regulator

        原文地址：http://lhsblog01.blog.163.com/blog/static/1020045192010221104120218/

        regulator是驱动中电源管理的基础设施。要先注册到内核中，然后使用这些电压输出的模块get其regulator,在驱动中的init里，在适当时间中进行电压电流的设置.

         Linux内核的动态电压和电流控制接口

         "LDO是low dropout regulator，意为低压差线性稳压器"，是相对于传统的线性稳压器来说的。传统的线性稳压器，如78xx系列的芯片都要求输入电压要比输出电压高出 2v~3V以上，否则就不能正常工作。但是在一些情况下，这样的条件显然是太苛刻了，如5v转3.3v,输入与输出的压差只有1.7v，显然是不满足条件 的。针对这种情况，才有了LDO类的电源转换芯片。生产LDO芯片的公司很多，常见的有ALPHA, Linear(LT), Micrel, National semiconductor,TI等。

       

in:twl4030-poweroff.c

一种称为校准器（regulator）的动态电压和电流控制的方法，很有参考意义和实际使用价值。

       

1:校准器的基本概念

所谓校准器实际是在软件控制下把输入的电源调节精心输出。

2:Consumer的API

regulator = regulator_get(dev, “Vcc”)；

其中，dev 是设备“Vcc”一个字符串代表，校准器（regulator）然后返回一个指针，也是regulator_put(regulator)使用的。

打开和关闭校准器（regulator）API如下。

int regulator_enable(regulator);

int regulator_disable(regulator);

3: 电压的API

消费者可以申请提供给它们的电压，如下所示。

int regulator_set_voltage(regulator, int min_uV, int max_uV);

在改变电压前要检查约束，如下所示。

regulator_set_voltage(regulator,100000,150000)

电压值下面的设置改变如下所示。

int regulator_get_voltage)struct regulator *regulator);

4:校准器的驱动和系统配置

在实际使用校准器之前，需要按照下面的结构写校准器的驱动程序，然后注册后通知给消费者使用。

//************************* linux regulator 模型******************************************//

static LIST_HEAD(regulator_list);     //整个regulator模型的所有regulator.

static LIST_HEAD(regulator_map_list); //整个regulator模型的map

struct regulator_consumer_supply : 用户支持的接口映射。  supply -> device

struct regulator_state： 用于表示 在整个系统的低功耗状态下的设备状态。

struct regulation_constraints ： 操作约束。

struct regulator_init_da ta   校准器平台初始化数据。

struct regulator_dev 向内核注册后 得到regulator设备结构

注册：

struct regulator_dev *regulator_register(struct regulator_desc *regulator_desc,struct device *dev, void *driver_da ta)

反注册：

要使用注册得到 regulator_dev:

void regulator_unregister(struct regulator_dev *rdev)

/* Regulator operating modes.**/

#define REGULATOR_MODE_FAST 0x1 //电压可以快速调

#define REGULATOR_MODE_NORMAL 0x2 //一般模式

#define REGULATOR_MODE_IDLE 0x4 //低load

#define REGULATOR_MODE_STANDBY 0x8 //sleep/ standby 状态下 低功耗

例子：

/* VSIM for OMAP VDD_MMC1A (i/o for DAT4..DAT7) */

static struct regulator_init_da ta zoom2_vsim = { //这个da ta被置于 对应的 platform_device 的da ta字段中。

.constraints = {

.min_uV = 1800000,

.max_uV = 3000000,

.valid_modes_mask = REGULATOR_MODE_NORMAL  /*这里设置*/

| REGULATOR_MODE_STANDBY,

.valid_ops_mask = REGULATOR_CHANGE_VOLTAGE /*这里设置这个regulator上可进行的操作。调电压，模式可变，可以打开关闭*/

| REGULATOR_CHANGE_MODE

| REGULATOR_CHANGE_STATUS,

},

.num_consumer_supplies  = 1,

.consumer_supplies      = &zoom2_vsim_supply,

};

// regulator 的初始化数据要放到  device 's  platform_da ta

struct regulator_init_da ta *init_da ta = dev->platform_da ta;

"重点"

//*************************** twl4030 regulator 的实现  ****************************//

struct twlreg_info ： 关联到驱动与设备的数据。驱动的私有数据，driver_da ta.

struct twlreg_info {

/* start of regulator's PM_RECEIVER control register bank */

u8 base;

/* twl4030 resource ID, for resource control state machine */

u8 id;

/* FIXED_LDO voltage */

u8 deciV;

/* voltage in mV = table[VSEL]; table_len must be a power-of-two */

u8 table_len;

const u16 *table;

/* used by regulator core */

struct regulator_desc desc;

};

//一个驱动(platform_driver)对应所有的regulator, 每个regulator在内核中表示为一个platform_device. 所以调用了许多次的probe

//在probe中，从全局数组中取出自定义的数据结构：　twlreg_info, 然后从platform_device中取出初始化数据（device's platform_da ta）,然后就可以向内核注册一个 regulator(会返回一个regulator_dev:类)。

"struct regulator_dev *regulator_register(struct regulator_desc *regulator_desc,struct device *dev, void *driver_da ta)"

1:每个regulator 的  "twlreg_info" 被 存于 regulator_dev 的 device 's driver_da ta, twlreg_info中的 table 存支持的电压值。

2:两种操作结构"regulator_ops"：twl4030fixed_ops(电压固定),  twl4030ldo_ops（电压可调）

3：传入每个 ops中的操作函数 的参数是:  regulator_dev.

4: 在  twl4030-core.c中，在添加 twl4030的 i2c_client时，添加了所有的　regulator 的　platform_device.

5: 在驱动初始化注册中，内核会自动去匹配 bus上的所有符合的 platform_device（代表regulator，init_da ta放于device's platform_da ta）, 所以一个驱动就可以匹配到 bus上所有对应的　regulator.

6: 每匹配一个 regulator的　platform_device时，就会从中，platform_device的　device 中的 platform_da ta　中得到　regulator的初始化数据：　regulator_init_da ta

7: 取出初始化数据后，　设置一下. "设置，即是当设备支持一定的功能后，由驱动来控制时，要匹配驱动能做到的功能。that is 两者　与（＆）　一下"

　　然后，从regulator模块的全局数组"twl4030_regs[]" 中取出　twlreg_info 

if (twl4030_regs[i].desc.id != pdev->id)

continue;

info = twl4030_regs + i;

就可以向内核注册这个 regulator了：

"rdev = regulator_register(&info->desc, &pdev->dev, info);"

"注册后返回一个　regulator_dev": 然后把这个rdev输入到　platform_device 's device 's driver_da ta... 主要用于 remove中？？？

regulator_dev：是一个类，其父是 本regulator的platform_device 's device.

8: // regulator_ops 存入了 regulator_desc, 然后注册时，desc 关联到了 regulator_dev-> desc = desc.

生成regualator_dev, 设置数据，注册sysfs，然后：　constraints, attribute, supply　,comsumer device.

struct regulator_dev *regulator_register(struct regulator_desc *regulator_desc, struct device *dev, void *driver_da ta)

9:另：

大部分的regulator的platform_device生成如下：

每个regulator设备注册到内核的时机是在　twl4030-core.c　中。

把regulator的初始化数据，放到新生成的platform_device　's device 's platform_da ta...

然后注册 platform_device　到内核中。

usb部分的regulator生成如下：(这里明显是由于ＯＭＡＰ不一定是有ＵＳＢ？？，然后在其ｂｏａｒｄ-ｚｏｏｍ２.ｃ中，"没有设置每个初始化数据"（包括：ｓｕｐｐｌｙ,ｃｏｎｓｔｒａｉｎｔｓ(ｍｉｎ,ｍａｘ,ｍａｓｋ)）)

而 对于usb模块的 regulator, 先生成对应的platform_device, 返回了platform_device->device, 然后利用这个device去形成多个：　regulator_consumer_supply.dev = device.

然后用这些 regulator_consumer_supply, 来做comsumer并生成　platform_device.注册

//**************************　使用regulator　***************************//

regulator已经向内核模型注册了，但如何使用呢，怎样调节电压？？

//注册后，内核中就已经有对应的regulator对应的 supply consumer. 然后在驱动中任何地方调用接口即可：

//regulator_get, regulator_enable, regulator_disable, regulator_set_voltage, regulator_get_voltage......

1:在twl4030-usb模块中，会用到　usb对应的　reuglator,,   fixed_ops

twl->usb3v1 = regulator_get(twl->dev, "usb3v1");

regulator_enable(twl->usb3v1);

regulator_disable(twl->usb1v5);

2:

regulator = regulator_get(dev, “Vcc”)；

其中，dev 是设备“Vcc”一个字符串代表，校准器（regulator）然后返回一个指针，也是regulator_put(regulator)使用的。

打开和关闭校准器（regulator）API如下。

int regulator_enable(regulator);

int regulator_disable(regulator);

 电压的API

消费者可以申请提供给它们的电压，如下所示。

int regulator_set_voltage(regulator, int min_uV, int max_uV);

在改变电压前要检查约束，如下所示。

regulator_set_voltage(regulator,100000,150000)

//************************************************//

/**

 * struct regulator_desc - Regulator descriptor

 *

 * Each regulator registered with the core is described with a structure of

 * this type.

 *

 * @name: Identifying name for the regulator.

 * @id: Numerical identifier for the regulator.

 * @n_voltages: Number of selectors available for ops.list_voltage().

 * @ops: Regulator operations table.

 * @irq: Interrupt number for the regulator.

 * @type: Indicates if the regulator is a voltage or current regulator.

 * @owner: Module providing the regulator, used for refcounting.

 */

struct regulator_desc {

const char *name;

int id;

unsigned n_voltages;

struct regulator_ops *ops;

int irq;

enum regulator_type type;

struct module *owner;

};

enum regulator_status {

REGULATOR_STATUS_OFF,

REGULATOR_STATUS_ON,

REGULATOR_STATUS_ERROR,

/* fast/normal/idle/standby are flavors of "on" */

REGULATOR_STATUS_FAST,

REGULATOR_STATUS_NORMAL,

REGULATOR_STATUS_IDLE,

REGULATOR_STATUS_STANDBY,

};

/*

 * struct regulator_dev

 *

 * Voltage / Current regulator class device. On e for each regulator.

 */

struct regulator_dev {

struct regulator_desc *desc;

int use_count;

/* lists we belong to */

struct list_head list; /* list of all regulators */

struct list_head slist; /* list of supplied regulators */

/* lists we own */

struct list_head consumer_list; /* consumers we supply */

struct list_head supply_list; /* regulators we supply */

struct blocking_notifier_head notifier;

struct mutex mutex; /* consumer lock */

struct module *owner;

struct device dev;

struct regulation_constraints *constraints;

struct regulator_dev *supply; /* for tree */

void *reg_da ta; /* regulator_dev da ta */

};

/*

 * struct regulator

 *

 * On e for each consumer device.

 */

struct regulator {

struct device *dev;

struct list_head list;

int uA_load;

int min_uV;

int max_uV;

int enabled; /* count of client enables */

char *supply_name;

struct device_attribute dev_attr;

struct regulator_dev *rdev;

};

/*

 * struct regulator_map

 *

 * Used to provide symbolic supply names to devices.

 */

struct regulator_map {

struct list_head list;

struct device *dev;

const char *supply;

struct regulator_dev *regulator;

};

/**

 * struct regulator_state - regulator state during low power syatem states

 *

 * This describes a regulators state during a system wide low power state.

 *

 * @uV: Operating voltage during suspend.

 * @mode: Operating mode during suspend.

 * @enabled: Enabled during suspend.

 */

struct regulator_state {

int uV; /* suspend voltage */

unsigned int mode; /* suspend regulator operating mode */

int enabled; /* is regulator enabled in this suspend state */

};

/**

 * struct regulation_constraints - regulator operating constraints.

 *

 * This struct describes regulator and board/machine specific constraints.

 *

 * @name: Descriptive name for the constraints, used for display purposes.

 *

 * @min_uV: Smallest voltage consumers may set.

 * @max_uV: Largest voltage consumers may set.

 *

 * @min_uA: Smallest consumers consumers may set.

 * @max_uA: Largest current consumers may set.

 *

 * @valid_modes_mask: Mask of modes which may be configured by consumers.

 * @valid_ops_mask: Operations which may be performed by consumers.

 *

 * @always_on: Set if the regulator should never be disabled.

 * @boot_on: Set if the regulator is enabled when the system is initially

 *           started.

 * @apply_uV: Apply the voltage constraint when initialising.

 *

 * @input_uV: Input voltage for regulator when supplied by another regulator.

 *

 * @state_disk: State for regulator when system is suspended in disk mode.

 * @state_mem: State for regulator when system is suspended in mem mode.

 * @state_standby: State for regulator when system is suspended in standby

 *                 mode.

 * @initial_state: Suspend state to set by default.

 */

struct regulation_constraints {

char *name;

/* voltage output range (inclusive) - for voltage control */

int min_uV;

int max_uV;

/* current output range (inclusive) - for current control */

int min_uA;

int max_uA;

/* valid regulator operating modes for this machine */

unsigned int valid_modes_mask;

/* valid operations for regulator on this machine */

unsigned int valid_ops_mask;

/* regulator input voltage - on ly if supply is another regulator */

int input_uV;

/* regulator suspend states for global PMIC STANDBY/HIBERNATE */

struct regulator_state state_disk;

struct regulator_state state_mem;

struct regulator_state state_standby;

suspend_state_t initial_state; /* suspend state to set at init */

/* constriant flags */

unsigned always_on:1; /* regulator never off when system is on */

unsigned boot_on:1; /* bootloader/firmware enabled regulator */

unsigned apply_uV:1; /* apply uV constraint iff min == max */

};

/**

 * struct regulator_consumer_supply - supply -> device mapping

 *

 * This maps a supply name to a device.

 *

 * @dev: Device structure for the consumer.

 * @supply: Name for the supply.

 */

struct regulator_consumer_supply {

struct device *dev; /* consumer */

const char *supply; /* consumer supply - e.g. "vcc" */

};

/**

 * struct regulator_desc - Regulator descriptor

 *

 * Each regulator registered with the core is described with a structure of

 * this type.

 *

 * @name: Identifying name for the regulator.

 * @id: Numerical identifier for the regulator.

 * @n_voltages: Number of selectors available for ops.list_voltage().

 * @ops: Regulator operations table.

 * @irq: Interrupt number for the regulator.

 * @type: Indicates if the regulator is a voltage or current regulator.

 * @owner: Module providing the regulator, used for refcounting.

 */

struct regulator_desc {

const char *name;

int id;

unsigned n_voltages;

struct regulator_ops *ops;

int irq;

enum regulator_type type;

struct module *owner;

};

/**

 * struct regulator_init_da ta - regulator platform initialisation da ta.

 *

 * Initialisation constraints, our supply and consumers supplies.

 *

 * @supply_regulator_dev: Parent regulator (if any).

 *

 * @constraints: Constraints.  These must be specified for the regulator to

 *               be usable.

 * @num_consumer_supplies: Number of consumer device supplies.

 * @consumer_supplies: Consumer device supply configuration.

 *

 * @regulator_init: Callback invoked when the regulator has been registered.

 * @driver_da ta: Da ta passed to regulator_init.

 */

struct regulator_init_da ta {

struct device *supply_regulator_dev; /* or NULL for LINE */

struct regulation_constraints constraints;

int num_consumer_supplies;

struct regulator_consumer_supply *consumer_supplies;

/* optional regulator machine specific init */

int (*regulator_init)(void *driver_da ta);

void *driver_da ta; /* core does not touch this */

};

/*

 * Regulator operation constraint flags. These flags are used to enable

 * certain regulator operations and can be OR'ed together.

 *

 * VOLTAGE:  Regulator output voltage can be changed by software on this

 *           board/machine.

 * CURRENT:  Regulator output current can be changed by software on this

 *           board/machine.

 * MODE:     Regulator operating mode can be changed by software on this

 *           board/machine.

 * STATUS:   Regulator can be enabled and disabled.

 * DRMS:     Dynamic Regulator Mode Switching is enabled for this regulator.

 */

#define REGULATOR_CHANGE_VOLTAGE 0x1

#define REGULATOR_CHANGE_CURRENT 0x2

#define REGULATOR_CHANGE_MODE 0x4

#define REGULATOR_CHANGE_STATUS 0x8

#define REGULATOR_CHANGE_DRMS 0x10

/*

 * Regulator operating modes.

 *

 * Regulators can run in a variety of different operating modes depending on

 * output load. This allows further system power savings by selecting the

 * best (and most efficient) regulator mode for a desired load.

 *

 * Most drivers will on ly care about NORMAL. The modes below are generic and

 * will probably not match the naming convention of your regulator da ta sheet

 * but should match the use cases in the datasheet.

 *

 * In order of power efficiency (least efficient at top).

 *

 *  Mode       Description

 *  FAST       Regulator can handle fast changes in it's load.

 *             e.g. useful in CPU voltage & frequency scaling where

 *             load can quickly increase with CPU frequency increases.

 *

 *  NORMAL     Normal regulator power supply mode. Most drivers will

 *             use this mode.

 *

 *  IDLE       Regulator runs in a more efficient mode for light

 *             loads. Can be used for devices that have a low power

 *             requirement during periods of inactivity. This mode

 *             may be more noisy than NORMAL and may not be able

 *             to handle fast load switching.

 *

 *  STANDBY    Regulator runs in the most efficient mode for very

 *             light loads. Can be used by devices when they are

 *             in a sleep/standby state. This mode is likely to be

 *             the most noisy and may not be able to handle fast load

 *             switching.

 *

 * NOTE: Most regulators will on ly support a subset of these modes. Some

 * will on ly just support NORMAL.

 *

 * These modes can be OR'ed together to make up a mask of valid register modes.

 */

#define REGULATOR_MODE_FAST 0x1

#define REGULATOR_MODE_NORMAL 0x2

#define REGULATOR_MODE_IDLE 0x4

#define REGULATOR_MODE_STANDBY 0x8