AM335x RTC DS3231 initialization

Hi, 

I am using:

• Beaglebone white
• Ezlinux sdk: root@user-virtual-machine:/home/user/ti-sdk-am335x-evm-07.00.00.00/board-support/linux-3.12.10-ti2013.12.01#
• and DS3231 Real Time Clock breakboard from Adafruit

Until now, I was able to detect the DS3231 at the I2C bus:

root@Teste01:~# i2cdetect -y -r 1

0    1 2  3 4  5  6  7  8  9  a  b  c  d  e  f
00:            -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- 68 -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --

I have enabled the DS3232 driver at menuconfig.

I have added the following code at am335x-bone-common.dtsi:

i2c1_pins: pinmux_i2c1_pins {
			pinctrl-single,pins = <
				0x158 (PIN_INPUT_PULLUP | MUX_MODE2)	/* spi0_d1.i2c1_sda */
				0x15c (PIN_INPUT_PULLUP | MUX_MODE2)	/* spi0_cs0.i2c1_scl */
			>;
		};

and

i2c1: i2c@4802a000 {
			pinctrl-names = "default";
			pinctrl-0 = <&i2c1_pins>;
			status = "okay";
			clock-frequency = <400000>;

			/* Set OPP50 (0.95V) for VDD core */
			sleep-sequence = /bits/ 8 <
				0x02 0x24 0x0b 0x6d /* Password unlock 1 */
				0x02 0x24 0x10 0x02 /* Set DCDC3 to 0.95V */
				0x02 0x24 0x0b 0x6d /* Password unlock 2 */
				0x02 0x24 0x10 0x02 /* Set DCDC3 to 0.95V */
				0x02 0x24 0x0b 0x6c /* Password unlock 1 */
				0x02 0x24 0x11 0x86 /* Apply DCDC changes */
				0x02 0x24 0x0b 0x6c /* Password unlock 2 */
				0x02 0x24 0x11 0x86 /* Apply DCDC changes */
			>;

			/* Set OPP100 (1.10V) for VDD core */
			wake-sequence = /bits/ 8 <
				0x02 0x24 0x0b 0x6d /* Password unlock 1 */
				0x02 0x24 0x10 0x08 /* Set DCDC3 to 1.1V */
				0x02 0x24 0x0b 0x6d /* Password unlock 2 */
				0x02 0x24 0x10 0x08 /* Set DCDC3 to 1.1V */
				0x02 0x24 0x0b 0x6c /* Password unlock 1 */
				0x02 0x24 0x11 0x86 /* Apply DCDC changes */
				0x02 0x24 0x0b 0x6c /* Password unlock 2 */
				0x02 0x24 0x11 0x86 /* Apply DCDC changes */
			>;

			DS3232: DS3232@68 {
				compatible = "Dallas/Maxim,DS3232";
				reg = <0x68>;
			};

		};

And I have added the following highlighted code at board-omap3beagle.c (I have not found board-am335xevm.c as advised in other posts):

static struct i2c_board_info __initdata beagle_i2c_eeprom[] = {
       {
               I2C_BOARD_INFO("eeprom", 0x50),
       },
       {
               I2C_BOARD_INFO("ds3231", 0x68),
       },
};

So I try to instantiate and I get an error:

root@PRC4-01:~# echo ds3231 0x68 > /sys/class/i2c-adapter/i2c-1/new_device
-sh: echo: write error: Invalid argument

What am I doing wrong? Do I have to add something more at the device tree to get DS3232 driver working and linked to the i2c-1? 

Thanks in advance and best regards!