linux驱动编写（电源管理驱动）

对于嵌入式设备来说，合适的电源管理，不仅可以延长电池的寿命，而且可以省电，延长设备运行时间，在提高用户体验方面有很大的好处。所以，各个soc厂家在这方面花了很多的功夫。下面，我们可以看看linux是如何处理电源管理驱动的。

1、代码目录

drivers/regulator

2、查看目录下的Kconfig文件

menuconfig REGULATORbool "Voltage and Current Regulator Support"helpGeneric Voltage and Current Regulator support.This framework is designed to provide a generic interface to voltageand current regulators within the Linux kernel. It's intended toprovide voltage and current control to client or consumer drivers andalso provide status information to user space applications through asysfs interface.The intention is to allow systems to dynamically control regulatoroutput in order to save power and prolong battery life. This appliesto both voltage regulators (where voltage output is controllable) andcurrent sinks (where current output is controllable).This framework safely compiles out if not selected so that clientdrivers can still be used in systems with no software controllableregulators.If unsure, say no.

3、阅读文件，得知REGULATOR是最核心的模块macro，那我们可以找一个设备的macro看看

config REGULATOR_STM32_VREFBUFtristate "STMicroelectronics STM32 VREFBUF"depends on ARCH_STM32 || COMPILE_TESThelpThis driver supports STMicroelectronics STM32 VREFBUF (voltagereference buffer) which can be used as voltage reference forinternal ADCs, DACs and also for external components throughdedicated Vref+ pin.This driver can also be built as a module. If so, the modulewill be called stm32-vrefbuf.

4、没有找到s3c，可以看一下stm32芯片的依赖属性，接着看Makefile

obj-$(CONFIG_REGULATOR) += core.o dummy.o fixed-helper.o helpers.o devres.o
obj-$(CONFIG_OF) += of_regulator.o
obj-$(CONFIG_REGULATOR_FIXED_VOLTAGE) += fixed.o
obj-$(CONFIG_REGULATOR_VIRTUAL_CONSUMER) += virtual.o
obj-$(CONFIG_REGULATOR_USERSPACE_CONSUMER) += userspace-consumer.oobj-$(CONFIG_REGULATOR_STM32_VREFBUF) += stm32-vrefbuf.o

5、看的出来stm32只依赖于stm32-verfbuf.c文件，继续查看

static const struct of_device_id stm32_vrefbuf_of_match[] = {{ .compatible = "st,stm32-vrefbuf", },{},
};
MODULE_DEVICE_TABLE(of, stm32_vrefbuf_of_match);static struct platform_driver stm32_vrefbuf_driver = {.probe = stm32_vrefbuf_probe,.remove = stm32_vrefbuf_remove,.driver = {.name  = "stm32-vrefbuf",.of_match_table = of_match_ptr(stm32_vrefbuf_of_match),},
};
module_platform_driver(stm32_vrefbuf_driver);

6、确认驱动为platform驱动，寻找regulator特有的数据结构

static const struct regulator_ops stm32_vrefbuf_volt_ops = {.enable     = stm32_vrefbuf_enable,.disable    = stm32_vrefbuf_disable,.is_enabled    = stm32_vrefbuf_is_enabled,.get_voltage_sel = stm32_vrefbuf_get_voltage_sel,.set_voltage_sel = stm32_vrefbuf_set_voltage_sel,.list_voltage   = regulator_list_voltage_table,
};static const struct regulator_desc stm32_vrefbuf_regu = {.name = "vref",.supply_name = "vdda",.volt_table = stm32_vrefbuf_voltages,.n_voltages = ARRAY_SIZE(stm32_vrefbuf_voltages),.ops = &stm32_vrefbuf_volt_ops,.type = REGULATOR_VOLTAGE,.owner = THIS_MODULE,
};

7、由代码得知，regulator_ops和regulator_desc才是特有的regulator数据结构，当然也少不了注册函数

 rdev = regulator_register(&stm32_vrefbuf_regu, &config);if (IS_ERR(rdev)) {ret = PTR_ERR(rdev);dev_err(&pdev->dev, "register failed with error %d\n", ret);goto err_clk_dis;}platform_set_drvdata(pdev, rdev);

8、进一步确认of_device_id是不是真实存在，可以在arch/arm/boot/dts/stm32h743.dtsi找到对应内容

     vrefbuf: regulator@58003C00 {compatible = "st,stm32-vrefbuf";reg = <0x58003C00 0x8>;clocks = <&rcc VREF_CK>;regulator-min-microvolt = <1500000>;regulator-max-microvolt = <2500000>;status = "disabled";};

linux驱动编写（电源管理驱动）相关推荐

关闭linux服务器电源,linux关闭ACPI电源管理模块
一.运行环境 # cat /etc/redhat-release CentOS release 6.2 (Final) # uname -a Linux web-server- 2.6.-.el6.x ...
Linux内核配置电源管理
最近测试板子辐射比较高,希望能在运行时降低功耗和辐射,CPU这部分没啥用到,可以降! [*] Power Management support //如果你想让你的Linux支持高级电源管理(也就是平常 ...
android电源驱动程序,[转]Android虚拟电源管理驱动
Android系统如果没有电源管理相关的驱动程序,在启动时将会提示如下错误: I/SystemServer( 50): Starting Battery Service. E/BatterySer ...
Linux运行911,韦东山-Linux下编写GT911触摸驱动 - 百问网嵌入式问答社区
源码在最下面问题一:资源获取Gt911数据手册在韦老师给的资料里,路径为\06_Datasheet\Extend_modules\7寸LCD模块\电容触控芯片GT911 Datasheet_121 ...
WinCE电源管理----驱动增加电源管理属性
原文地址::http://www.cnblogs.com/we-hjb/archive/2010/01/27/1657973.html 对于移动设备来说,电源管理是比较重要的.为了让设备有更长的待机和 ...
Linux内核学习--电源管理
目录一.引言二.电源管理 ------> 2.1.电源管理的两种模型三.系统Suspend ------> 3.1.系统睡眠模型Suspend ------> 3.2.开启su ...
linux时钟与电源管理,SOC的时钟和电源管理
SOC的时钟和电源管理 (2013-04-27 18:58:07) 标签: it dm3730 时钟 linux 电源现在的SOC,因为多用做手持设备,所以在节省能源方面都不遗余力.我看原因到不是为 ...
android Sensor 驱动编写--opt3001光感驱动为例
分析Android sensor Android sensor Framework 层以及APP如何读取sensor 数据.网上有很多文章不再累述. 由于我使用的是Android 5.1(kernel ...

linux驱动编写（电源管理驱动）

linux驱动编写（电源管理驱动）相关推荐

最新文章

热门文章