1 /* $OpenBSD: pwmleds.c,v 1.2 2023/04/25 11:12:38 tobhe Exp $ */ 2 /* 3 * Copyright (c) 2022 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/bus.h> 24 #include <machine/fdt.h> 25 26 #include <dev/ofw/openfirm.h> 27 #include <dev/ofw/ofw_misc.h> 28 #include <dev/ofw/fdt.h> 29 30 #include <dev/wscons/wsconsio.h> 31 32 extern int (*wskbd_get_backlight)(struct wskbd_backlight *); 33 extern int (*wskbd_set_backlight)(struct wskbd_backlight *); 34 35 struct pwmleds_softc { 36 struct device sc_dev; 37 38 /* Keyboard backlight. */ 39 uint32_t *sc_pwm; 40 int sc_pwm_len; 41 uint32_t sc_max_brightness; 42 struct pwm_state sc_ps_saved; 43 }; 44 45 int pwmleds_match(struct device *, void *, void *); 46 void pwmleds_attach(struct device *, struct device *, void *); 47 int pwmleds_activate(struct device *, int); 48 49 const struct cfattach pwmleds_ca = { 50 sizeof (struct pwmleds_softc), pwmleds_match, pwmleds_attach, NULL, 51 pwmleds_activate 52 }; 53 54 struct cfdriver pwmleds_cd = { 55 NULL, "pwmleds", DV_DULL 56 }; 57 58 int pwmleds_get_kbd_backlight(struct wskbd_backlight *); 59 int pwmleds_set_kbd_backlight(struct wskbd_backlight *); 60 61 int 62 pwmleds_match(struct device *parent, void *match, void *aux) 63 { 64 const struct fdt_attach_args *faa = aux; 65 66 return OF_is_compatible(faa->fa_node, "pwm-leds"); 67 } 68 69 void 70 pwmleds_attach(struct device *parent, struct device *self, void *aux) 71 { 72 struct pwmleds_softc *sc = (struct pwmleds_softc *)self; 73 struct fdt_attach_args *faa = aux; 74 char *function; 75 int len, node; 76 77 printf("\n"); 78 79 for (node = OF_child(faa->fa_node); node; node = OF_peer(node)) { 80 len = OF_getproplen(node, "function"); 81 if (len <= 0) 82 continue; 83 84 function = malloc(len, M_TEMP, M_WAITOK); 85 OF_getprop(node, "function", function, len); 86 if (strcmp(function, "kbd_backlight") != 0) { 87 free(function, M_TEMP, len); 88 continue; 89 } 90 free(function, M_TEMP, len); 91 92 len = OF_getproplen(node, "pwms"); 93 if (len <= 0) 94 continue; 95 96 sc->sc_pwm = malloc(len, M_DEVBUF, M_WAITOK); 97 OF_getpropintarray(node, "pwms", sc->sc_pwm, len); 98 sc->sc_pwm_len = len; 99 100 sc->sc_max_brightness = 101 OF_getpropint(node, "max-brightness", 0); 102 wskbd_get_backlight = pwmleds_get_kbd_backlight; 103 wskbd_set_backlight = pwmleds_set_kbd_backlight; 104 } 105 } 106 107 int 108 pwmleds_activate(struct device *self, int act) 109 { 110 struct pwmleds_softc *sc = (struct pwmleds_softc *)self; 111 struct pwm_state ps; 112 int error; 113 114 switch (act) { 115 case DVACT_QUIESCE: 116 error = pwm_get_state(sc->sc_pwm, &sc->sc_ps_saved); 117 if (error) 118 return error; 119 120 pwm_init_state(sc->sc_pwm, &ps); 121 ps.ps_pulse_width = 0; 122 ps.ps_enabled = 0; 123 return pwm_set_state(sc->sc_pwm, &ps); 124 case DVACT_WAKEUP: 125 return pwm_set_state(sc->sc_pwm, &sc->sc_ps_saved); 126 } 127 return 0; 128 } 129 130 struct pwmleds_softc * 131 pwmleds_kbd_backlight(void) 132 { 133 struct pwmleds_softc *sc; 134 int i; 135 136 for (i = 0; i < pwmleds_cd.cd_ndevs; i++) { 137 sc = pwmleds_cd.cd_devs[i]; 138 if (sc == NULL) 139 continue; 140 if (sc->sc_max_brightness > 0) 141 return sc; 142 } 143 144 return NULL; 145 } 146 147 int 148 pwmleds_get_kbd_backlight(struct wskbd_backlight *kbl) 149 { 150 struct pwmleds_softc *sc; 151 struct pwm_state ps; 152 int error; 153 154 sc = pwmleds_kbd_backlight(); 155 if (sc == NULL) 156 return ENOTTY; 157 158 error = pwm_get_state(sc->sc_pwm, &ps); 159 if (error) 160 return error; 161 162 kbl->min = 0; 163 kbl->max = sc->sc_max_brightness; 164 kbl->curval = (ps.ps_enabled) ? 165 ((uint64_t)ps.ps_pulse_width * kbl->max) / ps.ps_period : 0; 166 return 0; 167 } 168 169 int 170 pwmleds_set_kbd_backlight(struct wskbd_backlight *kbl) 171 { 172 struct pwmleds_softc *sc; 173 struct pwm_state ps; 174 175 sc = pwmleds_kbd_backlight(); 176 if (sc == NULL) 177 return ENOTTY; 178 179 if (kbl->curval < 0 || kbl->curval > sc->sc_max_brightness) 180 return EINVAL; 181 182 pwm_init_state(sc->sc_pwm, &ps); 183 ps.ps_pulse_width = 184 ((uint64_t)kbl->curval * ps.ps_period) / sc->sc_max_brightness; 185 ps.ps_enabled = (ps.ps_pulse_width > 0); 186 return pwm_set_state(sc->sc_pwm, &ps); 187 } 188