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

[Heinrich Schuchardt]

Am 10. Oktober 2023 01:14:58 MESZ schrieb Marek Vasut <marex at denx.de>:
>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.

Hello Marek,

could you, please, update doc/usage/cmd/mmc.rst.

Best regards

Heinrich

>
>Signed-off-by: Marek Vasut <marex at denx.de>
>---
>Cc: Abdellatif El Khlifi <abdellatif.elkhlifi at arm.com>
>Cc: Heinrich Schuchardt <xypron.glpk at gmx.de>
>Cc: Ilias Apalodimas <ilias.apalodimas at linaro.org>
>Cc: Jaehoon Chung <jh80.chung at samsung.com>
>Cc: Ramon Fried <rfried.dev at gmail.com>
>Cc: Roger Knecht <rknecht at pm.me>
>Cc: Sean Edmond <seanedmond at microsoft.com>
>Cc: Simon Glass <sjg at chromium.org>
>Cc: Tobias Waldekranz <tobias at waldekranz.com>
>---
> cmd/Kconfig |  8 +++++
> cmd/mmc.c   | 96 +++++++++++++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 104 insertions(+)
>
>diff --git a/cmd/Kconfig b/cmd/Kconfig
>index 6470b138d2f..dcd99757a1e 100644
>--- a/cmd/Kconfig
>+++ b/cmd/Kconfig
>@@ -1307,6 +1307,14 @@ 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 n
>+	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 c6bd81cebbc..c29f44b7a18 100644
>--- 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 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 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
> 	);
>