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

[Jagan Teki]

On Sun, Sep 2, 2018 at 11:56 PM, Marek Vasut <marek.vasut at gmail.com> wrote:
> On 09/02/2018 08:00 PM, Jagan Teki wrote:
>> On Sun, Aug 26, 2018 at 4:07 PM, Marek Vasut <marek.vasut at 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 at 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 at gmail.com>
>>>>> Cc: Nobuhiro Iwamatsu <iwamatsu at 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?
>
> I'd prefer to use the same driver for both SPL and U-Boot instead of
> hacking stuff up. Not sure what exactly you mean by "glue" though.

Something that bypass spi stack and read the flash with local code,
this usually suited for low SRAM size like silk example
spl_spi_sunxi.c