drivers/gpu/drm/drm_fb_cma_helper.c

   1 /*
   2  * drm kms/fb cma (contiguous memory allocator) helper functions
   3  *
   4  * Copyright (C) 2012 Analog Device Inc.
   5  *   Author: Lars-Peter Clausen <lars@metafoo.de>
   6  *
   7  * Based on udl_fbdev.c
   8  *  Copyright (C) 2012 Red Hat
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public License
  12  * as published by the Free Software Foundation; either version 2
  13  * of the License, or (at your option) any later version.
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  */
  19
  20 #include <drm/drmP.h>
  21 #include <drm/drm_client.h>
  22 #include <drm/drm_fb_helper.h>
  23 #include <drm/drm_framebuffer.h>
  24 #include <drm/drm_gem_cma_helper.h>
  25 #include <drm/drm_gem_framebuffer_helper.h>
  26 #include <drm/drm_fb_cma_helper.h>
  27 #include <drm/drm_print.h>
  28 #include <linux/module.h>
  29
  30 struct drm_fbdev_cma {
  31         struct drm_fb_helper    fb_helper;
  32 };
  33
  34 /**
  35  * DOC: framebuffer cma helper functions
  36  *
  37  * Provides helper functions for creating a cma (contiguous memory allocator)
  38  * backed framebuffer.
  39  *
  40  * drm_gem_fb_create() is used in the &drm_mode_config_funcs.fb_create
  41  * callback function to create a cma backed framebuffer.
  42  *
  43  * An fbdev framebuffer backed by cma is also available by calling
  44  * drm_fb_cma_fbdev_init(). drm_fb_cma_fbdev_fini() tears it down.
  45  */
  46
  47 static inline struct drm_fbdev_cma *to_fbdev_cma(struct drm_fb_helper *helper)
  48 {
  49         return container_of(helper, struct drm_fbdev_cma, fb_helper);
  50 }
  51
  52 /**
  53  * drm_fb_cma_get_gem_obj() - Get CMA GEM object for framebuffer
  54  * @fb: The framebuffer
  55  * @plane: Which plane
  56  *
  57  * Return the CMA GEM object for given framebuffer.
  58  *
  59  * This function will usually be called from the CRTC callback functions.
  60  */
  61 struct drm_gem_cma_object *drm_fb_cma_get_gem_obj(struct drm_framebuffer *fb,
  62                                                   unsigned int plane)
  63 {
  64         struct drm_gem_object *gem;
  65
  66         gem = drm_gem_fb_get_obj(fb, plane);
  67         if (!gem)
  68                 return NULL;
  69
  70         return to_drm_gem_cma_obj(gem);
  71 }
  72 EXPORT_SYMBOL_GPL(drm_fb_cma_get_gem_obj);
  73
  74 /**
  75  * drm_fb_cma_get_gem_addr() - Get physical address for framebuffer, for pixel
  76  * formats where values are grouped in blocks this will get you the beginning of
  77  * the block
  78  * @fb: The framebuffer
  79  * @state: Which state of drm plane
  80  * @plane: Which plane
  81  * Return the CMA GEM address for given framebuffer.
  82  *
  83  * This function will usually be called from the PLANE callback functions.
  84  */
  85 dma_addr_t drm_fb_cma_get_gem_addr(struct drm_framebuffer *fb,
  86                                    struct drm_plane_state *state,
  87                                    unsigned int plane)
  88 {
  89         struct drm_gem_cma_object *obj;
  90         dma_addr_t paddr;
  91         u8 h_div = 1, v_div = 1;
  92         u32 block_w = drm_format_info_block_width(fb->format, plane);
  93         u32 block_h = drm_format_info_block_height(fb->format, plane);
  94         u32 block_size = fb->format->char_per_block[plane];
  95         u32 sample_x;
  96         u32 sample_y;
  97         u32 block_start_y;
  98         u32 num_hblocks;
  99
 100         obj = drm_fb_cma_get_gem_obj(fb, plane);
 101         if (!obj)
 102                 return 0;
 103
 104         paddr = obj->paddr + fb->offsets[plane];
 105
 106         if (plane > 0) {
 107                 h_div = fb->format->hsub;
 108                 v_div = fb->format->vsub;
 109         }
 110
 111         sample_x = (state->src_x >> 16) / h_div;
 112         sample_y = (state->src_y >> 16) / v_div;
 113         block_start_y = (sample_y / block_h) * block_h;
 114         num_hblocks = sample_x / block_w;
 115
 116         paddr += fb->pitches[plane] * block_start_y;
 117         paddr += block_size * num_hblocks;
 118
 119         return paddr;
 120 }
 121 EXPORT_SYMBOL_GPL(drm_fb_cma_get_gem_addr);
 122
 123 /**
 124  * drm_fb_cma_fbdev_init() - Allocate and initialize fbdev emulation
 125  * @dev: DRM device
 126  * @preferred_bpp: Preferred bits per pixel for the device.
 127  *                 @dev->mode_config.preferred_depth is used if this is zero.
 128  * @max_conn_count: Maximum number of connectors.
 129  *                  @dev->mode_config.num_connector is used if this is zero.
 130  *
 131  * Returns:
 132  * Zero on success or negative error code on failure.
 133  */
 134 int drm_fb_cma_fbdev_init(struct drm_device *dev, unsigned int preferred_bpp,
 135                           unsigned int max_conn_count)
 136 {
 137         struct drm_fbdev_cma *fbdev_cma;
 138
 139         /* dev->fb_helper will indirectly point to fbdev_cma after this call */
 140         fbdev_cma = drm_fbdev_cma_init(dev, preferred_bpp, max_conn_count);
 141         return PTR_ERR_OR_ZERO(fbdev_cma);
 142 }
 143 EXPORT_SYMBOL_GPL(drm_fb_cma_fbdev_init);
 144
 145 /**
 146  * drm_fb_cma_fbdev_fini() - Teardown fbdev emulation
 147  * @dev: DRM device
 148  */
 149 void drm_fb_cma_fbdev_fini(struct drm_device *dev)
 150 {
 151         if (dev->fb_helper)
 152                 drm_fbdev_cma_fini(to_fbdev_cma(dev->fb_helper));
 153 }
 154 EXPORT_SYMBOL_GPL(drm_fb_cma_fbdev_fini);
 155
 156 static const struct drm_fb_helper_funcs drm_fb_cma_helper_funcs = {
 157         .fb_probe = drm_fb_helper_generic_probe,
 158 };
 159
 160 /**
 161  * drm_fbdev_cma_init() - Allocate and initializes a drm_fbdev_cma struct
 162  * @dev: DRM device
 163  * @preferred_bpp: Preferred bits per pixel for the device
 164  * @max_conn_count: Maximum number of connectors
 165  *
 166  * Returns a newly allocated drm_fbdev_cma struct or a ERR_PTR.
 167  */
 168 struct drm_fbdev_cma *drm_fbdev_cma_init(struct drm_device *dev,
 169         unsigned int preferred_bpp, unsigned int max_conn_count)
 170 {
 171         struct drm_fbdev_cma *fbdev_cma;
 172         struct drm_fb_helper *fb_helper;
 173         int ret;
 174
 175         fbdev_cma = kzalloc(sizeof(*fbdev_cma), GFP_KERNEL);
 176         if (!fbdev_cma)
 177                 return ERR_PTR(-ENOMEM);
 178
 179         fb_helper = &fbdev_cma->fb_helper;
 180
 181         ret = drm_client_init(dev, &fb_helper->client, "fbdev", NULL);
 182         if (ret)
 183                 goto err_free;
 184
 185         ret = drm_fb_helper_fbdev_setup(dev, fb_helper, &drm_fb_cma_helper_funcs,
 186                                         preferred_bpp, max_conn_count);
 187         if (ret)
 188                 goto err_client_put;
 189
 190         drm_client_add(&fb_helper->client);
 191
 192         return fbdev_cma;
 193
 194 err_client_put:
 195         drm_client_release(&fb_helper->client);
 196 err_free:
 197         kfree(fbdev_cma);
 198
 199         return ERR_PTR(ret);
 200 }
 201 EXPORT_SYMBOL_GPL(drm_fbdev_cma_init);
 202
 203 /**
 204  * drm_fbdev_cma_fini() - Free drm_fbdev_cma struct
 205  * @fbdev_cma: The drm_fbdev_cma struct
 206  */
 207 void drm_fbdev_cma_fini(struct drm_fbdev_cma *fbdev_cma)
 208 {
 209         drm_fb_helper_unregister_fbi(&fbdev_cma->fb_helper);
 210         /* All resources have now been freed by drm_fbdev_fb_destroy() */
 211 }
 212 EXPORT_SYMBOL_GPL(drm_fbdev_cma_fini);
 213
 214 /**
 215  * drm_fbdev_cma_restore_mode() - Restores initial framebuffer mode
 216  * @fbdev_cma: The drm_fbdev_cma struct, may be NULL
 217  *
 218  * This function is usually called from the &drm_driver.lastclose callback.
 219  */
 220 void drm_fbdev_cma_restore_mode(struct drm_fbdev_cma *fbdev_cma)
 221 {
 222         if (fbdev_cma)
 223                 drm_fb_helper_restore_fbdev_mode_unlocked(&fbdev_cma->fb_helper);
 224 }
 225 EXPORT_SYMBOL_GPL(drm_fbdev_cma_restore_mode);
 226
 227 /**
 228  * drm_fbdev_cma_hotplug_event() - Poll for hotpulug events
 229  * @fbdev_cma: The drm_fbdev_cma struct, may be NULL
 230  *
 231  * This function is usually called from the &drm_mode_config.output_poll_changed
 232  * callback.
 233  */
 234 void drm_fbdev_cma_hotplug_event(struct drm_fbdev_cma *fbdev_cma)
 235 {
 236         if (fbdev_cma)
 237                 drm_fb_helper_hotplug_event(&fbdev_cma->fb_helper);
 238 }
 239 EXPORT_SYMBOL_GPL(drm_fbdev_cma_hotplug_event);