Mux configuration
From IGEP - ISEE Wiki
Contents
Overview
Mux (or multiplexer) is a Omap peripheral that can be controlled via software. Its function is connect other Omap peripherals to some available Omap pads.
IgepV2 Board have a default mux configuration, but some cases is necessary change it, for example your project need UART2 at j990 connector to transmit data, for this purpose you need change some mux configurations to enable it and be sure that this modification don't break or interferes in other IC or peripherals. The mux options are vast.
This How-To is meant to be a starting point for people to learn configure mux for IGEP v2 devices as quickly and easily as possible. For this how-to i used Linaro Headless and Ubuntu 10.04 with Linaro toolchain.
Feedback and Contributing
At any point, if you see a mistake you can contribute to this How-To.
Available peripherals on external connector
The next tables show you all the mux capabilities:
J990 connector
| Pad: | Connect to: | Default peripheral (mode=0)(3) | Default function: | Other available peripherals: | Share with: |
| 1 | VIO 1V8 | - | Power 1v8 | - | - |
| 2 | DC 5V | - | Power 5v | - | - |
| 3 | MMC2_DAT7 | MMC2_DAT7 | Reset Wlan |
MMC2_CLKIN(mode=1) MMC3_DAT3(mode=3) GPIO_139(mode=4) |
Wlan: This pad can reset Wlan peripheral using Omap GPIO low level (GND). If you reset continuously Wlan all their pads are in High Impedance. Also you can disable Wlan from J990 low level. Omap: protect Omap pad if you don't
use it.(1)
|
| 5 | MMC2_DAT6 | MMC2_DAT6 | Power down Wlan |
MMC2_DIR_CMD(mode=1) MMC3_DAT2(mode=3) GPIO_138(mode=4) |
Wlan: This pad can power down Wlan peripheral using Omap GPIO low level (GND), power up removing GND. Also you can power down Wlan from J990 low level. Omap: protect Omap pad if you don't
use it.(1)
|
| 7 | MMC2_DAT5 | MMC2_DAT5 | Reset Bluethoot |
MMC2_DIR_DAT1(mode=1) MMC3_DAT1(mode=3) GPIO_137(mode=4) |
Bluethoot: This pad can reset Bluethoot
peripheral using Omap GPIO low level (GND). If you reset continuously Bluethoot all their pads are in High Impedance. Also you can disable Bluethoot from J990 low level.
|
| 9 | MMC2_DAT4 | MMC2_DAT4 | - |
MMC_DIR_DAT0(mode=1) MMC3_DAT0(mode=3) GPIO136(mode=4) |
Wlan: Protect Wlan if you don' use
it. See MMC2_DAT7 pad. Omap: protect Omap pad if you don't
use it.(1)
|
| 11 | MMC2_DAT3 | MMC2_DAT3 | Transfer data between Omap and Wlan |
McSPI3_CS0(mode=1) GPIO_135(mode=4) |
Wlan: Protect Wlan if you don' use
it. See MMC2_DAT7 pad. Omap: protect Omap pad if you don't
use it.(1) |
| 13 | MMC2_DAT2 | MMC2_DAT2 | Transfer data between Omap and Wlan |
McSPI3_CS1(mode=1) GPIO_134(mode=4) |
Wlan: Protect Wlan if you don' use
it. See MMC2_DAT7 pad. Omap: protect Omap pad if you don't
use it.(1)
|
| 15 | MMC2_DAT1 | MMC2_DAT1 | Transfer data between Omap and Wlan | GPIO_133(mode=4) | Wlan: Protect Wlan if you don' use
it. See MMC2_DAT7 pad. Omap: protect Omap pad if you don't
use it.(1)
|
| 17 | MMC2_DAT0 | MMC2_DAT0 | Transfer data between Omap and Wlan |
McSPI3_SOMI(mode=1) GPIO_132(mode=4) |
Wlan: Protect Wlan if you don' use
it. See MMC2_DAT7 pad. Omap: protect Omap pad if you don't
use it.(1)
|
| 19 | MMC2_CMD | MMC2_CMD | Control Wire for bus MMC2 (Wlan) |
McSPI3_SIMO(mode=1) GPIO_131(mode=4) |
Wlan: Protect Wlan if you don' use
it. See MMC2_DAT7 pad. Omap: protect Omap pad if you don't
use it.(1)
|
| 21 | MMC2_CLK0 | MMC2_CLK | Clock for MMC2 (Wlan) |
McSPI3_CLK(mode=1) GPIO_130(mode=4) |
Wlan: Protect Wlan if you don' use
it. See MMC2_DAT7 pad. Omap: protect Omap pad if you don't
use it.(1)</font</div>
|
| 4 | MCBSP3_DX | MCBSP3_DX | Transmitted serial Data (Bluethoot audio) |
UART2_CTS(mode=1) GPIO_140(mode=4) |
TPS65950: disable it via kernel (2) If
you don't use it.
|
| 6 | MCBSP3_CLKX | MCBSP3_CLKX | Transmitted serial Clock (Bluethoot audio) |
UART2_TX(mode=1) GPIO_142(mode=4) |
Bluethoot: Protect Bluethoot if you don'
use it. See MMC2_DAT5 pad. TPS65950: disable it via kernel (2) If
you don't use it.
|
| 8 | MCBSP3_FSX | MCBSP3_FSX | Transmited Frame Syncronisation (Bluethoot audio) |
UART2_RX(mode=1) GPIO_143(mode=4) |
Bluethoot: Protect Bluethoot if you don'
use it. See MMC2_DAT5 pad. TPS65950: disable it via kernel (2) If
you don't use it.
|
| 10 | MCBSP3_DR | MCBSP3_DR | Received Serial Data (Bluethoot audio) |
UART2_RTS(mode=1) GPIO_141(mode=4) |
TPS65950: disable it via kernel (2) If
you don't use it.
|
| 12 | MCBSP1_DX | MCBSP1_DX | Transmited serial Data (not used) |
McSPI4_SIMO(mode=1) McBSP3_DX(mode=2) GPIO_158(mode=4) |
- |
| 14 | MCBSP1_CLKX | MCBSP1_CLKX | Transmited serial clock (not used) |
McBSP3_CLKX(mode=2) GPIO_162(mode=4) |
- |
| 16 | MCBSP1_FSX | MCBSP1_FSX | Transmited Frame Syncronization (not used) |
McSPI4_CS0(mode=1) McBSP3_FSX(mode=2) GPIO_161(mode=4) |
- |
| 18 | MCBSP1_DR | MCBSP1_DR | Received Serial Data (not used) |
McSPI4_SOMI(mode=1) McBSP3_DR(mode=2) GPIO_159(mode=4) |
- |
| 20 | MCBSP1_CLKR | MCBSP1_CLKR | Received Clock (not used) |
GPIO_156(mode=4) |
- |
| 22 | MCBSP1_FSR | MCBSP1_FSR | Received frame syncronization (not used) |
GPIO_157(mode=4) |
- |
| 23 | I2C2_SDA | I2C2_SDA | I2C Data |
GPIO_183(mode=4) |
Cam connector: Check and RC14 is not welded or don't use it.
|
| 24 | I2C2_SCL | I2C2_SCL | I2C Clock |
GPIO_168(mode=4) |
Cam connector: Check and RC13 is not welded or don't use it. |
| 25 | REGEN | - | |
- | - |
| 26 | nRESET | - | Read Reset Omap | - | - |
| 27 | GND | - | GND | - | - |
| 28 | GND | - | GND | - | - |
(1): To protect Omap pads from esternal signals configure Mux in mode=7 (safe_mode). With this mode, buffer is configured in high impedance
(2): Disable TPS65950 go to file sound/soc/codecs/twl4030.c change line 54 Code:
0x00, /* REG_VOICE_IF (0xF) */
to Code:
0x04, /* REG_VOICE_IF (0xF) */
(3): Omap mux have 8 modes, somes modes are disable in some pads.
Under construction
