target/linux/bcm27xx/patches-5.4/950-0916-leds-Add-the-actpwr-trigger.patch

   1 From 6586d75915287dd336b71e17826f037be7926ebe Mon Sep 17 00:00:00 2001
   2 From: Phil Elwell <phil@raspberrypi.com>
   3 Date: Mon, 13 Jul 2020 10:33:19 +0100
   4 Subject: [PATCH] leds: Add the actpwr trigger
   5
   6 The actpwr trigger is a meta trigger that cycles between an inverted
   7 mmc0 and default-on. It is written in a way that could fairly easily
   8 be generalised to support alternative sets of source triggers.
   9
  10 Signed-off-by: Phil Elwell <phil@raspberrypi.com>
  11 ---
  12  drivers/leds/trigger/Kconfig          |  11 ++
  13  drivers/leds/trigger/Makefile         |   1 +
  14  drivers/leds/trigger/ledtrig-actpwr.c | 191 ++++++++++++++++++++++++++
  15  3 files changed, 203 insertions(+)
  16  create mode 100644 drivers/leds/trigger/ledtrig-actpwr.c
  17
  18 --- a/drivers/leds/trigger/Kconfig
  19 +++ b/drivers/leds/trigger/Kconfig
  20 @@ -151,4 +151,15 @@ config LEDS_TRIGGER_AUDIO
  21           the audio mute and mic-mute changes.
  22           If unsure, say N
  23
  24 +config LEDS_TRIGGER_ACTPWR
  25 +       tristate "ACT/PWR Input Trigger"
  26 +       depends on LEDS_TRIGGERS
  27 +       help
  28 +         This trigger is intended for platforms that have one software-
  29 +         controllable LED and no dedicated activity or power LEDs, hence the
  30 +         need to make the one LED perform both functions. It cycles between
  31 +         default-on and an inverted mmc0 every 500ms, guaranteeing that it is
  32 +         on for at least half of the time.
  33 +         If unsure, say N.
  34 +
  35  endif # LEDS_TRIGGERS
  36 --- a/drivers/leds/trigger/Makefile
  37 +++ b/drivers/leds/trigger/Makefile
  38 @@ -16,3 +16,4 @@ obj-$(CONFIG_LEDS_TRIGGER_PANIC)      += ledt
  39  obj-$(CONFIG_LEDS_TRIGGER_NETDEV)      += ledtrig-netdev.o
  40  obj-$(CONFIG_LEDS_TRIGGER_PATTERN)     += ledtrig-pattern.o
  41  obj-$(CONFIG_LEDS_TRIGGER_AUDIO)       += ledtrig-audio.o
  42 +obj-$(CONFIG_LEDS_TRIGGER_ACTPWR)      += ledtrig-actpwr.o
  43 --- /dev/null
  44 +++ b/drivers/leds/trigger/ledtrig-actpwr.c
  45 @@ -0,0 +1,191 @@
  46 +// SPDX-License-Identifier: GPL-2.0
  47 +/*
  48 + * Activity/power trigger
  49 + *
  50 + * Copyright (C) 2020 Raspberry Pi (Trading) Ltd.
  51 + *
  52 + * Based on Atsushi Nemoto's ledtrig-heartbeat.c, although there may be
  53 + * nothing left of the original now.
  54 + */
  55 +
  56 +#include <linux/module.h>
  57 +#include <linux/kernel.h>
  58 +#include <linux/init.h>
  59 +#include <linux/timer.h>
  60 +#include <linux/leds.h>
  61 +#include "../leds.h"
  62 +
  63 +enum {
  64 +       TRIG_ACT,
  65 +       TRIG_PWR,
  66 +
  67 +       TRIG_COUNT
  68 +};
  69 +
  70 +struct actpwr_trig_src {
  71 +       const char *name;
  72 +       int interval;
  73 +       bool invert;
  74 +};
  75 +
  76 +struct actpwr_vled {
  77 +       struct led_classdev cdev;
  78 +       struct actpwr_trig_data *parent;
  79 +       enum led_brightness value;
  80 +       unsigned int interval;
  81 +       bool invert;
  82 +};
  83 +
  84 +struct actpwr_trig_data {
  85 +       struct led_trigger trig;
  86 +       struct actpwr_vled virt_leds[TRIG_COUNT];
  87 +       struct actpwr_vled *active;
  88 +       struct timer_list timer;
  89 +       int next_active;
  90 +};
  91 +
  92 +static int actpwr_trig_activate(struct led_classdev *led_cdev);
  93 +static void actpwr_trig_deactivate(struct led_classdev *led_cdev);
  94 +
  95 +static const struct actpwr_trig_src actpwr_trig_sources[TRIG_COUNT] = {
  96 +       [TRIG_ACT] = { "mmc0", 500, true },
  97 +       [TRIG_PWR] = { "default-on", 500, false },
  98 +};
  99 +
 100 +static struct actpwr_trig_data actpwr_data = {
 101 +       {
 102 +               .name     = "actpwr",
 103 +               .activate = actpwr_trig_activate,
 104 +               .deactivate = actpwr_trig_deactivate,
 105 +       }
 106 +};
 107 +
 108 +static void actpwr_brightness_set(struct led_classdev *led_cdev,
 109 +                                 enum led_brightness value)
 110 +{
 111 +       struct actpwr_vled *vled = container_of(led_cdev, struct actpwr_vled,
 112 +                                              cdev);
 113 +       struct actpwr_trig_data *trig = vled->parent;
 114 +
 115 +       if (vled->invert)
 116 +               value = !value;
 117 +       vled->value = value;
 118 +
 119 +       if (vled == trig->active)
 120 +               led_trigger_event(&trig->trig, value);
 121 +}
 122 +
 123 +static int actpwr_brightness_set_blocking(struct led_classdev *led_cdev,
 124 +                                         enum led_brightness value)
 125 +{
 126 +       actpwr_brightness_set(led_cdev, value);
 127 +       return 0;
 128 +}
 129 +
 130 +static enum led_brightness actpwr_brightness_get(struct led_classdev *led_cdev)
 131 +{
 132 +       struct actpwr_vled *vled = container_of(led_cdev, struct actpwr_vled,
 133 +                                             cdev);
 134 +
 135 +       return vled->value;
 136 +}
 137 +
 138 +static void actpwr_trig_cycle(struct timer_list *t)
 139 +{
 140 +       struct actpwr_trig_data *trig  = &actpwr_data;
 141 +       struct actpwr_vled *active;
 142 +       enum led_brightness value;
 143 +
 144 +       active = &trig->virt_leds[trig->next_active];
 145 +       trig->active = active;
 146 +       trig->next_active = (trig->next_active + 1) % TRIG_COUNT;
 147 +
 148 +       led_trigger_event(&trig->trig, active->value);
 149 +
 150 +       mod_timer(&trig->timer, jiffies + msecs_to_jiffies(active->interval));
 151 +}
 152 +
 153 +static int actpwr_trig_activate(struct led_classdev *led_cdev)
 154 +{
 155 +       struct actpwr_trig_data *trig  = &actpwr_data;
 156 +
 157 +       /* Start the timer if this is the first LED */
 158 +       if (!trig->active)
 159 +               actpwr_trig_cycle(&trig->timer);
 160 +       else
 161 +               led_set_brightness_nosleep(led_cdev, trig->active->value);
 162 +
 163 +       return 0;
 164 +}
 165 +
 166 +static void actpwr_trig_deactivate(struct led_classdev *led_cdev)
 167 +{
 168 +       struct actpwr_trig_data *trig  = &actpwr_data;
 169 +
 170 +       if (list_empty(&trig->trig.led_cdevs)) {
 171 +               del_timer_sync(&trig->timer);
 172 +               trig->active = NULL;
 173 +       }
 174 +}
 175 +
 176 +static int __init actpwr_trig_init(void)
 177 +{
 178 +       struct actpwr_trig_data *trig  = &actpwr_data;
 179 +       int ret = 0;
 180 +       int i;
 181 +
 182 +       timer_setup(&trig->timer, actpwr_trig_cycle, 0);
 183 +
 184 +       /* Register one "LED" for each source trigger */
 185 +       for (i = 0; i < TRIG_COUNT; i++)
 186 +       {
 187 +               struct actpwr_vled *vled = &trig->virt_leds[i];
 188 +               struct led_classdev *cdev = &vled->cdev;
 189 +               const struct actpwr_trig_src *src = &actpwr_trig_sources[i];
 190 +
 191 +               vled->parent = trig;
 192 +               vled->interval = src->interval;
 193 +               vled->invert = src->invert;
 194 +               cdev->name = src->name;
 195 +               cdev->brightness_set = actpwr_brightness_set;
 196 +               cdev->brightness_set_blocking = actpwr_brightness_set_blocking;
 197 +               cdev->brightness_get = actpwr_brightness_get;
 198 +               cdev->default_trigger = src->name;
 199 +               ret = led_classdev_register(NULL, cdev);
 200 +               if (ret)
 201 +                       goto error_classdev;
 202 +       }
 203 +
 204 +       ret = led_trigger_register(&trig->trig);
 205 +       if (ret)
 206 +               goto error_classdev;
 207 +
 208 +       return 0;
 209 +
 210 +error_classdev:
 211 +       while (i > 0)
 212 +       {
 213 +               i--;
 214 +               led_classdev_unregister(&trig->virt_leds[i].cdev);
 215 +       }
 216 +
 217 +       return ret;
 218 +}
 219 +
 220 +static void __exit actpwr_trig_exit(void)
 221 +{
 222 +       int i;
 223 +
 224 +       led_trigger_unregister(&actpwr_data.trig);
 225 +       for (i = 0; i < TRIG_COUNT; i++)
 226 +       {
 227 +               led_classdev_unregister(&actpwr_data.virt_leds[i].cdev);
 228 +       }
 229 +}
 230 +
 231 +module_init(actpwr_trig_init);
 232 +module_exit(actpwr_trig_exit);
 233 +
 234 +MODULE_AUTHOR("Phil Elwell <phil@raspberrypi.com>");
 235 +MODULE_DESCRIPTION("ACT/PWR LED trigger");
 236 +MODULE_LICENSE("GPL v2");