freebsd-skq/sys/arm/freescale/fsl_ocotp.c
gonzo ee59b6a5e7 [ofw] fix errneous checks for OF_finddevice(9) return value
OF_finddevices returns ((phandle_t)-1) in case of failure. Some code
in existing drivers checked return value to be equal to 0 or
less/equal to 0 which is also wrong because phandle_t is unsigned
type. Most of these checks were for negative cases that were never
triggered so trhere was no impact on functionality.

Reviewed by:	nwhitehorn
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D14645
2018-03-20 00:03:49 +00:00

208 lines
5.1 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2014 Steven Lawrance <stl@koffein.net>
* 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("$FreeBSD$");
/*
* Access to the Freescale i.MX6 On-Chip One-Time-Programmable Memory
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/bus.h>
#include <sys/rman.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#include <machine/bus.h>
#include <arm/freescale/fsl_ocotpreg.h>
#include <arm/freescale/fsl_ocotpvar.h>
/*
* Find the physical address and size of the ocotp registers and devmap them,
* returning a pointer to the virtual address of the base.
*
* XXX This is temporary until we've worked out all the details of controlling
* the load order of devices. In an ideal world this device would be up and
* running before anything that needs it. When we're at a point to make that
* happen, this little block of code, and the few lines in fsl_ocotp_read_4()
* that refer to it can be deleted.
*/
#include <vm/vm.h>
#include <vm/pmap.h>
#include <dev/fdt/fdt_common.h>
#include <sys/devmap.h>
static uint32_t *ocotp_regs;
static vm_size_t ocotp_size;
static void
fsl_ocotp_devmap(void)
{
phandle_t child, root;
u_long base, size;
if ((root = OF_finddevice("/")) == -1)
goto fatal;
if ((child = fdt_depth_search_compatible(root, "fsl,imx6q-ocotp", 0)) == 0)
goto fatal;
if (fdt_regsize(child, &base, &size) != 0)
goto fatal;
ocotp_size = (vm_size_t)size;
if ((ocotp_regs = pmap_mapdev((vm_offset_t)base, ocotp_size)) == NULL)
goto fatal;
return;
fatal:
panic("cannot find/map the ocotp registers");
}
/* XXX end of temporary code */
struct ocotp_softc {
device_t dev;
struct resource *mem_res;
};
static struct ocotp_softc *ocotp_sc;
static inline uint32_t
RD4(struct ocotp_softc *sc, bus_size_t off)
{
return (bus_read_4(sc->mem_res, off));
}
static int
ocotp_detach(device_t dev)
{
/* The ocotp registers are always accessible. */
return (EBUSY);
}
static int
ocotp_attach(device_t dev)
{
struct ocotp_softc *sc;
int err, rid;
sc = device_get_softc(dev);
sc->dev = dev;
/* Allocate bus_space resources. */
rid = 0;
sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
RF_ACTIVE);
if (sc->mem_res == NULL) {
device_printf(dev, "Cannot allocate memory resources\n");
err = ENXIO;
goto out;
}
ocotp_sc = sc;
/* We're done with the temporary mapping now. */
if (ocotp_regs != NULL)
pmap_unmapdev((vm_offset_t)ocotp_regs, ocotp_size);
err = 0;
out:
if (err != 0)
ocotp_detach(dev);
return (err);
}
static int
ocotp_probe(device_t dev)
{
if (!ofw_bus_status_okay(dev))
return (ENXIO);
if (ofw_bus_is_compatible(dev, "fsl,imx6q-ocotp") == 0)
return (ENXIO);
device_set_desc(dev,
"Freescale On-Chip One-Time-Programmable Memory");
return (BUS_PROBE_DEFAULT);
}
uint32_t
fsl_ocotp_read_4(bus_size_t off)
{
if (off > FSL_OCOTP_LAST_REG)
panic("fsl_ocotp_read_4: offset out of range");
/* If we have a softcontext use the regular bus_space read. */
if (ocotp_sc != NULL)
return (RD4(ocotp_sc, off));
/*
* Otherwise establish a tempory device mapping if necessary, and read
* the device without any help from bus_space.
*
* XXX Eventually the code from there down can be deleted.
*/
if (ocotp_regs == NULL)
fsl_ocotp_devmap();
return (ocotp_regs[off / 4]);
}
static device_method_t ocotp_methods[] = {
/* Device interface */
DEVMETHOD(device_probe, ocotp_probe),
DEVMETHOD(device_attach, ocotp_attach),
DEVMETHOD(device_detach, ocotp_detach),
DEVMETHOD_END
};
static driver_t ocotp_driver = {
"ocotp",
ocotp_methods,
sizeof(struct ocotp_softc)
};
static devclass_t ocotp_devclass;
EARLY_DRIVER_MODULE(ocotp, simplebus, ocotp_driver, ocotp_devclass, 0, 0,
BUS_PASS_CPU + BUS_PASS_ORDER_FIRST);