-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 02/13/13 17:59, Tomi Valkeinen wrote: > On 2013-02-13 17:28, Tomi Valkeinen wrote: >> On 2013-02-13 17:16, Igor Grinberg wrote: >>> Hi Archit, >>> >>> On 02/13/13 16:21, Archit Taneja wrote: >>>> The cm-t35 board file currently requests gpios required to configure the tdo35s >>>> panel, and provides platform_enable/disable callbacks to configure them. >>>> >>>> These tasks have been moved to the generic dpi panel driver itself and shouldn't >>>> be done in the board files. >>>> >>>> Remove the gpio requests and the platform callbacks from the board file. >>>> Add the gpio information to generic dpi panel's platform data so that it's >>>> passed to the panel driver. >>>> >>>> Note: In cm_t35_init_display(), the gpios were disabled, and the LCD_EN gpio was >>>> enabled after a 50 millisecond delay. This code has been removed and is not >>>> taken care of in the generic panel driver. The impact of this needs to be >>>> tested. The panel's gpios are also not exported any more. Hence, they can't be >>>> accessed via sysfs interface. >>> >>> Indeed, there is an impact - the LCD no longer works. >>> The reason for the LCD_EN gpio being pushed high after the 50ms delay, >>> is to get the LCD out of reset, so the SPI transaction will succeed >>> and initialize the LCD. >>> Now, when you remove the gpio handling for the LCD_EN pin, >>> the LCD no longer works. >> >> So between what is the sleep done? It's not clear from the code. LCD_EN >> needs to be 0 for 50ms, or...? >> >> If the panel requires specific reset handling, does it work right even >> currently when the panel is turned off and later turned on? The msleep >> is only used at boot time. > > Okay, so I just realized there's an spi backlight driver used here, and > that backlight driver is actually handling the SPI transactions with the > panel, instead of the panel driver. So this looks quite messed up. Yep, it always was. The whole DSS specific panel handling inside the drivers/video/omap2/displays is a mess. Those panels can be (and are) used not only with OMAP based boards. > > For a quick solution, can we just set the LCD_EN at boot time (with the > msleep), and not touch it after that? That would be sensible for now, so this series can be merged. As a more appropriate (and long term) solution, I plan on moving the panel reset pin handling to the spi backlight driver itself. - -- Regards, Igor. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.17 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQIcBAEBAgAGBQJRHIqCAAoJEBDE8YO64Efamw0P/R2wt0tpCI1ecrnutVGMX4bF Pyjk2B65uDWqoqZ/cpJUqnvmupXl5UdrA7eqKjTBh1A+g81UVFcNDMuJsbPIIiYI 1pimZieAq0T6Vag00PKImKlkhJYfC7JVBbESij/NONlzYtPkbZ91Y+Ik4DZXnyZf 1TS4GbHQ25tjl73PkwlzLUcJIDIogsimSrkM+aWXPE8LmvrBEQs0LhAObPsAFtgL 1An3hvA2Tkhh9QgerWQd9YiqX994tv1PGRLBEXTbjh1yihzKSNleuvw3NdM+wf9i 9Y5l9IV6L2dtYBMLCpzkiGQBDdOzoq+fObRnSgK6Kr1mfXot+MAlLrk9gCeWcq1b c2oU/imKWB4sZys21pTnjIxAIzzRDoGW40qXuibTW4DoAYaVHuEBPtphjMVCBCcQ sJaIVXpsChQ3vvtHOgllnInMjCnlXJ3Piqr4y5glTPxu9mZHdPr6VDpWdqRmvyr9 V7fRQztwXB3Td+SZVDD1yBqoXKlKCX4QPlLAqH3FI9s1WhDHcJePcoDJY0/QyXB1 IeQRlEwBBEZAYy/kr9/pwbZzXeh5V5dK6wAq8aT+thS22zl3nJbKjW//vN06+ib+ WAnHRSZ8iCbUX2cRVF1k+DCQOTi8QCbI6WTcLsgenLeSrbEuzilfgsrsvd6LHfjD oTODiiD9QInP2sBfknUp =tWsB -----END PGP SIGNATURE----- -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
