diff options
Diffstat (limited to 'sys/dev/fdt/pwmreg.c')
| -rw-r--r-- | sys/dev/fdt/pwmreg.c | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/sys/dev/fdt/pwmreg.c b/sys/dev/fdt/pwmreg.c new file mode 100644 index 00000000000..2b63284ed34 --- /dev/null +++ b/sys/dev/fdt/pwmreg.c @@ -0,0 +1,161 @@ +/* $OpenBSD: pwmreg.c,v 1.1 2019/09/30 20:44:13 kettenis Exp $ */ +/* + * Copyright (c) 2019 Mark Kettenis <kettenis@openbsd.org> + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/device.h> +#include <sys/malloc.h> + +#include <machine/intr.h> +#include <machine/bus.h> +#include <machine/fdt.h> + +#include <dev/ofw/openfirm.h> +#include <dev/ofw/ofw_misc.h> +#include <dev/ofw/ofw_regulator.h> +#include <dev/ofw/fdt.h> + +struct pwmreg_softc { + struct device sc_dev; + uint32_t *sc_pwm; + uint32_t sc_dutycycle_unit; + uint32_t sc_dutycycle_range[2]; + + struct regulator_device sc_rd; +}; + +int pwmreg_match(struct device *, void *, void *); +void pwmreg_attach(struct device *, struct device *, void *); + +struct cfattach pwmreg_ca = { + sizeof (struct pwmreg_softc), pwmreg_match, pwmreg_attach +}; + +struct cfdriver pwmreg_cd = { + NULL, "pwmreg", DV_DULL +}; + + +uint32_t pwmreg_get_voltage(void *); +int pwmreg_set_voltage(void *, uint32_t); +int pwmreg_enable(void *, int); + +int +pwmreg_match(struct device *parent, void *match, void *aux) +{ + struct fdt_attach_args *faa = aux; + + return OF_is_compatible(faa->fa_node, "pwm-regulator"); +} + +void +pwmreg_attach(struct device *parent, struct device *self, void *aux) +{ + struct pwmreg_softc *sc = (struct pwmreg_softc *)self; + struct fdt_attach_args *faa = aux; + int len; + + if (OF_getproplen(faa->fa_node, "voltage-tables") > 0) { + printf(": voltage table mode unsupported\n"); + return; + } + + len = OF_getproplen(faa->fa_node, "pwms"); + if (len <= 4) { + printf(": no pwm\n"); + return; + } + + sc->sc_pwm = malloc(len, M_DEVBUF, M_WAITOK); + OF_getpropintarray(faa->fa_node, "pwms", sc->sc_pwm, len); + + sc->sc_dutycycle_unit = + OF_getpropint(faa->fa_node, "pwm-dutycycle-unit", 100); + sc->sc_dutycycle_range[0] = 0; + sc->sc_dutycycle_range[1] = 100; + OF_getpropintarray(faa->fa_node, "pwm-dutycycle-range", + sc->sc_dutycycle_range, sizeof(sc->sc_dutycycle_range)); + + printf("\n"); + + sc->sc_rd.rd_node = faa->fa_node; + sc->sc_rd.rd_cookie = sc; + sc->sc_rd.rd_get_voltage = pwmreg_get_voltage; + sc->sc_rd.rd_set_voltage = pwmreg_set_voltage; + sc->sc_rd.rd_enable = pwmreg_enable; + regulator_register(&sc->sc_rd); +} + +uint32_t +pwmreg_get_voltage(void *cookie) +{ + struct pwmreg_softc *sc = cookie; + struct pwm_state ps; + int32_t x0, x1, y0, y1; + int32_t x, y; + + if (pwm_get_state(sc->sc_pwm, &ps)) + return 0; + + x0 = sc->sc_dutycycle_range[0]; + x1 = sc->sc_dutycycle_range[1]; + y0 = sc->sc_rd.rd_volt_min; + y1 = sc->sc_rd.rd_volt_max; + x = (ps.ps_pulse_width * sc->sc_dutycycle_unit) / ps.ps_period; + y = y0 + (x - x0) * (y1 - y0) / (x1 - x0); + return y; +} + +int +pwmreg_set_voltage(void *cookie, uint32_t voltage) +{ + struct pwmreg_softc *sc = cookie; + struct pwm_state ps; + int32_t x0, x1, y0, y1; + int32_t x, y; + + if (pwm_init_state(sc->sc_pwm, &ps)) + return 0; + + x0 = sc->sc_rd.rd_volt_min; + x1 = sc->sc_rd.rd_volt_max; + y0 = sc->sc_dutycycle_range[0]; + y1 = sc->sc_dutycycle_range[1]; + x = voltage; + y = y0 + (x - x0) * (y1 - y0) / (x1 - x0); + + ps.ps_pulse_width = (y * ps.ps_period) / sc->sc_dutycycle_unit; + return pwm_set_state(sc->sc_pwm, &ps); +} + +int +pwmreg_enable(void *cookie, int on) +{ + struct pwmreg_softc *sc = cookie; + struct pwm_state ps; + int error; + + error = pwm_get_state(sc->sc_pwm, &ps); + if (error) + return error; + + if (ps.ps_enabled == on) + return 0; + + ps.ps_enabled = on; + return pwm_set_state(sc->sc_pwm, &ps); +} |