85 lines
3.0 KiB
C
85 lines
3.0 KiB
C
/* $NetBSD: bcm2835_gpio_subr.c,v 1.3 2014/04/22 18:51:35 kardel Exp $ */
|
|
|
|
/*
|
|
* Copyright (c) 2013 Jonathan A. Kollasch
|
|
* 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 COPYRIGHT HOLDERS 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 COPYRIGHT HOLDER 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>
|
|
__KERNEL_RCSID(0, "$NetBSD: bcm2835_gpio_subr.c,v 1.3 2014/04/22 18:51:35 kardel Exp $");
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/device.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/bus.h>
|
|
#include <sys/intr.h>
|
|
|
|
#include <arm/broadcom/bcm_amba.h>
|
|
#include <arm/broadcom/bcm2835reg.h>
|
|
#include <arm/broadcom/bcm2835_gpioreg.h>
|
|
#include <arm/broadcom/bcm2835_gpio_subr.h>
|
|
|
|
void
|
|
bcm2835gpio_function_select(u_int pin, u_int func)
|
|
{
|
|
const bus_space_tag_t iot = &bcm2835_bs_tag;
|
|
const bus_space_handle_t ioh = BCM2835_IOPHYSTOVIRT(BCM2835_GPIO_BASE);
|
|
const u_int mask = (1 << BCM2835_GPIO_GPFSEL_BITS_PER_PIN) - 1;
|
|
const u_int regid = (pin / BCM2835_GPIO_GPFSEL_PINS_PER_REGISTER);
|
|
const u_int shift = (pin % BCM2835_GPIO_GPFSEL_PINS_PER_REGISTER) *
|
|
BCM2835_GPIO_GPFSEL_BITS_PER_PIN;
|
|
uint32_t v;
|
|
|
|
KASSERT(func <= mask);
|
|
|
|
v = bus_space_read_4(iot, ioh, BCM2835_GPIO_GPFSEL(regid));
|
|
|
|
if (((v >> shift) & mask) == func) {
|
|
return;
|
|
}
|
|
|
|
aprint_debug("bcm2835: changing FSEL%u to %#o\n", pin, func);
|
|
|
|
v &= ~(mask << shift);
|
|
v |= (func << shift);
|
|
|
|
bus_space_write_4(iot, ioh, BCM2835_GPIO_GPFSEL(regid), v);
|
|
}
|
|
|
|
u_int
|
|
bcm2835gpio_function_read(u_int pin)
|
|
{
|
|
const bus_space_tag_t iot = &bcm2835_bs_tag;
|
|
const bus_space_handle_t ioh = BCM2835_IOPHYSTOVIRT(BCM2835_GPIO_BASE);
|
|
const u_int mask = (1 << BCM2835_GPIO_GPFSEL_BITS_PER_PIN) - 1;
|
|
const u_int regid = (pin / BCM2835_GPIO_GPFSEL_PINS_PER_REGISTER);
|
|
const u_int shift = (pin % BCM2835_GPIO_GPFSEL_PINS_PER_REGISTER) *
|
|
BCM2835_GPIO_GPFSEL_BITS_PER_PIN;
|
|
uint32_t v;
|
|
|
|
v = bus_space_read_4(iot, ioh, BCM2835_GPIO_GPFSEL(regid));
|
|
|
|
return ((v >> shift) & mask);
|
|
}
|