NetBSD/sys/dev/fdt/fdt_pwm.c

117 lines
3.3 KiB
C

/* $NetBSD: fdt_pwm.c,v 1.2 2018/06/30 20:34:43 jmcneill Exp $ */
/*-
* Copyright (c) 2018 Jared McNeill <jmcneill@invisible.ca>
* 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 ``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 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: fdt_pwm.c,v 1.2 2018/06/30 20:34:43 jmcneill Exp $");
#include <sys/param.h>
#include <sys/bus.h>
#include <sys/kmem.h>
#include <sys/queue.h>
#include <libfdt.h>
#include <dev/fdt/fdtvar.h>
struct fdtbus_pwm_controller {
device_t pc_dev;
int pc_phandle;
const struct fdtbus_pwm_controller_func *pc_funcs;
LIST_ENTRY(fdtbus_pwm_controller) pc_next;
};
static LIST_HEAD(, fdtbus_pwm_controller) fdtbus_pwm_controllers =
LIST_HEAD_INITIALIZER(fdtbus_pwm_controllers);
int
fdtbus_register_pwm_controller(device_t dev, int phandle,
const struct fdtbus_pwm_controller_func *funcs)
{
struct fdtbus_pwm_controller *pc;
pc = kmem_alloc(sizeof(*pc), KM_SLEEP);
pc->pc_dev = dev;
pc->pc_phandle = phandle;
pc->pc_funcs = funcs;
LIST_INSERT_HEAD(&fdtbus_pwm_controllers, pc, pc_next);
return 0;
}
static struct fdtbus_pwm_controller *
fdtbus_get_pwm_controller(int phandle)
{
struct fdtbus_pwm_controller *pc;
LIST_FOREACH(pc, &fdtbus_pwm_controllers, pc_next) {
if (pc->pc_phandle == phandle)
return pc;
}
return NULL;
}
pwm_tag_t
fdtbus_pwm_acquire(int phandle, const char *prop)
{
return fdtbus_pwm_acquire_index(phandle, prop, 0);
}
pwm_tag_t
fdtbus_pwm_acquire_index(int phandle, const char *prop, int index)
{
struct fdtbus_pwm_controller *pc;
const uint32_t *pwms, *p;
u_int n, pwm_cells;
int len, resid;
pwms = fdtbus_get_prop(phandle, prop, &len);
if (pwms == NULL)
return NULL;
p = pwms;
for (n = 0, resid = len; resid > 0; n++) {
const int pc_phandle =
fdtbus_get_phandle_from_native(be32toh(p[0]));
if (of_getprop_uint32(pc_phandle, "#pwm-cells", &pwm_cells))
break;
if (n == index) {
pc = fdtbus_get_pwm_controller(pc_phandle);
if (pc == NULL)
return NULL;
return pc->pc_funcs->get_tag(pc->pc_dev,
&p[0], (pwm_cells + 1) * 4);
}
resid -= (pwm_cells + 1) * 4;
p += pwm_cells + 1;
}
return NULL;
}