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 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 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 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 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 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 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 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