[U-Boot] [PATCH v5 1/3] mx6qsabresd: Document the mapping of USDHC[2-4]

[Otavio Salvador]

This documents the SD card identifier so it is easier for user to spot
which card number will be used, if need.

Signed-off-by: Otavio Salvador <otavio at ossystems.com.br>
---
Changes in v5:
- Improve comment in code for easier understanding (Fabio)

Changes in v4: None
Changes in v3: None
Changes in v2:
- Improve commit log

 board/freescale/mx6qsabresd/mx6qsabresd.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/board/freescale/mx6qsabresd/mx6qsabresd.c b/board/freescale/mx6qsabresd/mx6qsabresd.c
index 2b3926a..5ebbff3 100644
--- a/board/freescale/mx6qsabresd/mx6qsabresd.c
+++ b/board/freescale/mx6qsabresd/mx6qsabresd.c
@@ -160,6 +160,13 @@ int board_mmc_init(bd_t *bis)
 {
 	int i;
 
+	/*
+	 * According to the board_mmc_init() the following map is done:
+	 * (U-boot device node)    (Physical Port)
+	 * mmc0                    SD2
+	 * mmc1                    SD3
+	 * mmc2                    eMMC
+	 */
 	for (i = 0; i < CONFIG_SYS_FSL_USDHC_NUM; i++) {
 		switch (i) {
 		case 0:
-- 
1.8.1