1/*
 2 * Generic MMIO clocksource support
 3 *
 4 * This program is free software; you can redistribute it and/or modify
 5 * it under the terms of the GNU General Public License version 2 as
 6 * published by the Free Software Foundation.
 7 */
 8#include <linux/clocksource.h>
 9#include <linux/errno.h>
10#include <linux/init.h>
11#include <linux/slab.h>
12
13struct clocksource_mmio {
14	void __iomem *reg;
15	struct clocksource clksrc;
16};
17
18static inline struct clocksource_mmio *to_mmio_clksrc(struct clocksource *c)
19{
20	return container_of(c, struct clocksource_mmio, clksrc);
21}
22
23cycle_t clocksource_mmio_readl_up(struct clocksource *c)
24{
25	return readl_relaxed(to_mmio_clksrc(c)->reg);
26}
27
28cycle_t clocksource_mmio_readl_down(struct clocksource *c)
29{
30	return ~readl_relaxed(to_mmio_clksrc(c)->reg);
31}
32
33cycle_t clocksource_mmio_readw_up(struct clocksource *c)
34{
35	return readw_relaxed(to_mmio_clksrc(c)->reg);
36}
37
38cycle_t clocksource_mmio_readw_down(struct clocksource *c)
39{
40	return ~(unsigned)readw_relaxed(to_mmio_clksrc(c)->reg);
41}
42
43/**
44 * clocksource_mmio_init - Initialize a simple mmio based clocksource
45 * @base:	Virtual address of the clock readout register
46 * @name:	Name of the clocksource
47 * @hz:		Frequency of the clocksource in Hz
48 * @rating:	Rating of the clocksource
49 * @bits:	Number of valid bits
50 * @read:	One of clocksource_mmio_read*() above
51 */
52int __init clocksource_mmio_init(void __iomem *base, const char *name,
53	unsigned long hz, int rating, unsigned bits,
54	cycle_t (*read)(struct clocksource *))
55{
56	struct clocksource_mmio *cs;
57
58	if (bits > 32 || bits < 16)
59		return -EINVAL;
60
61	cs = kzalloc(sizeof(struct clocksource_mmio), GFP_KERNEL);
62	if (!cs)
63		return -ENOMEM;
64
65	cs->reg = base;
66	cs->clksrc.name = name;
67	cs->clksrc.rating = rating;
68	cs->clksrc.read = read;
69	cs->clksrc.mask = CLOCKSOURCE_MASK(bits);
70	cs->clksrc.flags = CLOCK_SOURCE_IS_CONTINUOUS;
71
72	return clocksource_register_hz(&cs->clksrc, hz);
73}

 1// SPDX-License-Identifier: GPL-2.0-only
 2/*
 3 * Generic MMIO clocksource support
 
 
 
 
 4 */
 5#include <linux/clocksource.h>
 6#include <linux/errno.h>
 7#include <linux/init.h>
 8#include <linux/slab.h>
 9
10struct clocksource_mmio {
11	void __iomem *reg;
12	struct clocksource clksrc;
13};
14
15static inline struct clocksource_mmio *to_mmio_clksrc(struct clocksource *c)
16{
17	return container_of(c, struct clocksource_mmio, clksrc);
18}
19
20u64 clocksource_mmio_readl_up(struct clocksource *c)
21{
22	return (u64)readl_relaxed(to_mmio_clksrc(c)->reg);
23}
24
25u64 clocksource_mmio_readl_down(struct clocksource *c)
26{
27	return ~(u64)readl_relaxed(to_mmio_clksrc(c)->reg) & c->mask;
28}
29
30u64 clocksource_mmio_readw_up(struct clocksource *c)
31{
32	return (u64)readw_relaxed(to_mmio_clksrc(c)->reg);
33}
34
35u64 clocksource_mmio_readw_down(struct clocksource *c)
36{
37	return ~(u64)readw_relaxed(to_mmio_clksrc(c)->reg) & c->mask;
38}
39
40/**
41 * clocksource_mmio_init - Initialize a simple mmio based clocksource
42 * @base:	Virtual address of the clock readout register
43 * @name:	Name of the clocksource
44 * @hz:		Frequency of the clocksource in Hz
45 * @rating:	Rating of the clocksource
46 * @bits:	Number of valid bits
47 * @read:	One of clocksource_mmio_read*() above
48 */
49int __init clocksource_mmio_init(void __iomem *base, const char *name,
50	unsigned long hz, int rating, unsigned bits,
51	u64 (*read)(struct clocksource *))
52{
53	struct clocksource_mmio *cs;
54
55	if (bits > 64 || bits < 16)
56		return -EINVAL;
57
58	cs = kzalloc(sizeof(struct clocksource_mmio), GFP_KERNEL);
59	if (!cs)
60		return -ENOMEM;
61
62	cs->reg = base;
63	cs->clksrc.name = name;
64	cs->clksrc.rating = rating;
65	cs->clksrc.read = read;
66	cs->clksrc.mask = CLOCKSOURCE_MASK(bits);
67	cs->clksrc.flags = CLOCK_SOURCE_IS_CONTINUOUS;
68
69	return clocksource_register_hz(&cs->clksrc, hz);
70}