drm_sysfb_screen_info.c

  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, "width", 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, "height", 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, res, 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(format, 0, width);
 62
 63	return drm_sysfb_get_validated_int0(dev, "stride", lfb_linelength, div64_u64(size, 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, "visible size", vsize, 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, &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(&pixel, &f->pixel)) {
 94			format = drm_format_info(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);