Qcom wled 方式背光控制

1 .註冊部分

    kernel/msm-3.18/drivers/leds/leds-qpnp-wled.c

------------------------------------------------------------------------------

    static int qpnp_wled_probe(struct spmi_device *spmi)

    {

        .................................

        INIT_WORK(&wled->work, qpnp_wled_work);
        wled->ramp_ms = QPNP_WLED_RAMP_DLY_MS;
        wled->ramp_step = 1; 


        wled->cdev.brightness_set = qpnp_wled_set;
        wled->cdev.brightness_get = qpnp_wled_get;


        wled->cdev.max_brightness = WLED_MAX_LEVEL_4095;


        rc = led_classdev_register(&spmi->dev, &wled->cdev);

        .................................

    }

2. 應用部分

    kernel/msm-3.18/drivers/leds/leds-qpnp-wled.c

-------------------------------------------------------------------------------

    static void qpnp_wled_set(struct led_classdev *led_cdev,  enum led_brightness level)
    {

        .................................

        schedule_work(&wled->work);

        ................................

    }

    static void qpnp_wled_work(struct work_struct *work)
    {

        ...........................................

        // 設置亮度

        rc = qpnp_wled_set_level(wled, level);

        ..........................................

        // 當打開或關閉背光時，設置使能寄存器

        rc = qpnp_wled_module_en(wled, wled->ctrl_base, !!level);

        .........................................

    }

    static int qpnp_wled_set_level(struct qpnp_wled *wled, int level)
   {

        ................................

        // 寫低位

        reg = level & QPNP_WLED_BRIGHT_LSB_MASK;
        rc = qpnp_wled_write_reg(wled, &reg, QPNP_WLED_BRIGHT_LSB_REG(wled->sink_base, wled->strings[i]));

       // 寫高位

        reg = level >> QPNP_WLED_BRIGHT_MSB_SHIFT;
        reg = reg & QPNP_WLED_BRIGHT_MSB_MASK;
        rc = qpnp_wled_write_reg(wled, &reg, QPNP_WLED_BRIGHT_MSB_REG(wled->sink_base, wled->strings[i]));

        ...................................
   } 

   static int qpnp_wled_module_en(struct qpnp_wled *wled,  u16 base_addr, bool state)
   {

        rc = qpnp_wled_read_reg(wled, &reg,
                        QPNP_WLED_MODULE_EN_REG(base_addr));
        if (rc < 0)
                return rc;
        reg &= QPNP_WLED_MODULE_EN_MASK;
        reg |= (state << QPNP_WLED_MODULE_EN_SHIFT);
        rc = qpnp_wled_write_reg(wled, &reg,
                        QPNP_WLED_MODULE_EN_REG(base_addr));
        if (rc)
                return rc;

   }

   

   static int qpnp_wled_write_reg(struct qpnp_wled *wled, u8 *data, u16 addr)
  {

      // 寫 pmi 寄存器

      rc = spmi_ext_register_writel(wled->spmi->ctrl, wled->spmi->sid, addr, data, 1);

  }

  kernel/msm-3.18/drivers/platform/msm/spmi/spmi.c

----------------------------------------------------------------------------

   int spmi_ext_register_writel(struct spmi_controller *ctrl,  u8 sid, u16 addr, u8 *buf, int len)
  {

  }