// SPDX-License-Identifier: GPL-2.0-only /* * Generic MMIO clocksource support */ #include <linux/clocksource.h> #include <linux/errno.h> #include <linux/init.h> #include <linux/slab.h> struct clocksource_mmio { void __iomem *reg; struct clocksource clksrc; }; static inline struct clocksource_mmio *to_mmio_clksrc(struct clocksource *c) { return container_of(c, struct clocksource_mmio, clksrc); } u64 clocksource_mmio_readl_up(struct clocksource *c) { return (u64)readl_relaxed(to_mmio_clksrc(c)->reg); } u64 clocksource_mmio_readl_down(struct clocksource *c) { return ~(u64)readl_relaxed(to_mmio_clksrc(c)->reg) & c->mask; } u64 clocksource_mmio_readw_up(struct clocksource *c) { return (u64)readw_relaxed(to_mmio_clksrc(c)->reg); } u64 clocksource_mmio_readw_down(struct clocksource *c) { return ~(u64)readw_relaxed(to_mmio_clksrc(c)->reg) & c->mask; } /** * clocksource_mmio_init - Initialize a simple mmio based clocksource * @base: Virtual address of the clock readout register * @name: Name of the clocksource * @hz: Frequency of the clocksource in Hz * @rating: Rating of the clocksource * @bits: Number of valid bits * @read: One of clocksource_mmio_read*() above */ int __init clocksource_mmio_init(void __iomem *base, const char *name, unsigned long hz, int rating, unsigned bits, u64 (*read)(struct clocksource *)) { struct clocksource_mmio *cs; if (bits > 64 || bits < 16) return -EINVAL; cs = kzalloc(sizeof(struct clocksource_mmio), GFP_KERNEL); if (!cs) return -ENOMEM; cs->reg = base; cs->clksrc.name = name; cs->clksrc.rating = rating; cs->clksrc.read = read; cs->clksrc.mask = CLOCKSOURCE_MASK(bits); cs->clksrc.flags = CLOCK_SOURCE_IS_CONTINUOUS; return clocksource_register_hz(&cs->clksrc, hz); }