[Galaxy Tab 2 Q&A, Help & Troubleshooting] wd5gnr:
This is the pinout:

http://pinoutsguide.com/PDA/samsung_galaxy_tab_pinout.shtml

and a source for connectors:

http://www.podgizmo.com/productag/45/Samsung

Logically, it seems that a "normal" charger sends charge over the USB power lines and requires a short between D+, D- since the same cable works for charging and sync. Well. Maybe. I guess it is possible that the standard cable connects the power to multiple places.

Note there does seem to be VOUT_CHARGER pins (must be from the host perspective, so VOUT is to the tablet?) So that bodes well, but it isn't clear where USB 5V goes.

The real key is ACCESSORY_ID / USB_ID I which, I think, is a resistor that tells the beast what it is plugged into. Here's the table from the kernel:

This is the table of resistances from kernel in arch/arm/mach-s5pv210/include/mach/fsa9480_i2c.h

typedef enum

{

RID_USB_OTG_MODE, /* 0 0 0 0 0 GND USB OTG Mode */

RID_AUD_SEND_END_BTN, /* 0 0 0 0 1 2K Audio Send_End Button*/

RID_AUD_REMOTE_S1_BTN, /* 0 0 0 1 0 2.604K Audio Remote S1 Button */

RID_AUD_REMOTE_S2_BTN, /* 0 0 0 1 1 3.208K Audio Remote S2 Button */

RID_AUD_REMOTE_S3_BTN, /* 0 0 1 0 0 4.014K Audio Remote S3 Button */

RID_AUD_REMOTE_S4_BTN, /* 0 0 1 0 1 4.82K Audio Remote S4 Button */

RID_AUD_REMOTE_S5_BTN, /* 0 0 1 1 0 6.03K Audio Remote S5 Button */

RID_AUD_REMOTE_S6_BTN, /* 0 0 1 1 1 8.03K Audio Remote S6 Button */

RID_AUD_REMOTE_S7_BTN, /* 0 1 0 0 0 10.03K Audio Remote S7 Button */

RID_AUD_REMOTE_S8_BTN, /* 0 1 0 0 1 12.03K Audio Remote S8 Button */

RID_AUD_REMOTE_S9_BTN, /* 0 1 0 1 0 14.46K Audio Remote S9 Button */

RID_AUD_REMOTE_S10_BTN, /* 0 1 0 1 1 17.26K Audio Remote S10 Button */

RID_AUD_REMOTE_S11_BTN, /* 0 1 1 0 0 20.5K Audio Remote S11 Button */

RID_AUD_REMOTE_S12_BTN, /* 0 1 1 0 1 24.07K Audio Remote S12 Button */

RID_RESERVED_1, /* 0 1 1 1 0 28.7K Reserved Accessory #1 */

RID_RESERVED_2, /* 0 1 1 1 1 34K Reserved Accessory #2 */

RID_RESERVED_3, /* 1 0 0 0 0 40.2K Reserved Accessory #3 */

RID_RESERVED_4, /* 1 0 0 0 1 49.9K Reserved Accessory #4 */

RID_RESERVED_5, /* 1 0 0 1 0 64.9K Reserved Accessory #5 */

RID_AUD_DEV_TY_2, /* 1 0 0 1 1 80.07K Audio Device Type 2 */

RID_PHONE_PWD_DEV, /* 1 0 1 0 0 102K Phone Powered Device */

RID_TTY_CONVERTER, /* 1 0 1 0 1 121K TTY Converter */

RID_UART_CABLE, /* 1 0 1 1 0 150K UART Cable */

RID_CEA936A_TY_1, /* 1 0 1 1 1 200K CEA936A Type-1 Charger(1) */

RID_FM_BOOT_OFF_USB, /* 1 1 0 0 0 255K Factory Mode Boot OFF-USB */

RID_FM_BOOT_ON_USB, /* 1 1 0 0 1 301K Factory Mode Boot ON-USB */

RID_AUD_VDO_CABLE, /* 1 1 0 1 0 365K Audio/Video Cable */

RID_CEA936A_TY_2, /* 1 1 0 1 1 442K CEA936A Type-2 Charger(1) */

RID_FM_BOOT_OFF_UART, /* 1 1 1 0 0 523K Factory Mode Boot OFF-UART */

RID_FM_BOOT_ON_UART, /* 1 1 1 0 1 619K Factory Mode Boot ON-UART */

RID_AUD_DEV_TY_1_REMOTE, /* 1 1 1 1 0 1000.07K Audio Device Type 1 with Remote(1) */

RID_AUD_DEV_TY_1_SEND = RID_AUD_DEV_TY_1_REMOTE , /* 1 1 1 1 0 1002K Audio Device Type 1 / Only Send-End(2) */

RID_USB_MODE, /* 1 1 1 1 1 Open USB Mode, Dedicated Charger or Accessory Detach */

RID_MAX

}FSA9480_RID_ENUM_TYPE;

Not sure what a type 1 vs type 2 charger would be. Maybe where the voltage goes?

Ha. After I wrote this I did a little research and found this:

http://xdaforums.com/showthread.php?t=1155065

Disregard above ;-) However, reading the whole thread it looks like the hardware may support it but the stock kernel may not.