On 10/25/2012 09:54 AM, Tomi Valkeinen wrote:
On 2012-10-25 17:31, Ricardo Neri wrote:
On 10/23/2012 11:29 PM, Tomi Valkeinen wrote:
On 2012-10-23 20:21, Ricardo Neri wrote:
If so, you could pass only that one address, instead of the whole HDMI
register space?
Yes, that could work. I thought about that but the common HDMI driver
would have to know the the IP-specific register, which it should not.
Argh, of course...
Perhaps the IP-specific register address can be passed by a IP-specific
function such as hdmi_get_audio_dma_port for the common HDMI driver to
populate the resource.
Btw, could this be another reason to convert the IP-specific libraries
to drivers?
Yes, I think it makes more and more sense to do that.
Even though this would allow our HDMI drivers to be more inline with
what other HDMI drivers do, things like power management and interrupts
are still handled by DSS, unlike x86, for instance [1][2]. So the audio
drivers will still depend on DSS. Also, the register layout is different
for OMAP5 and audio registers are even more scattered. Furthermore, the
common HDMI driver would have to know the IP-specific layout to know
what register spaces expose to the audio driver (another reason to have
IP-specific drivers?). So I would vote for continuing using the omapdss
audio interface.
Okay.
I think your approach is ok for the time being. I don't like passing the
whole register space to the audio driver, but that's the best we can do
with the current driver.
What about for now having a function in the IP library to be called from
the common driver to determine the address of the port? Something like[1]:
res = platform_get_resource_byname(hdmi.pdev,
IORESOURCE_MEM, "hdmi_wp");
aud_offset = hdmi.ip_data.ops->audio_get_dma_port_off();
aud_res[0].start = res->start + aud_offset;
aud_res[0].end = res->start + aud_offset + 3;
Yep, I think that looks quite clean. I wonder if there's a macro or func
to calculate the end position... It'd be more readable to set start and
size, instead if start and end.
I'll check.
Have you looked at converting to IP specific drivers? Any idea of the
effort? I'd like it to be done with the omap4 hdmi driver first, before
merging omap5 hdmi into the mainline, if at all possible.
As a first step, I have started implementing a separate driver for the
TPD12S015 as you suggested in the past. For converting the IP libraries
I'm not sure you can to the TPD as a separate driver currently. Or, at
least in the way I've imagined it to be. My thinking is that it should
be a "video entity" between OMAP's HDMI output and the HDMI monitor, but
we don't currently support these kind of chains. That's why I suggested
to just cleanly separate the TPD code in separate areas, and prefix the
funcs with tpd, etc.
What have you planned for it?
I was thinking that this driver would handle the LS_OE and the CT_CP_HDP
GPIOs and the HDP interrupt. Thus, the HDMI driver would call
tpd_ls_oe(1) instead of gpio_set_value. For the HPD interrupt, it would
call the HDMI driver to put the PHY in LDOON state. Of course, the
driver (or library or separate functions?) would get its info from the
DT or board data.
The interrupt would have to be handled with care to ensure that PHY is
never in TX when there is no cable attached.
For the DDC signals, only take care of the pull-up resistor settings.
Thus, my view of connecting the OMAP HDMI IP to the HDMI monitor is just
enabling the shifter or getting the HPD events.
into drivers, I still don't see how to keep them independent of omapdss
to be reusable by DaVinci platforms (but afaik they are not using our
libraries anyways). Maybe, a thin compatibility layer for omapdss (the
hdmi_panel)? I still don't have a clear idea. :/
Yeah, I think we need quite a bit of restructuring to convert the IP
libs to drivers. Or more precisely, redirections.
What I imagine we'd have is some kind of hdmi_ops struct, containing
function pointers for the operations. These calls would go to IP driver.
The IP driver would create this struct at probe time, and register
itself somewhere.
Could we have a sort of HDMI core driver? This is to serve as a hub of
the IP operations and a layer between the panel and the IP driver. The
IP driver would register with this driver. Also this core would handle
HDMI stuff that is specific to the protocol (e.g., N/CTS calculation,
Pclk vs TMDS clock for deep color, video timings, etc).
Then hdmi panel driver would get this hdmi_ops pointer from the place
where it was registered to, and use it to call the functions.
This would contain the omapdss specific stuff so that DaVinci can use
the HDMI core and IP drivers.
BR,
Ricardo
Tomi
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