1 /* $OpenBSD: pwmbl.c,v 1.8 2023/04/25 11:21:01 patrick Exp $ */
2 /*
3 * Copyright (c) 2019 Krystian Lewandowski
4 * Copyright (c) 2019 Mark Kettenis <kettenis@openbsd.org>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19 #include <sys/param.h>
20 #include <sys/systm.h>
21 #include <sys/device.h>
22 #include <sys/malloc.h>
23
24 #include <machine/fdt.h>
25 #include <machine/bus.h>
26
27 #include <dev/ofw/openfirm.h>
28 #include <dev/ofw/ofw_gpio.h>
29 #include <dev/ofw/ofw_misc.h>
30
31 #include <dev/wscons/wsconsio.h>
32 #include <dev/wscons/wsdisplayvar.h>
33
34 struct pwmbl_softc {
35 struct device sc_dev;
36 uint32_t *sc_pwm;
37 int sc_pwm_len;
38 uint32_t *sc_levels; /* NULL if simple ramp */
39 int sc_nlevels;
40 uint32_t sc_max_level;
41 uint32_t sc_def_level;
42 struct pwm_state sc_ps_saved;
43 };
44
45 struct pwmbl_softc *sc_pwmbl;
46
47 int pwmbl_match(struct device *, void *, void *);
48 void pwmbl_attach(struct device *, struct device *, void *);
49 int pwmbl_activate(struct device *, int);
50
51 const struct cfattach pwmbl_ca = {
52 sizeof(struct pwmbl_softc), pwmbl_match, pwmbl_attach, NULL,
53 pwmbl_activate
54 };
55
56 struct cfdriver pwmbl_cd = {
57 NULL, "pwmbl", DV_DULL
58 };
59
60 int pwmbl_get_brightness(void *, uint32_t *);
61 int pwmbl_set_brightness(void *, uint32_t);
62 int pwmbl_get_param(struct wsdisplay_param *);
63 int pwmbl_set_param(struct wsdisplay_param *);
64
65 int
pwmbl_match(struct device * parent,void * match,void * aux)66 pwmbl_match(struct device *parent, void *match, void *aux)
67 {
68 struct fdt_attach_args *faa = aux;
69
70 return OF_is_compatible(faa->fa_node, "pwm-backlight");
71 }
72
73 void
pwmbl_attach(struct device * parent,struct device * self,void * aux)74 pwmbl_attach(struct device *parent, struct device *self, void *aux)
75 {
76 struct pwmbl_softc *sc = (struct pwmbl_softc *)self;
77 struct fdt_attach_args *faa = aux;
78 uint32_t *gpios;
79 int len;
80
81 len = OF_getproplen(faa->fa_node, "pwms");
82 if (len < 0) {
83 printf(": no pwm\n");
84 return;
85 }
86
87 sc->sc_pwm = malloc(len, M_DEVBUF, M_WAITOK);
88 OF_getpropintarray(faa->fa_node, "pwms", sc->sc_pwm, len);
89 sc->sc_pwm_len = len;
90
91 len = OF_getproplen(faa->fa_node, "enable-gpios");
92 if (len > 0) {
93 gpios = malloc(len, M_TEMP, M_WAITOK);
94 OF_getpropintarray(faa->fa_node, "enable-gpios", gpios, len);
95 gpio_controller_config_pin(&gpios[0], GPIO_CONFIG_OUTPUT);
96 gpio_controller_set_pin(&gpios[0], 1);
97 free(gpios, M_TEMP, len);
98 }
99
100 len = OF_getproplen(faa->fa_node, "brightness-levels");
101 if (len >= (int)sizeof(uint32_t)) {
102 sc->sc_levels = malloc(len, M_DEVBUF, M_WAITOK);
103 OF_getpropintarray(faa->fa_node, "brightness-levels",
104 sc->sc_levels, len);
105 sc->sc_nlevels = len / sizeof(uint32_t);
106 sc->sc_max_level = sc->sc_levels[sc->sc_nlevels - 1];
107 sc->sc_def_level = OF_getpropint(faa->fa_node,
108 "default-brightness-level", sc->sc_nlevels - 1);
109 if (sc->sc_def_level >= sc->sc_nlevels)
110 sc->sc_def_level = sc->sc_nlevels - 1;
111 sc->sc_def_level = sc->sc_levels[sc->sc_def_level];
112 } else {
113 /* No levels, assume a simple 0..255 ramp. */
114 sc->sc_nlevels = 256;
115 sc->sc_max_level = sc->sc_def_level = sc->sc_nlevels - 1;
116 }
117
118 printf("\n");
119
120 pwmbl_set_brightness(sc, sc->sc_def_level);
121
122 sc_pwmbl = sc;
123 ws_get_param = pwmbl_get_param;
124 ws_set_param = pwmbl_set_param;
125 }
126
127 int
pwmbl_activate(struct device * self,int act)128 pwmbl_activate(struct device *self, int act)
129 {
130 struct pwmbl_softc *sc = (struct pwmbl_softc *)self;
131 struct pwm_state ps;
132 int error;
133
134 switch (act) {
135 case DVACT_QUIESCE:
136 error = pwm_get_state(sc->sc_pwm, &sc->sc_ps_saved);
137 if (error)
138 return error;
139
140 pwm_init_state(sc->sc_pwm, &ps);
141 ps.ps_pulse_width = 0;
142 ps.ps_enabled = 0;
143 return pwm_set_state(sc->sc_pwm, &ps);
144 case DVACT_WAKEUP:
145 return pwm_set_state(sc->sc_pwm, &sc->sc_ps_saved);
146 }
147 return 0;
148 }
149
150 int
pwmbl_get_brightness(void * cookie,uint32_t * level)151 pwmbl_get_brightness(void *cookie, uint32_t *level)
152 {
153 struct pwmbl_softc *sc = cookie;
154 struct pwm_state ps;
155
156 if (pwm_get_state(sc->sc_pwm, &ps))
157 return EINVAL;
158
159 *level = (ps.ps_pulse_width * sc->sc_max_level) / ps.ps_period;
160 return 0;
161 }
162
163 uint32_t
pwmbl_find_brightness(struct pwmbl_softc * sc,uint32_t level)164 pwmbl_find_brightness(struct pwmbl_softc *sc, uint32_t level)
165 {
166 uint32_t mid;
167 int i;
168
169 if (sc->sc_levels == NULL)
170 return level < sc->sc_nlevels ? level : sc->sc_nlevels - 1;
171
172 for (i = 0; i < sc->sc_nlevels - 1; i++) {
173 mid = (sc->sc_levels[i] + sc->sc_levels[i + 1]) / 2;
174 if (sc->sc_levels[i] <= level && level <= mid)
175 return sc->sc_levels[i];
176 if (mid < level && level <= sc->sc_levels[i + 1])
177 return sc->sc_levels[i + 1];
178 }
179 if (level < sc->sc_levels[0])
180 return sc->sc_levels[0];
181 else
182 return sc->sc_levels[i];
183 }
184
185 int
pwmbl_set_brightness(void * cookie,uint32_t level)186 pwmbl_set_brightness(void *cookie, uint32_t level)
187 {
188 struct pwmbl_softc *sc = cookie;
189 struct pwm_state ps;
190
191 if (pwm_init_state(sc->sc_pwm, &ps))
192 return EINVAL;
193
194 level = pwmbl_find_brightness(sc, level);
195
196 ps.ps_enabled = 1;
197 ps.ps_pulse_width = (ps.ps_period * level) / sc->sc_max_level;
198 return pwm_set_state(sc->sc_pwm, &ps);
199 }
200
201 int
pwmbl_get_param(struct wsdisplay_param * dp)202 pwmbl_get_param(struct wsdisplay_param *dp)
203 {
204 struct pwmbl_softc *sc = (struct pwmbl_softc *)sc_pwmbl;
205 uint32_t level;
206
207 switch (dp->param) {
208 case WSDISPLAYIO_PARAM_BRIGHTNESS:
209 if (pwmbl_get_brightness(sc, &level))
210 return -1;
211
212 dp->min = 0;
213 dp->max = sc->sc_max_level;
214 dp->curval = level;
215 return 0;
216 default:
217 return -1;
218 }
219 }
220
221 int
pwmbl_set_param(struct wsdisplay_param * dp)222 pwmbl_set_param(struct wsdisplay_param *dp)
223 {
224 struct pwmbl_softc *sc = (struct pwmbl_softc *)sc_pwmbl;
225
226 switch (dp->param) {
227 case WSDISPLAYIO_PARAM_BRIGHTNESS:
228 if (pwmbl_set_brightness(sc, dp->curval))
229 return -1;
230 return 0;
231 default:
232 return -1;
233 }
234 }
235