I2C0 console for Linux KERNEL

Alfred Espinosa

Hello All,

I'm trying to get access to i2c-0 that is in /dev/ in the kernel, but only seems that i have enable i2c-1 and i2c-3, kernel settings or pinmux doesn't help me at all. Can someone indicate me how to enable it?

Note: Read somewhere that i2c-1 was actually i2c-0 but i tested it and seems i didn't get favorable feedback, please let me know anything, thanks.

over 8 years ago

0 Yordan Kovachev over 8 years ago

TI__Guru**** 161600 points

Hi Alfred,

Which SDK & TI device (or TI development board) is this?

Is your i2c0 accessible from u-boot?

Best Regards,
Yordan

0 Alfred Espinosa over 8 years ago in reply to Yordan Kovachev

Intellectual 570 points

hi Yordan, the tools im using are:

SDK: ti-ezdk_c6a811x-evm_5_05_01_09
Board(i think this is): ti811x

The linux folder says Linux-2.63.37-psp04.07.00.02

I guess i2c-0 is used in the u-Boot, i read the documentation (http://processors.wiki.ti.com/index.php/TI81XX_PSP_04.04.00.02_Feature_Performance_Guide) and seems some other functionallities are using i2c-0, so it should work, is just that i dont see in console (it seems).

Let me know if you need anything else

0 Pavel Botev over 8 years ago in reply to Alfred Espinosa

TI__Guru**** 170625 points

Hi Alfred,

/dev/i2c-1 corresponds to I2C0 (0x48028000). On ti811x TI EVM there are devices attached to I2C0 (i2c-1) and I2C2 (i2c-3), and they are enabled in the linux kernel source code:

ti-ezsdk_c6a811x-evm_5_05_01_10/board-support/linux-2.6.37-psp04.07.00.02/arch/arm/mach-omap2/board-ti811xevm.c

static void __init ti811x_evm_init(void)
{
int bw; /* bus-width */

ti814x_mux_init(board_mux);
omap_serial_init();
ti814x_tsc_init();
ti814x_evm_i2c_init();
.......
}

static void __init ti814x_evm_i2c_init(void)
{
/* There are 4 instances of I2C in TI814X but currently only one
* instance is being used on the TI8148 EVM
*/
omap_register_i2c_bus(1, 100, ti814x_i2c_boardinfo,
ARRAY_SIZE(ti814x_i2c_boardinfo));
omap_register_i2c_bus(3, 100, ti811x_i2c_boardinfo1,
ARRAY_SIZE(ti811x_i2c_boardinfo1));

}

If you have ti811x custom board and add device to i2c1 (i2c-2), you should enable it. See the below wiki page for more details:

processors.wiki.ti.com/.../TI81xx_PSP_Porting_Guide

BR
Pavel

0 Pavel Botev over 8 years ago in reply to Pavel Botev

TI__Guru**** 170625 points

The latest version of the ti811x EZSDK is ti-ezsdk_c6a811x-evm_5_05_01_10. I would recommend you to use the latest version.

BR
Pavel

0 Alfred Espinosa over 8 years ago in reply to Pavel Botev

Intellectual 570 points

Thanks Pavel,

That is clear enough for me, seems i must did a mistake in the pinmux

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I2C0 console for Linux KERNEL