[U-Boot] [PATCH 1/3] samsung: board: support eMMC reset using DT

Joonyoung Shim
2015-01-08T05:44:25Z

Some exynos boards require special handling of SD4_nRESET_OUT line for
eMMC memory to perform complete reboot e.g. Odroid X2/U3/XU3 boards.

This will support eMMC reset using DT from reset_misc of samsung common
board file and each board files can support eMMC reset on non DT case.

Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
---
board/samsung/common/board.c | 27 ++++++++++++++++++++++++++
board/samsung/odroid/odroid.c | 2 +-
doc/device-tree-bindings/exynos/emmc-reset.txt | 15 ++++++++++++++
3 files changed, 43 insertions(+), 1 deletion(-)
create mode 100644 doc/device-tree-bindings/exynos/emmc-reset.txt

diff --git a/board/samsung/common/board.c b/board/samsung/common/board.c
index c04ab3c..3218463 100644
--- a/board/samsung/common/board.c
+++ b/board/samsung/common/board.c
@@ -40,6 +40,8 @@ __weak int exynos_power_init(void)
return 0;
}

+__weak void exynos_reset_misc(void) {}
+
#if defined CONFIG_EXYNOS_TMU
/* Boot Time Thermal Analysis for SoC temperature threshold breach */
static void boot_temp_check(void)
@@ -400,3 +402,28 @@ int misc_init_r(void)
return 0;
}
#endif
+
+void reset_misc(void)
+{
+#ifdef CONFIG_OF_CONTROL
+ struct gpio_desc gpio = {};
+ int node;
+
+ node = fdt_node_offset_by_compatible(gd->fdt_blob, 0,
+ "samsung,emmc-reset");
+ if (node < 0)
+ return;
+
+ gpio_request_by_name_nodev(gd->fdt_blob, node, "reset-gpio", 0, &gpio,
+ GPIOD_IS_OUT);
+
+ if (dm_gpio_is_valid(&gpio)) {
+ /* Reset eMMC*/
+ dm_gpio_set_value(&gpio, 0);
+ mdelay(10);
+ dm_gpio_set_value(&gpio, 1);
+ }
+#else
+ exynos_reset_misc();
+#endif
+}
diff --git a/board/samsung/odroid/odroid.c b/board/samsung/odroid/odroid.c
index 3f43e17..db35945 100644
--- a/board/samsung/odroid/odroid.c
+++ b/board/samsung/odroid/odroid.c
@@ -516,7 +516,7 @@ int board_usb_init(int index, enum usb_init_type init)
}
#endif

-void reset_misc(void)
+void exynos_reset_misc(void)
{
/* Reset eMMC*/
gpio_set_value(EXYNOS4X12_GPIO_K12, 0);
diff --git a/doc/device-tree-bindings/exynos/emmc-reset.txt b/doc/device-tree-bindings/exynos/emmc-reset.txt
new file mode 100644
index 0000000..e48e508
--- /dev/null
+++ b/doc/device-tree-bindings/exynos/emmc-reset.txt
@@ -0,0 +1,15 @@
+* Samsung eMMC reset
+
+Some exynos boards require special handling of SD4_nRESET_OUT line for eMMC
+memory to perform complete reboot.
+
+Required properties:
+- compatible: should be "samsung,emmc-reset"
+- reset-gpio: gpio chip for eMMC reset.
+
+Example:
+
+emmc-reset {
+ compatible = "samsung,emmc-reset";
+ reset-gpio = <&gpk1 2 0>;
+};
--
1.9.1