I2C地址限制

在調試一個I2C觸控螢幕的驅動時，它的I2C地址為0X01，最後尋找發現在\linux-3.0\drivers\i2c\i2c-core.c中有檢測I2C地址是否可用就是下面的函數：/* And this is a strict address validity check, used when probing. If a * device uses a reserved address, then it shouldn't be probed. 7-bit * addressing is assumed, 10-bit address devices are rare and should be * explicitly enumerated. */static int i2c_check_addr_validity(unsigned short addr)
/** Reserved addresses per I2C specification:*  0x00       General call address / START byte*  0x01       CBUS address*  0x02       Reserved for different bus format*  0x03       Reserved for future purposes*  0x04-0x07  Hs-mode master code*  0x78-0x7b  10-bit slave addressing*  0x7c-0x7f  Reserved for future purposes*/#if !defined(CONFIG_ARCH_SUN4I)if (addr < 0x08 || addr > 0x77)#else    if (addr < 0x03 || addr > 0x77)#endif        return -EINVAL;return 0;}
同樣在linux2.6.36 中也存在I2C地址的合法性的檢測 \linux-3.0\drivers\i2c\i2c-core.c中

/* Make sure the address is valid */if (addr < 0x03 || addr > 0x77) {dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n",addr);return -EINVAL;}