16 #include <linux/slab.h>
  17
  18 /**
  19  * DOC: overview
  20  *
  21  * This helper library provides helpers for drivers for simple display
  22  * hardware.
  23  *
  24  * drm_simple_display_pipe_init() initializes a simple display pipeline
  25  * which has only one full-screen scanout buffer feeding one output. The
  26  * pipeline is represented by struct &drm_simple_display_pipe and binds
  27  * together &drm_plane, &drm_crtc and &drm_encoder structures into one fixed
  28  * entity. Some flexibility for code reuse is provided through a separately
  29  * allocated &drm_connector object and supporting optional &drm_bridge
  30  * encoder drivers.
  31  */
  32
  33 static const struct drm_encoder_funcs drm_simple_kms_encoder_funcs = {
  34         .destroy = drm_encoder_cleanup,
  35 };
  36
  37 static void drm_simple_kms_crtc_enable(struct drm_crtc *crtc)
  38 {
  39         struct drm_simple_display_pipe *pipe;
  40
  41         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
  42         if (!pipe->funcs || !pipe->funcs->enable)
  43                 return;
  44
  45         pipe->funcs->enable(pipe, crtc->state);
  46 }
  47
  48 static void drm_simple_kms_crtc_disable(struct drm_crtc *crtc)
  49 {
  50         struct drm_simple_display_pipe *pipe;
  51
  52         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
  53         if (!pipe->funcs || !pipe->funcs->disable)
  54                 return;
  55
  56         pipe->funcs->disable(pipe);
  57 }
  58
  59 static const struct drm_crtc_helper_funcs drm_simple_kms_crtc_helper_funcs = {
  60         .disable = drm_simple_kms_crtc_disable,
  61         .enable = drm_simple_kms_crtc_enable,
  62 };
  63
  64 static const struct drm_crtc_funcs drm_simple_kms_crtc_funcs = {
  65         .reset = drm_atomic_helper_crtc_reset,
  66         .destroy = drm_crtc_cleanup,
  67         .set_config = drm_atomic_helper_set_config,
  68         .page_flip = drm_atomic_helper_page_flip,
  69         .atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
  70         .atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
  71 };
  72
  73 static int drm_simple_kms_plane_atomic_check(struct drm_plane *plane,
  74                                         struct drm_plane_state *plane_state)
  75 {
  76         struct drm_rect clip = { 0 };
  77         struct drm_simple_display_pipe *pipe;
  78         struct drm_crtc_state *crtc_state;
  79         int ret;
  80
  81         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
  82         crtc_state = drm_atomic_get_existing_crtc_state(plane_state->state,
  83                                                         &pipe->crtc);
  84         if (crtc_state->enable != !!plane_state->crtc)
  85                 return -EINVAL; /* plane must match crtc enable state */
  86
  87         if (!crtc_state->enable)
  88                 return 0; /* nothing to check when disabling or disabled */
  89
  90         clip.x2 = crtc_state->adjusted_mode.hdisplay;
  91         clip.y2 = crtc_state->adjusted_mode.vdisplay;
  92
  93         ret = drm_plane_helper_check_state(plane_state, &clip,
  94                                            DRM_PLANE_HELPER_NO_SCALING,
  95                                            DRM_PLANE_HELPER_NO_SCALING,
  96                                            false, true);
  97         if (ret)
  98                 return ret;
  99
 100         if (!plane_state->visible)
 101                 return -EINVAL;
 102
 103         if (!pipe->funcs || !pipe->funcs->check)
 104                 return 0;
 105
 106         return pipe->funcs->check(pipe, plane_state, crtc_state);
 107 }
 108
 109 static void drm_simple_kms_plane_atomic_update(struct drm_plane *plane,
 110                                         struct drm_plane_state *pstate)
 111 {
 112         struct drm_simple_display_pipe *pipe;
 113
 114         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 115         if (!pipe->funcs || !pipe->funcs->update)
 116                 return;
 117
 118         pipe->funcs->update(pipe, pstate);
 119 }
 120
 121 static const struct drm_plane_helper_funcs drm_simple_kms_plane_helper_funcs = {
 122         .atomic_check = drm_simple_kms_plane_atomic_check,
 123         .atomic_update = drm_simple_kms_plane_atomic_update,
 124 };
 125
 126 static const struct drm_plane_funcs drm_simple_kms_plane_funcs = {
 127         .update_plane           = drm_atomic_helper_update_plane,
 128         .disable_plane          = drm_atomic_helper_disable_plane,
 129         .destroy                = drm_plane_cleanup,
 130         .reset                  = drm_atomic_helper_plane_reset,
 131         .atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
 132         .atomic_destroy_state   = drm_atomic_helper_plane_destroy_state,
 133 };
 134
 135 /**
 136  * drm_simple_display_pipe_init - Initialize a simple display pipeline
 137  * @dev: DRM device
 138  * @pipe: simple display pipe object to initialize
 139  * @funcs: callbacks for the display pipe (optional)
 140  * @formats: array of supported formats (%DRM_FORMAT_*)
 141  * @format_count: number of elements in @formats
 142  * @connector: connector to attach and register
 143  *
 144  * Sets up a display pipeline which consist of a really simple
 145  * plane-crtc-encoder pipe coupled with the provided connector.
 146  * Teardown of a simple display pipe is all handled automatically by the drm
 147  * core through calling drm_mode_config_cleanup(). Drivers afterwards need to
 148  * release the memory for the structure themselves.
 149  *
 150  * Returns:
 151  * Zero on success, negative error code on failure.
 152  */
 153 int drm_simple_display_pipe_init(struct drm_device *dev,
 154                         struct drm_simple_display_pipe *pipe,
 155                         const struct drm_simple_display_pipe_funcs *funcs,
 156                         const uint32_t *formats, unsigned int format_count,
 157                         struct drm_connector *connector)
 158 {
 159         struct drm_encoder *encoder = &pipe->encoder;
 160         struct drm_plane *plane = &pipe->plane;
 161         struct drm_crtc *crtc = &pipe->crtc;
 162         int ret;
 163
 164         pipe->connector = connector;
 165         pipe->funcs = funcs;
 166
 167         drm_plane_helper_add(plane, &drm_simple_kms_plane_helper_funcs);
 168         ret = drm_universal_plane_init(dev, plane, 0,
 169                                        &drm_simple_kms_plane_funcs,
 170                                        formats, format_count,
 171                                        DRM_PLANE_TYPE_PRIMARY, NULL);
 172         if (ret)
 173                 return ret;
 174
 175         drm_crtc_helper_add(crtc, &drm_simple_kms_crtc_helper_funcs);
 176         ret = drm_crtc_init_with_planes(dev, crtc, plane, NULL,
 177                                         &drm_simple_kms_crtc_funcs, NULL);
 178         if (ret)
 179                 return ret;
 180
 181         encoder->possible_crtcs = 1 << drm_crtc_index(crtc);
 182         ret = drm_encoder_init(dev, encoder, &drm_simple_kms_encoder_funcs,
 183                                DRM_MODE_ENCODER_NONE, NULL);
 184         if (ret)
 185                 return ret;
 186
 187         return drm_mode_connector_attach_encoder(connector, encoder);
 188 }
 189 EXPORT_SYMBOL(drm_simple_display_pipe_init);
 190
 191 MODULE_LICENSE("GPL");