On Fri, Sep 24, 2010 at 03:08:52PM +0800, Zhu Richard-R65037 wrote: > Hi Wolfram: > See my comments. BTW can't you get your mailer to quote like all others do? It is inconvenient to read this way. > > It would bring the conveniences to maintain stuff in the future if we > > separate them. > > If you can name these conveniences and they are convincing, we can keep > them seperate. At the moment, I don't see them (what doesn't mean they > don't exist) > [<Zhu Richard-r65037>] As Anton's description different eSDHC IP on the > i.MX and the PPC may have the different IC bugs or limitations. Sure thing. I don't see any problem with that as I don't want to merge them completely, but just to share the common parts. Fixups can be done in the specific part. > As I know that although in the i.MX SOC family, there are a few > differences between different SOCs. And the behaviors of SW driver may > be impacted by these differences. If you have even more incarnations of a similar core in the future to come, that is another reason to share those parts which are in common. Smaller differences can easily be handled in sdhci-esdhc-imx.c, I think. For example, if stuff like if (cpu_is_mx35()) quirks |= SDHCI_QUIRKS_NO_MULTIBLOCK; will do, why would you want to duplicate all the code covering the non-standard register layouts? Check the imx-spi driver how to handle variations of a similar core. > I'm afraid that the differences of eSDHC IP module between i.MX and PPC > maybe bigger and bigger in future. If the core of a future IMX99 might be too different, we can have a custom driver then, but for now, I think a common driver is the way to go. > BTW, the block size of the i.MX eSDHC is not forced to 2K size. Up to > now, the default 512byes per sector is used in FSL i.MX Linux BSP. It is forced to 2K, because it would be otherwise set to 4K (according to the cap-register) which is not conform to the spec 2.0. What is the advantage of 512 byte? > > And there is already one set of eSDHC driver for all the i.MX SOCs. > > I am confused: which set do you mean? > [<Zhu Richard-r65037>] The driver used for i.MX eSDHC. The one used by > i.MX35 in Linux kernel now, and the coming MX51 and so on. > It is better that one driver supports all i.MX SOC's eSDHC modules in > future (MX25, MX35, MX51, MX53...). ? Now I am totally confused. That is what I am aiming for :D My driver was mainly tested on MX35 back then, but was clearly intended to be for MX51. It was clearly mentioned in the subject "[PATCH 0/4] Adding support for esdhc on mx35/51". Frankly, I was hoping for a patchset from you adding the stuff you need for you MX51-board on top of mine, and not a completely new series. Will have a look at that now... Regards, Wolfram -- Pengutronix e.K. | Wolfram Sang | Industrial Linux Solutions | http://www.pengutronix.de/ |
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