add eth-switch-enabled for en4, only drive output when low

* Only drive the output pin when set low (reset active), else leave pin
  floating since it has an external pull up. If instead the output pin
  is driven high, the ethernet switch locks up after a soft reboot.

1 files changed, 47 insertions, 4 deletions

diff --git a/io-module/mts_io.c b/io-module/mts_io.c
index a67c475..6316894 100644
--- a/io-module/mts_io.c
+++ b/io-module/mts_io.c
@@ -400,10 +400,10 @@ static struct gpio_pin gpio_pins_mt100eocg_0_0[] = {
 
 static struct gpio_pin gpio_pins_en4_0_0[] = {
 	{
-		.name = "ETH0_ENABLED",
-		.attr_name = "eth0-enabled",
+		.name = "NETH_RST",
+		.attr_name = "eth-switch-enabled",
 		.pin = AT91_PIN_PC6,
-		.direction = GPIO_DIR_OUTPUT,
+		.direction = GPIO_DIR_INPUT,
 		.output_value = 1,
 		.use_pullup = 0,
 	},
@@ -2229,6 +2229,49 @@ static struct device_attribute dev_attr_serial_mode = {
 	.store = mts_attr_store_serial_mode,
 };
 
+static ssize_t mts_attr_store_eth_switch_en(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t count)
+{
+	int value;
+	int err;
+	struct gpio_pin *pin = gpio_pin_by_attr_name(attr->attr.name);
+
+	if (!pin) {
+		return -ENODEV;
+	}
+
+	if (sscanf(buf, "%i", &value) != 1) {
+		return -EINVAL;
+	}
+
+	mutex_lock(&mts_io_mutex);
+
+	// set to input if high (floating), else set as output and drive low
+	if (value) {
+		err = at91_set_gpio_input(pin->pin, pin->use_pullup);
+	}
+	else {
+		err = at91_set_gpio_output_with_pullup(pin->pin, value, pin->use_pullup);
+	}
+
+	mutex_unlock(&mts_io_mutex);
+
+	if (err) {
+		return err;
+	}
+
+	return count;
+}
+
+static struct device_attribute dev_attr_eth_switch_enabled = {
+	.attr = {
+		.name = "eth-switch-enabled",
+		.mode = MTS_ATTR_MODE_RW,
+	},
+	.show = mts_attr_show_gpio_pin,
+	.store = mts_attr_store_eth_switch_en,
+};
+
 static struct attribute *mt100eocg_platform_attributes[] = {
 	&dev_attr_extserial_dtr.attr,
 	&dev_attr_extserial_cd.attr,
@@ -2279,7 +2322,7 @@ static struct attribute *en4_platform_attributes[] = {
 	&dev_attr_extserial_ri_gpio.attr,
 	&dev_attr_extserial_cd.attr,
 	&dev_attr_rsersrc.attr,
-	&dev_attr_eth0_enabled.attr,
+	&dev_attr_eth_switch_enabled.attr,
 	&dev_attr_bt_enabled.attr,
 	&dev_attr_wlan_enabled.attr,