[U-Boot] [PATCH] mtd: zynq: nand: Move board_nand_init() function to board.c

[Ezequiel Garcia]

Hi Wilson,

On 8 November 2017 at 06:24, Wilson Lee <wilson.lee at ni.com> wrote:
> Hi Michal,
>
> On Wed, 2017-11-08 at 08:54 +0100, Michal Simek wrote:
>> On 8.11.2017 03:44, Wilson Lee wrote:
>> >
>> > Putting board_nand_init() function inside NAND driver was not
>> > appropriate
>> > due to it doesn't allow board vendor to customise their NAND
>> > initialization code such as adding NAND lock/unlock code.
>> >
>> > This commit was to move the board_nand_init() function from NAND
>> > driver
>> > to board.c file. This allow customization of board_nand_init()
>> > function.
>> >
>> > Signed-off-by: Wilson Lee <wilson.lee at ni.com>
>> > Cc: Joe Hershberger <joe.hershberger at ni.com>
>> > Cc: Keng Soon Cheah <keng.soon.cheah at ni.com>
>> > Cc: Chen Yee Chew <chen.yee.chew at ni.com>
>> > Cc: Albert Aribaud <albert.u.boot at aribaud.net>
>> > Cc: Michal Simek <michal.simek at xilinx.com>
>> > Cc: Siva Durga Prasad Paladugu <siva.durga.paladugu at xilinx.com>
>> > Cc: Scott Wood <oss at buserror.net>
>> > ---
>> >  arch/arm/mach-zynq/include/mach/nand.h |  9 +++++++++
>> >  board/xilinx/zynq/board.c              | 10 ++++++++++
>> >  drivers/mtd/nand/zynq_nand.c           | 12 +-----------
>> >  3 files changed, 20 insertions(+), 11 deletions(-)
>> >  create mode 100644 arch/arm/mach-zynq/include/mach/nand.h
>> >
>> > diff --git a/arch/arm/mach-zynq/include/mach/nand.h
>> > b/arch/arm/mach-zynq/include/mach/nand.h
>> > new file mode 100644
>> > index 0000000..61ef45f
>> > --- /dev/null
>> > +++ b/arch/arm/mach-zynq/include/mach/nand.h
>> > @@ -0,0 +1,9 @@
>> > +/*
>> > + * Copyright (C) 2017 National Instruments Corp.
>> > + *
>> > + * SPDX-License-Identifier:        GPL-2.0+
>> > + */
>> > +
>> > +#include <nand.h>
>> > +
>> > +void zynq_nand_init(void);
>> > diff --git a/board/xilinx/zynq/board.c b/board/xilinx/zynq/board.c
>> > index 90ef542..8bcb830 100644
>> > --- a/board/xilinx/zynq/board.c
>> > +++ b/board/xilinx/zynq/board.c
>> > @@ -9,6 +9,7 @@
>> >  #include <fpga.h>
>> >  #include <mmc.h>
>> >  #include <zynqpl.h>
>> > +#include <asm/arch/nand.h>
>> >  #include <asm/arch/hardware.h>
>> >  #include <asm/arch/sys_proto.h>
>> >
>> > @@ -156,3 +157,12 @@ int dram_init(void)
>> >     return 0;
>> >  }
>> >  #endif
>> > +
>> > +static struct nand_chip nand_chip[CONFIG_SYS_MAX_NAND_DEVICE];
>> > +void board_nand_init(void)
>> > +{
>> > +   struct nand_chip *nand = &nand_chip[0];
>> > +
>> > +   if (zynq_nand_init(nand, 0))
>> > +           puts("ZYNQ NAND init failed\n");
>> > +}
>> This is probably not enough for platforms which don't enable NAND.
>>
>> >
>> > diff --git a/drivers/mtd/nand/zynq_nand.c
>> > b/drivers/mtd/nand/zynq_nand.c
>> > index dec2c41..9be6856 100644
>> > --- a/drivers/mtd/nand/zynq_nand.c
>> > +++ b/drivers/mtd/nand/zynq_nand.c
>> > @@ -1006,7 +1006,7 @@ static int zynq_nand_device_ready(struct
>> > mtd_info *mtd)
>> >     return 0;
>> >  }
>> >
>> > -static int zynq_nand_init(struct nand_chip *nand_chip, int devnum)
>> > +int zynq_nand_init(struct nand_chip *nand_chip, int devnum)
>> >  {
>> >     struct zynq_nand_info *xnand;
>> >     struct mtd_info *mtd;
>> > @@ -1191,13 +1191,3 @@ fail:
>> >     free(xnand);
>> >     return err;
>> >  }
>> > -
>> > -static struct nand_chip nand_chip[CONFIG_SYS_MAX_NAND_DEVICE];
>> > -
>> > -void board_nand_init(void)
>> > -{
>> > -   struct nand_chip *nand = &nand_chip[0];
>> > -
>> > -   if (zynq_nand_init(nand, 0))
>> > -           puts("ZYNQ NAND init failed\n");
>> > -}
>> >
>> What's the sequence which you want to add?
>
> Actually we wish to perform a NAND unlock right after the NAND was
> begin initialized. So that, we can do some write operation (ubifs table
> R/W) when we mount it as ubifs.
>

Why do you need to export board_nand_init
in order to add do a NAND unlock after NAND initialization?

Perhaps you could point me at your U-Boot repo to see
what you need exactly.

I'm seeing at least two ways of doing this:

1) Using a script that calls nand unlock command
and then does the UBIFS stuff.

2) Using board_late_init like this:

static void unlock_nand(void)
{
        int dev = nand_curr_device;
        struct mtd_info *mtd;

        mtd = get_nand_dev_by_index(dev);
        nand_unlock(mtd, 0, mtd->size, 0);
}

int board_late_init(void)
{
        /* some other stuff .... */

        unlock_nand();
}

To be honest, I dislike this patch quite a bit,
because it's code meant for out-of-tree ports.

We tend to avoid keeping infra for out-of-tree code,
because it makes the code hard to improve or cleanup
without breaking the out-of-tree port doing so.

>> Isn't it better just to include this there or create a hook here?
>
> I was thinking for adding a hook here before. But, it will be more make
> sense to me if we correct the NAND driver by moving board_nand to
> board.c file.
>
>>
>> Definitely some platforms moved this to board file and not a problem
>> with moving it because it shouldn't be in nand driver.
>>
>> Thanks,
>> Michal
>>
>
> Thanks, Michal.
>
> Best Regards,
> Wilson Lee
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-- 
Ezequiel García, VanguardiaSur
www.vanguardiasur.com.ar