How to set up UART2 in J990
From IGEP - ISEE Wiki
Overview
This How-To is meant to be a starting point for people to learn to set up UART2 for IGEPv2 J990 connector as quickly and easily as possible. In this how-to, we use Linaro Headless with Kernel 2.6.35.y. This How-To is focused for revisions RC1/RC3/RC4/RC6 (WIFI/BT versions).
More information about UART.
There are two modes to configure UART2 in J990: via user space (fast mode) or editing kernel source and compile it (slow mode).
Feedback and Contributing
At any point, if you see a mistake you can contribute to this How-To.
Configure IGEP
Fast Mode, set up UART2 until system reboot or halt. Using space to configure mux and disabling bluethoot. Default kernel binaries and source have disabled TWL4030 PCM voice interface output pins to high impedance, otherwise this module forces the level of mcbsp3_fsx and mcbsp3_clkx pins. To make sure, go to ~/sound/soc/codecs/twl4030.c file already read:
0x04, /* REG_VOICE_IF (0xF) */
Make sure that IGEPv2 Expansion is disabled, go to igep.ini file:
;buddy=igep0022
Log with root user via SSH or Serial cable.
Go to /sys/kernel/debug/omap_mux/.
Disable Bluethoot:
Set sdmmc2_dat5 to GPIO137 mode(4):
echo 0x004 > sdmmc2_dat5
Check that:
root@localhost:/sys/kernel/debug/omap_mux# cat sdmmc2_dat5 name: sdmmc2_dat5.gpio_137 (0x48002166/0x136 = 0x0004), b ah3, t NA mode: OMAP_PIN_OUTPUT | OMAP_MUX_MODE4 signals: sdmmc2_dat5 | sdmmc2_dir_dat1 | cam_global_reset | sdmmc3_dat1 | gpio_137 | hsusb3_tll_stp | mm3_rxdp | safe_mode
Disable Bluethoot:
Go to: /sys/class/gpio/
Export Gpio137 if you don't have it:
echo 137 > /sys/class/gpio/export
Check that:
l