freebsd-skq/sys/arm/broadcom/bcm2835/bcm2836.c
Andrew Turner 4e46a66e4a Add support for the Raspberry Pi 2. As the chip is based on the bcm2835 in
the Raspberry Pi B we support most of the devices are already supported,
however the base address has changed.

A few items are not working, or missing. The main ones are:
 * DMA doesn't work in the sdhci driver.
 * Enabling vchiq halts the boot, may be interrupt related.
 * There is no U-Boot port yet so the DTB is embedded in the kernel.

The last point will make it difficult to boot FreeBSD, however there is
support for the Raspberry Pi 2 in the U-Boot git repo. As I have not tested
this it is left as an open task to create a port to build.

X-MFC:		When the above issues are fixed
Sponsored by:	ABT Systems Ltd
2015-03-25 10:59:42 +00:00

185 lines
4.5 KiB
C

/*
* Copyright 2015 Andrew Turner.
* 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/rman.h>
#include <machine/bus.h>
#include <machine/resource.h>
#include <dev/ofw/ofw_bus_subr.h>
#include <dev/ofw/ofw_bus.h>
#include <arm/broadcom/bcm2835/bcm2836.h>
#define ARM_LOCAL_BASE 0x40000000
#define ARM_LOCAL_SIZE 0x00001000
#define ARM_LOCAL_CONTROL 0x00
#define ARM_LOCAL_PRESCALER 0x08
#define PRESCALER_19_2 0x80000000 /* 19.2 MHz */
#define ARM_LOCAL_INT_TIMER(n) (0x40 + (n) * 4)
#define ARM_LOCAL_INT_MAILBOX(n) (0x50 + (n) * 4)
#define ARM_LOCAL_INT_PENDING(n) (0x60 + (n) * 4)
#define INT_PENDING_MASK 0x0f
/*
* A driver for features of the bcm2836.
*/
struct bcm2836_softc {
device_t sc_dev;
struct resource *sc_mem;
};
static device_identify_t bcm2836_identify;
static device_probe_t bcm2836_probe;
static device_attach_t bcm2836_attach;
struct bcm2836_softc *softc;
static void
bcm2836_identify(driver_t *driver, device_t parent)
{
if (BUS_ADD_CHILD(parent, 0, "bcm2836", -1) == NULL)
device_printf(parent, "add child failed\n");
}
static int
bcm2836_probe(device_t dev)
{
if (softc != NULL)
return (ENXIO);
device_set_desc(dev, "Broadcom bcm2836");
return (BUS_PROBE_DEFAULT);
}
static int
bcm2836_attach(device_t dev)
{
int i, rid;
softc = device_get_softc(dev);
softc->sc_dev = dev;
rid = 0;
softc->sc_mem = bus_alloc_resource(dev, SYS_RES_MEMORY, &rid,
ARM_LOCAL_BASE, ARM_LOCAL_BASE + ARM_LOCAL_SIZE, ARM_LOCAL_SIZE,
RF_ACTIVE);
if (softc->sc_mem == NULL) {
device_printf(dev, "could not allocate memory resource\n");
return (ENXIO);
}
bus_write_4(softc->sc_mem, ARM_LOCAL_CONTROL, 0);
bus_write_4(softc->sc_mem, ARM_LOCAL_PRESCALER, PRESCALER_19_2);
for (i = 0; i < 4; i++)
bus_write_4(softc->sc_mem, ARM_LOCAL_INT_TIMER(i), 0);
for (i = 0; i < 4; i++)
bus_write_4(softc->sc_mem, ARM_LOCAL_INT_MAILBOX(i), 1);
return (0);
}
int
bcm2836_get_next_irq(int last_irq)
{
uint32_t reg;
int cpu;
int irq;
cpu = PCPU_GET(cpuid);
reg = bus_read_4(softc->sc_mem, ARM_LOCAL_INT_PENDING(cpu));
reg &= INT_PENDING_MASK;
if (reg == 0)
return (-1);
irq = ffs(reg) - 1;
return (irq);
}
void
bcm2836_mask_irq(uintptr_t irq)
{
uint32_t reg;
int i;
for (i = 0; i < 4; i++) {
reg = bus_read_4(softc->sc_mem, ARM_LOCAL_INT_TIMER(i));
reg &= ~(1 << irq);
bus_write_4(softc->sc_mem, ARM_LOCAL_INT_TIMER(i), reg);
}
}
void
bcm2836_unmask_irq(uintptr_t irq)
{
uint32_t reg;
int i;
for (i = 0; i < 4; i++) {
reg = bus_read_4(softc->sc_mem, ARM_LOCAL_INT_TIMER(i));
reg |= (1 << irq);
bus_write_4(softc->sc_mem, ARM_LOCAL_INT_TIMER(i), reg);
}
}
static device_method_t bcm2836_methods[] = {
/* Device interface */
DEVMETHOD(device_identify, bcm2836_identify),
DEVMETHOD(device_probe, bcm2836_probe),
DEVMETHOD(device_attach, bcm2836_attach),
DEVMETHOD_END
};
static devclass_t bcm2836_devclass;
static driver_t bcm2836_driver = {
"bcm2836",
bcm2836_methods,
sizeof(struct bcm2836_softc),
};
EARLY_DRIVER_MODULE(bcm2836, nexus, bcm2836_driver, bcm2836_devclass, 0, 0,
BUS_PASS_INTERRUPT + BUS_PASS_ORDER_MIDDLE);