[PATCH v1] board: colibri_imx7: fix emmc detection

[Hiago De Franco]

From: Marcel Ziswiler <marcel.ziswiler at toradex.com>

Later versions of Colibri iMX7D V1.1B modules use a "new" SoC fusing. The
difference lies in whether we enable the boot ROM to use the eMMC reset
signal. Depending on the SoC fuse, the boot ROM configures this pin as a
GPIO output to drive the reset signal. Our eMMC vs NAND detection
currently only sets that signal to a GPIO without explicitly setting any
direction. Previously, by default, it was set as an input. As the boot ROM
now configures it as an output, we receive a value of zero instead of one,
indicating the absence of the pull-up on eMMC modules.

To fix this, set the SION bit, allowing the reading back of the value
even if it is configured as an output by the boot ROM. It's important to
note that with the new SoC fusing, we now read back what the boot ROM
drives rather than the real value caused by the pull-up resistor. However,
if it were ever driven low, the eMMC would permanently be reset.

In addition, remove hard-coded variant in the eMMC build case as since the
commit 0c39564d0281 ("toradex: colibri_imx7: Enable nand/emmc detection
and set boot variant") will anyways always get overridden by the detection
routing in board code.

Fixes: 0c39564d ("toradex: colibri_imx7: Enable nand/emmc detection and set boot variant")
Signed-off-by: Marcel Ziswiler <marcel.ziswiler at toradex.com>
Signed-off-by: Hiago De Franco <hiago.franco at toradex.com>
---
 board/toradex/colibri_imx7/colibri_imx7.c | 6 +++---
 include/configs/colibri_imx7.h            | 1 -
 2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/board/toradex/colibri_imx7/colibri_imx7.c b/board/toradex/colibri_imx7/colibri_imx7.c
index f0356af008..3e7c5d64c3 100644
--- a/board/toradex/colibri_imx7/colibri_imx7.c
+++ b/board/toradex/colibri_imx7/colibri_imx7.c
@@ -66,7 +66,7 @@ int dram_init(void)
 }
 
 static iomux_v3_cfg_t const flash_detection_pads[] = {
-	MX7D_PAD_SD3_RESET_B__GPIO6_IO11 | MUX_PAD_CTRL(FLASH_DETECTION_CTRL),
+	MX7D_PAD_SD3_RESET_B__GPIO6_IO11 | MUX_PAD_CTRL(FLASH_DETECTION_CTRL) | MUX_MODE_SION,
 };
 
 static iomux_v3_cfg_t const uart1_pads[] = {
@@ -193,9 +193,9 @@ int board_init(void)
 	gd->bd->bi_boot_params = PHYS_SDRAM + 0x100;
 
 	/*
-	 * Enable GPIO on NAND_WE_B/eMMC_RST with 100k pull-down. eMMC_RST
+	 * Enable GPIO SION on NAND_WE_B/eMMC_RST with 100k pull-down. eMMC_RST
 	 * is pulled high with 4.7k for eMMC devices. This allows to reliably
-	 * detect eMMC/NAND flash
+	 * detect eMMC vs NAND flash.
 	 */
 	imx_iomux_v3_setup_multiple_pads(flash_detection_pads, ARRAY_SIZE(flash_detection_pads));
 	gpio_request(FLASH_DET_GPIO, "flash-detection-gpio");
diff --git a/include/configs/colibri_imx7.h b/include/configs/colibri_imx7.h
index 03f8ed1478..7a9f4afe7d 100644
--- a/include/configs/colibri_imx7.h
+++ b/include/configs/colibri_imx7.h
@@ -101,7 +101,6 @@
 	UBI_BOOTCMD
 #elif defined(CONFIG_TARGET_COLIBRI_IMX7_EMMC)
 #define MODULE_EXTRA_ENV_SETTINGS \
-	"variant=-emmc\0" \
 	EMMC_ANDROID_BOOTCMD
 #endif
 
-- 
2.43.0