On 18 April 2014 17:40, Tony Lindgren <tony@xxxxxxxxxxx> wrote: > * Joachim Eastwood <manabian@xxxxxxxxx> [140418 04:05]: >> On 18 April 2014 04:50, Tony Lindgren <tony@xxxxxxxxxxx> wrote: >> > * Tony Lindgren <tony@xxxxxxxxxxx> [140417 15:50]: >> >> * Joachim Eastwood <manabian@xxxxxxxxx> [140417 13:51]: >> >> > On 17 April 2014 21:22, Tony Lindgren <tony@xxxxxxxxxxx> wrote: >> >> > > * Joachim Eastwood <manabian@xxxxxxxxx> [140417 11:05]: >> >> > >> Hi Tomi, >> >> > >> >> >> > >> My VAR-DVK-OM44 (OMAP4460) has both a HDMI and a LCD panel. As HDMI is >> >> > >> now working (thanks) I also taken a look at panel-dpi. >> >> > >> >> >> > >> I found the DT patch for panel-dpi on the mailing list. >> >> > >> OMAPDSS: panel-dpi: Add DT support: >> >> > >> http://marc.info/?l=devicetree&m=139030201815380&w=2 >> >> > >> >> >> > >> And I got my display working with DT :) >> >> > >> So you add can my: Tested-by: Joachim Eastwood <manabian@xxxxxxxxx> >> >> > >> >> >> > >> Could you upstream the panel-dpi DT support and the HDMI connector >> >> > >> gpio hpd patch in 3.16? >> >> > >> I hope it's easier to upstream the stuff when it gets some users in DT. >> >> > > >> >> > > Good to hear. The DPI panel support should use gpio-backlight >> >> > > driver as discussed in the DPI thread. Did you have to patch >> >> > > anything for the timings etc? >> >> > >> >> > The only driver patches I use are those two from Tomi mentioned above. >> >> > (panel-dpi DT support and HDMI connector gpio-hpd) >> >> > >> >> > > If you have the board working, care to take a look at making >> >> > > the gpio-backlight change? >> >> > >> >> > I am already using the gpio-backlight driver. >> >> >> >> OK great, so then we can just drop that GPIO backlight handling >> >> from the DPI DT patch I presume. >> >> >> >> > You can take a look at the device tree for VAR-DVK-OM44 here: >> >> > http://slexy.org/raw/s2Pz4BELGe >> >> > >> >> > I'll post the patch set on list tomorrow. >> >> >> >> Thanks for the link, that pretty much clarifies all the parts >> >> I was wondering about. >> > >> > OK so based on the link above, I got the LDP panel DPI working with >> > the quirks now shrunk to the two panel specific GPIOs. >> > >> > Probably best to set those up based on "omapdss,panel-dpi-ldp" >> > compatible flag? >> > >> > That is after removing the backlight_gpio from panel_dpi_probe_of() >> > so the panel specific GPIOs can be handled easily based on the >> > compatible flag. Current work in progress patch below for reference >> > in case anybody has better ideas for dealing with the remaining >> > to GPIOs. >> >> A reset gpio could be useful on more panels I think. >> omapdss,panel-dsi-cm already have a reset-gpios property so maybe >> omapdss,panel-dpi should have one too. > > OK. For handling the GPIOs, looks like gpio_backlight_probe_dt > is doing: > > gbl->active = (gpio_flags & OF_GPIO_ACTIVE_LOW) ? 0 : 1 > > To handle the polarity. We should probably do the same for the > panels as we at least used to have the polarity flags in the > platform data earlier. Yes, that sounds good. >> A lot of panels have mode pins, but usually these are hard coded on >> the circuit board. >> If it's just a bunch of static gpio values that need to be set maybe >> you could have something like this: >> mode-gpios = <&gpio1 10 0 &gpio1 11 0>; >> mode-gpios-values = <1 1>; >> >> Driver would set these gpios to values at init. > > If mode-gpios can be is Linux generic, then it makes sense to add > it. But if it's specific to this panel, I'd like to avoid setting > up yet another custom DT *-gpios property.. > > In any case, with (gpio_flags & OF_GPIO_ACTIVE_LOW) mode-gpio-values > should not be needed. Yes, that's a good idea. > If it does not make sense to set up a generic mode-gpios for the > panels, then panel dpi can parse the first two GPIOs for enable > and reset. Then we can allow the rest of the array be parsed if > needed based on the compatible flag. Looking through the panels in omap2/display-new the most common gpio pins are; backlight, reset and enable. So it makes sense to have enable and reset as properties. Gpio is used for mode setting in: nl8048hl11 and ls037v7dw01. nl8048hl11 has just a qvga gpio, while the other one has no less than 3 mode pins (qvga and 2 scanning direction pins). All these mode pins are set once and then never touched again. Using gpios property for setting up an arbitrary amount of mode pins so like a solution to me. regards Joachim Eastwood -- 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
