文章目录
- Power按键
-
- 短按休眠和长按关机
- 关机命令
-
- poweroff命令关机
RK3399平台支持底板power按键休眠唤醒以及关机功能，Linux命令行也可以通过命令进行关机，下面对这两种方式进行简单的解析。
Power按键
power按键的休眠唤醒功能一般是与PMIC芯片和CPU相关的，硬件上该按键会连接到PMIC的PWRON引脚和CPU对应的引脚上。
先来看power按键在PMIC侧的响应机制，POWER键按下以后，经过TdbPWRONF时间以后，INT引脚变为低电平，触发中断。内核驱动响应中断，执行休眠程序。
如果PWRON继续保持低电平超过TdPWRONLP，PMIC就会响应，进行关机。
短按休眠和长按关机
log信息：
[root@rk3399:/]# [ 10.249921] PM: suspend entry 2019-01-01 00:01:01.967707087 UTC
[ 10.250531] PM: Syncing filesystems ... done.
[ 10.255148] test message. //加入的测试信息
[ 10.256842] Freezing user space processes ... (elapsed 0.003 seconds) done.
[ 10.260770] Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done.
[ 10.263308] Suspending console(s) (use no_console_suspend to debug)
INFO: sleep mode config[0xde]:
INFO: AP_PWROFF
INFO: SLP_ARMPD
INFO: SLP_PLLPD
INFO: DDR_RET
INFO: SLP_CENTER_PD
INFO: wakeup source config[0x804]:
INFO: GPIO interrupt can wakeup system
INFO: PWM interrupt can wakeup system
INFO: PWM CONFIG[0x4]:
INFO: PWM: PWM2D_REGULATOR_EN
INFO: APIOS info[0x0]:
INFO: not config
INFO: GPIO POWER INFO:
INFO: GPIO1_C1
INFO: GPIO1_B6
INFO: PMU_MODE_CONG: 0x1477bf51
涉及驱动文件
kernel/kernel/power/suspend.c
/*** enter_state - Do common work needed to enter system sleep state.* @state: System sleep state to enter.** Make sure that no one else is trying to put the system into a sleep state.* Fail if that's not the case. Otherwise, prepare for system suspend, make the* system enter the given sleep state and clean up after wakeup.*/
static int enter_state(suspend_state_t state)
{int error;trace_suspend_resume(TPS("suspend_enter"), state, true);if (state == PM_SUSPEND_FREEZE) {
#ifdef CONFIG_PM_DEBUGif (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {pr_warning("PM: Unsupported test mode for suspend to idle,""please choose none/freezer/devices/platform.\n");return -EAGAIN;}
#endif} else if (!valid_state(state)) {return -EINVAL;}if (!mutex_trylock(&pm_mutex))return -EBUSY;if (state == PM_SUSPEND_FREEZE)freeze_begin();#ifndef CONFIG_SUSPEND_SKIP_SYNCtrace_suspend_resume(TPS("sync_filesystems"), 0, true);printk(KERN_INFO "PM: Syncing filesystems ... ");sys_sync();printk("done.\n");trace_suspend_resume(TPS("sync_filesystems"), 0, false);
#endifpr_debug("PM: Preparing system for sleep (%s)\n", pm_states[state]);pm_suspend_clear_flags();error = suspend_prepare(state);if (error)goto Unlock;if (suspend_test(TEST_FREEZER))goto Finish;trace_suspend_resume(TPS("suspend_enter"), state, false);pr_debug("PM: Suspending system (%s)\n", pm_states[state]);pm_restrict_gfp_mask();error = suspend_devices_and_enter(state);pm_restore_gfp_mask();Finish:pr_debug("PM: Finishing wakeup.\n");suspend_finish();Unlock:mutex_unlock(&pm_mutex);return error;
}
通过代码可知，power按键触发的休眠和关机会执行sys_sync函数，进行系统数据的保存，这与突然掉电导致的异常关机是有很大区别的。
关机命令
Linux的关机命令有shutdown、halt、poweroff命令等.
poweroff命令关机
log信息：
[root@rk3399:/]# poweroff
[root@rk3399:/]# stop finishedStopping input-event-daemon: done
stop auto-reboot finished
Stopping dnsmasq: OK
Stopping vsftpd: stopped vsftpd (pid 1072)
OK
[ 20.099392] [BT_RFKILL]: bt shut off power
[ 20.132245] configfs-gadget gadget: unbind function 'Function FS Gadget'/ffffffc07b025a38
Stopping sshd: OK
Stopping lighttpd: OK
Gracefully shutting down php-fpm . done
Stopping dhcpcd...
stopped /sbin/dhcpcd (pid 924)
killall: rkisp_3A_server: no process killed
Stopping network: OK
stop finishedStopping system message bus: done
Saving random seed... done.
Stopping logging: OK
umount: can't remount adb read-only
umount: devtmpfs busy - remounted read-only
[ 21.589884] EXT4-fs (mmcblk2p8): re-mounted. Opts: (null)
The system is going down NOW!
Sent SIGTERM to all processes
Sent SIGKILL to all processes
Requesting system poweroff
[ 23.597578] cpu cpu4: min=816000, max=816000
[ 23.598572] cpu cpu0: min=816000, max=816000
[ 23.669985] I : [File] : drivers/gpu/arm/midgard_for_linux/platform/rk/mali_kbase_config_rk.c; [Line] : 274; [Func] : kbase_platform_rk_shutdown(); to make vdd_gpu enabled for turning off pd_gpu in pm_framework.
[ 23.671701] rk-vcodec ff660000.rkvdec: shutdown
[ 23.672132] rk-vcodec ff650000.vpu_service: shutdown
[ 23.673046] rk808 0-001b: System power off
[ 23.673419] rk808 0-001b: test message //加入的测试信息
[root@rk3399:/]# poweroff --help
BusyBox v1.27.2 (2020-03-19 09:39:13 UTC) multi-call binary.Usage: poweroff [-d DELAY] [-n] [-f]Halt and shut off power-d SEC Delay interval-n Do not sync-f Force (don't go through init)
poweroff命令做的事可以从打印信息上看出来，其实可以分为两部分，一是配置系统，停止当前的服务，进行数据保存。二是调用电源管理驱动对应的接口，完成电源配置，进行关机。
涉及驱动文件
kernel/drivers/mfd/rk808.c
static void rk808_syscore_shutdown(void)
{int ret;struct rk808 *rk808 = i2c_get_clientdata(rk808_i2c_client);if (!rk808) {dev_warn(&rk808_i2c_client->dev,"have no rk808, so do nothing here\n");return;}/* close rtc int when power off */regmap_update_bits(rk808->regmap,RK808_INT_STS_MSK_REG1,(0x3 << 5), (0x3 << 5));regmap_update_bits(rk808->regmap,RK808_RTC_INT_REG,(0x3 << 2), (0x0 << 2));/** For PMIC that power off supplies by write register via i2c bus,* it's better to do power off at syscore shutdown here.** Because when run to kernel's "pm_power_off" call, i2c may has* been stopped or PMIC may not be able to get i2c transfer while* there are too many devices are competiting.*/if (system_state == SYSTEM_POWER_OFF) {/* power off supplies ! */if (pm_shutdown) {dev_info(&rk808_i2c_client->dev, "System power off\n");ret = pm_shutdown(rk808->regmap);if (ret)dev_err(&rk808_i2c_client->dev,"System power off error!\n");mdelay(10);dev_info(&rk808_i2c_client->dev,"Cpu should never reach here, stop!\n");while (1);}}
}
#define DEV_OFF_RST BIT(3)static int rk808_shutdown(struct regmap *regmap)
{int ret;ret = regmap_update_bits(regmap,RK808_DEVCTRL_REG,DEV_OFF_RST, DEV_OFF_RST);return ret;
}
最终调用的的rk808_shutdown接口函数，对RK808_DEVCTRL_REG寄存器写入DEV_OFF_RST，触发关机
