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Mux instructions

3,140 bytes added, 19:30, 13 February 2013
Overview
= Notes Overview =
This wiki page has more detailed information about mux on IGEPv2. <br> Read general [[Mux configuration|this 'Mux configuration' page]] before use this wikiit.This article contains: <br>
= Overview =*How-to disable some external peripherals to avoid interferences This wiki explained more *Some detailed how-to configure mux<br>examples.
= Disable Peripherals =
'''Compile kernel source code'''
Use this [[Linux Kernel 2.6.35.y|tutorial]] (Kernel) and this [http://labs.igep.es/index.php/The_IGEP_X-loader other] (IGEPxloader) to install Linaro Headless (or Poky) with your custom kernel in SD card.&nbsp; You can compile the IGEPxloader, but is not necessary.<br>
==== WIFI ====
'''Compile kernel source code'''
Use this [[Linux Kernel 2.6.35.y|tutorial]] (Kernel) and this [http://labs.igep.es/index.php/The_IGEP_X-loader other] (IGEPxloader) to install Linaro Headless (or Poky) with your custom kernel in SD card.&nbsp; You can compile the IGEPxloader, but is not necessary.<br>
=== TP65950 PCM VSP ===
=== TFP410 ===
This external peripheral converts DVI signal to HDMI. To use some JA41/JA42 pads for other purpose is necessary disable it. GPIO_170 control TFP410 Power down(PD pad).
Power down (active low). In the powerdown state, only the digital I/O buffers and I2C interface remain active. A high level selects the normal operating mode. A low level selects the powerdown mode.<br>
 
It was tested using alternate peripherals like UARTs and GPIOs. Caution, in powerdown mode, pads aren't in safe mode (high impedance).
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<br>  ===== First way: =====  This mode has a issue, when your system reboot or shutdown you will need to configure again. Using user space to configure mux and powerdown TFP410.  Logging with root user via SSH or Serial cable.<br>  NOTE: Poky distribution does not have debug filesystem enabled. Mount it: <pre>mount -t debugfs none /sys/kernel/debug</pre> Go to /sys/kernel/debug/omap_mux/<br>  Set hdq_sio to gpio170 (mode 4): <pre>echo 0x104 &gt; hdp_sio</pre> Revise that: <pre>root@localhost:/sys/kernel/debug/omap_mux# cat hdq_sio name: hdq_sio.gpio_170 (0x480021c6/0x196 = 0x0104), b j25, t NAmode: OMAP_PIN_INPUT | OMAP_MUX_MODE4signals: hdq_sio | sys_altclk | i2c2_sccbe | i2c3_sccbe | gpio_170 | NA | NA | safe_moderoot@localhost:/sys/kernel/debug/omap_mux# </pre> Go to: /sys/class/gpio/  Check that gpio170 is in user space: <pre>root@localhost:/sys/class/gpio# lsexport gpio137 gpio138 gpio139 gpio170 gpio64 gpiochip0 gpiochip128 gpiochip160 gpiochip192 gpiochip32 gpiochip64 gpiochip96 unexportroot@localhost:/sys/class/gpio# <span /pre> If you don't have it, you should export gpio170: <br> <pre>echo 170 &gt; /sys/class="editsection" /gpio/export </pre>Set gpio170 to low value to disable TFP410: <span pre>echo 0 &gt; /sys/class="mw-headline"/gpio/gpio170/value</pre> Revise that: <pre>First wayroot@localhost:/sys/class/gpio# cat /sys/class/gpio/gpio170/value 0root@localhost: /sys/class/gpio# </spanpre> ===== Second way&nbsp;: =====
Configure kernel sources. Configuration will be permanent. There are many ways to edit source code, this method is focused for igep0020 RC without igep0022 support. <br>Go to [http://git.igep.es/?p=pub/scm/linux-omap-2.6.git;a=blob_plain;f=arch/arm/mach-omap2/board-igep0020.c;hb=db3cb47adf10504d3847d54927de50b2fa94c008 $(kernel path)/arch/arm/mach-omap2/board-igep0020.c] and search next line: <br> <pre> static inline void igep0020_display_init(void)static int igep0020_enable_dvi(struct omap_dss_device *dssdev){ gpio_direction_output(GPIO_DVI_PUP, 1);
===== return 0;}<span class=/pre> "mw-headlinestatic int igep0020_enable_dvi">Second wayinitialize DVI. Edit to disable it: </spanpre> =====static int igep0020_enable_dvi(struct omap_dss_device *dssdev){ gpio_direction_output(GPIO_DVI_PUP, 0);
return 0;}</pre> '''Under constructionCompile kernel source code''' Use this [[Linux Kernel 2.6.35.y|tutorial]] (Kernel) and this [http://labs.igep.es/index.php/The_IGEP_X-loader other] (IGEPxloader) to install Linaro Headless (or Poky) with your custom kernel in SD card.&nbsp; You can compile the IGEPxloader, but is not necessary.<br>
= Edit mux =
 
Here you can found some detailed examples to configure mux. You can add more.
=== UART1 in J960 ===
=== UART3 in J960 ===
Edit igep.ini to disable serial debug, comment next linelines:
<pre>; Setup the Kernel console params
;console=ttyO2,115200n8;console=ttyS2,115200n8 ; Enable early printk;earlyprintk=serial,tty02,115200;earlyprintk=serial,ttyS2,115200 </pre>  Poky linux starts an user terminal at UART3, You must disable it to avoid interferences. Comment next lines in /etc/inittab: <pre># Normally not reached, but fallthrough in case of emergency.#z6:6:respawn:/sbin/sulogin#S:2345:respawn:/sbin/getty 115200 ttyO2# /sbin/getty invocations for the runlevels.</pre>  
You can test new configuration using [[How to use UARTs|this tutorial]]<br>
Edit&nbsp; [http://git.igep.es/?p=pub/scm/linux-omap-2.6.git;a=blob_plain;f=arch/arm/mach-omap2/board-igep00x0.c;hb=e620ef8e577d73681f16ab80471332286c1b9fd5 $(kernel path)/arch/arm/mach-omap2/board-igep00x0.c]&nbsp; or [http://git.igep.es/?p=pub/scm/linux-omap-2.6.git;a=blob_plain;f=arch/arm/mach-omap2/board-igep0020.c;hb=refs/heads/linux-2.6.35.y $(kernel path)/arch/arm/mach-omap2/board-igep0020.c] to configure GPIO via Kernel source, example [[How to set up UART2 in J990#Third_way|here]].<br>
'''Under construction'''  [[Category:CommunicationsPeripherals]]
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