From: Ash C. <ash...@gm...> - 2011-10-03 03:46:34
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Hey James, On Sun, Oct 2, 2011 at 7:08 PM, JamesAng <ang...@gm...> wrote: > Do you or Ash or members of Gumstix have any comments on the little NOTES > that Laurent has added into the patch regarding the PIN MUX? Can you point a link to the notes? -Ash |
From: JamesAng <ang...@gm...> - 2011-10-03 09:48:05
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Hi Ash, Ash Charles wrote: > > Hey James, > > On Sun, Oct 2, 2011 at 7:08 PM, JamesAng <ang...@gm...> wrote: >> Do you or Ash or members of Gumstix have any comments on the little NOTES >> that Laurent has added into the patch regarding the PIN MUX? > > Can you point a link to the notes? > -Ash > In the patch, @@ -497,6 +558,23 @@ static const struct usbhs_omap_board_data usbhs_bdata __initconst = { #ifdef CONFIG_OMAP_MUX static struct omap_board_mux board_mux[] __initdata = { + /* + * Camera + * + * The level shifters used on the Caspa camera module have a 4k output + * impedance. Combined with the 100uA pull-up resistors in the OMAP3, + * this raises the ground level to 400mV. Adding crosstalk between the + * pixel clock and the HS/VS signals on the flat cable (a ground line in + * between would have been nice), logic 0 levels can raise up to 650mV. + * This exceeds the camera input pins VIL maximum voltage. + * + * To work around the issue, disable pull-ups on the PCLK, HS and VS + * signals. + */ + OMAP3_MUX(CAM_PCLK, OMAP_MUX_MODE0 | OMAP_PIN_INPUT), + OMAP3_MUX(CAM_HS, OMAP_MUX_MODE0 | OMAP_PIN_INPUT), + OMAP3_MUX(CAM_VS, OMAP_MUX_MODE0 | OMAP_PIN_INPUT), + { .reg_offset = OMAP_MUX_TERMINATOR }, }; #endif For me without this additional changes, my board will hang when running yavta. I saw steve's repo does not have this.. Thanks. James. -- View this message in context: http://old.nabble.com/Caspa-Camera-on-2.6.39-Kernel-tp32435194p32581396.html Sent from the Gumstix mailing list archive at Nabble.com. |
From: Steve S. <sa...@gm...> - 2011-10-03 23:20:50
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On Mon, Oct 3, 2011 at 2:47 AM, JamesAng <ang...@gm...> wrote: >> On Sun, Oct 2, 2011 at 7:08 PM, JamesAng <ang...@gm...> wrote: >>> Do you or Ash or members of Gumstix have any comments on the little NOTES >>> that Laurent has added into the patch regarding the PIN MUX? I've done this pinmux change in u-boot and submitted the patch upstream: http://www.sakoman.com/cgi-bin/gitweb.cgi?p=u-boot.git;a=commitdiff;h=d4013af00f6ed8dbfce7d89cd51378a9d9e71858 Steve |
From: JamesAng <ang...@gm...> - 2011-10-04 01:18:46
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Hi Steve, sakoman wrote: > > On Mon, Oct 3, 2011 at 2:47 AM, JamesAng <ang...@gm...> wrote: > >>> On Sun, Oct 2, 2011 at 7:08 PM, JamesAng <ang...@gm...> wrote: >>>> Do you or Ash or members of Gumstix have any comments on the little >>>> NOTES >>>> that Laurent has added into the patch regarding the PIN MUX? > > I've done this pinmux change in u-boot and submitted the patch upstream: > > http://www.sakoman.com/cgi-bin/gitweb.cgi?p=u-boot.git;a=commitdiff;h=d4013af00f6ed8dbfce7d89cd51378a9d9e71858 > > Steve > Nice~~ I see that it was done recently.. Thus, it explains why I had the lockup if without the codes in board-overo.c. (^^,) I raised this similar option to Laurent during over conversation (either in board code or others) and he has reservation as to putting it upstream as he doesn't know what/if there might be damage done to the board/OMAP if there is no camara attached to the port in such workaround. Do you think it's 'safe' (for the OMAP chip) to have it permanently in u-boot as some user might not have a camera attached? Your thoughts? Cheers~! James -- View this message in context: http://old.nabble.com/Caspa-Camera-on-2.6.39-Kernel-tp32435194p32586283.html Sent from the Gumstix mailing list archive at Nabble.com. |
From: Steve S. <sa...@gm...> - 2011-10-04 16:24:22
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On Mon, Oct 3, 2011 at 6:18 PM, JamesAng <ang...@gm...> wrote: >>>>> Do you or Ash or members of Gumstix have any comments on the little >>>>> NOTES >>>>> that Laurent has added into the patch regarding the PIN MUX? >> >> I've done this pinmux change in u-boot and submitted the patch upstream: >> >> http://www.sakoman.com/cgi-bin/gitweb.cgi?p=u-boot.git;a=commitdiff;h=d4013af00f6ed8dbfce7d89cd51378a9d9e71858 > Nice~~ I see that it was done recently.. > Thus, it explains why I had the lockup if without the codes in > board-overo.c. (^^,) > > I raised this similar option to Laurent during over conversation (either in > board code or others) and he has reservation as to putting it upstream as he > doesn't know what/if there might be damage done to the board/OMAP if there > is no camara attached to the port in such workaround. > > Do you think it's 'safe' (for the OMAP chip) to have it permanently in > u-boot as some user might not have a camera attached? > > Your thoughts? I think this is a pretty safe change. I don't see that it is any different than many other similarly configured unused balls on the OMAP. Steve |
From: JamesAng <ang...@gm...> - 2011-10-05 01:19:23
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H Steve, sakoman wrote: > > On Mon, Oct 3, 2011 at 6:18 PM, JamesAng <ang...@gm...> wrote: > >>>>>> Do you or Ash or members of Gumstix have any comments on the little >>>>>> NOTES >>>>>> that Laurent has added into the patch regarding the PIN MUX? >>> >>> I've done this pinmux change in u-boot and submitted the patch upstream: >>> >>> http://www.sakoman.com/cgi-bin/gitweb.cgi?p=u-boot.git;a=commitdiff;h=d4013af00f6ed8dbfce7d89cd51378a9d9e71858 > >> Nice~~ I see that it was done recently.. >> Thus, it explains why I had the lockup if without the codes in >> board-overo.c. (^^,) >> >> I raised this similar option to Laurent during over conversation (either >> in >> board code or others) and he has reservation as to putting it upstream as >> he >> doesn't know what/if there might be damage done to the board/OMAP if >> there >> is no camara attached to the port in such workaround. >> >> Do you think it's 'safe' (for the OMAP chip) to have it permanently in >> u-boot as some user might not have a camera attached? >> >> Your thoughts? > > I think this is a pretty safe change. I don't see that it is any > different than many other similarly configured unused balls on the > OMAP. > > Steve > Noted. Out of curiosity, I've been wondering why the 2.6.34 driver does not need this additional mod to work. I don't have the knowledge to investigate but might be good to know the reason and see if future HW/SW need to take this into consideration. Thanks. James -- View this message in context: http://old.nabble.com/Caspa-Camera-on-2.6.39-Kernel-tp32435194p32593680.html Sent from the Gumstix mailing list archive at Nabble.com. |