The video DSI mode had not really been tested. These fixes makes
it more likely to work on real hardware:
- Put the active width (x width) in the right bits and the VSA
(vertical sync active) in the right bits (those were swapped).
- Calculate the packet sizes in bytes as in the vendor driver,
rather than in bits. Test the calculations agains a
spreadsheet and confirmed by debug prints to be reasonable.
- Also verified the register values with relative confidence
to register dumps from the Samsung GT-I8190 boot loader
graphics. We are not identical but not off by far either.
- Error out if the current mode and refresh frequency doesn't
work out. (In the future we may simply want to scale down
the vrefresh.)
- Handle negative result in front/back/sync packages and fall
back to zero like in the vendor driver.
- Put in lots of clarifying comments and references to the
documentation where the code is hard to understand.
- Set the DSI_VID_VCA_SETTING2 field
DSI_VID_VCA_SETTING2_MAX_LINE_LIMIT to blkline_pck - 6 as in
the vendor driver and mask the field properly.
- Set the DSI_VID_VCA_SETTING1 field
DSI_VID_VCA_SETTING1_MAX_BURST_LIMIT to blkeol_pck - 6 to
blkeol_duration - 6 as in the vendor driver.
Cc: Stephan Gerhold <stephan@gerhold.net>
Fixes: 5fc537bfd0 ("drm/mcde: Add new driver for ST-Ericsson MCDE")
Link: https://patchwork.freedesktop.org/patch/msgid/20191217150959.17215-1-linus.walleij@linaro.org
Reviewed-by: Stephan Gerhold <stephan@gerhold.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Triggering an error conditions in DSI video mode only results in
a very generic "some video mode error status" error message
at the moment.
Make this more clear by adding separate error messages for each bit.
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20191106165835.2863-4-stephan@gerhold.net
This adds a new DRM driver for the ST-Ericsson Multi Channel
Display Engine, MCDE display controller.
This hardware has three independent DSI hosts and can composit
and display several memory buffers onto an LCD display. It
was developed for several years inside of ST-Ericsson and
shipped with a few million mobile phones from Sony and Samsung,
as well as with the Snowball community development board.
The driver is currently pretty rudimentary but supports a
simple framebuffer so we can get penguins and graphics when
using these SoCs.
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190524092019.19355-1-linus.walleij@linaro.org
