[U-Boot] [PATCH] mmc: Tinification of the mmc code

[Simon Glass]

Hi Marek,

On 26 May 2016 at 12:41, Marek Vasut <marex at denx.de> wrote:
> Add new configuration option CONFIG_MMC_TINY which strips away all
> memory allocation within the MMC code and code for handling multiple
> cards. This allows extremely space-constrained SPL code use the MMC
> framework.
>
> Signed-off-by: Marek Vasut <marex at denx.de>
> Cc: Tom Rini <trini at konsulko.com>
> Cc: Simon Glass <sjg at chromium.org>
> ---
>  common/spl/spl_mmc.c |  4 ++++
>  drivers/mmc/Makefile |  2 ++
>  drivers/mmc/mmc.c    | 59 +++++++++++++++++++++++++++++++++++++++++++++++++++-
>  include/mmc.h        |  1 +
>  4 files changed, 65 insertions(+), 1 deletion(-)

Can CONFIG_MMC_TINY be a Kconfig? Also I suggest CONFIG_SPL_MMC_TINY.

>
> diff --git a/common/spl/spl_mmc.c b/common/spl/spl_mmc.c
> index ae42221..51f0f24 100644
> --- a/common/spl/spl_mmc.c
> +++ b/common/spl/spl_mmc.c
> @@ -300,7 +300,11 @@ int spl_mmc_load_image(u32 boot_device)
>                         if (part == 7)
>                                 part = 0;
>
> +#ifdef CONFIG_MMC_TINY

if (CONFIG_IS_ENABLED(MMC_TINY))

to avoid #ifdef

> +                       err = mmc_switch_part(mmc, part);
> +#else
>                         err = blk_dselect_hwpart(mmc_get_blk_desc(mmc), part);
> +#endif
>                         if (err) {
>  #ifdef CONFIG_SPL_LIBCOMMON_SUPPORT
>                                 puts("spl: mmc partition switch failed\n");
> diff --git a/drivers/mmc/Makefile b/drivers/mmc/Makefile
> index 3da4817..4d986cb 100644
> --- a/drivers/mmc/Makefile
> +++ b/drivers/mmc/Makefile
> @@ -10,8 +10,10 @@ obj-$(CONFIG_GENERIC_MMC) += mmc-uclass.o
>  endif
>
>  ifndef CONFIG_BLK
> +ifndef CONFIG_MMC_TINY
>  obj-$(CONFIG_GENERIC_MMC) += mmc_legacy.o
>  endif
> +endif
>
>  obj-$(CONFIG_ARM_PL180_MMCI) += arm_pl180_mmci.o
>  obj-$(CONFIG_ATMEL_SDHCI) += atmel_sdhci.o
> diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
> index d687345..1f240ed 100644
> --- a/drivers/mmc/mmc.c
> +++ b/drivers/mmc/mmc.c
> @@ -21,6 +21,29 @@
>  #include <div64.h>
>  #include "mmc_private.h"
>
> +#if defined(CONFIG_MMC_TINY)
> +static struct mmc mmc_static;
> +struct mmc *find_mmc_device(int dev_num)
> +{
> +       return &mmc_static;
> +}
> +
> +void mmc_do_preinit(void)
> +{
> +       struct mmc *m = &mmc_static;
> +#ifdef CONFIG_FSL_ESDHC_ADAPTER_IDENT
> +       mmc_set_preinit(m, 1);
> +#endif
> +       if (m->preinit)
> +               mmc_start_init(m);
> +}
> +
> +struct blk_desc *mmc_get_blk_desc(struct mmc *mmc)
> +{
> +       return &mmc->block_dev;
> +}
> +#endif
> +
>  __weak int board_mmc_getwp(struct mmc *mmc)
>  {
>         return -1;
> @@ -238,7 +261,11 @@ static ulong mmc_bread(struct blk_desc *block_dev, lbaint_t start,
>         if (!mmc)
>                 return 0;
>
> +#ifdef CONFIG_MMC_TINY
> +       err = mmc_switch_part(mmc, block_dev->hwpart);
> +#else
>         err = blk_dselect_hwpart(block_dev, block_dev->hwpart);
> +#endif
>         if (err < 0)
>                 return 0;
>
> @@ -568,7 +595,7 @@ static int mmc_set_capacity(struct mmc *mmc, int part_num)
>         return 0;
>  }
>
> -static int mmc_switch_part(struct mmc *mmc, unsigned int part_num)
> +int mmc_switch_part(struct mmc *mmc, unsigned int part_num)
>  {
>         int ret;
>
> @@ -1585,6 +1612,34 @@ int mmc_unbind(struct udevice *dev)
>         return 0;
>  }
>
> +#elif defined(CONFIG_MMC_TINY)
> +static struct mmc mmc_static = {
> +       .dsr_imp                = 0,
> +       .dsr                    = 0xffffffff,
> +       .block_dev = {
> +               .if_type        = IF_TYPE_MMC,
> +               .removable      = 1,
> +               .devnum         = 0,
> +               .block_read     = mmc_bread,
> +               .block_write    = mmc_bwrite,
> +               .block_erase    = mmc_berase,
> +               .part_type      = 0,
> +       },
> +};
> +
> +struct mmc *mmc_create(const struct mmc_config *cfg, void *priv)
> +{
> +       struct mmc *mmc = &mmc_static;
> +
> +       mmc->cfg = cfg;
> +       mmc->priv = priv;
> +
> +       return mmc;
> +}
> +
> +void mmc_destroy(struct mmc *mmc)
> +{
> +}
>  #else
>  struct mmc *mmc_create(const struct mmc_config *cfg, void *priv)
>  {
> @@ -1834,8 +1889,10 @@ int mmc_initialize(bd_t *bis)
>         initialized = 1;
>
>  #ifndef CONFIG_BLK
> +#ifndef CONFIG_MMC_TINY
>         mmc_list_init();
>  #endif
> +#endif
>         ret = mmc_probe(bis);
>         if (ret)
>                 return ret;
> diff --git a/include/mmc.h b/include/mmc.h
> index a5c6573..08a59c2 100644
> --- a/include/mmc.h
> +++ b/include/mmc.h
> @@ -444,6 +444,7 @@ struct mmc *find_mmc_device(int dev_num);
>  int mmc_set_dev(int dev_num);
>  void print_mmc_devices(char separator);
>  int get_mmc_num(void);
> +int mmc_switch_part(struct mmc *mmc, unsigned int part_num);
>  int mmc_hwpart_config(struct mmc *mmc, const struct mmc_hwpart_conf *conf,
>                       enum mmc_hwpart_conf_mode mode);
>  int mmc_getcd(struct mmc *mmc);
> --
> 2.7.0
>

This is partially undoing the legacy block device work. How much does
this patch save?

Regards,
Simon