mmc: add bkops-enable command

Add new command that provides possibility to enable the
background operations handshake functionality
(BKOPS_EN, EXT_CSD byte [163]) on eMMC devices.

This is an optional feature of eMMCs, the setting is write-once.
The command must be explicitly taken into use with
CONFIG_CMD_BKOPS_ENABLE.

Signed-off-by: Tomas Melin <tomas.melin@vaisala.com>

diff --git a/cmd/Kconfig b/cmd/Kconfig
index b16c603..7653c60 100644 (file)
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -572,6 +572,15 @@ config SYS_AMBAPP_PRINT_ON_STARTUP
        help
          Show AMBA Plug-n-Play information on startup.
 
+config CMD_BKOPS_ENABLE
+       bool "mmc bkops enable"
+       depends on CMD_MMC
+       default n
+       help
+         Enable command for setting manual background operations handshake
+         on a eMMC device. The feature is optionally available on eMMC devices
+         conforming to standard >= 4.41.
+
 config CMD_BLOCK_CACHE
        bool "blkcache - control and stats for block cache"
        depends on BLOCK_CACHE

diff --git a/cmd/mmc.c b/cmd/mmc.c
index b2761e9..b8dcc26 100644 (file)
--- a/cmd/mmc.c
+++ b/cmd/mmc.c
@@ -729,6 +729,31 @@ static int do_mmc_setdsr(cmd_tbl_t *cmdtp, int flag,
        return ret;
 }
 
+#ifdef CONFIG_CMD_BKOPS_ENABLE
+static int do_mmc_bkops_enable(cmd_tbl_t *cmdtp, int flag,
+                                  int argc, char * const argv[])
+{
+       int dev;
+       struct mmc *mmc;
+
+       if (argc != 2)
+               return CMD_RET_USAGE;
+
+       dev = simple_strtoul(argv[1], NULL, 10);
+
+       mmc = init_mmc_device(dev, false);
+       if (!mmc)
+               return CMD_RET_FAILURE;
+
+       if (IS_SD(mmc)) {
+               puts("BKOPS_EN only exists on eMMC\n");
+               return CMD_RET_FAILURE;
+       }
+
+       return mmc_set_bkops_enable(mmc);
+}
+#endif
+
 static cmd_tbl_t cmd_mmc[] = {
        U_BOOT_CMD_MKENT(info, 1, 0, do_mmcinfo, "", ""),
        U_BOOT_CMD_MKENT(read, 4, 1, do_mmc_read, "", ""),
@@ -749,6 +774,9 @@ static cmd_tbl_t cmd_mmc[] = {
        U_BOOT_CMD_MKENT(rpmb, CONFIG_SYS_MAXARGS, 1, do_mmcrpmb, "", ""),
 #endif
        U_BOOT_CMD_MKENT(setdsr, 2, 0, do_mmc_setdsr, "", ""),
+#ifdef CONFIG_CMD_BKOPS_ENABLE
+       U_BOOT_CMD_MKENT(bkops-enable, 2, 0, do_mmc_bkops_enable, "", ""),
+#endif
 };
 
 static int do_mmcops(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
@@ -813,6 +841,10 @@ U_BOOT_CMD(
        "mmc rpmb counter - read the value of the write counter\n"
 #endif
        "mmc setdsr <value> - set DSR register value\n"
+#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
        );
 
 /* Old command kept for compatibility. Same as 'mmc info' */

diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index d6b7e4f..434eb28 100644 (file)
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -1817,3 +1817,37 @@ int mmc_initialize(bd_t *bis)
        mmc_do_preinit();
        return 0;
 }
+
+#ifdef CONFIG_CMD_BKOPS_ENABLE
+int mmc_set_bkops_enable(struct mmc *mmc)
+{
+       int err;
+       ALLOC_CACHE_ALIGN_BUFFER(u8, ext_csd, MMC_MAX_BLOCK_LEN);
+
+       err = mmc_send_ext_csd(mmc, ext_csd);
+       if (err) {
+               puts("Could not get ext_csd register values\n");
+               return err;
+       }
+
+       if (!(ext_csd[EXT_CSD_BKOPS_SUPPORT] & 0x1)) {
+               puts("Background operations not supported on device\n");
+               return -EMEDIUMTYPE;
+       }
+
+       if (ext_csd[EXT_CSD_BKOPS_EN] & 0x1) {
+               puts("Background operations already enabled\n");
+               return 0;
+       }
+
+       err = mmc_switch(mmc, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_BKOPS_EN, 1);
+       if (err) {
+               puts("Failed to enable manual background operations\n");
+               return err;
+       }
+
+       puts("Enabled manual background operations\n");
+
+       return 0;
+}
+#endif

diff --git a/include/mmc.h b/include/mmc.h
index e815eb3..2285323 100644 (file)
--- a/include/mmc.h
+++ b/include/mmc.h
@@ -174,6 +174,7 @@
 #define EXT_CSD_MAX_ENH_SIZE_MULT      157     /* R */
 #define EXT_CSD_PARTITIONING_SUPPORT   160     /* RO */
 #define EXT_CSD_RST_N_FUNCTION         162     /* R/W */
+#define EXT_CSD_BKOPS_EN               163     /* R/W & R/W/E */
 #define EXT_CSD_WR_REL_PARAM           166     /* R */
 #define EXT_CSD_WR_REL_SET             167     /* R/W */
 #define EXT_CSD_RPMB_MULT              168     /* RO */
@@ -188,6 +189,7 @@
 #define EXT_CSD_HC_WP_GRP_SIZE         221     /* RO */
 #define EXT_CSD_HC_ERASE_GRP_SIZE      224     /* RO */
 #define EXT_CSD_BOOT_MULT              226     /* RO */
+#define EXT_CSD_BKOPS_SUPPORT          502     /* RO */
 
 /*
  * EXT_CSD field definitions
@@ -540,6 +542,10 @@ int mmc_rpmb_read(struct mmc *mmc, void *addr, unsigned short blk,
                  unsigned short cnt, unsigned char *key);
 int mmc_rpmb_write(struct mmc *mmc, void *addr, unsigned short blk,
                   unsigned short cnt, unsigned char *key);
+#ifdef CONFIG_CMD_BKOPS_ENABLE
+int mmc_set_bkops_enable(struct mmc *mmc);
+#endif
+
 /**
  * Start device initialization and return immediately; it does not block on
  * polling OCR (operation condition register) status.  Then you should call