samsung: board: support eMMC reset using DT

[karo-tx-uboot.git] / board / samsung / common / board.c

diff --git a/board/samsung/common/board.c b/board/samsung/common/board.c
index 8b4c8e9a9db90f882a1349e1b5c6e1258fc77ce3..da2245ff9d6c21aa1a6ae05fcaa590564069acf2 100644 (file)
--- a/board/samsung/common/board.c
+++ b/board/samsung/common/board.c
@@ -355,3 +355,31 @@ int misc_init_r(void)
        return 0;
 }
 #endif
+
+void reset_misc(void)
+{
+       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
+                *
+                * FIXME: Need to optimize delay time. Minimum 1usec pulse is
+                *        required by 'JEDEC Standard No.84-A441' (eMMC)
+                *        document but real delay time is expected to greater
+                *        than 1usec.
+                */
+               dm_gpio_set_value(&gpio, 0);
+               mdelay(10);
+               dm_gpio_set_value(&gpio, 1);
+       }
+}