1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2020 Emmanuel Vadot <manu@FreeBSD.org> 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 * 27 * $FreeBSD$ 28 */ 29 30 #include <sys/cdefs.h> 31 __FBSDID("$FreeBSD$"); 32 33 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/bio.h> 37 #include <sys/bus.h> 38 #include <sys/conf.h> 39 #include <sys/endian.h> 40 #include <sys/fcntl.h> 41 #include <sys/ioccom.h> 42 #include <sys/kernel.h> 43 #include <sys/kthread.h> 44 #include <sys/lock.h> 45 #include <sys/malloc.h> 46 #include <sys/module.h> 47 #include <sys/mutex.h> 48 #include <sys/priv.h> 49 #include <sys/slicer.h> 50 #include <sys/sysctl.h> 51 #include <sys/time.h> 52 53 #include <dev/ofw/ofw_bus.h> 54 #include <dev/ofw/ofw_bus_subr.h> 55 56 #include <dev/extres/regulator/regulator.h> 57 58 #include <dev/backlight/backlight.h> 59 60 #include <dev/pwm/ofw_pwm.h> 61 62 #include "backlight_if.h" 63 #include "pwmbus_if.h" 64 65 struct pwm_backlight_softc { 66 device_t pwmdev; 67 struct cdev *cdev; 68 69 pwm_channel_t channel; 70 uint32_t *levels; 71 ssize_t nlevels; 72 int default_level; 73 ssize_t current_level; 74 75 regulator_t power_supply; 76 uint64_t period; 77 uint64_t duty; 78 bool enabled; 79 }; 80 81 static int pwm_backlight_find_level_per_percent(struct pwm_backlight_softc *sc, int percent); 82 83 static struct ofw_compat_data compat_data[] = { 84 { "pwm-backlight", 1 }, 85 { NULL, 0 } 86 }; 87 88 static int 89 pwm_backlight_probe(device_t dev) 90 { 91 92 if (!ofw_bus_search_compatible(dev, compat_data)->ocd_data) 93 return (ENXIO); 94 95 device_set_desc(dev, "PWM Backlight"); 96 return (BUS_PROBE_DEFAULT); 97 } 98 99 static int 100 pwm_backlight_attach(device_t dev) 101 { 102 struct pwm_backlight_softc *sc; 103 phandle_t node; 104 int rv; 105 106 sc = device_get_softc(dev); 107 node = ofw_bus_get_node(dev); 108 109 rv = pwm_get_by_ofw_propidx(dev, node, "pwms", 0, &sc->channel); 110 if (rv != 0) { 111 device_printf(dev, "Cannot map pwm channel %d\n", rv); 112 return (ENXIO); 113 } 114 115 if (regulator_get_by_ofw_property(dev, 0, "power-supply", 116 &sc->power_supply) != 0) { 117 device_printf(dev, "No power-supply property\n"); 118 return (ENXIO); 119 } 120 121 if (OF_hasprop(node, "brightness-levels")) { 122 sc->nlevels = OF_getencprop_alloc(node, "brightness-levels", 123 (void **)&sc->levels); 124 if (sc->nlevels <= 0) { 125 device_printf(dev, "Cannot parse brightness levels\n"); 126 return (ENXIO); 127 } 128 sc->nlevels /= sizeof(uint32_t); 129 130 if (OF_getencprop(node, "default-brightness-level", 131 &sc->default_level, sizeof(uint32_t)) <= 0) { 132 device_printf(dev, "No default-brightness-level while brightness-levels is specified\n"); 133 return (ENXIO); 134 } else { 135 if (sc->default_level > sc->nlevels) { 136 device_printf(dev, "default-brightness-level isn't present in brightness-levels range\n"); 137 return (ENXIO); 138 } 139 sc->channel->duty = sc->channel->period * sc->levels[sc->default_level] / 100; 140 } 141 142 if (bootverbose) { 143 device_printf(dev, "Number of levels: %zd\n", sc->nlevels); 144 device_printf(dev, "Configured period time: %ju\n", (uintmax_t)sc->channel->period); 145 device_printf(dev, "Default duty cycle: %ju\n", (uintmax_t)sc->channel->duty); 146 } 147 } else { 148 /* Get the current backlight level */ 149 PWMBUS_CHANNEL_GET_CONFIG(sc->channel->dev, 150 sc->channel->channel, 151 (unsigned int *)&sc->channel->period, 152 (unsigned int *)&sc->channel->duty); 153 if (sc->channel->duty > sc->channel->period) 154 sc->channel->duty = sc->channel->period; 155 if (bootverbose) { 156 device_printf(dev, "Configured period time: %ju\n", (uintmax_t)sc->channel->period); 157 device_printf(dev, "Default duty cycle: %ju\n", (uintmax_t)sc->channel->duty); 158 } 159 } 160 161 regulator_enable(sc->power_supply); 162 sc->channel->enabled = true; 163 PWMBUS_CHANNEL_CONFIG(sc->channel->dev, sc->channel->channel, 164 sc->channel->period, sc->channel->duty); 165 PWMBUS_CHANNEL_ENABLE(sc->channel->dev, sc->channel->channel, 166 sc->channel->enabled); 167 168 sc->current_level = pwm_backlight_find_level_per_percent(sc, 169 sc->channel->period / sc->channel->duty); 170 sc->cdev = backlight_register("pwm_backlight", dev); 171 if (sc->cdev == NULL) 172 device_printf(dev, "Cannot register as a backlight\n"); 173 174 return (0); 175 } 176 177 static int 178 pwm_backlight_detach(device_t dev) 179 { 180 struct pwm_backlight_softc *sc; 181 182 sc = device_get_softc(dev); 183 if (sc->nlevels > 0) 184 OF_prop_free(sc->levels); 185 regulator_disable(sc->power_supply); 186 backlight_destroy(sc->cdev); 187 return (0); 188 } 189 190 static int 191 pwm_backlight_find_level_per_percent(struct pwm_backlight_softc *sc, int percent) 192 { 193 int i; 194 int diff; 195 196 if (percent < 0 || percent > 100) 197 return (-1); 198 199 for (i = 0, diff = 0; i < sc->nlevels; i++) { 200 if (sc->levels[i] == percent) 201 return (i); 202 else if (sc->levels[i] < percent) 203 diff = percent - sc->levels[i]; 204 else { 205 if (diff < abs((percent - sc->levels[i]))) 206 return (i - 1); 207 else 208 return (i); 209 } 210 } 211 212 return (-1); 213 } 214 215 static int 216 pwm_backlight_update_status(device_t dev, struct backlight_props *props) 217 { 218 struct pwm_backlight_softc *sc; 219 int reg_status; 220 int error; 221 222 sc = device_get_softc(dev); 223 224 if (sc->nlevels != 0) { 225 error = pwm_backlight_find_level_per_percent(sc, 226 props->brightness); 227 if (error < 0) 228 return (ERANGE); 229 sc->current_level = error; 230 sc->channel->duty = sc->channel->period * 231 sc->levels[sc->current_level] / 100; 232 } else { 233 if (props->brightness > 100 || props->brightness < 0) 234 return (ERANGE); 235 sc->channel->duty = sc->channel->period * 236 props->brightness / 100; 237 } 238 sc->channel->enabled = true; 239 PWMBUS_CHANNEL_CONFIG(sc->channel->dev, sc->channel->channel, 240 sc->channel->period, sc->channel->duty); 241 PWMBUS_CHANNEL_ENABLE(sc->channel->dev, sc->channel->channel, 242 sc->channel->enabled); 243 error = regulator_status(sc->power_supply, ®_status); 244 if (error != 0) 245 device_printf(dev, 246 "Cannot get power-supply status: %d\n", error); 247 else { 248 if (props->brightness > 0) { 249 if (reg_status != REGULATOR_STATUS_ENABLED) 250 regulator_enable(sc->power_supply); 251 } else { 252 if (reg_status == REGULATOR_STATUS_ENABLED) 253 regulator_disable(sc->power_supply); 254 } 255 } 256 257 return (0); 258 } 259 260 static int 261 pwm_backlight_get_status(device_t dev, struct backlight_props *props) 262 { 263 struct pwm_backlight_softc *sc; 264 int i; 265 266 sc = device_get_softc(dev); 267 268 if (sc->nlevels != 0) { 269 props->brightness = sc->levels[sc->current_level]; 270 props->nlevels = sc->nlevels; 271 for (i = 0; i < sc->nlevels; i++) 272 props->levels[i] = sc->levels[i]; 273 } else { 274 props->brightness = sc->channel->duty * 100 / sc->channel->period; 275 props->nlevels = 0; 276 } 277 return (0); 278 } 279 280 static int 281 pwm_backlight_get_info(device_t dev, struct backlight_info *info) 282 { 283 284 info->type = BACKLIGHT_TYPE_PANEL; 285 strlcpy(info->name, "pwm-backlight", BACKLIGHTMAXNAMELENGTH); 286 return (0); 287 } 288 289 static device_method_t pwm_backlight_methods[] = { 290 /* device_if */ 291 DEVMETHOD(device_probe, pwm_backlight_probe), 292 DEVMETHOD(device_attach, pwm_backlight_attach), 293 DEVMETHOD(device_detach, pwm_backlight_detach), 294 295 /* backlight interface */ 296 DEVMETHOD(backlight_update_status, pwm_backlight_update_status), 297 DEVMETHOD(backlight_get_status, pwm_backlight_get_status), 298 DEVMETHOD(backlight_get_info, pwm_backlight_get_info), 299 DEVMETHOD_END 300 }; 301 302 driver_t pwm_backlight_driver = { 303 "pwm_backlight", 304 pwm_backlight_methods, 305 sizeof(struct pwm_backlight_softc), 306 }; 307 308 DRIVER_MODULE(pwm_backlight, simplebus, pwm_backlight_driver, 0, 0); 309 MODULE_DEPEND(pwm_backlight, backlight, 1, 1, 1); 310 OFWBUS_PNP_INFO(compat_data); 311