~~NOCACHE~~
<embed en:templates:tabs>
  <label lang>en</label>
  <label mod_name>tqma35</label>
  <label mod_name_head>TQMa35</label>
  <label mod_arch>arm</label>
  <label bsp_name>Linux</label>
  <label bsp_name_head>Linux</label>
</embed>
\\

===== How-to =====

====== Kernel command line parameters ======

In the following section special commandline parameters for the TQMa35 kernel are given:

==== Display selection ====

Selects desplay and configures backlight curve.

video=mx3fb:< EDT480272 | EVERVGG482270 | ETV570 | CLAA070LC0ACW | FG0700K5DSSWBG01 | AUOG104SN02 >

==== USB OTG mode selection ====

Configures the USB OTG controller

otg_mode=<host | device>

==== LVDS ====

<WRAP round important>MBa35 only</WRAP>

Configures the LVDS Transmitter at power up

default: 0 (Off)

lvds=<0 | 1> 

==== eMMC ====

Enable / Disable the eSDHC3 controller at power up

  * default: emmc
  * emmc: maps the pins, binds the driver and try detect card
  * none: do nothing. Pins can be used freely <wrap important> only for TQMa35 without eMMC </wrap>

emmc_mode=<none | emmc>

====== Display ======

Framebuffer console and Bootlogo support are not compiled in. To test fuctionality you can use fbtest utility:

<code bash>
root@tqma35 $ fbtest 
</code>

====== GPIO ======

All GPIO pins are exported using sysfs and are accessible using their value node.

To set an output write "0" or "1" to the value node of gpio n:

<code bash>
root@tqma35 $ echo "1" > /sys/class/gpio/gpio<n>/value 
root@tqma35 $ echo "0" > /sys/class/gpio/gpio<n>/value 
</code>

To query current state of gpio n:

<code bash>
root@tqma35 $ cat /sys/class/gpio/gpio<n>/value 
</code>

====== Backlight ======

===== Switching the backlight using sysfs =====

To switch the backlight sysfs file nodes are provided. Use

<code bash>
root@tqma35 $ echo "0" > /sys/devices/platform/mx3_sdc_fb/graphics/fb0/mx3_sdc_bl0/bl_power
</code>

to switch on and 

<code bash>
root@tqma35 $ echo "1" > /sys/devices/platform/mx3_sdc_fb/graphics/fb0/mx3_sdc_bl0/bl_power
</code>

to switch off.

===== Dimming of the backlight using sysfs =====

To dim the backlight sysfs files are provided.

To query max / current brightness use:

<code bash>
$ cat /sys/devices/platform/mx3_sdc_fb/graphics/fb0/mx3_sdc_bl0/max_brightness
$ cat /sys/devices/platform/mx3_sdc_fb/graphics/fb0/mx3_sdc_bl0/brightness
</code>

To dim the backlight use (value in the range of 1 ... max_brightness):

<code bash>
$ echo "<value>" > /sys/devices/platform/mx3_sdc_fb/graphics/fb0/mx3_sdc_bl0/brightness
</code>

====== System updates using U-boot ======

==== Linux Kernel update ====

<WRAP round important>U-Boot has to be configured to work with your TFTP-Server</WRAP>

Make sure the following environment variables existing and are configured correctly:

  * kernel: Filename for kernel image on TFTP server
  * kernel_addr: Offset in NOR-flash where to store the kernel, depends on partitioning scheme

Configure update helper:

<code>
MX35 U-Boot > setenv prg_kernel tftpboot ${loadaddr} ${kernel}; erase ${kernel_addr} A02FFFFF; cp.b ${loadaddr} ${kernel_addr} ${filesize}; setenv filesize
MX35 U-Boot > saveenv
</code>

Now the kernel image can be updated using the following shortcut:

<code>
MX35 U-Boot > run prg_kernel
</code>

==== Rootfs update ====

<WRAP round important>U-Boot has to be configured to work with your TFTP-Server</WRAP>
<WRAP round important>This works only for JFFS2 rootfs on NOR flash</WRAP>

Make sure the following environment variables existing and are configured correctly:

  * rootfs: Filename for rootfs image on TFTP server
  * ramdisk_addr: Offset in NOR-flash where to store the rootfs, depends on partitioning scheme

<code>
MX35 U-Boot > setenv ramdisk_end a1ffffff (für 32MB Flash)
MX35 U-Boot > setenv prg_rootfs tftpboot ${loadaddr} ${rootfs}; erase ${ramdisk_addr} +${filesize}; ${ramdisk_addr} ${ramdisk_end}; cp.b ${loadaddr} ${ramdisk_addr} ${filesize}; setenv filesize
MX35 U-Boot > saveenv
</code>

Now the rootfs can be updated using the following shortcut:

<code>
MX35 U-Boot > run prg_rootfs
</code>