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

Phillip Warren81

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 Biser Gatchev-XID over 9 years ago

TI__Guru**** 393215 points

Hi,

I will ask the Linux team to help on this.

0 Kemal R. Shakir over 9 years ago in reply to Biser Gatchev-XID

TI__Guru 55345 points

Hello Phillip,

It seems the initialization is missing.

You can use the i2c2 for reference:

Pinmuxing:

static struct pinmux_config i2c2_pin_mux[] = {
{"uart1_ctsn.i2c2_sda", OMAP_MUX_MODE3 | AM33XX_SLEWCTRL_SLOW |
AM33XX_PULL_UP | AM33XX_INPUT_EN},
{"uart1_rtsn.i2c2_scl", OMAP_MUX_MODE3 | AM33XX_SLEWCTRL_SLOW |
AM33XX_PULL_UP | AM33XX_INPUT_EN},
{NULL, 0},
};

Initialization:

static struct i2c_board_info am335x_i2c2_boardinfo[] = {
};

static void i2c2_init(int evm_id, int profile)
{
setup_pin_mux(i2c2_pin_mux);
omap_register_i2c_bus(3, 100, am335x_i2c2_boardinfo,
ARRAY_SIZE(am335x_i2c2_boardinfo));
return;
}

i2c2_init invocation:

/* Beaglebone Black */
static struct evm_dev_cfg beagleboneblack_dev_cfg[] = {
{am335x_rtc_init, DEV_ON_BASEBOARD, PROFILE_NONE},
{clkout2_enable, DEV_ON_BASEBOARD, PROFILE_NONE},
{tps65217_init, DEV_ON_BASEBOARD, PROFILE_NONE},
{mii1_init, DEV_ON_BASEBOARD, PROFILE_NONE},
{usb0_init, DEV_ON_BASEBOARD, PROFILE_NONE},
{usb1_init, DEV_ON_BASEBOARD, PROFILE_NONE},
{mmc1_emmc_init, DEV_ON_BASEBOARD, PROFILE_NONE},
{mmc0_init, DEV_ON_BASEBOARD, PROFILE_NONE},
{i2c2_init, DEV_ON_BASEBOARD, PROFILE_NONE},
{sgx_init, DEV_ON_BASEBOARD, PROFILE_NONE},
{NULL, 0, 0},
};

Best regards,
Kemal

0 Phillip Warren81 over 9 years ago in reply to Kemal R. Shakir

Prodigy 80 points

Hi Kemal,

Thank you for your response. I had originally posted this under the Linux forum:

e2e.ti.com/.../1663802

but copied to Sitara as I thought it might be more relevant here....there is an ongoing discussion in the Linux forum. Can you move this thread to so we're not duplicating efforts?

Thanks!
Phillip

0 Kemal R. Shakir over 9 years ago in reply to Phillip Warren81

TI__Guru 55345 points

Okay, I'll close this one as a duplicate of this thread e2e.ti.com/.../463197

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