简单的i2c读写函数的实现

直接上代码

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static int pcf8563_read_block_data(struct i2c_client *client, unsigned char reg,                                                                                  |" Press <F1>, ? for help
                   unsigned char length, unsigned char *buf)                                                                                                      |
{                                                                                                                                                                 |▶ macros
    struct i2c_msg msgs[] = {                                                                                                                                     |
        {/* setup read ptr */                                                                                                                                     |▶ prototypes
            .addr = client->addr,                                                                                                                                 |
            .len = 1,                                                                                                                                             |▼-pcf8563 : struct
            .buf = &reg,                                                                                                                                          |    [members]
        },                                                                                                                                                        |   +c_polarity
        {                                                                                                                                                         |   +client
            .addr = client->addr,                                                                                                                                 |   +rtc
            .flags = I2C_M_RD,                                                                                                                                    |   +voltage_low
            .len = length,                                                                                                                                        |
            .buf = buf                                                                                                                                            |▼ variables
        },                                                                                                                                                        |   -alarmboot
    };                                                                                                                                                            |   -pcf8563_driver
                                                                                                                                                                  |   -pcf8563_driver
    if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {                                                                                                          |    pcf8563_exit
        dev_err(&client->dev, "%s: read error\n", __func__);                                                                                                      |   -pcf8563_id
        return -EIO;                                                                                                                                              |    pcf8563_init
    }                                                                                                                                                             |   -pcf8563_rtc_ops
                                                                                                                                                                  |
    return 0;                                                                                                                                                     |▼ functions
}                                                                                                                                                                 |   -pcf8563_exit(void)
                                                                                                                                                                  |   -pcf8563_get_alarm_mode(struct i
static int pcf8563_write_block_data(struct i2c_client *client,                                                                                                    |   -pcf8563_get_datetime(struct i2c
                   unsigned char reg, unsigned char length,                                                                                                       |   -pcf8563_init(void)
                   unsigned char *buf)                                                                                                                            |   -pcf8563_irq(int irq, void *dev_
{                                                                                                                                                                 |   -pcf8563_irq_enable(struct devic
    int i, err;                                                                                                                                                   |   -pcf8563_probe(struct i2c_client
                                                                                                                                                                  |   -pcf8563_read_block_data(struct 
    for (i = 0; i < length; i++) {                                                                                                                                |   -pcf8563_rtc_read_alarm(struct d
        unsigned char data[2] = { reg + i, buf[i] };                                                                                                              |   -pcf8563_rtc_read_time(struct de
                                                                                                                                                                  |   -pcf8563_rtc_set_alarm(struct de
        err = i2c_master_send(client, data, sizeof(data));                                                                                                         |   -pcf8563_rtc_set_time(struct dev
        if (err != sizeof(data)) {                                                                                                                                 |   -pcf8563_set_alarm_mode(struct i
            dev_err(&client->dev,                                                                                                                                  |   -pcf8563_set_datetime(struct i2c
                "%s: err=%d addr=%02x, data=%02x\n",                                                                                                               |   -pcf8563_write_block_data(struct
                __func__, err, data[0], data[1]);                                                                                                                  |   -rtc_sysfs_show_alarmboot(struct
            return -EIO;                                                                                                                                           |~                                  
        }                                                                                                                                                          |~                                  
    }
}