AM335x SDK 06 (linux-3.2.0-psp04.06.00.11) - How to enable i2c0 in kernel Template Board File

Phillip Warren81

Other Parts Discussed in Thread: TMP102

Hi, we have a custom board that is unlike the BBB or am335x_evm. We found the best approach for our development is to start with the -Template version of the board port kernel source in SDK 06 and incrementally add support from the -Base for those features we do have in common with the BBB & am335x_evm.

We'd like to enable the i2c0 peripheral for use in user space and have added the following code to /arch/arm/mach-omap2/board-am335xevm.c

#ifdef CONFIG_OMAP_MUX

static struct omap_board_mux board_mux[] __initdata = {
     /*
     * Setting SYSBOOT[5] should set xdma_event_intr0 pin to mode 3 thereby
     * allowing clkout1 to be available on xdma_event_intr0.
     * However, on some boards (like EVM-SK), SYSBOOT[5] isn't properly
     * latched.
     * To be extra cautious, setup the pin-mux manually.
     * If any modules/usecase requries it in different mode, then subsequent
     * module init call will change the mux accordingly.

/*AM33XX_MUX(XDMA_EVENT_INTR0, OMAP_MUX_MODE3 | AM33XX_PIN_OUTPUT),*/

     AM33XX_MUX(I2C0_SDA, OMAP_MUX_MODE0 | AM33XX_SLEWCTRL_SLOW |
               AM33XX_INPUT_EN | AM33XX_PIN_OUTPUT),
     AM33XX_MUX(I2C0_SCL, OMAP_MUX_MODE0 | AM33XX_SLEWCTRL_SLOW |
               AM33XX_INPUT_EN | AM33XX_PIN_OUTPUT),
     { .reg_offset = OMAP_MUX_TERMINATOR },
};
#else
#define     board_mux     NULL

#endif

As well as in static void __init am335x_evm_init(void) function replaced am33xx_mux_init(NULL); with am33xx_mux_init(board_mux);

These changes alone don't seem to be enough to make the kernel aware of the i2c0 peripheral. What are we missing?

Thank you.

Phillip

over 9 years ago

0 Phillip Warren81 over 9 years ago

Prodigy 80 points

Posted this question in Sitara™ Processors forum as it may be a more relevant topic there.

0 Schuyler Patton over 9 years ago in reply to Phillip Warren81

TI__Mastermind 40080 points

Is there a reason for using such an old kernel on a new board?

0 Phillip Warren81 over 9 years ago in reply to Schuyler Patton

Prodigy 80 points

Schuyler Patton said:
Is there a reason for using such an old kernel on a new board?

The board design pre-dates the release of SDK 06. We have a stable release based on SDK 06 and just need to enable the i2c0 bus. Thanks!

0 Shankari G over 9 years ago

TI__Mastermind 43955 points

Hi Philip,
Apart from PINMUX configuration, you have to enable I2C platform driver initialization in board file.

------------------

0 Phillip Warren81 over 9 years ago in reply to Shankari G

Prodigy 80 points

Hi Shankari,

Thank you for your response. Including the pinmux definition above, does the code to enable the i2c-0 platform driver initialization in the board file look like the code below, assuming:
1. We only use i2c-0
2. The only devices attached to i2c-0 are TMP10 & MMA8453

static struct i2c_board_info __initdata am335x_i2c0_boardinfo[] = {
{
I2C_BOARD_INFO("tmp102", 0x49),

I2C_BOARD_INFO("mma8453", 0x1C),
},
};

static void __init am335x_evm_i2c_init(void)
{
omap_register_i2c_bus(1, 100, am335x_i2c0_boardinfo,
ARRAY_SIZE(am335x_i2c0_boardinfo));
}

static void __init am335x_evm_init(void)
{

am33xx_mux_init(board_mux);

am335x_evm_i2c_init();

}

0 Phillip Warren81 over 9 years ago in reply to Phillip Warren81

Prodigy 80 points

Correction for syntax error:

static struct i2c_board_info __initdata am335x_i2c0_boardinfo[] = {
{
I2C_BOARD_INFO("tmp102", 0x49)
},

{
I2C_BOARD_INFO("mma8453", 0x1C),
},

};