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notro / fbtft

Linux Framebuffer drivers for small TFT LCD display modules. Development has moved to https://git.kernel.org/cgit/linux/kernel/git/gregkh/staging.git/tree/drivers/staging/fbtft?h=staging-testing
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Multiple displays #51

Closed asmecher closed 10 years ago

asmecher commented 10 years ago

Hi! Thanks for your excellent work --

It says on in the documentation that "a driver can support more than one device." Does this mean that fbtft is working with multiple displays? I have two SSD1331s (I just submitted the driver in a pull request, based on the SSD1351 driver), each with its own CS line, but I'm not sure how/if FBTFT supports both. Could you describe this briefly?

notro commented 10 years ago

I haven't tried two displays with the same driver (only different drivers), but in theory it should work. fbtft_device however, can only register one device. When I tested with two displays, I added the SPI devices into the kernel (kernel build needed). This shows where to add this info: https://github.com/notro/fbtft/wiki/Build-kernel-and-fbtft-drivers#configure-devices

asmecher commented 10 years ago

Confirmed, thanks. It looks like it's not possible to run two of the same display using modules, but building it into the kernel using bcm2708_spi_devices worked.

asmecher commented 10 years ago

By the way, I don't think this is suitable for a pull request, but I've implemented an additional driver that allows for two SSD1331 displays to be supported by a single framebuffer device in above/below configuration for stereoscopic video. See https://github.com/asmecher/fbtft/commit/0283653dae7ac21f2961420253d3d77ed7fe8ad9 for the driver and http://cassettepunk.com/blog/2013/11/12/view-master-video-player-hacking/ for the whole project. Thanks again for your work on FBTFT!

notro commented 10 years ago

That's so cool :smile:

I have added it to the wiki: https://github.com/notro/fbtft/wiki/More-LCD-Modules#drivers-in-forked-repos