/* SPDX-License-Identifier: GPL-2.0-only * * I/O 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 __iomem *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 __iomem *base = p->screen_base; 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) { #if BITS_PER_LONG == 32 fb_writel(val, dst->address + offset * (BITS_PER_LONG / BITS_PER_BYTE)); #else fb_writeq(val, dst->address + offset * (BITS_PER_LONG / BITS_PER_BYTE)); #endif } /* framebuffer read access */ static inline unsigned long fb_read_offset(int offset, const struct fb_address *src) { #if BITS_PER_LONG == 32 return fb_readl(src->address + offset * (BITS_PER_LONG / BITS_PER_BYTE)); #else return fb_readq(src->address + offset * (BITS_PER_LONG / BITS_PER_BYTE)); #endif }