Add a driver for the imx6 on-chip realtime clock.
This driver is standard rather than optional because it can always provide time after a reboot, but it will only provide time after a power cycle if battery power is supplied to the chip's SNVS power domain.
This commit is contained in:
Ian Lepore
parent
1698cbd919
commit
3a28d1b6e3
@ -14,6 +14,7 @@ arm/freescale/imx/imx6_ccm.c standard
|
|||||||
arm/freescale/imx/imx6_machdep.c standard
|
arm/freescale/imx/imx6_machdep.c standard
|
||||||
arm/freescale/imx/imx6_mp.c optional smp
|
arm/freescale/imx/imx6_mp.c optional smp
|
||||||
arm/freescale/imx/imx6_pl310.c standard
|
arm/freescale/imx/imx6_pl310.c standard
|
||||||
|
arm/freescale/imx/imx6_snvs.c standard
|
||||||
arm/freescale/imx/imx6_src.c standard
|
arm/freescale/imx/imx6_src.c standard
|
||||||
arm/freescale/imx/imx_epit.c standard
|
arm/freescale/imx/imx_epit.c standard
|
||||||
arm/freescale/imx/imx_iomux.c standard
|
arm/freescale/imx/imx_iomux.c standard
|
||||||
|
|||||||
228
sys/arm/freescale/imx/imx6_snvs.c
Normal file
228
sys/arm/freescale/imx/imx6_snvs.c
Normal file
@ -0,0 +1,228 @@
|
|||||||
|
/*-
|
||||||
|
* Copyright (c) 2017 Ian Lepore <ian@freebsd.org>
|
||||||
|
* 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 AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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>
|
||||||
|
__FBSDID("$FreeBSD$");
|
||||||
|
|
||||||
|
/*
|
||||||
|
* Driver for imx6 Secure Non-Volatile Storage system, which really means "all
|
||||||
|
* the stuff that's powered by a battery when main power is off". This includes
|
||||||
|
* realtime clock, tamper monitor, and power-management functions. Currently
|
||||||
|
* this driver provides only realtime clock support.
|
||||||
|
*/
|
||||||
|
|
||||||
|
#include <sys/param.h>
|
||||||
|
#include <sys/systm.h>
|
||||||
|
#include <sys/bus.h>
|
||||||
|
#include <sys/clock.h>
|
||||||
|
#include <sys/kernel.h>
|
||||||
|
#include <sys/module.h>
|
||||||
|
#include <machine/bus.h>
|
||||||
|
|
||||||
|
#include <dev/ofw/ofw_bus_subr.h>
|
||||||
|
|
||||||
|
#include "clock_if.h"
|
||||||
|
|
||||||
|
#define SNVS_LPCR 0x38 /* Control register */
|
||||||
|
#define LPCR_LPCALB_VAL_SHIFT 10 /* Calibration shift */
|
||||||
|
#define LPCR_LPCALB_VAL_MASK 0x1f /* Calibration mask */
|
||||||
|
#define LPCR_LPCALB_EN (1u << 8) /* Calibration enable */
|
||||||
|
#define LPCR_SRTC_ENV (1u << 0) /* RTC enabled/valid */
|
||||||
|
|
||||||
|
#define SNVS_LPSRTCMR 0x50 /* Counter MSB */
|
||||||
|
#define SNVS_LPSRTCLR 0x54 /* Counter LSB */
|
||||||
|
|
||||||
|
#define RTC_RESOLUTION_US (1000000 / 32768) /* 32khz clock */
|
||||||
|
|
||||||
|
/*
|
||||||
|
* The RTC is a 47-bit counter clocked at 32KHz and organized as a 32.15
|
||||||
|
* fixed-point binary value. Shifting by SBT_LSB bits translates between
|
||||||
|
* counter and sbintime values.
|
||||||
|
*/
|
||||||
|
#define RTC_BITS 47
|
||||||
|
#define SBT_BITS 64
|
||||||
|
#define SBT_LSB (SBT_BITS - RTC_BITS)
|
||||||
|
|
||||||
|
struct snvs_softc {
|
||||||
|
device_t dev;
|
||||||
|
struct resource * memres;
|
||||||
|
uint32_t lpcr;
|
||||||
|
};
|
||||||
|
|
||||||
|
static struct ofw_compat_data compat_data[] = {
|
||||||
|
{"fsl,sec-v4.0-mon", true},
|
||||||
|
{NULL, false}
|
||||||
|
};
|
||||||
|
|
||||||
|
static inline uint32_t
|
||||||
|
RD4(struct snvs_softc *sc, bus_size_t offset)
|
||||||
|
{
|
||||||
|
|
||||||
|
return (bus_read_4(sc->memres, offset));
|
||||||
|
}
|
||||||
|
|
||||||
|
static inline void
|
||||||
|
WR4(struct snvs_softc *sc, bus_size_t offset, uint32_t value)
|
||||||
|
{
|
||||||
|
|
||||||
|
bus_write_4(sc->memres, offset, value);
|
||||||
|
}
|
||||||
|
|
||||||
|
static void
|
||||||
|
snvs_rtc_enable(struct snvs_softc *sc, bool enable)
|
||||||
|
{
|
||||||
|
uint32_t enbit;
|
||||||
|
|
||||||
|
if (enable)
|
||||||
|
sc->lpcr |= LPCR_SRTC_ENV;
|
||||||
|
else
|
||||||
|
sc->lpcr &= ~LPCR_SRTC_ENV;
|
||||||
|
WR4(sc, SNVS_LPCR, sc->lpcr);
|
||||||
|
|
||||||
|
/* Wait for the hardware to achieve the requested state. */
|
||||||
|
enbit = sc->lpcr & LPCR_SRTC_ENV;
|
||||||
|
while ((RD4(sc, SNVS_LPCR) & LPCR_SRTC_ENV) != enbit)
|
||||||
|
continue;
|
||||||
|
}
|
||||||
|
|
||||||
|
static int
|
||||||
|
snvs_gettime(device_t dev, struct timespec *ts)
|
||||||
|
{
|
||||||
|
struct snvs_softc *sc;
|
||||||
|
sbintime_t counter1, counter2;
|
||||||
|
|
||||||
|
sc = device_get_softc(dev);
|
||||||
|
|
||||||
|
/* If the clock is not enabled and valid, we can't help. */
|
||||||
|
if (!(RD4(sc, SNVS_LPCR) & LPCR_SRTC_ENV)) {
|
||||||
|
return (EINVAL);
|
||||||
|
}
|
||||||
|
|
||||||
|
/*
|
||||||
|
* The counter is clocked asynchronously to cpu accesses; read and
|
||||||
|
* assemble the pieces of the counter until we get the same value twice.
|
||||||
|
* The counter is 47 bits, organized as a 32.15 binary fixed-point
|
||||||
|
* value. If we shift it up to the high order part of a 64-bit word it
|
||||||
|
* turns into an sbintime.
|
||||||
|
*/
|
||||||
|
do {
|
||||||
|
counter1 = (uint64_t)RD4(sc, SNVS_LPSRTCMR) << (SBT_LSB + 32);
|
||||||
|
counter1 |= (uint64_t)RD4(sc, SNVS_LPSRTCLR) << (SBT_LSB);
|
||||||
|
counter2 = (uint64_t)RD4(sc, SNVS_LPSRTCMR) << (SBT_LSB + 32);
|
||||||
|
counter2 |= (uint64_t)RD4(sc, SNVS_LPSRTCLR) << (SBT_LSB);
|
||||||
|
} while (counter1 != counter2);
|
||||||
|
|
||||||
|
*ts = sbttots(counter1);
|
||||||
|
|
||||||
|
return (0);
|
||||||
|
}
|
||||||
|
|
||||||
|
static int
|
||||||
|
snvs_settime(device_t dev, struct timespec *unused)
|
||||||
|
{
|
||||||
|
struct snvs_softc *sc;
|
||||||
|
struct bintime bt;
|
||||||
|
sbintime_t sbt;
|
||||||
|
|
||||||
|
sc = device_get_softc(dev);
|
||||||
|
|
||||||
|
/*
|
||||||
|
* Ignore the inaccurate time passed in from the common clock code and
|
||||||
|
* obtain a time worthy of our 30us accuracy.
|
||||||
|
*/
|
||||||
|
bintime(&bt);
|
||||||
|
bt.sec -= utc_offset();
|
||||||
|
sbt = bttosbt(bt);
|
||||||
|
|
||||||
|
/*
|
||||||
|
* It takes two clock cycles for the counter to start after setting the
|
||||||
|
* enable bit, so add two SBT_LSBs to what we're about to set.
|
||||||
|
*/
|
||||||
|
sbt += 2 << SBT_LSB;
|
||||||
|
snvs_rtc_enable(sc, false);
|
||||||
|
WR4(sc, SNVS_LPSRTCMR, (uint32_t)(sbt >> (SBT_LSB + 32)));
|
||||||
|
WR4(sc, SNVS_LPSRTCLR, (uint32_t)(sbt >> (SBT_LSB)));
|
||||||
|
snvs_rtc_enable(sc, true);
|
||||||
|
|
||||||
|
return (0);
|
||||||
|
}
|
||||||
|
|
||||||
|
static int
|
||||||
|
snvs_probe(device_t dev)
|
||||||
|
{
|
||||||
|
|
||||||
|
if (!ofw_bus_status_okay(dev))
|
||||||
|
return (ENXIO);
|
||||||
|
|
||||||
|
if (!ofw_bus_search_compatible(dev, compat_data)->ocd_data)
|
||||||
|
return (ENXIO);
|
||||||
|
|
||||||
|
device_set_desc(dev, "i.MX6 SNVS RTC");
|
||||||
|
return (BUS_PROBE_DEFAULT);
|
||||||
|
}
|
||||||
|
|
||||||
|
static int
|
||||||
|
snvs_attach(device_t dev)
|
||||||
|
{
|
||||||
|
struct snvs_softc *sc;
|
||||||
|
int rid;
|
||||||
|
|
||||||
|
sc = device_get_softc(dev);
|
||||||
|
sc->dev = dev;
|
||||||
|
|
||||||
|
rid = 0;
|
||||||
|
sc->memres = bus_alloc_resource_any(sc->dev, SYS_RES_MEMORY, &rid,
|
||||||
|
RF_ACTIVE);
|
||||||
|
if (sc->memres == NULL) {
|
||||||
|
device_printf(sc->dev, "could not allocate registers\n");
|
||||||
|
return (ENXIO);
|
||||||
|
}
|
||||||
|
|
||||||
|
clock_register(sc->dev, RTC_RESOLUTION_US);
|
||||||
|
|
||||||
|
return (0);
|
||||||
|
}
|
||||||
|
|
||||||
|
static device_method_t snvs_methods[] = {
|
||||||
|
DEVMETHOD(device_probe, snvs_probe),
|
||||||
|
DEVMETHOD(device_attach, snvs_attach),
|
||||||
|
|
||||||
|
/* clock_if methods */
|
||||||
|
DEVMETHOD(clock_gettime, snvs_gettime),
|
||||||
|
DEVMETHOD(clock_settime, snvs_settime),
|
||||||
|
|
||||||
|
DEVMETHOD_END
|
||||||
|
};
|
||||||
|
|
||||||
|
static driver_t snvs_driver = {
|
||||||
|
"snvs",
|
||||||
|
snvs_methods,
|
||||||
|
sizeof(struct snvs_softc),
|
||||||
|
};
|
||||||
|
|
||||||
|
static devclass_t snvs_devclass;
|
||||||
|
|
||||||
|
DRIVER_MODULE(snvs, simplebus, snvs_driver, snvs_devclass, 0, 0);
|
||||||
Loading…
Reference in New Issue
Block a user