1/*	$NetBSD: exynos_rtc.c,v 1.4 2021/01/27 03:10:19 thorpej Exp $ */
2
3/*-
4* Copyright (c) 2015 The NetBSD Foundation, Inc.
5* All rights reserved.
6*
7* This code is derived from software contributed to The NetBSD Foundation
8* by Marty Fouts
9*
10* Redistribution and use in source and binary forms, with or without
11* modification, are permitted provided that the following conditions
12* are met:
13* 1. Redistributions of source code must retain the above copyright
14*    notice, this list of conditions and the following disclaimer.
15* 2. Redistributions in binary form must reproduce the above copyright
16*    notice, this list of conditions and the following disclaimer in the
17*    documentation and/or other materials provided with the distribution.
18*
19* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22* PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29* POSSIBILITY OF SUCH DAMAGE.
30*/
31
32#include "opt_exynos.h"
33#include "opt_arm_debug.h"
34#include "gpio.h"
35
36#include <sys/cdefs.h>
37__KERNEL_RCSID(1, "$NetBSD: exynos_rtc.c,v 1.4 2021/01/27 03:10:19 thorpej Exp $");
38
39#include <sys/param.h>
40#include <sys/bus.h>
41#include <sys/device.h>
42#include <sys/intr.h>
43#include <sys/systm.h>
44#include <sys/kernel.h>
45#include <sys/kmem.h>
46
47#include <dev/clock_subr.h>
48
49#include <arm/samsung/exynos_reg.h>
50#include <arm/samsung/exynos_intr.h>
51
52#include <dev/fdt/fdtvar.h>
53
54struct exynos_rtc_softc {
55	device_t		sc_dev;
56	bus_space_tag_t		sc_bst;
57	bus_space_handle_t	sc_bsh;
58
59	struct todr_chip_handle sc_todr;
60};
61
62static int exynos_rtc_match(device_t, cfdata_t, void *);
63static void exynos_rtc_attach(device_t, device_t, void *);
64
65static int	exynos_rtc_gettime(todr_chip_handle_t, struct timeval *);
66static int	exynos_rtc_settime(todr_chip_handle_t, struct timeval *);
67
68CFATTACH_DECL_NEW(exynos_rtc, sizeof(struct exynos_rtc_softc),
69	exynos_rtc_match, exynos_rtc_attach, NULL, NULL);
70
71#define RTC_READ(sc, reg)	\
72	bus_space_read_4((sc)->sc_bst, (sc)->sc_bsh, (reg))
73#define RTC_WRITE(sc, reg, val)	\
74	bus_space_write_4((sc)->sc_bst, (sc)->sc_bsh, (reg), (val))
75
76static const struct device_compatible_entry compat_data[] = {
77	{ .compat = "samsung,s3c6410-rtc" },
78	DEVICE_COMPAT_EOL
79};
80
81static int
82exynos_rtc_match(device_t parent, cfdata_t cf, void *aux)
83{
84	struct fdt_attach_args * const faa = aux;
85
86	return of_compatible_match(faa->faa_phandle, compat_data);
87}
88
89static void
90exynos_rtc_attach(device_t parent, device_t self, void *aux)
91{
92	struct exynos_rtc_softc * const sc
93		= kmem_zalloc(sizeof(*sc), KM_SLEEP);
94	struct fdt_attach_args * const faa = aux;
95	bus_addr_t addr;
96	bus_size_t size;
97	int error;
98
99	if (fdtbus_get_reg(faa->faa_phandle, 0, &addr, &size) != 0) {
100		aprint_error(": couldn't get registers\n");
101		return;
102	}
103
104	aprint_normal(" @ 0x%08x", (uint)addr);
105	sc->sc_dev = self;
106	sc->sc_bst = faa->faa_bst;
107	error = bus_space_map(sc->sc_bst, addr, size, 0, &sc->sc_bsh);
108	if (error) {
109		aprint_error(": couldn't map %#" PRIxBUSADDR ": %d",
110			     addr, error);
111		return;
112	}
113
114	aprint_naive("\n");
115	aprint_normal(": RTC\n");
116
117	sc->sc_todr.todr_gettime = exynos_rtc_gettime;
118	sc->sc_todr.todr_settime = exynos_rtc_settime;
119	sc->sc_todr.cookie = sc;
120	todr_attach(&sc->sc_todr);
121
122}
123
124static int
125exynos_rtc_gettime(todr_chip_handle_t tch, struct timeval *tv)
126{
127	struct exynos_rtc_softc * const sc = tch->cookie;
128
129	tv->tv_sec = RTC_READ(sc, EXYNOS5_RTC_OFFSET);
130	tv->tv_usec = 0;
131
132	return 0;
133}
134
135static int
136exynos_rtc_settime(todr_chip_handle_t tch, struct timeval *tv)
137{
138	struct exynos_rtc_softc * const sc = tch->cookie;
139	int retry = 500;
140
141	while (--retry > 0) {
142		if (!RTC_READ(sc, EXYNOS5_RTC_OFFSET))
143			break;
144		delay(1);
145	}
146	if (retry == 0) {
147		device_printf(sc->sc_dev, "RTC write failed (BUSY)\n");
148		return ETIMEDOUT;
149	}
150
151	RTC_WRITE(sc, EXYNOS5_RTC_OFFSET, tv->tv_sec);
152
153	return 0;
154}
155