cmd: mmc: Add mmc reg read command for reading card registers

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.

Tested-by: Jaehoon Chung <jh80.chung@samsung.com>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Marek Vasut <marex@denx.de>
Reviewed-by: Fabio Estevam <festevam@gmail.com>

diff --git a/cmd/Kconfig b/cmd/Kconfig
index 60aed2c307caa5c6f5a37401aaa14e942fc14188..fd16c3a48e5c5032ab1cd69c9368da515f92201a 100644 (file)
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -1313,6 +1313,13 @@ 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
+       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 c6bd81cebbcec4323118ed5b1d58af7d288000d1..96befb27eec6c434fee4d0e33c8b8f03429cccfe 100644 (file)
--- a/cmd/mmc.c
+++ b/cmd/mmc.c
@@ -1110,6 +1110,93 @@ static int do_mmc_boot_wp(struct cmd_tbl *cmdtp, int flag,
        return CMD_RET_SUCCESS;
 }
 
+#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;
+       }
+
+       off = simple_strtoul(argv[3], NULL, 10);
+       if (!strcmp(argv[2], "cid")) {
+               if (off > 3)
+                       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) {
+               ret = mmc_send_ext_csd(mmc, ext_csd);
+               if (ret)
+                       return CMD_RET_FAILURE;
+               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 struct cmd_tbl cmd_mmc[] = {
        U_BOOT_CMD_MKENT(info, 1, 0, do_mmcinfo, "", ""),
        U_BOOT_CMD_MKENT(read, 4, 1, do_mmc_read, "", ""),
@@ -1142,6 +1229,9 @@ static struct cmd_tbl cmd_mmc[] = {
        U_BOOT_CMD_MKENT(bkops-enable, 2, 0, do_mmc_bkops_enable, "", ""),
        U_BOOT_CMD_MKENT(bkops, 4, 0, do_mmc_bkops, "", ""),
 #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,
@@ -1229,6 +1319,12 @@ U_BOOT_CMD(
        "   WARNING: This is a write-once setting.\n"
        "mmc bkops <dev> [auto|manual] [enable|disable]\n"
        " - configure background operations handshake on device\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"
+       " - reg: cid/csd/dsr/ocr/rca/extcsd\n"
+       " - offset: for cid/csd [0..3], for extcsd [0..511,all]\n"
 #endif
        );
 

diff --git a/doc/usage/cmd/mmc.rst b/doc/usage/cmd/mmc.rst
index 71a0303109c1d2d783ee57806e18cb7f37d82a43..c0924ba5769a1e002e4f9393d60ab1a9c4d76147 100644 (file)
--- a/doc/usage/cmd/mmc.rst
+++ b/doc/usage/cmd/mmc.rst
@@ -21,6 +21,7 @@ Synopsis
     mmc bootpart-resize <dev> <dev part size MB> <RPMB part size MB>
     mmc partconf <dev> [[varname] | [<boot_ack> <boot_partition> <partition_access>]]
     mmc rst-function <dev> <value>
+    mmc reg read <reg> <offset> [env]
 
 Description
 -----------
@@ -183,6 +184,31 @@ The 'mmc rst-function' command changes the RST_n_FUNCTION field.
         0x3
             Reserved
 
+The 'mmc reg read <reg> <offset> [env]' reads eMMC card register and
+either print it to standard output, or store the value in environment
+variable.
+
+<reg> with
+optional offset <offset> into the register array, and print it to
+standard output or store it into environment variable [env].
+
+    reg
+        cid
+            The Device IDentification (CID) register. Uses offset.
+        csd
+            The Device-Specific Data (CSD) register. Uses offset.
+        dsr
+            The driver stage register (DSR).
+        ocr
+            The operation conditions register (OCR).
+        rca
+            The relative Device address (RCA) register.
+        extcsd
+            The Extended CSD register. Uses offset.
+    offset
+        For 'cid'/'csd' 128 bit registers '[0..3]' in 32-bit increments. For 'extcsd' 512 bit register '[0..512,all]' in 8-bit increments, or 'all' to read the entire register.
+    env
+        Optional environment variable into which 32-bit value read from register should be stored.
 
 Examples
 --------