Content in/sys/bus/I2C/devices and i2c_board_info struct

I2C devices in the system can be found in the/sys/bus/I2C/devices directory, as follows:

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# Ls
0-0034
0-0030
0-0011
0-0058
# Ls
0-0034
0-0030
0-0011
0-0058

These devices exist in the system.

How did these devices come from?

In your machine configuration, you will execute the "i2c_register_board_info" function, which will register an i2c_board_info struct into the system,

The i2c_board_info struct describes information about all I2C devices on the board, as shown in the following example:

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Static struct i2c_board_info littleton_i2c_board_info [] = {
# If defined (config_pxa3xx_micco) | defined (config_pxa3xx_micco_module)
{
. Type = "Micco ",
. ADDR = 0x34,
. Platform_data = & micco_data,
. IRQ = irq_gpio (mfp_to_gpio (mfp_pin_gpio18 )),
},
# Endif
# If defined (config_gpio_max7320) | defined (config_gpio_max7320_module)
{
. Type = "max7320 ",
. ADDR = 0x50,
. Platform_data = & exp0_pdata,
},
# Endif
# If defined (config_gpio_max7321) | defined (config_gpio_max7321_module)
{
/* On 8385 WLAN Board */
. Type = "max7321 ",
. ADDR = 0x60,
. Platform_data = & exp1_pdata [board_8385_wlan],
},
{
/* On UMTS Board */
. Type = "max7321 ",
. ADDR = 0x61,
. Platform_data = & exp1_pdata [board_umts],
},
{
/* On Siemens baseband radio interposer Board */
. Type = "max7321 ",
. ADDR = 0x62,
. Platform_data = & exp1_pdata [board_siemens_baseband],
},
{
/* On 8688 WLAN/camera Board */
. Type = "max7321 ",
. ADDR = 0x63,
. Platform_data = & exp1_pdata [board_8688_wlan_camera],
},
{
/* On camera Board */
. Type = "max7321 ",
. ADDR = 0x64,
. Platform_data = & exp1_pdata [board_camera],
},
{
/* On 8686 WLAN/camera Board */
. Type = "max7321 ",
. ADDR = 0x66,
. Platform_data = & exp1_pdata [board_81__wlan_camera],
},
{
/* On 8385 WLAN/camera Board */
. Type = "max7321 ",
. ADDR = 0x6c,
. Platform_data = & exp1_pdata [board_81__wlan_camera],
},
{
/* On 8688 WLAN Board */
. Type = "max7321 ",
. ADDR = 0x6d,
. Platform_data = & exp1_pdata [board_8688_wlan],
. IRQ = irq_gpio (mfp_to_gpio (mfp_pin_gpio77 )),
},
# Endif
# If defined (config_pxa_camera)
{
. Type = "sensor_ov7673 ",
. ADDR = 0x21,
. Platform_data = & ov7673_sensor_data,
},
{
. Type = "sensor_ov5623 ",
. ADDR = 0x30,
. Platform_data = & ov5623_sensor_data,
},
# Endif
};
Static struct i2c_board_info littleton_i2c_board_info [] = {
# If defined (config_pxa3xx_micco) | defined (config_pxa3xx_micco_module)
{
. Type = "Micco ",
. ADDR = 0x34,
. Platform_data = & micco_data,
. IRQ = irq_gpio (mfp_to_gpio (mfp_pin_gpio18 )),
},
# Endif
# If defined (config_gpio_max7320) | defined (config_gpio_max7320_module)
{
. Type = "max7320 ",
. ADDR = 0x50,
. Platform_data = & exp0_pdata,
},
# Endif
# If defined (config_gpio_max7321) | defined (config_gpio_max7321_module)
{
/* On 8385 WLAN Board */
. Type = "max7321 ",
. ADDR = 0x60,
. Platform_data = & exp1_pdata [board_8385_wlan],
},
{
/* On UMTS Board */
. Type = "max7321 ",
. ADDR = 0x61,
. Platform_data = & exp1_pdata [board_umts],
},
{
/* On Siemens baseband radio interposer Board */
. Type = "max7321 ",
. ADDR = 0x62,
. Platform_data = & exp1_pdata [board_siemens_baseband],
},
{
/* On 8688 WLAN/camera Board */
. Type = "max7321 ",
. ADDR = 0x63,
. Platform_data = & exp1_pdata [board_8688_wlan_camera],
},
{
/* On camera Board */
. Type = "max7321 ",
. ADDR = 0x64,
. Platform_data = & exp1_pdata [board_camera],
},
{
/* On 8686 WLAN/camera Board */
. Type = "max7321 ",
. ADDR = 0x66,
. Platform_data = & exp1_pdata [board_81__wlan_camera],
},
{
/* On 8385 WLAN/camera Board */
. Type = "max7321 ",
. ADDR = 0x6c,
. Platform_data = & exp1_pdata [board_81__wlan_camera],
},
{
/* On 8688 WLAN Board */
. Type = "max7321 ",
. ADDR = 0x6d,
. Platform_data = & exp1_pdata [board_8688_wlan],
. IRQ = irq_gpio (mfp_to_gpio (mfp_pin_gpio77 )),
},
# Endif
# If defined (config_pxa_camera)
{
. Type = "sensor_ov7673 ",
. ADDR = 0x21,
. Platform_data = & ov7673_sensor_data,
},
{
. Type = "sensor_ov5623 ",
. ADDR = 0x30,
. Platform_data = & ov5623_sensor_data,
},
# Endif
};
 

It can be found that the device under the/sys/bus/I2C/devices directory is the I2C device described in the i2c_board_info structure,

The device names under/sys/bus/I2C/devices are named according to the I2C address defined in the i2c_board_info struct.

This article from the csdn blog, reproduced please indicate the source: http://blog.csdn.net/codehat/archive/2010/03/04/5344897.aspx