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
drm_sysfb_get_validated_size0(struct drm_device * dev,const char * name,u64 value,u64 max)13 static 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
drm_sysfb_get_width_si(struct drm_device * dev,const struct screen_info * si)26 int drm_sysfb_get_width_si(struct drm_device *dev, const struct screen_info *si)
27 {
28 return drm_sysfb_get_validated_int0(dev, "width", si->lfb_width, U16_MAX);
29 }
30 EXPORT_SYMBOL(drm_sysfb_get_width_si);
31
drm_sysfb_get_height_si(struct drm_device * dev,const struct screen_info * si)32 int drm_sysfb_get_height_si(struct drm_device *dev, const struct screen_info *si)
33 {
34 return drm_sysfb_get_validated_int0(dev, "height", si->lfb_height, U16_MAX);
35 }
36 EXPORT_SYMBOL(drm_sysfb_get_height_si);
37
drm_sysfb_get_memory_si(struct drm_device * dev,const struct screen_info * si,struct resource * res)38 struct 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, res, 1);
45 if (!num) {
46 drm_warn(dev, "memory resource not found\n");
47 return NULL;
48 }
49
50 return res;
51 }
52 EXPORT_SYMBOL(drm_sysfb_get_memory_si);
53
drm_sysfb_get_stride_si(struct drm_device * dev,const struct screen_info * si,const struct drm_format_info * format,unsigned int width,unsigned int height,u64 size)54 int 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(format, 0, width);
62
63 return drm_sysfb_get_validated_int0(dev, "stride", lfb_linelength, div64_u64(size, height));
64 }
65 EXPORT_SYMBOL(drm_sysfb_get_stride_si);
66
drm_sysfb_get_visible_size_si(struct drm_device * dev,const struct screen_info * si,unsigned int height,unsigned int stride,u64 size)67 u64 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, "visible size", vsize, size);
73 }
74 EXPORT_SYMBOL(drm_sysfb_get_visible_size_si);
75
drm_sysfb_get_format_si(struct drm_device * dev,const struct drm_sysfb_format * formats,size_t nformats,const struct screen_info * si)76 const 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 u32 bits_per_pixel;
83 size_t i;
84
85 bits_per_pixel = __screen_info_lfb_bits_per_pixel(si);
86
87 for (i = 0; i < nformats; ++i) {
88 const struct pixel_format *f = &formats[i].pixel;
89
90 if (bits_per_pixel == f->bits_per_pixel &&
91 si->red_size == f->red.length &&
92 si->red_pos == f->red.offset &&
93 si->green_size == f->green.length &&
94 si->green_pos == f->green.offset &&
95 si->blue_size == f->blue.length &&
96 si->blue_pos == f->blue.offset) {
97 format = drm_format_info(formats[i].fourcc);
98 break;
99 }
100 }
101
102 if (!format)
103 drm_warn(dev, "No compatible color format found\n");
104
105 return format;
106 }
107 EXPORT_SYMBOL(drm_sysfb_get_format_si);
108