mmc: Add a function to dump the mmc capabilities

This adds a simple helper function to display information (bus width and
mode) based on a capability mask. Useful for debug.

Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>

drivers/mmc/mmc.c

@@ -1136,6 +1136,30 @@ static void mmc_set_bus_width(struct mmc *mmc, uint width)
 	mmc_set_ios(mmc);
 }
 
+#if CONFIG_IS_ENABLED(MMC_VERBOSE) || defined(DEBUG)
+/*
+ * helper function to display the capabilities in a human
+ * friendly manner. The capabilities include bus width and
+ * supported modes.
+ */
+void mmc_dump_capabilities(const char *text, uint caps)
+{
+	enum bus_mode mode;
+
+	printf("%s: widths [", text);
+	if (caps & MMC_MODE_8BIT)
+		printf("8, ");
+	if (caps & MMC_MODE_4BIT)
+		printf("4, ");
+	printf("1] modes [");
+
+	for (mode = MMC_LEGACY; mode < MMC_MODES_END; mode++)
+		if (MMC_CAP(mode) & caps)
+			printf("%s, ", mmc_mode_name(mode));
+	printf("\b\b]\n");
+}
+#endif
+
 static int sd_select_bus_freq_width(struct mmc *mmc)
 {
 	int err;

include/mmc.h

@@ -426,6 +426,7 @@ enum bus_mode {
 };
 
 const char *mmc_mode_name(enum bus_mode mode);
+void mmc_dump_capabilities(const char *text, uint caps);
 
 /*
  * With CONFIG_DM_MMC enabled, struct mmc can be accessed from the MMC device