storm: deassert SW_RESET signal at startup

The proto0.2 hardware connects gpio26 (sw reset) to the ethernet
switch reset pit. The output stays low (or high-z) after power up,
which holds the switch in reset. Deassert the signal at startup on
hardware rev 1 and later.

BUG=chrome-os-partner:31780
TEST=with this patch applied, when proto0.2 boots, the ethernet
     switch's LED blink once, as was the case with proto0.

Change-Id: I4c5a0cc499563a33aa7d29be7767d0ec5d93c20f
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 6788962172c6e29e193fa3e85ca79cb83a96e154
Original-Change-Id: I81b3dccb1d1d43c5c1e6dcb5400af8eed6dee870
Original-Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/217087
Original-Reviewed-by: David Hendricks <dhendrix@chromium.org>
Reviewed-on: http://review.coreboot.org/9120
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

1 files changed, 14 insertions, 0 deletions

diff --git a/src/mainboard/google/storm/mainboard.c b/src/mainboard/google/storm/mainboard.c
index ded423aa9f..ebe284911d 100644
--- a/src/mainboard/google/storm/mainboard.c
+++ b/src/mainboard/google/storm/mainboard.c
@@ -91,10 +91,24 @@ static void setup_tpm(void)
 	gpio_set_out_value(TPM_RESET_GPIO, 1);
 }
 
+#define SW_RESET_GPIO 26
+static void deassert_sw_reset(void)
+{
+	if (board_id() == 0)
+		return;
+
+	/* only proto0.2 and later care about this. */
+	gpio_tlmm_config_set(SW_RESET_GPIO, FUNC_SEL_GPIO,
+			     GPIO_PULL_UP, GPIO_4MA, GPIO_ENABLE);
+
+	gpio_set_out_value(SW_RESET_GPIO, 1);
+}
+
 static void mainboard_init(device_t dev)
 {
 	 setup_mmu();
 	 setup_usb();
+	 deassert_sw_reset();
 	 setup_tpm();
 }