如何新建自己的网站,网站页面,如何常看wordpress默认编辑器,方维制网站目录 一、简介
二、解决方法
A、底层驱动
B、上层调用
C、验证 一、简介
1、需求#xff1a;这里是用2个gpio口来控制LED灯#xff0c;开机时默认亮蓝灯#xff0c;按开机键#xff0c;休眠亮红灯#xff0c;唤醒亮蓝灯。
原理图#xff1a; 这里由于主板上电阻R63…目录 一、简介
二、解决方法
A、底层驱动
B、上层调用
C、验证 一、简介
1、需求这里是用2个gpio口来控制LED灯开机时默认亮蓝灯按开机键休眠亮红灯唤醒亮蓝灯。
原理图 这里由于主板上电阻R635未贴所以led_sleep不启用。
2、分析
a.一开始是想将这2个gpio口的控制写在背光pwm驱动中但是该设备是不接屏幕(mipi/edp/lvds)的直接由cpu输出信号到hdmi屏所以无法控制背光pwm。
同理想写在和屏启动相关的驱动里面也是无法控制的。例如由i2c控制的gm8775c。
b.所以想到在底层驱动写一个文件节点由上层应用去控制。
二、解决方法
A、底层驱动
这里写了一个c文件gpio_led.c
/** Driver for keys on GPIO lines capable of generating interrupts.** Copyright (C) 2015, Fuzhou Rockchip Electronics Co., Ltd* Copyright 2005 Phil Blundell** This program is free software; you can redistribute it and/or modify* it under the terms of the GNU General Public License version 2 as* published by the Free Software Foundation.*/#include linux/module.h
#include linux/init.h
#include linux/fs.h
#include linux/interrupt.h
#include linux/irq.h
#include linux/sched.h
#include linux/pm.h
#include linux/sysctl.h
#include linux/proc_fs.h
#include linux/delay.h
#include linux/platform_device.h
#include linux/input.h
#include linux/slab.h
#include linux/wakelock.h#include linux/gpio.h
#include linux/of.h
#include linux/of_gpio.hstruct vanzeak_gpio_drvdata {struct gpio_desc *power_gpio;struct gpio_desc *sleep_gpio;
};static const struct of_device_id vanzeak_gpio_match[] {{ .compatible vanzeak,gpio, .data NULL},{},
};
MODULE_DEVICE_TABLE(of, vanzeak_gpio_match);static ssize_t led_enable_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t size)
{struct vanzeak_gpio_drvdata *ddata dev_get_drvdata(dev);int val val simple_strtol(buf, NULL, 8);if(val){gpiod_direction_output(ddata-power_gpio, 1);gpiod_direction_output(ddata-sleep_gpio, 0);}else{gpiod_direction_output(ddata-power_gpio, 0);gpiod_direction_output(ddata-sleep_gpio, 1);}return size;
}static ssize_t led_enable_show(struct device *dev, struct device_attribute *attr, char *buf)
{return 0;
}static DEVICE_ATTR(led_enable, 0644, led_enable_show, led_enable_store);static struct attribute *led_enable_attrs[] {dev_attr_led_enable.attr,NULL,
};static struct attribute_group led_enable_attr_group {.name led_enable,.attrs led_enable_attrs,
};static int vanzeak_gpio_probe(struct platform_device *pdev)
{struct vanzeak_gpio_drvdata *ddata NULL;struct device *dev pdev-dev;int ret;ddata devm_kzalloc(dev, sizeof(struct vanzeak_gpio_drvdata),GFP_KERNEL);
// if(ddata NULL)
// return -1;platform_set_drvdata(pdev, ddata);dev_set_drvdata(pdev-dev, ddata);ddata-power_gpio devm_gpiod_get_optional(dev, enable, 0);if (IS_ERR(ddata-power_gpio)) {ret PTR_ERR(ddata-power_gpio);dev_err(dev, failed to request power GPIO: %d\n, ret);goto fail0;}ddata-sleep_gpio devm_gpiod_get_optional(dev, sleep, 0);if (IS_ERR(ddata-sleep_gpio)) {ret PTR_ERR(ddata-sleep_gpio);dev_err(dev, failed to request sleep GPIO: %d\n, ret);goto fail0;}gpiod_direction_output(ddata-power_gpio, 1);gpiod_direction_output(ddata-sleep_gpio, 0);ret sysfs_create_group(pdev-dev.kobj, led_enable_attr_group);if (ret) {pr_err(failed to create attr group\n);}return 0;fail0:platform_set_drvdata(pdev, NULL);return -1;
}static int vanzeak_gpio_remove(struct platform_device *pdev)
{return 0;
}#ifdef CONFIG_PM
static int vanzeak_gpio_suspend(struct device *dev)
{struct vanzeak_gpio_drvdata *ddata dev_get_drvdata(dev);printk(DICKE printk %s : %d\n, __func__, __LINE__);gpiod_direction_output(ddata-power_gpio, 0);return 0;
}static int vanzeak_gpio_resume(struct device *dev)
{struct vanzeak_gpio_drvdata *ddata dev_get_drvdata(dev);printk(DICKE printk %s : %d\n, __func__, __LINE__);gpiod_direction_output(ddata-power_gpio, 1);return 0;
}static const struct dev_pm_ops vanzeak_gpio_pm_ops {.suspend vanzeak_gpio_suspend,.resume vanzeak_gpio_resume,
};
#endifstatic struct platform_driver vanzeak_gpio_device_driver {.probe vanzeak_gpio_probe,.remove vanzeak_gpio_remove,.driver {.name vanzeak-gpio,.owner THIS_MODULE,.of_match_table vanzeak_gpio_match,
#ifdef CONFIG_PM.pm vanzeak_gpio_pm_ops,
#endif}
};static int __init vanzeak_gpio_driver_init(void)
{return platform_driver_register(vanzeak_gpio_device_driver);
}static void __exit vanzeak_gpio_driver_exit(void)
{platform_driver_unregister(vanzeak_gpio_device_driver);
}module_init(vanzeak_gpio_driver_init);
module_exit(vanzeak_gpio_driver_exit);
B、上层调用
由上层的休眠唤醒来控制LED的亮灭。
diff --git a/services/core/java/com/android/server/power/PowerManagerService.java b/services/core/java/com/android/server/power/PowerManagerService.java
index af7d91cf7ba6..1bbc51a9ed91 100644
--- a/services/core/java/com/android/server/power/PowerManagerService.javab/services/core/java/com/android/server/power/PowerManagerService.java-119,6 119,14 import java.util.Arrays;import java.util.List;import java.util.Objects;import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.FileInputStream;
import java.io.InputStream;
import java.io.OutputStreamWriter;
import java.io.BufferedWriter;
/*** The power manager service is responsible for coordinating power management* functions on the device.-1598,6 1606,46 public final class PowerManagerService extends SystemService}} private void closeLed(int i){String path /sys/devices/platform/vanzeak-gpio/led_enable/led_enable;String value;if(i 1)value 1;else if(i 0)value 0;else{Slog.e(TAG, data error);return;}// Log.i(TAG,setGpioValue, path [ path ] value [ value ]);File file new File(path); if (!file.exists()) {Slog.i(dxb,initOpenGpio , file is not exist!!!!);return;}FileOutputStream fileOutputStream null;BufferedWriter bufferedWriter null;try {fileOutputStream new FileOutputStream(file);bufferedWriter new BufferedWriter(new OutputStreamWriter(fileOutputStream, utf-8)); bufferedWriter.write(value);bufferedWriter.flush();bufferedWriter.close();} catch (Exception e) {e.printStackTrace();Slog.i(dxb,input data error e.getMessage());} finally {if (bufferedWriter ! null) {try {bufferedWriter.close();} catch (IOException e) {e.printStackTrace();}}}}
private boolean userActivityNoUpdateLocked(long eventTime, int event, int flags, int uid) {if (DEBUG_SPEW) {Slog.d(TAG, userActivityNoUpdateLocked: eventTime eventTime-1690,6 1738,8 public final class PowerManagerService extends SystemServiceTrace.traceBegin(Trace.TRACE_TAG_POWER, wakeUp);try {Slog.i(TAG, ctrol led to working mode);closeLed(1);Slog.i(TAG, Waking up from PowerManagerInternal.wakefulnessToString(getWakefulnessLocked()) (uid reasonUid-1748,6 1798,8 public final class PowerManagerService extends SystemServicetry {reason Math.min(PowerManager.GO_TO_SLEEP_REASON_MAX,Math.max(reason, PowerManager.GO_TO_SLEEP_REASON_MIN));Slog.i(TAG, ctrol led to sleeping mode);closeLed(0);Slog.i(TAG, Going to sleep due to PowerManager.sleepReasonToString(reason) (uid uid )...);
C、验证
按开机键休眠亮红灯唤醒亮蓝灯。
