/* SPDX-License-Identifier: GPL-2.0-only * * Virtual memory framebuffer access for drawing routines * * Copyright (C) 2025 Zsolt Kajtar (soci@c64.rulez.org) */ /* keeps track of a bit address in framebuffer memory */ struct fb_address { void *address; int bits; }; /* initialize the bit address pointer to the beginning of the frame buffer */ static inline struct fb_address fb_address_init(struct fb_info *p) { void *base = p->screen_buffer; struct fb_address ptr; ptr.address = PTR_ALIGN_DOWN(base, BITS_PER_LONG / BITS_PER_BYTE); ptr.bits = (base - ptr.address) * BITS_PER_BYTE; return ptr; } /* framebuffer write access */ static inline void fb_write_offset(unsigned long val, int offset, const struct fb_address *dst) { unsigned long *mem = dst->address; mem[offset] = val; } /* framebuffer read access */ static inline unsigned long fb_read_offset(int offset, const struct fb_address *src) { unsigned long *mem = src->address; return mem[offset]; }