On Sun, Dec 10, 2017 at 11:10 PM, David Lechner <david@xxxxxxxxxxxxxx> wrote: > This adds a new device tree binding for Sitronix ST7735R display panels, > such as the Adafruit 1.8" TFT. > > Signed-off-by: David Lechner <david@xxxxxxxxxxxxxx> > Acked-by: Rob Herring <robh@xxxxxxxxxx> (...) > Limor brought up an interesting point in an off-list discussion. The > same controller can be wired to the same LCD in different ways. This is > evident in the fbftf drivers in staging. There is an "adafruit18" and an > "adafruit18_green" in fbftf_devices.c where apparently, two otherwise > identical displays were wired slightly differently at the factory so that > on one, the on-board GRAM word 0 does not correspond to pixel 0,0 on the > LCD. It requires a special offset to the GRAM starting address in order to > have the image displayed correctly. > > Additionally, fbtft supports a SainSmart 1.8" TFT [3] that uses the same > controller, but it appears that these have different gamma curves (perhaps > they use different LCDs?). The available pins are exactly the same as the > Adafruit display though. This discussion came up in relation to the Ilitek ILI9322 bindings, here are some links: https://marc.info/?l=dri-devel&m=150300267811979&w=2 https://marc.info/?l=devicetree&m=150438702909506&w=2 https://marc.info/?l=dri-devel&m=150628542603682&w=2 The last mail from Rob clearly indicates that he doesn't like this kind of open-ended configuration data stashed up in the DTS. > There was a binding acked recently for the LCD on a D-Link DIR-685 Wireless > N Storage Router [8]. This uses the compound compatible string of "dlink, > dir-685-panel", "ilitek,ili9322". If we want to try to keep things > consistent, perhaps I should be adopting this pattern as well? I think so. > And perhaps > it would be better to use the better known vendor name instead of the > obscure vendors from the datasheets that I have found? For example, > "adafruit,618" "sitronix,st7735r" instead of "jianda,jd-t18003-t01"? I don't know this, just that it should be: "vendor,specific-system-config", "vendor,ip-part"; Yours, Linus Walleij -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
