Hi, On Fri, 2009-12-04 at 11:53 +0100, ext Grazvydas Ignotas wrote: > hi, > > it seems DSS block in OMAP needs SDI/DSI supplies to operate properly > even with parallel displays, or else it doesn't drive some data lines > resulting in missing/wrong colors. Take a look at figure 15-1 on OMAP3 > TRM (page 2119 on spruf98d), some dss_data lines are going out of > SDI/DSI blocks, which are fed by vdds_sdi and vdds_dsi supplies > (vdss_sdi in fig 15-1 seems to be a typo). Those 2 are typically > connected to VPLL2 on TWL4030/TPS65950 (see fig. 25-2 on p3482), so > that regulator needs to be activated for proper operation (if you have > a parallel display and a board with TWL4030 you can reproduce this by > not enabling VPLL2 in bootloader and kernel; mainline u-boot enables > it). Hmm, this would explain the color errors. Have you seen this on some other board than TI's SDP? To me the fig 15-1 does not tell that the powers are needed. The DSS_DATA[] pins do not come from SDI/DSI blocks, but from the main DSS block. And the pin muxing component is outside also. This of course doesn't really prove anything. =) > Right now DSS2 requests vdds_dsi in DSI driver only, any plans to > request vdds_dsi/vdds_sdi for parallel displays too? I didn't have any plans, but if what you said is true, it sure needs to be added. Tomi Ps. Adding l-o, as others may be interested also. -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
