^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * Backlight emulation LED trigger
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Copyright 2008 (C) Rodolfo Giometti <giometti@linux.it>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) * Copyright 2008 (C) Eurotech S.p.A. <info@eurotech.it>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/fb.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <linux/leds.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include "../leds.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #define BLANK 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #define UNBLANK 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) struct bl_trig_notifier {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) struct led_classdev *led;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) int brightness;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) int old_status;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) struct notifier_block notifier;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) unsigned invert;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) static int fb_notifier_callback(struct notifier_block *p,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) unsigned long event, void *data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) struct bl_trig_notifier *n = container_of(p,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) struct bl_trig_notifier, notifier);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) struct led_classdev *led = n->led;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) struct fb_event *fb_event = data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) int *blank;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) int new_status;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) /* If we aren't interested in this event, skip it immediately ... */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) if (event != FB_EVENT_BLANK)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) blank = fb_event->data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) new_status = *blank ? BLANK : UNBLANK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) if (new_status == n->old_status)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) if ((n->old_status == UNBLANK) ^ n->invert) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) n->brightness = led->brightness;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) led_set_brightness_nosleep(led, LED_OFF);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) led_set_brightness_nosleep(led, n->brightness);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) n->old_status = new_status;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) static ssize_t bl_trig_invert_show(struct device *dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) struct device_attribute *attr, char *buf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) struct bl_trig_notifier *n = led_trigger_get_drvdata(dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) return sprintf(buf, "%u\n", n->invert);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) static ssize_t bl_trig_invert_store(struct device *dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) struct device_attribute *attr, const char *buf, size_t num)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) struct led_classdev *led = led_trigger_get_led(dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) struct bl_trig_notifier *n = led_trigger_get_drvdata(dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) unsigned long invert;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) ret = kstrtoul(buf, 10, &invert);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) if (ret < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) if (invert > 1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) n->invert = invert;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) /* After inverting, we need to update the LED. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) if ((n->old_status == BLANK) ^ n->invert)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) led_set_brightness_nosleep(led, LED_OFF);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) led_set_brightness_nosleep(led, n->brightness);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) return num;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) static DEVICE_ATTR(inverted, 0644, bl_trig_invert_show, bl_trig_invert_store);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) static struct attribute *bl_trig_attrs[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) &dev_attr_inverted.attr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) NULL,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) ATTRIBUTE_GROUPS(bl_trig);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) static int bl_trig_activate(struct led_classdev *led)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) struct bl_trig_notifier *n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) n = kzalloc(sizeof(struct bl_trig_notifier), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) if (!n)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) led_set_trigger_data(led, n);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) n->led = led;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) n->brightness = led->brightness;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) n->old_status = UNBLANK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) n->notifier.notifier_call = fb_notifier_callback;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) ret = fb_register_client(&n->notifier);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) dev_err(led->dev, "unable to register backlight trigger\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) static void bl_trig_deactivate(struct led_classdev *led)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) struct bl_trig_notifier *n = led_get_trigger_data(led);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) fb_unregister_client(&n->notifier);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) kfree(n);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) static struct led_trigger bl_led_trigger = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) .name = "backlight",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) .activate = bl_trig_activate,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) .deactivate = bl_trig_deactivate,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) .groups = bl_trig_groups,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) module_led_trigger(bl_led_trigger);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) MODULE_DESCRIPTION("Backlight emulation LED trigger");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) MODULE_LICENSE("GPL v2");
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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