^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) * ledtrig-cpu.c - LED trigger based on CPU activity
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * This LED trigger will be registered for first 8 CPUs and named
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) * as cpu0..cpu7. There's additional trigger called cpu that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) * is on when any CPU is active.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) * If you want support for arbitrary number of CPUs, make it one trigger,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) * with additional sysfs file selecting which CPU to watch.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) * It can be bound to any LED just like other triggers using either a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) * board file or via sysfs interface.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) * An API named ledtrig_cpu is exported for any user, who want to add CPU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) * activity indication in their code.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) * Copyright 2011 Linus Walleij <linus.walleij@linaro.org>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) * Copyright 2011 - 2012 Bryan Wu <bryan.wu@canonical.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) #include <linux/percpu.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) #include <linux/syscore_ops.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) #include <linux/rwsem.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) #include <linux/cpu.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) #include "../leds.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) #define MAX_NAME_LEN 8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) struct led_trigger_cpu {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) bool is_active;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) char name[MAX_NAME_LEN];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) struct led_trigger *_trig;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) static DEFINE_PER_CPU(struct led_trigger_cpu, cpu_trig);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) static struct led_trigger *trig_cpu_all;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) static atomic_t num_active_cpus = ATOMIC_INIT(0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) * ledtrig_cpu - emit a CPU event as a trigger
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) * @evt: CPU event to be emitted
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) * Emit a CPU event on a CPU core, which will trigger a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) * bound LED to turn on or turn off.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) void ledtrig_cpu(enum cpu_led_event ledevt)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) struct led_trigger_cpu *trig = this_cpu_ptr(&cpu_trig);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) bool is_active = trig->is_active;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) /* Locate the correct CPU LED */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) switch (ledevt) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) case CPU_LED_IDLE_END:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) case CPU_LED_START:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) /* Will turn the LED on, max brightness */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) is_active = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) case CPU_LED_IDLE_START:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) case CPU_LED_STOP:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) case CPU_LED_HALTED:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) /* Will turn the LED off */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) is_active = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) /* Will leave the LED as it is */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) if (is_active != trig->is_active) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) unsigned int active_cpus;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) unsigned int total_cpus;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) /* Update trigger state */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) trig->is_active = is_active;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) atomic_add(is_active ? 1 : -1, &num_active_cpus);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) active_cpus = atomic_read(&num_active_cpus);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) total_cpus = num_present_cpus();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) led_trigger_event(trig->_trig,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) is_active ? LED_FULL : LED_OFF);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) led_trigger_event(trig_cpu_all,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) DIV_ROUND_UP(LED_FULL * active_cpus, total_cpus));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) EXPORT_SYMBOL(ledtrig_cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) static int ledtrig_cpu_syscore_suspend(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) ledtrig_cpu(CPU_LED_STOP);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) static void ledtrig_cpu_syscore_resume(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) ledtrig_cpu(CPU_LED_START);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) static void ledtrig_cpu_syscore_shutdown(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) ledtrig_cpu(CPU_LED_HALTED);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) static struct syscore_ops ledtrig_cpu_syscore_ops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) .shutdown = ledtrig_cpu_syscore_shutdown,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) .suspend = ledtrig_cpu_syscore_suspend,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) .resume = ledtrig_cpu_syscore_resume,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) static int ledtrig_online_cpu(unsigned int cpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) ledtrig_cpu(CPU_LED_START);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) static int ledtrig_prepare_down_cpu(unsigned int cpu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) ledtrig_cpu(CPU_LED_STOP);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) static int __init ledtrig_cpu_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) int cpu;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) /* Supports up to 9999 cpu cores */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) BUILD_BUG_ON(CONFIG_NR_CPUS > 9999);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) * Registering a trigger for all CPUs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) led_trigger_register_simple("cpu", &trig_cpu_all);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) * Registering CPU led trigger for each CPU core here
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) * ignores CPU hotplug, but after this CPU hotplug works
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) * fine with this trigger.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) for_each_possible_cpu(cpu) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) struct led_trigger_cpu *trig = &per_cpu(cpu_trig, cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) if (cpu >= 8)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) snprintf(trig->name, MAX_NAME_LEN, "cpu%d", cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) led_trigger_register_simple(trig->name, &trig->_trig);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) register_syscore_ops(&ledtrig_cpu_syscore_ops);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "leds/trigger:starting",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) ledtrig_online_cpu, ledtrig_prepare_down_cpu);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) if (ret < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) pr_err("CPU hotplug notifier for ledtrig-cpu could not be registered: %d\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) pr_info("ledtrig-cpu: registered to indicate activity on CPUs\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) device_initcall(ledtrig_cpu_init);
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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