Julian Calaby <[email protected]> writes: > Hi Jens,
Hi, > On Fri, Feb 27, 2015 at 1:41 AM, Jens Thiele <[email protected]> wrote: >> Do you think it is reasonable to expect the display/touchscreen of two >> Allwinner based tablets sold by the same name (including model number) >> are identical, or do they use different displays / touchscreen elements >> all the time? > > I think the answer is "It depends" > > I have two Allwinner SoC based tablets, one is a "generic" board that > has been put into at least three different tablets I'm aware of. The > FEX file and Android instance for it have configuration and drivers > for at least three different models of touch screen. are those resistive touchscreens => sun4i-ts driver? are the fex files available on git://github.com/linux-sunxi/sunxi-boards.git ? (see also below) > The other is manufactured by HP and I believe that while the > particular board is put into at least 2 different models, they're all > slight variations on the same thing (different / cheaper LCD) and > consequently should all have the same touch screen chip. The differences I see are with the resistive touchscreen panels / cover themself / even the surface feels different ... hard to explain those parts: https://www.olimex.com/Products/OLinuXino/LCD/A13-TS7/ https://www.olimex.com/Products/OLinuXino/LCD/A13-TS10/ > I think the general consensus is that one can assume that all tablets > with the same name and details will have the same touch screen. In > your case, with development boards, that's less viable and we possibly > should be using device tree overlays (or whatever they're called) to > separate peripheral configuration (the LCD + touch screen board) from > system configuration (the development board itself) but I'm hazy on > the details. > > IMHO, you should write the patch to get the value from device tree and > worry about the board configuration details when submitting that. Just wanted to start with this, but then had look at the fex files from git://github.com/linux-sunxi/sunxi-boards.git having "rtp_used = 1". They nearly all have the same rtp_para block: [rtp_para] rtp_used = 1 rtp_screen_size = 5 rtp_regidity_level = 5 rtp_press_threshold_enable = 0 rtp_press_threshold = 0x1f40 rtp_sensitive_level = 0xf rtp_exchange_x_y_flag = 0 The exceptions are: ./a10/iteaduino_plus_a10.fex [rtp_para] rtp_used = 1 rtp_screen_size = 7 rtp_regidity_level = 5 rtp_press_threshold_enable = 1 rtp_press_threshold = 0x1f40 rtp_sensitive_level = 0xf rtp_exchange_x_y_flag = 0 ./a13/ampe_a76.fex [rtp_para] rtp_used = 1 rtp_screen_size = 7 rtp_regidity_level = 5 rtp_press_threshold_enable = 0 rtp_press_threshold = 0x1f40 rtp_sensitive_level = 0xf rtp_exchange_x_y_flag = 0 But both use rtp_sensitive_level = 0xf, too. Now I am not sure, it is really worth it. Greetings, jens -- Prisirah - Building digital photo frames for family and friends using open-source hardware. http://karme.de/prisirah/ -- You received this message because you are subscribed to the Google Groups "linux-sunxi" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
