[PATCH] cmd: mmc: Add mmc reg read command for reading card registers

Michael Nazzareno Trimarchi michael at amarulasolutions.com
Sat Jun 20 14:35:08 CEST 2020


Hi

On Sat, Jun 20, 2020 at 2:30 PM Marek Vasut <marex at denx.de> wrote:
>
> Add extension to the 'mmc' command to read out the card registers.
> Currently, only the eMMC OCR/CID/CSD/EXTCSD/RCA/DSR register are
> supported. A register value can either be displayed or read into
> an environment variable.
>
> Signed-off-by: Marek Vasut <marex at denx.de>
> ---
>  cmd/Kconfig |  8 +++++
>  cmd/mmc.c   | 94 +++++++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 102 insertions(+)
>
> diff --git a/cmd/Kconfig b/cmd/Kconfig
> index 192b3b262f..a0cf03c911 100644
> --- a/cmd/Kconfig
> +++ b/cmd/Kconfig
> @@ -1104,6 +1104,14 @@ config CMD_BKOPS_ENABLE
>           on a eMMC device. The feature is optionally available on eMMC devices
>           conforming to standard >= 4.41.
>
> +config CMD_MMC_REG
> +       bool "Enable support for reading card registers in the mmc command"
> +       depends on CMD_MMC
> +       default y
> +       help
> +         Enable the commands for reading card registers. This is useful
> +         mostly for debugging or extracting details from the card.
> +
>  config CMD_MMC_RPMB
>         bool "Enable support for RPMB in the mmc command"
>         depends on SUPPORT_EMMC_RPMB
> diff --git a/cmd/mmc.c b/cmd/mmc.c
> index 1529a3e05d..55fbfe822e 100644
> --- a/cmd/mmc.c
> +++ b/cmd/mmc.c
> @@ -912,6 +912,93 @@ static int do_mmc_bkops_enable(struct cmd_tbl *cmdtp, int flag,
>  }
>  #endif
>
> +#if CONFIG_IS_ENABLED(CMD_MMC_REG)
> +static int do_mmc_reg(struct cmd_tbl *cmdtp, int flag,
> +                        int argc, char *const argv[])
> +{
> +       ALLOC_CACHE_ALIGN_BUFFER(u8, ext_csd, MMC_MAX_BLOCK_LEN);
> +       struct mmc *mmc;
> +       int i, ret;
> +       u32 off;
> +
> +       if (argc < 3 || argc > 5)
> +               return CMD_RET_USAGE;
> +
> +       mmc = find_mmc_device(curr_device);
> +       if (!mmc) {
> +               printf("no mmc device at slot %x\n", curr_device);
> +               return CMD_RET_FAILURE;
> +       }
> +
> +       if (IS_SD(mmc)) {
> +               printf("SD registers are not supported\n");
> +               return CMD_RET_FAILURE;
> +       } else {

else is not needed

> +               off = simple_strtoul(argv[3], NULL, 10);
> +               if (!strcmp(argv[2], "cid")) {
> +                       if (off > 1)
> +                               return CMD_RET_USAGE;
> +                       printf("CID[%i]: 0x%08x\n", off, mmc->cid[off]);
> +                       if (argv[4])
> +                               env_set_hex(argv[4], mmc->cid[off]);
> +                       return CMD_RET_SUCCESS;
> +               }
> +               if (!strcmp(argv[2], "csd")) {
> +                       if (off > 3)
> +                               return CMD_RET_USAGE;
> +                       printf("CSD[%i]: 0x%08x\n", off, mmc->csd[off]);
> +                       if (argv[4])
> +                               env_set_hex(argv[4], mmc->csd[off]);
> +                       return CMD_RET_SUCCESS;
> +               }
> +               if (!strcmp(argv[2], "dsr")) {
> +                       printf("DSR: 0x%08x\n", mmc->dsr);
> +                       if (argv[4])
> +                               env_set_hex(argv[4], mmc->dsr);
> +                       return CMD_RET_SUCCESS;
> +               }
> +               if (!strcmp(argv[2], "ocr")) {
> +                       printf("OCR: 0x%08x\n", mmc->ocr);
> +                       if (argv[4])
> +                               env_set_hex(argv[4], mmc->ocr);
> +                       return CMD_RET_SUCCESS;
> +               }
> +               if (!strcmp(argv[2], "rca")) {
> +                       printf("RCA: 0x%08x\n", mmc->rca);
> +                       if (argv[4])
> +                               env_set_hex(argv[4], mmc->rca);
> +                       return CMD_RET_SUCCESS;
> +               }
> +               if (!strcmp(argv[2], "extcsd") &&
> +                   mmc->version >= MMC_VERSION_4_41) {

Can you factorize all the conditions?
string, function

Even use strcmp("extcsd", arg

Michael

> +                       ret = mmc_send_ext_csd(mmc, ext_csd);
> +                       if (ret)
> +                               return ret;
> +                       if (!strcmp(argv[3], "all")) {
> +                               /* Dump the entire register */
> +                               printf("EXT_CSD:");
> +                               for (i = 0; i < MMC_MAX_BLOCK_LEN; i++) {
> +                                       if (!(i % 10))
> +                                               printf("\n%03i: ", i);
> +                                       printf(" %02x", ext_csd[i]);
> +                               }
> +                               printf("\n");
> +                               return CMD_RET_SUCCESS;
> +                       }
> +                       off = simple_strtoul(argv[3], NULL, 10);
> +                       if (off > 512)
> +                               return CMD_RET_USAGE;
> +                       printf("EXT_CSD[%i]: 0x%02x\n", off, ext_csd[off]);
> +                       if (argv[4])
> +                               env_set_hex(argv[4], ext_csd[off]);
> +                       return CMD_RET_SUCCESS;
> +               }
> +       }
> +
> +       return CMD_RET_FAILURE;
> +}
> +#endif
> +
>  static int do_mmc_boot_wp(struct cmd_tbl *cmdtp, int flag,
>                           int argc, char * const argv[])
>  {
> @@ -963,6 +1050,9 @@ static struct cmd_tbl cmd_mmc[] = {
>  #ifdef CONFIG_CMD_BKOPS_ENABLE
>         U_BOOT_CMD_MKENT(bkops-enable, 2, 0, do_mmc_bkops_enable, "", ""),
>  #endif
> +#if CONFIG_IS_ENABLED(CMD_MMC_REG)
> +       U_BOOT_CMD_MKENT(reg, 5, 0, do_mmc_reg, "", ""),
> +#endif
>  };
>
>  static int do_mmcops(struct cmd_tbl *cmdtp, int flag, int argc,
> @@ -1037,6 +1127,10 @@ U_BOOT_CMD(
>  #ifdef CONFIG_CMD_BKOPS_ENABLE
>         "mmc bkops-enable <dev> - enable background operations handshake on device\n"
>         "   WARNING: This is a write-once setting.\n"
> +#endif
> +#if CONFIG_IS_ENABLED(CMD_MMC_REG)
> +       "mmc reg read <reg> <offset> [env] - read card register <reg> offset <offset>\n"
> +       "   (optionally into [env] variable)\n"
>  #endif
>         );
>
> --
> 2.27.0
>


-- 
| Michael Nazzareno Trimarchi                     Amarula Solutions BV |
| COO  -  Founder                                      Cruquiuskade 47 |
| +31(0)851119172                                 Amsterdam 1018 AM NL |
|                  [`as] http://www.amarulasolutions.com               |


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