Steps required to add a new LCD type on a BeagleBone Cape

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1

Hi,
I have made a cape that has an lcd panel with pwm back light & 4 wire touch. (AUO G057VN01V1 5.7" 640x480)

So far I can not get any of the above to work. Can anyone give me some clues of what I am missing?

By following the examples for the existing lcd capes I have made the following changes.

board-am335xevm.c:
recognize new cape in function beaglebone_cape_setup()
setup_pin_mux( typical lcd pins)
struct lcd_ctrl_config ----added new display info
struct da8xx_lcdcplatform_data — to reference above structure
config_disp_pll() -----not sure how to determine this value but extrapolated a value I want a 25mhz clock
am33xx_register_lcdc(_pdata)
tsc_init() enable touch screen
enable_ehrpwm1() enable back light

drivers/video/da8xx-fb.c
extended struct da8xx_panel known_lcd_panels[] to include lcd

/usr/bin/cape.sh, /usr/bin/cape-stop.sh added new cape to allow pwm for backlight

dmesg result of cape registery:

[ 0.262029] at24 3-0054: 32768 byte 24c256 EEPROM, writable, 64 bytes/write
[ 0.285105] BeagleBone cape EEPROM: found eeprom at address 0x54
[ 0.285132] BeagleBone cape partnumber: BLM02CBD-001

[ 0.285149] BeagleBone cape: initializing AUO 5.7" LCD for BLM02CBD
[ 0.285490] da8xx_lcdc.0: alias fck already exists
[ 0.285696] da8xx_lcdc da8xx_lcdc.0: GLCD: Found G057VN01V1 panel
[ 0.295144] Console: switching to colour frame buffer device 80x30
[ 0.303395] BeagleBone cape: initializing touchscreen for BLM02CBD
[ 0.303409] TSC connected to BeagleBone
[ 0.303740] BeagleBone cape: Registering PWM backlight for BLM02CBD
[ 0.303753] BeagleBone cape: initializing CAN1 for BLM02CBD
[ 0.303818] d_can.1: alias fck already exists
[ 0.303932] BeagleBone cape: initializing SPI0 for BLM02CBD
[ 0.304230] BeagleBone cape: initializing uart4 for BLM02CBD
[ 0.304272] BeagleBone cape: initializing GPIO_16 for BLM02CBD

Any help is appreciated!

Thanks
David

2

Hi,
I have made a cape that has an lcd panel with pwm back light & 4 wire touch.
(AUO G057VN01V1 5.7" 640x480)

So far I can not get any of the above to work. Can anyone give me some clues
of what I am missing?

The below makes it sound like you've got a pretty good start. For
this type of discussion, I find it best to include an actual code
patch, perhaps to meta-ti that includes all the patches, or perhaps
just to the kernel itself. Having the code will enable developers to
point out more possibilities for what might be going wrong where you
might not actually be doing what you intend.

In the past, I extracted information about the BeagleBoard-xM ULCD7 to
enable a patch in Android and the list was pretty similar (although
slightly simpler) than what you have below, so nothing obvious stands
out that you are missing.

3

Thanks Jason,

Please let me know if it is appropriate to paste patch in like I have done.
I rearanged a few lines of existing code to eliminate warnings, that I probably shouldn’t have messed with.

Index: git/arch/arm/mach-omap2/board-am335xevm.c

4

David,

Not sure if this helps but we have a nice set of patches for the 7" LCD cape for beaglebone at https://gitorious.org/sitara-board-port/sitara-board-port-linux, just look at the LCD, backlight, and touchscreen commits.

Sincerely,
Chase Maupin

5

Chase,

Thanks for that, I have studied your referenced patches, not seeing anything I missed yet. The BeagleBone version of the git/arch/arm/mach-omap2/board-am335xevm.c (Same file as yours but now newer?) has 3 or 4 LCD examples, seems like I should be able to figure it out from that but no.
I may change my code to use the new bone_io_config_from_cape_eeprom() as I have spent the time putting the pin info into the cape eeprom.

Grateful for the help,
David

6

I changed cape init code in git/arch/arm/mach-omap2/board-am335xevm.c to use the bone_io_config_from_cape_eeprom() function and now the AUO display,touch and backlight work. So initial post stated steps for adding a new display seem to be valid.

Thank you for this resource and all that contribute.
David

7

Vào 02:56:05 UTC+5 Thứ bảy, ngày 14 tháng bảy năm 2012, David Hallberg đã viết:

8

Hi David, i meed same problem, i make a custom LVDS panel 10" 1024x600, default resolution of dvi cape 1024x768 ( i used eerom of dvi cape) so that my panel display ia not correct resolution ( but i can see image and insall lxde well). i has changer some code and rebuild kernel but resolution not change. Please so me about steps of adding new LCD? thank!

Vào 02:56:05 UTC+5 Thứ bảy, ngày 14 tháng bảy năm 2012, David Hallberg đã viết:

9

How did you determine the horizontal and vertical sync pulse width/height? I’m struggling getting a custom LCD to work and I need some help. Page 13 of the datasheet has the timing diagrams.
http://www.koe-europe.com/doc/TX18D46VM2BAA.pdf

/* KOE 7" Display */
[6] = {
.name = “TX18D46VM2BAA”,
.width = 800,
.height = 480,
.hfp = 20,
.hbp = 216,
.hsw = ???,
.vfp = 5,
.vbp = 35,
.vsw = ???,
.pxl_clk = 32320000,
.invert_pxl_clk = 0,
},