[U-Boot] [PATCH] mtd: spi: Add DM support to SH QSPI driver

[Jagan Teki <jagan@amarulasolutions.com>]

On Sun, Aug 26, 2018 at 4:07 PM, Marek Vasut <marek.vasut@gmail.com> wrote:
> On 08/26/2018 08:45 AM, Jagan Teki wrote:
>> On Sat, Aug 25, 2018 at 11:04 PM, Marek Vasut <marek.vasut@gmail.com> wrote:
>>> Add DM support to the SH QSPI driver while retaining non-DM support.
>>> The later is required as this driver is used in SPL which has a size
>>> limitation of 16 kiB.
>>>
>>> Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
>>> Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
>>> ---
>>>  drivers/spi/sh_qspi.c | 215 +++++++++++++++++++++++++++++++++++---------------
>>>  1 file changed, 150 insertions(+), 65 deletions(-)
>>>
>>> diff --git a/drivers/spi/sh_qspi.c b/drivers/spi/sh_qspi.c
>>> index e9123e2c39..64dfd748d6 100644
>>> --- a/drivers/spi/sh_qspi.c
>>> +++ b/drivers/spi/sh_qspi.c
>>> @@ -67,15 +67,12 @@ struct sh_qspi_regs {
>>>  };
>>>
>>>  struct sh_qspi_slave {
>>> +#ifndef CONFIG_DM_SPI
>>
>> We are trying to drop non-dm code as much as possible (with
>> MIGRATION.txt policy), how about adding PLTADATA or spi read glue code
>> or any other?
>
> The SPL on that board (silk) has 16 kiB limit, right now I am at 15500 B
> with gcc 7.x already, adding any more overhead will make it overflow. So
> while I'd like to have it all fancy DM and stuff, it's not possible.

How about having simple glue code for SPL, since it anyway used for
read in real?