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freebsd/sys/arm/amlogic/aml8726/aml8726_pic.c
Andrew Turner a6ffc42f7a Clean up the Amlogic interrupt controller driver to handle the case where
we have both the Amlogic pic and a GIC. This may be the case in some
configurations.

Differential Revision:	https://reviews.freebsd.org/D2432
Submitted by:	John Wehle <john@feith.com>
2015-05-18 11:04:07 +00:00

279 lines
6.9 KiB
C

/*-
* Copyright 2013-2015 John Wehle <john@feith.com>
* 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.
*/
/*
* Amlogic aml8726 PIC driver.
*
* The current implementation doesn't include support for FIQ.
*
* There is a set of four interrupt controllers per cpu located in adjacent
* memory addresses (the set for cpu 1 starts right after the set for cpu 0)
* ... this allows for interrupt handling to be spread across the cpus.
*
* The multicore chips also have a GIC ... typically they run SMP kernels
* which include the GIC driver in which case this driver is simply used
* to disable the PIC.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/resource.h>
#include <sys/rman.h>
#include <machine/bus.h>
#include <machine/intr.h>
#include <dev/fdt/fdt_common.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
struct aml8726_pic_softc {
device_t dev;
struct resource * res[1];
};
static struct resource_spec aml8726_pic_spec[] = {
{ SYS_RES_MEMORY, 0, RF_ACTIVE },
{ -1, 0 }
};
/*
* devclass_get_device / device_get_softc could be used
* to dynamically locate this, however the pic is a
* required device which can't be unloaded so there's
* no need for the overhead.
*/
static struct aml8726_pic_softc *aml8726_pic_sc = NULL;
#define AML_PIC_NCNTRLS 4
#define AML_PIC_IRQS_PER_CNTRL 32
#define AML_PIC_NIRQS (AML_PIC_NCNTRLS * AML_PIC_IRQS_PER_CNTRL)
#define AML_PIC_0_STAT_REG 0
#define AML_PIC_0_STAT_CLR_REG 4
#define AML_PIC_0_MASK_REG 8
#define AML_PIC_0_FIRQ_SEL 12
#define AML_PIC_1_STAT_REG 16
#define AML_PIC_1_STAT_CLR_REG 20
#define AML_PIC_1_MASK_REG 24
#define AML_PIC_1_FIRQ_SEL 28
#define AML_PIC_2_STAT_REG 32
#define AML_PIC_2_STAT_CLR_REG 36
#define AML_PIC_2_MASK_REG 40
#define AML_PIC_2_FIRQ_SEL 44
#define AML_PIC_3_STAT_REG 48
#define AML_PIC_3_STAT_CLR_REG 52
#define AML_PIC_3_MASK_REG 56
#define AML_PIC_3_FIRQ_SEL 60
#define AML_PIC_CTRL(x) ((x) >> 5)
#define AML_PIC_BIT(x) (1 << ((x) & 0x1f))
#define AML_PIC_STAT_REG(x) (AML_PIC_0_STAT_REG + AML_PIC_CTRL(x) * 16)
#define AML_PIC_STAT_CLR_REG(x) (AML_PIC_0_STAT_CLR_REG + AML_PIC_CTRL(x) * 16)
#define AML_PIC_MASK_REG(x) (AML_PIC_0_MASK_REG + AML_PIC_CTRL(x) * 16)
#define AML_PIC_FIRQ_SEL(x) (AML_PIC_0_FIRQ_REG + AML_PIC_CTRL(x) * 16)
#define CSR_WRITE_4(sc, reg, val) bus_write_4((sc)->res[0], reg, (val))
#define CSR_READ_4(sc, reg) bus_read_4((sc)->res[0], reg)
#define CSR_BARRIER(sc, reg) bus_barrier((sc)->res[0], reg, 4, \
(BUS_SPACE_BARRIER_READ | BUS_SPACE_BARRIER_WRITE))
static void
aml8726_pic_eoi(void *arg)
{
uintptr_t nb = (uintptr_t) arg;
if (nb >= AML_PIC_NIRQS)
return;
arm_irq_memory_barrier(nb);
CSR_WRITE_4(aml8726_pic_sc, AML_PIC_STAT_CLR_REG(nb), AML_PIC_BIT(nb));
CSR_BARRIER(aml8726_pic_sc, AML_PIC_STAT_CLR_REG(nb));
}
static int
aml8726_pic_probe(device_t dev)
{
if (!ofw_bus_status_okay(dev))
return (ENXIO);
if (!ofw_bus_is_compatible(dev, "amlogic,aml8726-pic"))
return (ENXIO);
device_set_desc(dev, "Amlogic aml8726 PIC");
return (BUS_PROBE_DEFAULT);
}
static int
aml8726_pic_attach(device_t dev)
{
struct aml8726_pic_softc *sc = device_get_softc(dev);
int i;
/* There should be exactly one instance. */
if (aml8726_pic_sc != NULL)
return (ENXIO);
sc->dev = dev;
if (bus_alloc_resources(dev, aml8726_pic_spec, sc->res)) {
device_printf(dev, "could not allocate resources for device\n");
return (ENXIO);
}
/*
* Disable, clear, and set the interrupts to normal mode.
*/
for (i = 0; i < AML_PIC_NCNTRLS; i++) {
CSR_WRITE_4(sc, AML_PIC_0_MASK_REG + i * 16, 0);
CSR_WRITE_4(sc, AML_PIC_0_STAT_CLR_REG + i * 16, ~0u);
CSR_WRITE_4(sc, AML_PIC_0_FIRQ_SEL + i * 16, 0);
}
#ifndef DEV_GIC
arm_post_filter = aml8726_pic_eoi;
#else
device_printf(dev, "disabled in favor of gic\n");
#endif
aml8726_pic_sc = sc;
return (0);
}
static int
aml8726_pic_detach(device_t dev)
{
return (EBUSY);
}
static device_method_t aml8726_pic_methods[] = {
/* Device interface */
DEVMETHOD(device_probe, aml8726_pic_probe),
DEVMETHOD(device_attach, aml8726_pic_attach),
DEVMETHOD(device_detach, aml8726_pic_detach),
DEVMETHOD_END
};
static driver_t aml8726_pic_driver = {
"pic",
aml8726_pic_methods,
sizeof(struct aml8726_pic_softc),
};
static devclass_t aml8726_pic_devclass;
EARLY_DRIVER_MODULE(pic, simplebus, aml8726_pic_driver, aml8726_pic_devclass,
0, 0, BUS_PASS_INTERRUPT);
#ifndef DEV_GIC
int
arm_get_next_irq(int last)
{
uint32_t value;
int irq;
int start;
/*
* The extra complexity is simply so that all IRQs are checked
* round robin so a particularly busy interrupt can't prevent
* other interrupts from being serviced.
*/
start = (last + 1) % AML_PIC_NIRQS;
irq = start;
for ( ; ; ) {
value = CSR_READ_4(aml8726_pic_sc, AML_PIC_STAT_REG(irq));
for ( ; ; ) {
if ((value & AML_PIC_BIT(irq)) != 0)
return (irq);
irq = (irq + 1) % AML_PIC_NIRQS;
if (irq == start)
return (-1);
if ((irq % AML_PIC_IRQS_PER_CNTRL) == 0)
break;
}
}
}
void
arm_mask_irq(uintptr_t nb)
{
uint32_t mask;
if (nb >= AML_PIC_NIRQS)
return;
mask = CSR_READ_4(aml8726_pic_sc, AML_PIC_MASK_REG(nb));
mask &= ~AML_PIC_BIT(nb);
CSR_WRITE_4(aml8726_pic_sc, AML_PIC_MASK_REG(nb), mask);
CSR_BARRIER(aml8726_pic_sc, AML_PIC_MASK_REG(nb));
aml8726_pic_eoi((void *)nb);
}
void
arm_unmask_irq(uintptr_t nb)
{
uint32_t mask;
if (nb >= AML_PIC_NIRQS)
return;
arm_irq_memory_barrier(nb);
mask = CSR_READ_4(aml8726_pic_sc, AML_PIC_MASK_REG(nb));
mask |= AML_PIC_BIT(nb);
CSR_WRITE_4(aml8726_pic_sc, AML_PIC_MASK_REG(nb), mask);
CSR_BARRIER(aml8726_pic_sc, AML_PIC_MASK_REG(nb));
}
#endif