LED设备驱动开发一之驱动模型和结构体

1、LED设备驱动模型

     

2、LED驱动涉及计的结构体

  将LED设备以平台设备的形式注册进内核；

//LED设备的抽象

  struct led_classdev {

    const char        *name;

    int          brightness;

    int          max_brightness;

    int          flags;

    /* Lower 16 bitsreflect status */

#define LED_SUSPENDED     (1<< 0)

    /* Upper 16 bitsreflect control information */

#define LED_CORE_SUSPENDRESUME (1<< 16)

    /* Set LED brightnesslevel */

    /* Must not sleep, usea workqueue if needed */

    void (*brightness_set)(structled_classdev *led_cdev, enum led_brightness brightness);

    /* Get LED brightnesslevel */

    enum led_brightness(*brightness_get)(struct led_classdev *led_cdev);

    int (*blink_set)(structled_classdev *led_cdev,unsigned long *delay_on, unsigned long *delay_off);

    struct device         *dev;

    struct list_head  node;            /*LED Device list */

    const char        *default_trigger; /* Trigger to use */

 

    #ifdef CONFIG_LEDS_TRIGGERS

    /* Protects the triggerdata below */

    struct rw_semaphore   trigger_lock;

 

    struct led_trigger    *trigger;

    struct list_head  trig_list;

    void         *trigger_data;

#endif

};

//LED设备数据 （driver文件中定义，供操作使用使用）

 struct gpio_led_data {

    struct led_classdevcdev;

    unsigned gpio;

    struct work_structwork;

    u8 new_level;

    u8 can_sleep;

    u8 active_low;

    int(*platform_gpio_blink_set)(unsigned gpio,

             unsigned long*delay_on, unsigned long *delay_off);

};

 

//LED的驱动数据（dev文件中定义工driver文件使用）

struct gpio_led {

    const char *name;

    const char*default_trigger;

    unsigned     gpio;

    unsigned active_low : 1;

    unsigned retain_state_suspended : 1;

    unsigned default_state : 2;

    /* default_state shouldbe one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */

};

//LED的平台设备数据

struct gpio_led_platform_data {

    int      num_leds;

    struct gpio_led *leds;

    int (*gpio_blink_set)(unsigned gpio,unsigned long*delay_on,unsigned long *delay_off);

};