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 28 #include <sys/param.h> 29 #include <sys/systm.h> 30 #include <sys/bio.h> 31 #include <sys/bus.h> 32 #include <sys/conf.h> 33 #include <sys/endian.h> 34 #include <sys/fcntl.h> 35 #include <sys/ioccom.h> 36 #include <sys/kernel.h> 37 #include <sys/kthread.h> 38 #include <sys/lock.h> 39 #include <sys/malloc.h> 40 #include <sys/module.h> 41 #include <sys/mutex.h> 42 #include <sys/priv.h> 43 #include <sys/slicer.h> 44 #include <sys/sysctl.h> 45 #include <sys/time.h> 46 47 #include <dev/ofw/ofw_bus.h> 48 #include <dev/ofw/ofw_bus_subr.h> 49 50 #include <dev/regulator/regulator.h> 51 52 #include <dev/backlight/backlight.h> 53 54 #include <dev/pwm/ofw_pwm.h> 55 56 #include "backlight_if.h" 57 #include "pwmbus_if.h" 58 59 struct pwm_backlight_softc { 60 device_t pwmdev; 61 struct cdev *cdev; 62 63 pwm_channel_t channel; 64 uint32_t *levels; 65 ssize_t nlevels; 66 int default_level; 67 ssize_t current_level; 68 69 regulator_t power_supply; 70 uint64_t period; 71 uint64_t duty; 72 bool enabled; 73 }; 74 75 static int pwm_backlight_find_level_per_percent(struct pwm_backlight_softc *sc, int percent); 76 77 static struct ofw_compat_data compat_data[] = { 78 { "pwm-backlight", 1 }, 79 { NULL, 0 } 80 }; 81 82 static int 83 pwm_backlight_probe(device_t dev) 84 { 85 86 if (!ofw_bus_search_compatible(dev, compat_data)->ocd_data) 87 return (ENXIO); 88 89 device_set_desc(dev, "PWM Backlight"); 90 return (BUS_PROBE_DEFAULT); 91 } 92 93 static int 94 pwm_backlight_attach(device_t dev) 95 { 96 struct pwm_backlight_softc *sc; 97 phandle_t node; 98 int rv; 99 100 sc = device_get_softc(dev); 101 node = ofw_bus_get_node(dev); 102 103 rv = pwm_get_by_ofw_propidx(dev, node, "pwms", 0, &sc->channel); 104 if (rv != 0) { 105 device_printf(dev, "Cannot map pwm channel %d\n", rv); 106 return (ENXIO); 107 } 108 109 if (regulator_get_by_ofw_property(dev, 0, "power-supply", 110 &sc->power_supply) != 0) { 111 device_printf(dev, "No power-supply property\n"); 112 return (ENXIO); 113 } 114 115 if (OF_hasprop(node, "brightness-levels")) { 116 sc->nlevels = OF_getencprop_alloc(node, "brightness-levels", 117 (void **)&sc->levels); 118 if (sc->nlevels <= 0) { 119 device_printf(dev, "Cannot parse brightness levels\n"); 120 return (ENXIO); 121 } 122 sc->nlevels /= sizeof(uint32_t); 123 124 if (OF_getencprop(node, "default-brightness-level", 125 &sc->default_level, sizeof(uint32_t)) <= 0) { 126 device_printf(dev, "No default-brightness-level while brightness-levels is specified\n"); 127 return (ENXIO); 128 } else { 129 if (sc->default_level > sc->nlevels) { 130 device_printf(dev, "default-brightness-level isn't present in brightness-levels range\n"); 131 return (ENXIO); 132 } 133 sc->channel->duty = sc->channel->period * sc->levels[sc->default_level] / 100; 134 } 135 136 if (bootverbose) { 137 device_printf(dev, "Number of levels: %zd\n", sc->nlevels); 138 device_printf(dev, "Configured period time: %ju\n", (uintmax_t)sc->channel->period); 139 device_printf(dev, "Default duty cycle: %ju\n", (uintmax_t)sc->channel->duty); 140 } 141 } else { 142 /* Get the current backlight level */ 143 PWMBUS_CHANNEL_GET_CONFIG(sc->channel->dev, 144 sc->channel->channel, 145 (unsigned int *)&sc->channel->period, 146 (unsigned int *)&sc->channel->duty); 147 if (sc->channel->duty > sc->channel->period) 148 sc->channel->duty = sc->channel->period; 149 if (bootverbose) { 150 device_printf(dev, "Configured period time: %ju\n", (uintmax_t)sc->channel->period); 151 device_printf(dev, "Default duty cycle: %ju\n", (uintmax_t)sc->channel->duty); 152 } 153 } 154 155 regulator_enable(sc->power_supply); 156 sc->channel->enabled = true; 157 PWMBUS_CHANNEL_CONFIG(sc->channel->dev, sc->channel->channel, 158 sc->channel->period, sc->channel->duty); 159 PWMBUS_CHANNEL_ENABLE(sc->channel->dev, sc->channel->channel, 160 sc->channel->enabled); 161 162 sc->current_level = pwm_backlight_find_level_per_percent(sc, 163 sc->channel->period / sc->channel->duty); 164 sc->cdev = backlight_register("pwm_backlight", dev); 165 if (sc->cdev == NULL) 166 device_printf(dev, "Cannot register as a backlight\n"); 167 168 return (0); 169 } 170 171 static int 172 pwm_backlight_detach(device_t dev) 173 { 174 struct pwm_backlight_softc *sc; 175 176 sc = device_get_softc(dev); 177 if (sc->nlevels > 0) 178 OF_prop_free(sc->levels); 179 regulator_disable(sc->power_supply); 180 backlight_destroy(sc->cdev); 181 return (0); 182 } 183 184 static int 185 pwm_backlight_find_level_per_percent(struct pwm_backlight_softc *sc, int percent) 186 { 187 int i; 188 int diff; 189 190 if (percent < 0 || percent > 100) 191 return (-1); 192 193 for (i = 0, diff = 0; i < sc->nlevels; i++) { 194 if (sc->levels[i] == percent) 195 return (i); 196 else if (sc->levels[i] < percent) 197 diff = percent - sc->levels[i]; 198 else { 199 if (diff < abs((percent - sc->levels[i]))) 200 return (i - 1); 201 else 202 return (i); 203 } 204 } 205 206 return (-1); 207 } 208 209 static int 210 pwm_backlight_update_status(device_t dev, struct backlight_props *props) 211 { 212 struct pwm_backlight_softc *sc; 213 int reg_status; 214 int error; 215 216 sc = device_get_softc(dev); 217 218 if (sc->nlevels != 0) { 219 error = pwm_backlight_find_level_per_percent(sc, 220 props->brightness); 221 if (error < 0) 222 return (ERANGE); 223 sc->current_level = error; 224 sc->channel->duty = sc->channel->period * 225 sc->levels[sc->current_level] / 100; 226 } else { 227 if (props->brightness > 100 || props->brightness < 0) 228 return (ERANGE); 229 sc->channel->duty = sc->channel->period * 230 props->brightness / 100; 231 } 232 sc->channel->enabled = true; 233 PWMBUS_CHANNEL_CONFIG(sc->channel->dev, sc->channel->channel, 234 sc->channel->period, sc->channel->duty); 235 PWMBUS_CHANNEL_ENABLE(sc->channel->dev, sc->channel->channel, 236 sc->channel->enabled); 237 error = regulator_status(sc->power_supply, ®_status); 238 if (error != 0) 239 device_printf(dev, 240 "Cannot get power-supply status: %d\n", error); 241 else { 242 if (props->brightness > 0) { 243 if (reg_status != REGULATOR_STATUS_ENABLED) 244 regulator_enable(sc->power_supply); 245 } else { 246 if (reg_status == REGULATOR_STATUS_ENABLED) 247 regulator_disable(sc->power_supply); 248 } 249 } 250 251 return (0); 252 } 253 254 static int 255 pwm_backlight_get_status(device_t dev, struct backlight_props *props) 256 { 257 struct pwm_backlight_softc *sc; 258 int i; 259 260 sc = device_get_softc(dev); 261 262 if (sc->nlevels != 0) { 263 props->brightness = sc->levels[sc->current_level]; 264 props->nlevels = sc->nlevels; 265 for (i = 0; i < sc->nlevels; i++) 266 props->levels[i] = sc->levels[i]; 267 } else { 268 props->brightness = sc->channel->duty * 100 / sc->channel->period; 269 props->nlevels = 0; 270 } 271 return (0); 272 } 273 274 static int 275 pwm_backlight_get_info(device_t dev, struct backlight_info *info) 276 { 277 278 info->type = BACKLIGHT_TYPE_PANEL; 279 strlcpy(info->name, "pwm-backlight", BACKLIGHTMAXNAMELENGTH); 280 return (0); 281 } 282 283 static device_method_t pwm_backlight_methods[] = { 284 /* device_if */ 285 DEVMETHOD(device_probe, pwm_backlight_probe), 286 DEVMETHOD(device_attach, pwm_backlight_attach), 287 DEVMETHOD(device_detach, pwm_backlight_detach), 288 289 /* backlight interface */ 290 DEVMETHOD(backlight_update_status, pwm_backlight_update_status), 291 DEVMETHOD(backlight_get_status, pwm_backlight_get_status), 292 DEVMETHOD(backlight_get_info, pwm_backlight_get_info), 293 DEVMETHOD_END 294 }; 295 296 driver_t pwm_backlight_driver = { 297 "pwm_backlight", 298 pwm_backlight_methods, 299 sizeof(struct pwm_backlight_softc), 300 }; 301 302 DRIVER_MODULE(pwm_backlight, simplebus, pwm_backlight_driver, 0, 0); 303 MODULE_DEPEND(pwm_backlight, backlight, 1, 1, 1); 304 OFWBUS_PNP_INFO(compat_data); 305