NetBSD/sys/arch/arm/nvidia/tegra_rtc.c
2015-12-13 17:39:19 +00:00

141 lines
4.0 KiB
C

/* $NetBSD: tegra_rtc.c,v 1.2 2015/12/13 17:39:19 jmcneill Exp $ */
/*-
* Copyright (c) 2015 Jared D. McNeill <jmcneill@invisible.ca>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: tegra_rtc.c,v 1.2 2015/12/13 17:39:19 jmcneill Exp $");
#include <sys/param.h>
#include <sys/bus.h>
#include <sys/device.h>
#include <sys/intr.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/kmem.h>
#include <dev/clock_subr.h>
#include <arm/nvidia/tegra_reg.h>
#include <arm/nvidia/tegra_rtcreg.h>
#include <arm/nvidia/tegra_var.h>
#include <dev/fdt/fdtvar.h>
static int tegra_rtc_match(device_t, cfdata_t, void *);
static void tegra_rtc_attach(device_t, device_t, void *);
struct tegra_rtc_softc {
device_t sc_dev;
bus_space_tag_t sc_bst;
bus_space_handle_t sc_bsh;
struct todr_chip_handle sc_todr;
};
static int tegra_rtc_gettime(todr_chip_handle_t, struct timeval *);
static int tegra_rtc_settime(todr_chip_handle_t, struct timeval *);
CFATTACH_DECL_NEW(tegra_rtc, sizeof(struct tegra_rtc_softc),
tegra_rtc_match, tegra_rtc_attach, NULL, NULL);
#define RTC_READ(sc, reg) \
bus_space_read_4((sc)->sc_bst, (sc)->sc_bsh, (reg))
#define RTC_WRITE(sc, reg, val) \
bus_space_write_4((sc)->sc_bst, (sc)->sc_bsh, (reg), (val))
static int
tegra_rtc_match(device_t parent, cfdata_t cf, void *aux)
{
const char * const compatible[] = { "nvidia,tegra124-rtc", NULL };
struct fdt_attach_args * const faa = aux;
return of_match_compatible(faa->faa_phandle, compatible);
}
static void
tegra_rtc_attach(device_t parent, device_t self, void *aux)
{
struct tegra_rtc_softc * const sc = device_private(self);
struct fdt_attach_args * const faa = aux;
bus_addr_t addr;
bus_size_t size;
int error;
if (fdtbus_get_reg(faa->faa_phandle, 0, &addr, &size) != 0) {
aprint_error(": couldn't get registers\n");
return;
}
sc->sc_dev = self;
sc->sc_bst = faa->faa_bst;
error = bus_space_map(sc->sc_bst, addr, size, 0, &sc->sc_bsh);
if (error) {
aprint_error(": couldn't map %#llx: %d", (uint64_t)addr, error);
return;
}
aprint_naive("\n");
aprint_normal(": RTC\n");
sc->sc_todr.todr_gettime = tegra_rtc_gettime;
sc->sc_todr.todr_settime = tegra_rtc_settime;
sc->sc_todr.cookie = sc;
todr_attach(&sc->sc_todr);
}
static int
tegra_rtc_gettime(todr_chip_handle_t tch, struct timeval *tv)
{
struct tegra_rtc_softc * const sc = tch->cookie;
tv->tv_sec = RTC_READ(sc, RTC_SECONDS_REG);
tv->tv_usec = 0;
return 0;
}
static int
tegra_rtc_settime(todr_chip_handle_t tch, struct timeval *tv)
{
struct tegra_rtc_softc * const sc = tch->cookie;
int retry = 500;
while (--retry > 0) {
if ((RTC_READ(sc, RTC_BUSY_REG) & RTC_BUSY_STATUS) == 0)
break;
delay(1);
}
if (retry == 0) {
device_printf(sc->sc_dev, "RTC write failed (BUSY)\n");
return ETIMEDOUT;
}
RTC_WRITE(sc, RTC_SECONDS_REG, tv->tv_sec);
return 0;
}