freebsd-dev/sys/arm/ti/am335x/am335x_scm.c
Luiz Otavio O Souza ab8fdacc82 Fixes the sensor initialization, always reset the digital outputs to start.
Obtained from:	pfSense
MFC after:	3 days
Sponsored by:	Rubicon Communications, LLC (Netgate)
2016-12-31 02:18:08 +00:00

173 lines
4.6 KiB
C

/*-
* Copyright (c) 2016 Rubicon Communications, LLC (Netgate)
* 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("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/sysctl.h>
#include <machine/bus.h>
#include <arm/ti/am335x/am335x_scm.h>
#include <arm/ti/ti_cpuid.h>
#include <arm/ti/ti_scm.h>
#define TZ_ZEROC 2731
struct am335x_scm_softc {
int sc_last_temp;
struct sysctl_oid *sc_temp_oid;
};
static int
am335x_scm_temp_sysctl(SYSCTL_HANDLER_ARGS)
{
device_t dev;
int i, temp;
struct am335x_scm_softc *sc;
uint32_t reg;
dev = (device_t)arg1;
sc = device_get_softc(dev);
/* Read the temperature and convert to Kelvin. */
for(i = 50; i > 0; i--) {
ti_scm_reg_read_4(SCM_BGAP_CTRL, &reg);
if ((reg & SCM_BGAP_EOCZ) == 0)
break;
DELAY(50);
}
if ((reg & SCM_BGAP_EOCZ) == 0) {
sc->sc_last_temp =
(reg >> SCM_BGAP_TEMP_SHIFT) & SCM_BGAP_TEMP_MASK;
sc->sc_last_temp *= 10;
}
temp = sc->sc_last_temp + TZ_ZEROC;
return (sysctl_handle_int(oidp, &temp, 0, req));
}
static void
am335x_scm_identify(driver_t *driver, device_t parent)
{
device_t child;
/* AM335x only. */
if (ti_chip() != CHIP_AM335X)
return;
/* Make sure we attach only once. */
if (device_find_child(parent, "am335x_scm", -1) != NULL)
return;
child = device_add_child(parent, "am335x_scm", -1);
if (child == NULL)
device_printf(parent, "cannot add ti_scm child\n");
}
static int
am335x_scm_probe(device_t dev)
{
device_set_desc(dev, "AM335x Control Module Extension");
return (BUS_PROBE_DEFAULT);
}
static int
am335x_scm_attach(device_t dev)
{
struct am335x_scm_softc *sc;
struct sysctl_ctx_list *ctx;
struct sysctl_oid_list *tree;
uint32_t reg;
/* Reset the digital outputs. */
ti_scm_reg_write_4(SCM_BGAP_CTRL, 0);
ti_scm_reg_read_4(SCM_BGAP_CTRL, &reg);
DELAY(500);
/* Set continous mode. */
ti_scm_reg_write_4(SCM_BGAP_CTRL, SCM_BGAP_CONTCONV);
ti_scm_reg_read_4(SCM_BGAP_CTRL, &reg);
DELAY(500);
/* Start the ADC conversion. */
reg = SCM_BGAP_CLRZ | SCM_BGAP_CONTCONV | SCM_BGAP_SOC;
ti_scm_reg_write_4(SCM_BGAP_CTRL, reg);
/* Temperature sysctl. */
sc = device_get_softc(dev);
ctx = device_get_sysctl_ctx(dev);
tree = SYSCTL_CHILDREN(device_get_sysctl_tree(dev));
sc->sc_temp_oid = SYSCTL_ADD_PROC(ctx, tree, OID_AUTO,
"temperature", CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE,
dev, 0, am335x_scm_temp_sysctl, "IK", "Current temperature");
return (0);
}
static int
am335x_scm_detach(device_t dev)
{
struct am335x_scm_softc *sc;
sc = device_get_softc(dev);
/* Remove temperature sysctl. */
if (sc->sc_temp_oid != NULL)
sysctl_remove_oid(sc->sc_temp_oid, 1, 0);
/* Stop the bandgap ADC. */
ti_scm_reg_write_4(SCM_BGAP_CTRL, SCM_BGAP_BGOFF);
return (0);
}
static device_method_t am335x_scm_methods[] = {
DEVMETHOD(device_identify, am335x_scm_identify),
DEVMETHOD(device_probe, am335x_scm_probe),
DEVMETHOD(device_attach, am335x_scm_attach),
DEVMETHOD(device_detach, am335x_scm_detach),
DEVMETHOD_END
};
static driver_t am335x_scm_driver = {
"am335x_scm",
am335x_scm_methods,
sizeof(struct am335x_scm_softc),
};
static devclass_t am335x_scm_devclass;
DRIVER_MODULE(am335x_scm, ti_scm, am335x_scm_driver, am335x_scm_devclass, 0, 0);
MODULE_VERSION(am335x_scm, 1);
MODULE_DEPEND(am335x_scm, ti_scm, 1, 1, 1);