1 /* $OpenBSD: pwmreg.c,v 1.1 2019/09/30 20:44:13 kettenis Exp $ */ 2 /* 3 * Copyright (c) 2019 Mark Kettenis <kettenis@openbsd.org> 4 * 5 * Permission to use, copy, modify, and distribute this software for any 6 * purpose with or without fee is hereby granted, provided that the above 7 * copyright notice and this permission notice appear in all copies. 8 * 9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16 */ 17 18 #include <sys/param.h> 19 #include <sys/systm.h> 20 #include <sys/device.h> 21 #include <sys/malloc.h> 22 23 #include <machine/intr.h> 24 #include <machine/bus.h> 25 #include <machine/fdt.h> 26 27 #include <dev/ofw/openfirm.h> 28 #include <dev/ofw/ofw_misc.h> 29 #include <dev/ofw/ofw_regulator.h> 30 #include <dev/ofw/fdt.h> 31 32 struct pwmreg_softc { 33 struct device sc_dev; 34 uint32_t *sc_pwm; 35 uint32_t sc_dutycycle_unit; 36 uint32_t sc_dutycycle_range[2]; 37 38 struct regulator_device sc_rd; 39 }; 40 41 int pwmreg_match(struct device *, void *, void *); 42 void pwmreg_attach(struct device *, struct device *, void *); 43 44 struct cfattach pwmreg_ca = { 45 sizeof (struct pwmreg_softc), pwmreg_match, pwmreg_attach 46 }; 47 48 struct cfdriver pwmreg_cd = { 49 NULL, "pwmreg", DV_DULL 50 }; 51 52 53 uint32_t pwmreg_get_voltage(void *); 54 int pwmreg_set_voltage(void *, uint32_t); 55 int pwmreg_enable(void *, int); 56 57 int 58 pwmreg_match(struct device *parent, void *match, void *aux) 59 { 60 struct fdt_attach_args *faa = aux; 61 62 return OF_is_compatible(faa->fa_node, "pwm-regulator"); 63 } 64 65 void 66 pwmreg_attach(struct device *parent, struct device *self, void *aux) 67 { 68 struct pwmreg_softc *sc = (struct pwmreg_softc *)self; 69 struct fdt_attach_args *faa = aux; 70 int len; 71 72 if (OF_getproplen(faa->fa_node, "voltage-tables") > 0) { 73 printf(": voltage table mode unsupported\n"); 74 return; 75 } 76 77 len = OF_getproplen(faa->fa_node, "pwms"); 78 if (len <= 4) { 79 printf(": no pwm\n"); 80 return; 81 } 82 83 sc->sc_pwm = malloc(len, M_DEVBUF, M_WAITOK); 84 OF_getpropintarray(faa->fa_node, "pwms", sc->sc_pwm, len); 85 86 sc->sc_dutycycle_unit = 87 OF_getpropint(faa->fa_node, "pwm-dutycycle-unit", 100); 88 sc->sc_dutycycle_range[0] = 0; 89 sc->sc_dutycycle_range[1] = 100; 90 OF_getpropintarray(faa->fa_node, "pwm-dutycycle-range", 91 sc->sc_dutycycle_range, sizeof(sc->sc_dutycycle_range)); 92 93 printf("\n"); 94 95 sc->sc_rd.rd_node = faa->fa_node; 96 sc->sc_rd.rd_cookie = sc; 97 sc->sc_rd.rd_get_voltage = pwmreg_get_voltage; 98 sc->sc_rd.rd_set_voltage = pwmreg_set_voltage; 99 sc->sc_rd.rd_enable = pwmreg_enable; 100 regulator_register(&sc->sc_rd); 101 } 102 103 uint32_t 104 pwmreg_get_voltage(void *cookie) 105 { 106 struct pwmreg_softc *sc = cookie; 107 struct pwm_state ps; 108 int32_t x0, x1, y0, y1; 109 int32_t x, y; 110 111 if (pwm_get_state(sc->sc_pwm, &ps)) 112 return 0; 113 114 x0 = sc->sc_dutycycle_range[0]; 115 x1 = sc->sc_dutycycle_range[1]; 116 y0 = sc->sc_rd.rd_volt_min; 117 y1 = sc->sc_rd.rd_volt_max; 118 x = (ps.ps_pulse_width * sc->sc_dutycycle_unit) / ps.ps_period; 119 y = y0 + (x - x0) * (y1 - y0) / (x1 - x0); 120 return y; 121 } 122 123 int 124 pwmreg_set_voltage(void *cookie, uint32_t voltage) 125 { 126 struct pwmreg_softc *sc = cookie; 127 struct pwm_state ps; 128 int32_t x0, x1, y0, y1; 129 int32_t x, y; 130 131 if (pwm_init_state(sc->sc_pwm, &ps)) 132 return 0; 133 134 x0 = sc->sc_rd.rd_volt_min; 135 x1 = sc->sc_rd.rd_volt_max; 136 y0 = sc->sc_dutycycle_range[0]; 137 y1 = sc->sc_dutycycle_range[1]; 138 x = voltage; 139 y = y0 + (x - x0) * (y1 - y0) / (x1 - x0); 140 141 ps.ps_pulse_width = (y * ps.ps_period) / sc->sc_dutycycle_unit; 142 return pwm_set_state(sc->sc_pwm, &ps); 143 } 144 145 int 146 pwmreg_enable(void *cookie, int on) 147 { 148 struct pwmreg_softc *sc = cookie; 149 struct pwm_state ps; 150 int error; 151 152 error = pwm_get_state(sc->sc_pwm, &ps); 153 if (error) 154 return error; 155 156 if (ps.ps_enabled == on) 157 return 0; 158 159 ps.ps_enabled = on; 160 return pwm_set_state(sc->sc_pwm, &ps); 161 } 162