1// SPDX-License-Identifier: GPL-2.0-only
2
3#include <linux/export.h>
4#include <linux/limits.h>
5#include <linux/minmax.h>
6#include <linux/screen_info.h>
7
8#include <drm/drm_fourcc.h>
9#include <drm/drm_print.h>
10
11#include "drm_sysfb_helper.h"
12
13static s64 drm_sysfb_get_validated_size0(struct drm_device *dev, const char *name,
14 u64 value, u64 max)
15{
16 if (!value) {
17 drm_warn(dev, "%s of 0 not allowed\n", name);
18 return -EINVAL;
19 } else if (value > min(max, S64_MAX)) {
20 drm_warn(dev, "%s of %llu exceeds maximum of %llu\n", name, value, max);
21 return -EINVAL;
22 }
23 return value;
24}
25
26int drm_sysfb_get_width_si(struct drm_device *dev, const struct screen_info *si)
27{
28 return drm_sysfb_get_validated_int0(dev, name: "width", value: si->lfb_width, U16_MAX);
29}
30EXPORT_SYMBOL(drm_sysfb_get_width_si);
31
32int drm_sysfb_get_height_si(struct drm_device *dev, const struct screen_info *si)
33{
34 return drm_sysfb_get_validated_int0(dev, name: "height", value: si->lfb_height, U16_MAX);
35}
36EXPORT_SYMBOL(drm_sysfb_get_height_si);
37
38struct resource *drm_sysfb_get_memory_si(struct drm_device *dev,
39 const struct screen_info *si,
40 struct resource *res)
41{
42 ssize_t num;
43
44 num = screen_info_resources(si, r: res, num: 1);
45 if (!num) {
46 drm_warn(dev, "memory resource not found\n");
47 return NULL;
48 }
49
50 return res;
51}
52EXPORT_SYMBOL(drm_sysfb_get_memory_si);
53
54int drm_sysfb_get_stride_si(struct drm_device *dev, const struct screen_info *si,
55 const struct drm_format_info *format,
56 unsigned int width, unsigned int height, u64 size)
57{
58 u64 lfb_linelength = si->lfb_linelength;
59
60 if (!lfb_linelength)
61 lfb_linelength = drm_format_info_min_pitch(info: format, plane: 0, buffer_width: width);
62
63 return drm_sysfb_get_validated_int0(dev, name: "stride", value: lfb_linelength, max: div64_u64(dividend: size, divisor: height));
64}
65EXPORT_SYMBOL(drm_sysfb_get_stride_si);
66
67u64 drm_sysfb_get_visible_size_si(struct drm_device *dev, const struct screen_info *si,
68 unsigned int height, unsigned int stride, u64 size)
69{
70 u64 vsize = PAGE_ALIGN(height * stride);
71
72 return drm_sysfb_get_validated_size0(dev, name: "visible size", value: vsize, max: size);
73}
74EXPORT_SYMBOL(drm_sysfb_get_visible_size_si);
75
76const struct drm_format_info *drm_sysfb_get_format_si(struct drm_device *dev,
77 const struct drm_sysfb_format *formats,
78 size_t nformats,
79 const struct screen_info *si)
80{
81 const struct drm_format_info *format = NULL;
82 struct pixel_format pixel;
83 size_t i;
84 int ret;
85
86 ret = screen_info_pixel_format(si, f: &pixel);
87 if (ret)
88 return NULL;
89
90 for (i = 0; i < nformats; ++i) {
91 const struct drm_sysfb_format *f = &formats[i];
92
93 if (pixel_format_equal(lhs: &pixel, rhs: &f->pixel)) {
94 format = drm_format_info(format: f->fourcc);
95 break;
96 }
97 }
98
99 if (!format)
100 drm_warn(dev, "No compatible color format found\n");
101
102 return format;
103}
104EXPORT_SYMBOL(drm_sysfb_get_format_si);
105

source code of linux/drivers/gpu/drm/sysfb/drm_sysfb_screen_info.c