On Thu, 20 May 2010, Tomi Valkeinen wrote: > On Thu, 2010-05-20 at 10:07 +0200, ext Guennadi Liakhovetski wrote: > > > Yes, right, I should have said "they are related";) How about calling the > > header mipi_display.h? This would then unite DSI, DCS, DBI and DPI? > > Creating a separate header for each of these standards seems like an > > overkill to me. We could then put MIPI CSI and CPI standards in an > > include/media/mipi_camera.h. Not sure where to put various other MIPI > > standards, I guess, we'll have to think about it as a need arises. > > mipi_display.h sounds good to me. > > > > Well, true, this is not a clear thing. MIPI DSI spec talks about "turn > > > on peripheral command". But the numbers are DSI data types, according to > > > the spec, and not all of them are commands. > > > > Ok, how about "telegram types" then? > > I wouldn't invent a new word for this =). The DSI spec talks about > commands, data types and transactions, I think we should pick one of > them. > > Perhaps this is already approaching nitpicking, but: > > As only some of the commands/datatypes/transactions are commands, I > think that's not proper word. All of them have a data type number, and I > guess they all are transactions. So "Turn On Peripheral Command" is a > transaction, and its data type is 0x32. Yes, transaction looks good to me. > I guess if the enum is named, it should then be mipi_dsi_transaction. > > But then, which one of these would be more correct: > > dsi_send(enum mipi_dsi_transaction transaction) > dsi_send(u8 datatype) > > As I said previously, I haven't seen any panel using custom datatypes, > but I wouldn't be surprised if some panel does. In that sense I would go > for using u8, and then perhaps leaving the enum unnamed. > > What do you think? Yes, I'd use u8 too, because the specs define "transaction types" to take 6 bits and "DCS commands" to be 8-bit ints. But, you know, doesn't our case fall under case (b) of Chapter 5 "Typedefs" of CodingStyle?:) I mean, wouldn't it make sense to create two typedefs for these to add some type-safety? In fact, transaction types cannot be user-defined / proprietary, right? So, for that an enum would work. It's only DCS commands that allow extensions. But making transaction type an enum and command a typedef would be ugly, and making a typedef for an enum is frowned upon too... > > As others voted for unnamed enums, how about using them? > > Sounds good. > > > Concerning omap2 display drivers, AFAICS the only thing we want to change > > there is to switch them too to using the common header and telegram type > > Yep, I think that's the only change for now. > > > and command names? So far I don't see a need for a generic MIPI (display) > > subsystem in the kernel with an own bus type, API etc. We could of course > > create a simpe bus with callbacks for sending short and long packets and > > reading data back, but do we really need it ATM? > > This is something I've been thinking about for some time. I even made > some prototypes for it, but I didn't have time to go forward with it. > > It would of course be nice to use the same panel driver on different > boards, so I think this is definitely something to think about in the > future. But you only need specific panel drivers if you want to support their proprietary commands? Otherwise you only need a set of parameters - timeing requirements etc. - which you can perfectly just pass in platform data? Thanks Guennadi --- Guennadi Liakhovetski, Ph.D. Freelance Open-Source Software Developer http://www.open-technology.de/ -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
