mtd: make onenand/generic.c more generic

From: Magnus Damm <damm@igel.co.jp>

This patch removes the ARM dependency from the generic "onenand"
platform device driver. This change makes the driver useful for
other architectures as well. Needed for the SuperH kfr2r09 board.

Apart from the obvious Kconfig bits, the most important change
is the move away from ARM specific includes and platform data.
Together with this change the only in-tree board code gets an
update, and the driver name is also changed gracefully break
potential out of tree drivers.

The driver is also updated to allow NULL as platform data together
with a few changes to make use of resource_size() and dev_name().

Signed-off-by: Magnus Damm <damm@igel.co.jp>
---

 Tested on the sh7724 kfr2r09 board with a separate platform data patch.

 arch/arm/mach-omap2/board-apollon.c |    4 ++--
 drivers/mtd/onenand/Kconfig         |    1 -
 drivers/mtd/onenand/generic.c       |   24 ++++++++++++++----------
 include/linux/mtd/onenand.h         |    8 ++++++++
 4 files changed, 24 insertions(+), 13 deletions(-)

Hi

Good idea add the onenand_platform_data, but dont' agree the renaming
the onenand-flash.
Other boards are use it even though it's not released it

Others are good.

Thank you,
Kyungmin Park

On Tue, Aug 4, 2009 at 6:20 PM, Magnus Damm<magnus.damm@gmail.com> wrote:
> From: Magnus Damm <damm@igel.co.jp>
>
> This patch removes the ARM dependency from the generic "onenand"
> platform device driver. This change makes the driver useful for
> other architectures as well. Needed for the SuperH kfr2r09 board.
>
> Apart from the obvious Kconfig bits, the most important change
> is the move away from ARM specific includes and platform data.
> Together with this change the only in-tree board code gets an
> update, and the driver name is also changed gracefully break
> potential out of tree drivers.
>
> The driver is also updated to allow NULL as platform data together
> with a few changes to make use of resource_size() and dev_name().
>
> Signed-off-by: Magnus Damm <damm@igel.co.jp>
> ---
>
>  Tested on the sh7724 kfr2r09 board with a separate platform data patch.
>
>  arch/arm/mach-omap2/board-apollon.c |    4 ++--
>  drivers/mtd/onenand/Kconfig         |    1 -
>  drivers/mtd/onenand/generic.c       |   24 ++++++++++++++----------
>  include/linux/mtd/onenand.h         |    8 ++++++++
>  4 files changed, 24 insertions(+), 13 deletions(-)
>
> --- 0001/arch/arm/mach-omap2/board-apollon.c
> +++ work/arch/arm/mach-omap2/board-apollon.c    2009-08-04 17:01:18.000000000 +0900
> @@ -87,7 +87,7 @@ static struct mtd_partition apollon_part
>        },
>  };
>
> -static struct flash_platform_data apollon_flash_data = {
> +static struct onenand_platform_data apollon_flash_data = {
>        .parts          = apollon_partitions,
>        .nr_parts       = ARRAY_SIZE(apollon_partitions),
>  };
> @@ -99,7 +99,7 @@ static struct resource apollon_flash_res
>  };
>
>  static struct platform_device apollon_onenand_device = {
> -       .name           = "onenand",
> +       .name           = "onenand-flash",
>        .id             = -1,
>        .dev            = {
>                .platform_data  = &apollon_flash_data,
> --- 0001/drivers/mtd/onenand/Kconfig
> +++ work/drivers/mtd/onenand/Kconfig    2009-08-04 17:01:18.000000000 +0900
> @@ -23,7 +23,6 @@ config MTD_ONENAND_VERIFY_WRITE
>
>  config MTD_ONENAND_GENERIC
>        tristate "OneNAND Flash device via platform device driver"
> -       depends on ARM
>        help
>          Support for OneNAND flash via platform device driver.
>
> --- 0001/drivers/mtd/onenand/generic.c
> +++ work/drivers/mtd/onenand/generic.c  2009-08-04 17:12:00.000000000 +0900
> @@ -19,12 +19,16 @@
>  #include <linux/mtd/mtd.h>
>  #include <linux/mtd/onenand.h>
>  #include <linux/mtd/partitions.h>
> -
>  #include <asm/io.h>
> -#include <asm/mach/flash.h>
> -
> -#define DRIVER_NAME    "onenand"
>
> +/*
> + * Note: Driver name and platform data format have been updated!
> + *
> + * This version of the driver is named "onenand-flash" and takes struct
> + * onenand_platform_data as platform data. The old ARM-specific version
> + * with the name "onenand" used to take struct flash_platform_data.
> + */
> +#define DRIVER_NAME    "onenand-flash"
>
>  #ifdef CONFIG_MTD_PARTITIONS
>  static const char *part_probes[] = { "cmdlinepart", NULL,  };
> @@ -39,16 +43,16 @@ struct onenand_info {
>  static int __devinit generic_onenand_probe(struct platform_device *pdev)
>  {
>        struct onenand_info *info;
> -       struct flash_platform_data *pdata = pdev->dev.platform_data;
> +       struct onenand_platform_data *pdata = pdev->dev.platform_data;
>        struct resource *res = pdev->resource;
> -       unsigned long size = res->end - res->start + 1;
> +       unsigned long size = resource_size(res);
>        int err;
>
>        info = kzalloc(sizeof(struct onenand_info), GFP_KERNEL);
>        if (!info)
>                return -ENOMEM;
>
> -       if (!request_mem_region(res->start, size, pdev->dev.driver->name)) {
> +       if (!request_mem_region(res->start, size, dev_name(&pdev->dev))) {
>                err = -EBUSY;
>                goto out_free_info;
>        }
> @@ -59,7 +63,7 @@ static int __devinit generic_onenand_pro
>                goto out_release_mem_region;
>        }
>
> -       info->onenand.mmcontrol = pdata->mmcontrol;
> +       info->onenand.mmcontrol = pdata ? pdata->mmcontrol : 0;
>        info->onenand.irq = platform_get_irq(pdev, 0);
>
>        info->mtd.name = dev_name(&pdev->dev);
> @@ -75,7 +79,7 @@ static int __devinit generic_onenand_pro
>        err = parse_mtd_partitions(&info->mtd, part_probes, &info->parts, 0);
>        if (err > 0)
>                add_mtd_partitions(&info->mtd, info->parts, err);
> -       else if (err <= 0 && pdata->parts)
> +       else if (err <= 0 && pdata && pdata->parts)
>                add_mtd_partitions(&info->mtd, pdata->parts, pdata->nr_parts);
>        else
>  #endif
> @@ -99,7 +103,7 @@ static int __devexit generic_onenand_rem
>  {
>        struct onenand_info *info = platform_get_drvdata(pdev);
>        struct resource *res = pdev->resource;
> -       unsigned long size = res->end - res->start + 1;
> +       unsigned long size = resource_size(res);
>
>        platform_set_drvdata(pdev, NULL);
>
> --- 0001/include/linux/mtd/onenand.h
> +++ work/include/linux/mtd/onenand.h    2009-08-04 17:01:18.000000000 +0900
> @@ -214,4 +214,12 @@ unsigned onenand_block(struct onenand_ch
>  loff_t onenand_addr(struct onenand_chip *this, int block);
>  int flexonenand_region(struct mtd_info *mtd, loff_t addr);
>
> +struct mtd_partition;
> +
> +struct onenand_platform_data {
> +       void            (*mmcontrol)(struct mtd_info *mtd, int sync_read);
> +       struct mtd_partition *parts;
> +       unsigned int    nr_parts;
> +};
> +
>  #endif /* __LINUX_MTD_ONENAND_H */
> --
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>

Hi Kyungmin!

> On Tue, Aug 4, 2009 at 6:20 PM, Magnus Damm<magnus.damm@gmail.com> wrote:
>> From: Magnus Damm <damm@igel.co.jp>
>>
>> This patch removes the ARM dependency from the generic "onenand"
>> platform device driver. This change makes the driver useful for
>> other architectures as well. Needed for the SuperH kfr2r09 board.

On Wed, Aug 5, 2009 at 1:24 PM, Kyungmin Park<kmpark@infradead.org> wrote:
> Good idea add the onenand_platform_data, but dont' agree the renaming
> the onenand-flash.
> Other boards are use it even though it's not released it

I suspected so. But this is the only reason why changed the name. =)

If we don't change the name then the platform device will be attached
to the platform driver as usual, but the old platform data structure
will use a different binary format compated to what the driver
expects.

Changing the driver name makes sure that the old device disappears and
that people can move over to the new name and at the same time update
the platform data to the new format.

> Others are good.

Thanks.

I can post an updated version where I keep the driver name unchanged
if you prefer that. But I'm pretty sure out-of-tree drivers will break
with NULL pointer accesses or similar if we update the platform data
format without changing the name. I don't think you want that. =)

Cheers,

/ magnus

On Wed, Aug 5, 2009 at 1:41 PM, Magnus Damm<magnus.damm@gmail.com> wrote:
>> On Tue, Aug 4, 2009 at 6:20 PM, Magnus Damm<magnus.damm@gmail.com> wrote:
>>> From: Magnus Damm <damm@igel.co.jp>
>>>
>>> This patch removes the ARM dependency from the generic "onenand"
>>> platform device driver. This change makes the driver useful for
>>> other architectures as well. Needed for the SuperH kfr2r09 board.
>
> On Wed, Aug 5, 2009 at 1:24 PM, Kyungmin Park<kmpark@infradead.org> wrote:
>> Good idea add the onenand_platform_data, but dont' agree the renaming
>> the onenand-flash.
>> Other boards are use it even though it's not released it
>
> I suspected so. But this is the only reason why changed the name. =)
>
> If we don't change the name then the platform device will be attached
> to the platform driver as usual, but the old platform data structure
> will use a different binary format compated to what the driver
> expects.
>
> Changing the driver name makes sure that the old device disappears and
> that people can move over to the new name and at the same time update
> the platform data to the new format.
>
>> Others are good.
>
> Thanks.
>
> I can post an updated version where I keep the driver name unchanged
> if you prefer that. But I'm pretty sure out-of-tree drivers will break
> with NULL pointer accesses or similar if we update the platform data
> format without changing the name. I don't think you want that. =)

Any update on this?

I posted a platform device patch for the kfr2r09 board to the linux-sh
list yesterday, so with that platform device patch and this driver
patch all in-tree users are converted.

Thanks in advance,

/ magnus

On Fri, Aug 07, 2009 at 02:28:01PM +0900, Magnus Damm wrote:
> On Wed, Aug 5, 2009 at 1:41 PM, Magnus Damm<magnus.damm@gmail.com> wrote:
> >> On Tue, Aug 4, 2009 at 6:20 PM, Magnus Damm<magnus.damm@gmail.com> wrote:
> >>> From: Magnus Damm <damm@igel.co.jp>
> >>>
> >>> This patch removes the ARM dependency from the generic "onenand"
> >>> platform device driver. This change makes the driver useful for
> >>> other architectures as well. Needed for the SuperH kfr2r09 board.
> >
> > On Wed, Aug 5, 2009 at 1:24 PM, Kyungmin Park<kmpark@infradead.org> wrote:
> >> Good idea add the onenand_platform_data, but dont' agree the renaming
> >> the onenand-flash.
> >> Other boards are use it even though it's not released it
> >
> > I suspected so. But this is the only reason why changed the name. =)
> >
> > If we don't change the name then the platform device will be attached
> > to the platform driver as usual, but the old platform data structure
> > will use a different binary format compated to what the driver
> > expects.
> >
> > Changing the driver name makes sure that the old device disappears and
> > that people can move over to the new name and at the same time update
> > the platform data to the new format.
> >
> >> Others are good.
> >
> > Thanks.
> >
> > I can post an updated version where I keep the driver name unchanged
> > if you prefer that. But I'm pretty sure out-of-tree drivers will break
> > with NULL pointer accesses or similar if we update the platform data
> > format without changing the name. I don't think you want that. =)
> 
> Any update on this?
> 
You have failed at reading your email:

http://lists.infradead.org/pipermail/linux-mtd/2009-August/026805.html
http://lists.infradead.org/pipermail/linux-mtd/2009-August/026809.html

On Fri, Aug 7, 2009 at 2:30 PM, Paul Mundt<lethal@linux-sh.org> wrote:
> On Fri, Aug 07, 2009 at 02:28:01PM +0900, Magnus Damm wrote:
>> On Wed, Aug 5, 2009 at 1:41 PM, Magnus Damm<magnus.damm@gmail.com> wrote:
>> >> On Tue, Aug 4, 2009 at 6:20 PM, Magnus Damm<magnus.damm@gmail.com> wrote:
>> >>> From: Magnus Damm <damm@igel.co.jp>
>> >>>
>> >>> This patch removes the ARM dependency from the generic "onenand"
>> >>> platform device driver. This change makes the driver useful for
>> >>> other architectures as well. Needed for the SuperH kfr2r09 board.
>> >
>> Any update on this?
>>
> You have failed at reading your email:
>
> http://lists.infradead.org/pipermail/linux-mtd/2009-August/026805.html
> http://lists.infradead.org/pipermail/linux-mtd/2009-August/026809.html

As usual, sorry about that. I'll solve that soon enough by signing off
with a different address.

/ magnus