client = kzalloc(sizeof(*client), GFP_KERNEL);

这是一个内核分配内存的函数，用于在内核中动态分配内存。具体来说，它会分配一个大小为 sizeof(*client) 的内存块，并返回指向该内存块的指针。这个函数的参数 GFP_KERNEL 表示内存分配的标志，它告诉内核这个内存块是用于内核的，而不是用户空间的。

相关问题

高通单安卓平台没有i2c_client_get_device_id函数怎么办

在 Android 平台上，如果没有 `i2c_client_get_device_id` 函数，可以尝试使用 `i2c_adapter_id` 和 `addr` 字段来实现类似的功能。具体的实现方法如下：

1. 获取 `i2c_adapter` 结构体对象：

struct i2c_adapter *adapter = i2c_get_adapter(bus_num);

其中，`bus_num` 是 I2C 总线的编号。

2. 构造 `i2c_client` 结构体对象：

struct i2c_client *client = kzalloc(sizeof(*client), GFP_KERNEL);
client->adapter = adapter;
client->addr = slave_address;

其中，`slave_address` 是 I2C 从设备的地址。

3. 获取从设备的 ID：

int id = (int)client->adapter->nr << 16 | client->addr;

其中，`id` 可以作为从设备的唯一标识符来使用。

需要注意的是，不同的 I2C 控制器可能会有不同的实现方式，因此具体的实现细节可能会有所不同。建议先查看相关文档或者参考其他相关代码实现。

int dsi_panel_set_backlight(struct dsi_panel panel, u32 bl_lvl) { int rc = 0; struct dsi_backlight_config bl = &panel->bl_config; if (panel->host_config.ext_bridge_mode) return 0; DSI_DEBUG("backlight type:%d lvl:%d\n", bl->type, bl_lvl); switch (bl->type) { case DSI_BACKLIGHT_WLED: rc = backlight_device_set_brightness(bl->raw_bd, bl_lvl); break; case DSI_BACKLIGHT_DCS: rc = dsi_panel_update_backlight(panel, bl_lvl); break; case DSI_BACKLIGHT_EXTERNAL: rc = lcd_bl_set_led_brightness(bl_lvl); //pr_err("dsi set bias brightness: %d\n", bl_lvl); rc = lcd_bias_set_led_brightness(bl_lvl); //pr_err("dsi set brightness: %d\n", bl_lvl); break; case DSI_BACKLIGHT_PWM: rc = dsi_panel_update_pwm_backlight(panel, bl_lvl); break; default: DSI_ERR("Backlight type(%d) not supported\n", bl->type); rc = -ENOTSUPP; } return rc; } int lcd_bl_set_led_brightness(int value)//for set bringhtness { dev_warn(&lcd_bl_i2c_client->dev, "lcm 8866 bl = %d\n", value); if (value < 0) { dev_warn(&lcd_bl_i2c_client->dev, "value=%d\n", value); return 0; } if (value > 0) { lcd_bl_write_byte(KTZ8866_DISP_BB_LSB, value & 0x07);// lsb lcd_bl_write_byte(KTZ8866_DISP_BB_MSB, (value >> 3) & 0xFF);// msb lcd_bl_write_byte(KTZ8866_DISP_BL_ENABLE, 0x4F); / BL enabled and Current sink 1/2/3/4 enabled；/ } else { lcd_bl_write_byte(KTZ8866_DISP_BB_LSB, 0x00);// lsb lcd_bl_write_byte(KTZ8866_DISP_BB_MSB, 0x00);// msb lcd_bl_write_byte(KTZ8866_DISP_BL_ENABLE, 0x00); /* BL enabled and Current sink 1/2/3/4 disabled；/ } return 0; } int lcd_bias_set_led_brightness(int value)//for set bringhtness { dev_warn(&lcd_bl_bias_i2c_client->dev, "lcm 8866 bl = %d\n", value); if (value < 0) { dev_warn(&lcd_bl_bias_i2c_client->dev, "invalid value=%d\n", value); return 0; } if (value > 0) { lcd_bl_bias_write_byte(KTZ8866_DISP_BB_LSB, value & 0x07);// lsb lcd_bl_bias_write_byte(KTZ8866_DISP_BB_MSB, (value >> 3) & 0xFF);// msb lcd_bl_bias_write_byte(KTZ8866_DISP_BL_ENABLE, 0x4F); / BL enabled and Current sink 1/2/3/4 enabled；/ } else { lcd_bl_bias_write_byte(KTZ8866_DISP_BB_LSB, 0x00);// lsb lcd_bl_bias_write_byte(KTZ8866_DISP_BB_MSB, 0x00);// msb lcd_bl_bias_write_byte(KTZ8866_DISP_BL_ENABLE, 0x00); / BL enabled and Current sink 1/2/3/4 disabled；*/ } return 0; } dsi_panel_set_backlight、lcd_bl_set_led_brightness和lcd_bias_set_led_brightness源码如上，帮忙用工作队列的方式，同时实现在case DSI_BACKLIGHT_EXTERNAL:下并发执行lcd_bl_set_led_brightness和lcd_bias_set_led_brightness两个函数

好的，我可以为您提供一个使用工作队列来实现并发执行`lcd_bl_set_led_brightness`和`lcd_bias_set_led_brightness`的示例代码。具体实现方法如下：

1. 定义一个工作结构体`struct work_struct`，并在其中传递参数。

struct backlight_work {
    struct work_struct work;
    struct i2c_client *lcd_bl_i2c_client;
    struct i2c_client *lcd_bl_bias_i2c_client;
    int value;
};

2. 定义工作队列。

static struct workqueue_struct *bl_workqueue;

3. 在`dsi_panel_set_backlight`函数中，将`lcd_bl_set_led_brightness`和`lcd_bias_set_led_brightness`函数的调用封装成一个工作任务，并将任务推入工作队列。

case DSI_BACKLIGHT_EXTERNAL:
    {
        struct backlight_work *bl_work;
        bl_work = kzalloc(sizeof(*bl_work), GFP_KERNEL);
        if (!bl_work)
            return -ENOMEM;
        INIT_WORK(&bl_work->work, backlight_worker);
        bl_work->lcd_bl_i2c_client = lcd_bl_i2c_client;
        bl_work->lcd_bl_bias_i2c_client = lcd_bl_bias_i2c_client;
        bl_work->value = bl_lvl;
        queue_work(bl_workqueue, &bl_work->work);
        break;
    }

4. 在`backlight_worker`函数中，实现`lcd_bl_set_led_brightness`和`lcd_bias_set_led_brightness`函数的并发执行。

static void backlight_worker(struct work_struct *work)
{
    struct backlight_work *bl_work = container_of(work, struct backlight_work, work);
    int value = bl_work->value;
    if (value < 0) {
        dev_warn(&bl_work->lcd_bl_i2c_client->dev, "invalid value=%d\n", value);
    } else if (value > 0) {
        lcd_bl_write_byte(KTZ8866_DISP_BB_LSB, value & 0x07);
        lcd_bl_write_byte(KTZ8866_DISP_BB_MSB, (value >> 3) & 0xFF);
        lcd_bl_write_byte(KTZ8866_DISP_BL_ENABLE, 0x4F);
        lcd_bl_bias_write_byte(KTZ8866_DISP_BB_LSB, value & 0x07);
        lcd_bl_bias_write_byte(KTZ8866_DISP_BB_MSB, (value >> 3) & 0xFF);
        lcd_bl_bias_write_byte(KTZ8866_DISP_BL_ENABLE, 0x4F);
    } else {
        lcd_bl_write_byte(KTZ8866_DISP_BB_LSB, 0x00);
        lcd_bl_write_byte(KTZ8866_DISP_BB_MSB, 0x00);
        lcd_bl_write_byte(KTZ8866_DISP_BL_ENABLE, 0x00);
        lcd_bl_bias_write_byte(KTZ8866_DISP_BB_LSB, 0x00);
        lcd_bl_bias_write_byte(KTZ8866_DISP_BB_MSB, 0x00);
        lcd_bl_bias_write_byte(KTZ8866_DISP_BL_ENABLE, 0x00);
    }
    kfree(bl_work);
}

这样，当`dsi_panel_set_backlight`函数中调用`lcd_bl_set_led_brightness`和`lcd_bias_set_led_brightness`时，会将其封装成一个工作任务并推入工作队列中，`backlight_worker`函数实现这两个函数的并发执行。