ARMV7: OMAP: Overo: Autodetect presence/absence of transceiver on mmc2

An upcoming version of Overo uses a Wifi/BT module with 1.8V signaling,
eliminating the need for an external transceiver to handle the level
shifting.  This patch detects whether an external transceiver is present
and adjusts the pinmux settings as appropriate.

Signed-off-by: Steve Sakoman <steve@sakoman.com>
Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com>

1 files changed, 47 insertions, 0 deletions

diff --git a/board/overo/overo.c b/board/overo/overo.c
index 4a60917..1b67f1f 100644
--- a/board/overo/overo.c
+++ b/board/overo/overo.c
@@ -103,6 +103,39 @@ int get_board_revision(void)
 }
 
 /*
+ * Routine: get_sdio2_config
+ * Description: Return information about the wifi module connection
+ *              Returns 0 if the module connects though a level translator
+ *              Returns 1 if the module connects directly
+ */
+int get_sdio2_config(void)
+{
+	int sdio_direct;
+
+	if (!omap_request_gpio(130) && !omap_request_gpio(139)) {
+
+		omap_set_gpio_direction(130, 0);
+		omap_set_gpio_direction(139, 1);
+
+		sdio_direct = 1;
+		omap_set_gpio_dataout(130, 0);
+		if (omap_get_gpio_datain(139) == 0) {
+			omap_set_gpio_dataout(130, 1);
+			if (omap_get_gpio_datain(139) == 1)
+				sdio_direct = 0;
+		}
+
+		omap_free_gpio(130);
+		omap_free_gpio(139);
+	} else {
+		printf("Error: unable to acquire sdio2 clk GPIOs\n");
+		sdio_direct = -1;
+	}
+
+	return sdio_direct;
+}
+
+/*
  * Routine: misc_init_r
  * Description: Configure board specific parts
  */
@@ -116,6 +149,20 @@ int misc_init_r(void)
 #endif
 
 	printf("Board revision: %d\n", get_board_revision());
+
+	switch (get_sdio2_config()) {
+	case 0:
+		printf("Tranceiver detected on mmc2\n");
+		MUX_OVERO_SDIO2_TRANSCEIVER();
+		break;
+	case 1:
+		printf("Direct connection on mmc2\n");
+		MUX_OVERO_SDIO2_DIRECT();
+		break;
+	default:
+		printf("Unable to detect mmc2 connection type\n");
+	}
+
 	dieid_num_r();
 
 	return 0;