On Mon, 17 Jun 2019 15:23:55 +0200 Marek Vasut marex@denx.de wrote:
On 6/17/19 2:27 PM, Lukasz Majewski wrote:
Hi Marek,
On 6/17/19 8:49 AM, Lukasz Majewski wrote:
Hi Marek,
On 6/16/19 12:34 AM, Lukasz Majewski wrote:
This commit converts mxs_spi driver to support DM/DTS.
Signed-off-by: Lukasz Majewski lukma@denx.de
Is the non-DM part needed for anything ?
Do you mean the non-DM part of the mxs_gpio driver? Yes, it is used by not converted boards.
This is a SPI driver though.
I recall the SPL jumps back to BootROM when loading the U-Boot proper. So if not, drop it.
Also, please don't do partial conversion for iMX28 only, do the iMX23 part as well, it cannot be hard.
Maybe it is not hard, but I cannot test it properly as I don't have i.MX23 device. If you are offering your help with testing (i.e. you do have the access to i.MX23 device and you will test those changes) I can add support for it.
Otherwise, NO, I will not add ANY new untested code.
In general, you don't have to add any code, the iMX23/28 SPI IP is very much the same hardware, DTTO for most of the other blocks. If there are any differences between iMX23/28, they are already handled in the existing driver(s).
Half-way converted drivers in fact increase maintenance burden, because then we have to deal with two different variants of the code, instead of only one.
I cannot agree with this sentence.
Do you think maintaining - one DM driver which supports both iMX23 and iMX28 - is more burden than maintaining - one driver which supports DM, but only for iMX28 and non-DM for iMX23 and iMX28 ? I don't think so.
The conversion would be done for i.MX28, which is then tested and validated (and clearly stated in the cover letter/commit message that only supported was i.MX28).> If I don't need to adjust common, reused code (which already supports both variants as it is the case with mxs_spi.c), then I don't mind.
Well, that is what I said above, you don't.
To make myself clear - If I can reuse the common code (which supports both imx23 and 28) for DM/DTS conversion then I'm OK with doing so.
If you require me to add untested code specific to i.MX23 - then NO.
For more intrusive changes - the driver needs to be tested and validated (by somebody who has the HW for testing).
That's up to board maintainers.
That's why I would like to see this practice go away wherever possible, and in this case it is possible.
In this particular case it is possible to add support for both as SoC specific changes (i.MX23 vs i.MX28) is performed in common code (e.g. mxs_spi_xfer_dma).
Both SPI and DMA blocks are basically the same on iMX23 and iMX28.
If I can reuse the common code, then I'm fine to do it.
If you need someone to test your changes, CC the board maintainers, that's standard practice.
As fair as I remember only Angelo and Michael had also interest in testing converted code for i.MX28 based board.
There was NO reply from other people when this (and few others) driver was marked as DEPRECATED.
Well, too bad, clearly the interest in this platform is low.
This means that people are using either some old U-Boot version, or there are a few people who want to refurbish the old HW with new code (e.g. Michael, Angelo).
That does not mean we should do sub-par upstream work, does it ?
We shall not add untested code.
Best regards,
Lukasz Majewski
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