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
pwm_backlight_probe(device_t dev)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
pwm_backlight_attach(device_t dev)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
pwm_backlight_detach(device_t dev)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
pwm_backlight_find_level_per_percent(struct pwm_backlight_softc * sc,int percent)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
pwm_backlight_update_status(device_t dev,struct backlight_props * props)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
pwm_backlight_get_status(device_t dev,struct backlight_props * props)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
pwm_backlight_get_info(device_t dev,struct backlight_info * info)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