1 /*
2 * Generic GPIO led
3 *
4 * Copyright (C) 2019 - 2020 Andy Green <andy@warmcat.com>
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to
8 * deal in the Software without restriction, including without limitation the
9 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
10 * sell copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
21 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
22 * IN THE SOFTWARE.
23 */
24 #include "private-lib-core.h"
25
26 #include "drivers/led/private-lib-drivers-led.h"
27
28 /*
29 * 64 entry interpolated CIE correction
30 * https://en.wikipedia.org/wiki/Lightness
31 */
32
33 uint16_t cie[] = {
34 0, 113, 227, 340, 454, 568, 688, 824, 976, 1146,
35 1335, 1543, 1772, 2023, 2296, 2592, 2914, 3260, 3633, 4034,
36 4463, 4921, 5409, 5929, 6482, 7067, 7687, 8341, 9032, 9761,
37 10527, 11332, 12178, 13064, 13993, 14964, 15980, 17040, 18146, 19299,
38 20500, 21750, 23049, 24400, 25802, 27256, 28765, 30328, 31946, 33622,
39 35354, 37146, 38996, 40908, 42881, 44916, 47014, 49177, 51406, 53700,
40 56062, 58492, 60992, 63561,
41 65535 /* for interpolation */
42 };
43
44 /*
45 * This is the default intensity correction function, it can be overridden
46 * per-led to eg, normalize intensity of different leds
47 */
48
49 static lws_led_intensity_t
cie_antilog(lws_led_intensity_t lin)50 cie_antilog(lws_led_intensity_t lin)
51 {
52 return (cie[lin >> 10] * (0x3ff - (lin & 0x3ff)) +
53 cie[(lin >> 10) + 1] * (lin & 0x3ff)) / 0x3ff;
54 }
55
56 static void
lws_seq_advance(lws_led_state_t * lcs,lws_led_state_ch_t * ch)57 lws_seq_advance(lws_led_state_t *lcs, lws_led_state_ch_t *ch)
58 {
59 if (!ch->seq)
60 return;
61
62 if (ch->phase_budget != LWS_SEQ_LEDPHASE_TOTAL_ENDLESS &&
63 (ch->phase_budget < ch->step || !ch->phase_budget)) {
64
65 /* we are done */
66
67 ch->seq = NULL;
68 if (!(--lcs->timer_refcount)) {
69 #if defined(LWS_PLAT_TIMER_STOP)
70 LWS_PLAT_TIMER_STOP(lcs->timer);
71 #endif
72 }
73
74 return;
75 }
76
77 ch->ph += ch->step;
78 if (ch->phase_budget != LWS_SEQ_LEDPHASE_TOTAL_ENDLESS)
79 ch->phase_budget -= ch->step;
80 }
81
82 static lws_led_intensity_t
lws_seq_sample(const lws_led_gpio_map_t * map,lws_led_state_chs_t * chs)83 lws_seq_sample(const lws_led_gpio_map_t *map, lws_led_state_chs_t *chs)
84 {
85 unsigned int i;
86
87 if (chs->seqs[LLSI_CURR].seq)
88 chs->seqs[LLSI_CURR].last = chs->seqs[LLSI_CURR].seq->
89 func(chs->seqs[LLSI_CURR].ph);
90
91 if (chs->seqs[LLSI_TRANS].seq) {
92 /*
93 * If a transition is ongoing, we need to use the transition
94 * intensity as the mixing factor between the still-live current
95 * and newly-live next sequences
96 */
97 chs->seqs[LLSI_TRANS].last = chs->seqs[LLSI_TRANS].seq->
98 func(chs->seqs[LLSI_TRANS].ph);
99
100 if (chs->seqs[LLSI_NEXT].seq)
101 chs->seqs[LLSI_NEXT].last = chs->seqs[LLSI_NEXT].seq->
102 func(chs->seqs[LLSI_NEXT].ph);
103
104 i = (lws_led_intensity_t)(((
105 (unsigned int)chs->seqs[LLSI_CURR].last *
106 (65535 - chs->seqs[LLSI_TRANS].last) >> 16) +
107 (((unsigned int)chs->seqs[LLSI_NEXT].last *
108 (unsigned int)chs->seqs[LLSI_TRANS].last) >> 16)));
109 } else
110 i = chs->seqs[LLSI_CURR].last;
111
112 return map->intensity_correction ? map->intensity_correction(i) :
113 cie_antilog((lws_led_intensity_t)i);
114 }
115
116 void
lws_seq_timer_handle(lws_led_state_t * lcs)117 lws_seq_timer_handle(lws_led_state_t *lcs)
118 {
119 lws_led_gpio_controller_t *lgc = lcs->controller;
120 lws_led_state_chs_t *chs = (lws_led_state_chs_t *)&lcs[1];
121 const lws_led_gpio_map_t *map = &lgc->led_map[0];
122 unsigned int n;
123
124 for (n = 0; n < lgc->count_leds; n++) {
125
126 lgc->led_ops.intensity(&lgc->led_ops, map->name,
127 lws_seq_sample(map, chs));
128
129 lws_seq_advance(lcs, &chs->seqs[LLSI_CURR]);
130
131 if (chs->seqs[LLSI_TRANS].seq) {
132 lws_seq_advance(lcs, &chs->seqs[LLSI_NEXT]);
133 lws_seq_advance(lcs, &chs->seqs[LLSI_TRANS]);
134
135 /*
136 * When we finished the transition, we can make the
137 * "next" sequence the current sequence and no need for
138 * a "next" or a transition any more.
139 */
140
141 if (!chs->seqs[LLSI_TRANS].seq) {
142 chs->seqs[LLSI_CURR] = chs->seqs[LLSI_NEXT];
143 chs->seqs[LLSI_NEXT].seq = NULL;
144 }
145 }
146
147 map++;
148 chs++;
149 }
150 }
151
152 static int
lws_led_set_chs_seq(struct lws_led_state * lcs,lws_led_state_ch_t * dest,const lws_led_sequence_def_t * def)153 lws_led_set_chs_seq(struct lws_led_state *lcs, lws_led_state_ch_t *dest,
154 const lws_led_sequence_def_t *def)
155 {
156 int steps;
157
158 dest->seq = def;
159 dest->ph = def->ledphase_offset;
160 dest->phase_budget = def->ledphase_total;
161
162 /*
163 * We need to compute the incremental phase angle step to cover the
164 * total number of phases in the indicated ms, incrementing at the
165 * timer rate of LWS_LED_SEQUENCER_UPDATE_RATE_HZ. Eg,
166 *
167 * 65536 phase steps (one cycle) in 2000ms at 30Hz timer rate means we
168 * will update 2000ms / 33ms = 60 times, so we must step at at
169 * 65536 / 60 = 1092 phase angle resolution
170 */
171
172 steps = def->ms / LWS_LED_SEQUENCER_UPDATE_INTERVAL_MS;
173 dest->step = (def->ledphase_total != LWS_SEQ_LEDPHASE_TOTAL_ENDLESS ?
174 def->ledphase_total : LWS_LED_FUNC_PHASE) / (steps ? steps : 1);
175
176 if (!lcs->timer_refcount++) {
177 #if defined(LWS_PLAT_TIMER_START)
178 LWS_PLAT_TIMER_START(lcs->timer);
179 #endif
180 }
181
182 return steps;
183 }
184
185 int
lws_led_transition(struct lws_led_state * lcs,const char * name,const lws_led_sequence_def_t * next,const lws_led_sequence_def_t * trans)186 lws_led_transition(struct lws_led_state *lcs, const char *name,
187 const lws_led_sequence_def_t *next,
188 const lws_led_sequence_def_t *trans)
189 {
190 lws_led_state_chs_t *chs = (lws_led_state_chs_t *)&lcs[1];
191 int index = lws_led_gpio_lookup(&lcs->controller->led_ops, name);
192
193 if (index < 0)
194 return 1;
195
196 lws_led_set_chs_seq(lcs, &chs[index].seqs[LLSI_TRANS], trans);
197 lws_led_set_chs_seq(lcs, &chs[index].seqs[LLSI_NEXT], next);
198
199 return 0;
200 }
201