251 lines
6.9 KiB
C
251 lines
6.9 KiB
C
/* $NetBSD: gpioregulator.c,v 1.1 2017/08/13 18:27:31 jmcneill Exp $ */
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/*-
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* Copyright (c) 2017 Jared McNeill <jmcneill@invisible.ca>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__KERNEL_RCSID(0, "$NetBSD: gpioregulator.c,v 1.1 2017/08/13 18:27:31 jmcneill Exp $");
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/device.h>
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#include <sys/kmem.h>
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#include <sys/bus.h>
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#include <sys/gpio.h>
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#include <dev/fdt/fdtvar.h>
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static int gpioregulator_match(device_t, cfdata_t, void *);
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static void gpioregulator_attach(device_t, device_t, void *);
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static int gpioregulator_acquire(device_t);
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static void gpioregulator_release(device_t);
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static int gpioregulator_enable(device_t, bool);
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static int gpioregulator_set_voltage(device_t, u_int, u_int);
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static int gpioregulator_get_voltage(device_t, u_int *);
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static const struct fdtbus_regulator_controller_func gpioregulator_funcs = {
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.acquire = gpioregulator_acquire,
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.release = gpioregulator_release,
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.enable = gpioregulator_enable,
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.set_voltage = gpioregulator_set_voltage,
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.get_voltage = gpioregulator_get_voltage,
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};
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struct gpioregulator_state {
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u_int st_val;
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u_int st_mask;
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};
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struct gpioregulator_softc {
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device_t sc_dev;
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int sc_phandle;
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struct fdtbus_gpio_pin *sc_pin_enable;
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struct fdtbus_gpio_pin **sc_pins;
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u_int sc_npins;
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struct gpioregulator_state *sc_states;
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u_int sc_nstates;
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bool sc_always_on;
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bool sc_boot_on;
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bool sc_enable_val;
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uint32_t sc_delay;
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int sc_gpioflags;
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};
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CFATTACH_DECL_NEW(gregulator, sizeof(struct gpioregulator_softc),
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gpioregulator_match, gpioregulator_attach, NULL, NULL);
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static int
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gpioregulator_match(device_t parent, cfdata_t cf, void *aux)
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{
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const char * const compatible[] = { "regulator-gpio", NULL };
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const struct fdt_attach_args *faa = aux;
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return of_match_compatible(faa->faa_phandle, compatible);
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}
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static void
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gpioregulator_attach(device_t parent, device_t self, void *aux)
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{
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struct gpioregulator_softc * const sc = device_private(self);
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const struct fdt_attach_args *faa = aux;
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const int phandle = faa->faa_phandle;
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const uint32_t *pstates;
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uint32_t mask;
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char *name;
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int len, n;
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sc->sc_dev = self;
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sc->sc_phandle = phandle;
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aprint_naive("\n");
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len = OF_getproplen(phandle, "regulator-name");
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if (len > 0) {
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name = kmem_zalloc(len, KM_SLEEP);
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if (OF_getprop(phandle, "regulator-name", name, len) == len) {
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aprint_normal(": %s\n", name);
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} else {
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aprint_normal("\n");
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}
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kmem_free(name, len);
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} else {
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aprint_normal("\n");
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}
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pstates = fdtbus_get_prop(phandle, "states", &len);
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if (pstates == NULL || len < 8 || len % 8 != 0) {
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aprint_error_dev(self, "invalid 'states' property\n");
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return;
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}
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mask = 0;
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sc->sc_nstates = len / (sizeof(uint32_t) * 2);
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sc->sc_states = kmem_zalloc(
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sc->sc_nstates * sizeof(struct gpioregulator_state), KM_SLEEP);
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for (n = 0; n < sc->sc_nstates; n++) {
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sc->sc_states[n].st_val = be32toh(pstates[n * 2 + 0]);
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sc->sc_states[n].st_mask = be32toh(pstates[n * 2 + 1]);
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mask |= sc->sc_states[n].st_mask;
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}
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sc->sc_gpioflags = GPIO_PIN_OUTPUT;
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if (of_getprop_bool(phandle, "gpio-open-drain"))
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sc->sc_gpioflags |= GPIO_PIN_OPENDRAIN;
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sc->sc_always_on = of_getprop_bool(phandle, "regulator-always-on");
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sc->sc_boot_on = of_getprop_bool(phandle, "regulator-boot-on");
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sc->sc_enable_val = of_getprop_bool(phandle, "enable-active-high");
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if (of_getprop_uint32(phandle, "startup-delay-us", &sc->sc_delay) != 0)
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sc->sc_delay = 0;
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/* "enable-gpio" property (optional) */
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sc->sc_pin_enable = fdtbus_gpio_acquire(phandle, "enable-gpio",
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sc->sc_gpioflags);
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/* "gpios" property */
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sc->sc_npins = 32 - __builtin_clz(mask);
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sc->sc_pins = kmem_zalloc(sc->sc_npins * sizeof(sc->sc_pins), KM_SLEEP);
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for (n = 0; n < sc->sc_npins; n++) {
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sc->sc_pins[n] = fdtbus_gpio_acquire_index(phandle, "gpios",
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n, sc->sc_gpioflags);
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if (sc->sc_pins[n] == NULL) {
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aprint_error_dev(self, "cannot get pin %d\n", n);
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return;
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}
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}
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fdtbus_register_regulator_controller(self, phandle,
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&gpioregulator_funcs);
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/*
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* If the regulator is flagged as always on or enabled at boot,
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* ensure that it is enabled
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*/
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if (sc->sc_always_on || sc->sc_boot_on)
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gpioregulator_enable(self, true);
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}
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static int
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gpioregulator_acquire(device_t dev)
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{
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return 0;
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}
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static void
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gpioregulator_release(device_t dev)
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{
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}
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static int
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gpioregulator_enable(device_t dev, bool enable)
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{
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struct gpioregulator_softc * const sc = device_private(dev);
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if (enable) {
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if (sc->sc_pin_enable != NULL)
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fdtbus_gpio_write_raw(sc->sc_pin_enable, sc->sc_enable_val);
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if (sc->sc_delay > 0)
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delay(sc->sc_delay);
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} else {
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if (sc->sc_always_on)
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return EIO;
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fdtbus_gpio_write_raw(sc->sc_pin_enable, !sc->sc_enable_val);
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}
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return 0;
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}
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static int
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gpioregulator_set_voltage(device_t dev, u_int min_uvolt, u_int max_uvolt)
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{
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struct gpioregulator_softc * const sc = device_private(dev);
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const struct gpioregulator_state *state = NULL;
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int n;
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for (n = 0; n < sc->sc_nstates; n++)
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if (sc->sc_states[n].st_val >= min_uvolt &&
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sc->sc_states[n].st_val <= max_uvolt) {
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state = &sc->sc_states[n];
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break;
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}
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if (state == NULL)
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return EINVAL;
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for (n = 0; n < sc->sc_npins; n++)
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fdtbus_gpio_write(sc->sc_pins[n], (state->st_mask >> n) & 1);
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if (sc->sc_delay > 0)
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delay(sc->sc_delay);
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return 0;
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}
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static int
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gpioregulator_get_voltage(device_t dev, u_int *puvolt)
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{
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struct gpioregulator_softc * const sc = device_private(dev);
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uint32_t mask = 0;
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int n, val;
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for (n = 0; n < sc->sc_npins; n++) {
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val = fdtbus_gpio_read(sc->sc_pins[n]);
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mask |= (val << n);
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}
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for (n = 0; n < sc->sc_nstates; n++)
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if (sc->sc_states[n].st_mask == mask) {
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*puvolt = sc->sc_states[n].st_val;
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return 0;
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}
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return EIO;
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}
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