1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * drm kms/fb cma (contiguous memory allocator) helper functions
4 *
5 * Copyright (C) 2012 Analog Devices Inc.
6 * Author: Lars-Peter Clausen <lars@metafoo.de>
7 *
8 * Based on udl_fbdev.c
9 * Copyright (C) 2012 Red Hat
10 */
11
12 #include <drm/drm_fb_cma_helper.h>
13 #include <drm/drm_fourcc.h>
14 #include <drm/drm_framebuffer.h>
15 #include <drm/drm_gem_cma_helper.h>
16 #include <drm/drm_gem_framebuffer_helper.h>
17 #include <drm/drm_plane.h>
18 #include <linux/module.h>
19
20 /**
21 * DOC: framebuffer cma helper functions
22 *
23 * Provides helper functions for creating a cma (contiguous memory allocator)
24 * backed framebuffer.
25 *
26 * drm_gem_fb_create() is used in the &drm_mode_config_funcs.fb_create
27 * callback function to create a cma backed framebuffer.
28 */
29
30 /**
31 * drm_fb_cma_get_gem_obj() - Get CMA GEM object for framebuffer
32 * @fb: The framebuffer
33 * @plane: Which plane
34 *
35 * Return the CMA GEM object for given framebuffer.
36 *
37 * This function will usually be called from the CRTC callback functions.
38 */
drm_fb_cma_get_gem_obj(struct drm_framebuffer * fb,unsigned int plane)39 struct drm_gem_cma_object *drm_fb_cma_get_gem_obj(struct drm_framebuffer *fb,
40 unsigned int plane)
41 {
42 struct drm_gem_object *gem;
43
44 gem = drm_gem_fb_get_obj(fb, plane);
45 if (!gem)
46 return NULL;
47
48 return to_drm_gem_cma_obj(gem);
49 }
50 EXPORT_SYMBOL_GPL(drm_fb_cma_get_gem_obj);
51
52 /**
53 * drm_fb_cma_get_gem_addr() - Get physical address for framebuffer, for pixel
54 * formats where values are grouped in blocks this will get you the beginning of
55 * the block
56 * @fb: The framebuffer
57 * @state: Which state of drm plane
58 * @plane: Which plane
59 * Return the CMA GEM address for given framebuffer.
60 *
61 * This function will usually be called from the PLANE callback functions.
62 */
drm_fb_cma_get_gem_addr(struct drm_framebuffer * fb,struct drm_plane_state * state,unsigned int plane)63 dma_addr_t drm_fb_cma_get_gem_addr(struct drm_framebuffer *fb,
64 struct drm_plane_state *state,
65 unsigned int plane)
66 {
67 struct drm_gem_cma_object *obj;
68 dma_addr_t paddr;
69 u8 h_div = 1, v_div = 1;
70 u32 block_w = drm_format_info_block_width(fb->format, plane);
71 u32 block_h = drm_format_info_block_height(fb->format, plane);
72 u32 block_size = fb->format->char_per_block[plane];
73 u32 sample_x;
74 u32 sample_y;
75 u32 block_start_y;
76 u32 num_hblocks;
77
78 obj = drm_fb_cma_get_gem_obj(fb, plane);
79 if (!obj)
80 return 0;
81
82 paddr = obj->paddr + fb->offsets[plane];
83
84 if (plane > 0) {
85 h_div = fb->format->hsub;
86 v_div = fb->format->vsub;
87 }
88
89 sample_x = (state->src_x >> 16) / h_div;
90 sample_y = (state->src_y >> 16) / v_div;
91 block_start_y = (sample_y / block_h) * block_h;
92 num_hblocks = sample_x / block_w;
93
94 paddr += fb->pitches[plane] * block_start_y;
95 paddr += block_size * num_hblocks;
96
97 return paddr;
98 }
99 EXPORT_SYMBOL_GPL(drm_fb_cma_get_gem_addr);
100
