Merge branch 'mdio-gpio'

Guenter Roeck says:

====================
net: mdio-gpio enhancements

The following series of patches adds support for active-low gpio pins
as well as for systems with separate MDI and MDO pins to the mdio-gpio
driver.

A board using those features is based on a COM Express CPU board.
The COM Express standard supports GPIO pins on its connector,
with one caveat: The pins on the connector have fixed direction
and are hard configured either as input or output pins.
The COM Express Design Guide [1] provides additional details.

The hardware uses three of the GPO/GPI pins from the COM Express board
to drive an MDIO bus. Connectivity between GPI/GPO pins and the MDIO bus
is as follows.

GPI2 --------------------+------------ MDIO
                         |
            +--------+   |
GPO2 ---+---G        |   |
        |   |        |   |
       4.7k | 2N7002 D---+
	|   |        |
	+---S        |
	|   +--------+
       GND

GPO1 --------------------------------- MDC

To support this hardware, two extensions to the driver were necessary.

- Due to the FET in the MDO path (GPO2), the MDO signal is inverted.
  The driver therefore has to support active-low GPIO pins.

- The MDIO signal must be separated into MDI and MDO.

Those changes are implemented in patch 2/3 and 3/3.
Patch 1/3 simplifies the error path and thus the subsequent
patches.

[1] http://www.picmg.org/pdf/picmg_comdg_100.pdf
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 52 insertions, 21 deletions

diff --git a/drivers/net/phy/mdio-gpio.c b/drivers/net/phy/mdio-gpio.c
index e701433bf52f..9c4defdec67b 100644
--- a/drivers/net/phy/mdio-gpio.c
+++ b/drivers/net/phy/mdio-gpio.c
@@ -32,29 +32,39 @@
 
 struct mdio_gpio_info {
 	struct mdiobb_ctrl ctrl;
-	int mdc, mdio;
+	int mdc, mdio, mdo;
+	int mdc_active_low, mdio_active_low, mdo_active_low;
 };
 
 static void *mdio_gpio_of_get_data(struct platform_device *pdev)
 {
 	struct device_node *np = pdev->dev.of_node;
 	struct mdio_gpio_platform_data *pdata;
+	enum of_gpio_flags flags;
 	int ret;
 
 	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 	if (!pdata)
 		return NULL;
 
-	ret = of_get_gpio(np, 0);
+	ret = of_get_gpio_flags(np, 0, &flags);
 	if (ret < 0)
 		return NULL;
 
 	pdata->mdc = ret;
+	pdata->mdc_active_low = flags & OF_GPIO_ACTIVE_LOW;
 
-	ret = of_get_gpio(np, 1);
+	ret = of_get_gpio_flags(np, 1, &flags);
 	if (ret < 0)
 		return NULL;
 	pdata->mdio = ret;
+	pdata->mdio_active_low = flags & OF_GPIO_ACTIVE_LOW;
+
+	ret = of_get_gpio_flags(np, 2, &flags);
+	if (ret > 0) {
+		pdata->mdo = ret;
+		pdata->mdo_active_low = flags & OF_GPIO_ACTIVE_LOW;
+	}
 
 	return pdata;
 }
@@ -64,8 +74,19 @@ static void mdio_dir(struct mdiobb_ctrl *ctrl, int dir)
 	struct mdio_gpio_info *bitbang =
 		container_of(ctrl, struct mdio_gpio_info, ctrl);
 
+	if (bitbang->mdo) {
+		/* Separate output pin. Always set its value to high
+		 * when changing direction. If direction is input,
+		 * assume the pin serves as pull-up. If direction is
+		 * output, the default value is high.
+		 */
+		gpio_set_value(bitbang->mdo, 1 ^ bitbang->mdo_active_low);
+		return;
+	}
+
 	if (dir)
-		gpio_direction_output(bitbang->mdio, 1);
+		gpio_direction_output(bitbang->mdio,
+				      1 ^ bitbang->mdio_active_low);
 	else
 		gpio_direction_input(bitbang->mdio);
 }
@@ -75,7 +96,7 @@ static int mdio_get(struct mdiobb_ctrl *ctrl)
 	struct mdio_gpio_info *bitbang =
 		container_of(ctrl, struct mdio_gpio_info, ctrl);
 
-	return gpio_get_value(bitbang->mdio);
+	return gpio_get_value(bitbang->mdio) ^ bitbang->mdio_active_low;
 }
 
 static void mdio_set(struct mdiobb_ctrl *ctrl, int what)
@@ -83,7 +104,10 @@ static void mdio_set(struct mdiobb_ctrl *ctrl, int what)
 	struct mdio_gpio_info *bitbang =
 		container_of(ctrl, struct mdio_gpio_info, ctrl);
 
-	gpio_set_value(bitbang->mdio, what);
+	if (bitbang->mdo)
+		gpio_set_value(bitbang->mdo, what ^ bitbang->mdo_active_low);
+	else
+		gpio_set_value(bitbang->mdio, what ^ bitbang->mdio_active_low);
 }
 
 static void mdc_set(struct mdiobb_ctrl *ctrl, int what)
@@ -91,7 +115,7 @@ static void mdc_set(struct mdiobb_ctrl *ctrl, int what)
 	struct mdio_gpio_info *bitbang =
 		container_of(ctrl, struct mdio_gpio_info, ctrl);
 
-	gpio_set_value(bitbang->mdc, what);
+	gpio_set_value(bitbang->mdc, what ^ bitbang->mdc_active_low);
 }
 
 static struct mdiobb_ops mdio_gpio_ops = {
@@ -110,18 +134,22 @@ static struct mii_bus *mdio_gpio_bus_init(struct device *dev,
 	struct mdio_gpio_info *bitbang;
 	int i;
 
-	bitbang = kzalloc(sizeof(*bitbang), GFP_KERNEL);
+	bitbang = devm_kzalloc(dev, sizeof(*bitbang), GFP_KERNEL);
 	if (!bitbang)
 		goto out;
 
 	bitbang->ctrl.ops = &mdio_gpio_ops;
 	bitbang->ctrl.reset = pdata->reset;
 	bitbang->mdc = pdata->mdc;
+	bitbang->mdc_active_low = pdata->mdc_active_low;
 	bitbang->mdio = pdata->mdio;
+	bitbang->mdio_active_low = pdata->mdio_active_low;
+	bitbang->mdo = pdata->mdo;
+	bitbang->mdo_active_low = pdata->mdo_active_low;
 
 	new_bus = alloc_mdio_bitbang(&bitbang->ctrl);
 	if (!new_bus)
-		goto out_free_bitbang;
+		goto out;
 
 	new_bus->name = "GPIO Bitbanged MDIO",
 
@@ -138,11 +166,18 @@ static struct mii_bus *mdio_gpio_bus_init(struct device *dev,
 
 	snprintf(new_bus->id, MII_BUS_ID_SIZE, "gpio-%x", bus_id);
 
-	if (gpio_request(bitbang->mdc, "mdc"))
+	if (devm_gpio_request(dev, bitbang->mdc, "mdc"))
+		goto out_free_bus;
+
+	if (devm_gpio_request(dev, bitbang->mdio, "mdio"))
 		goto out_free_bus;
 
-	if (gpio_request(bitbang->mdio, "mdio"))
-		goto out_free_mdc;
+	if (bitbang->mdo) {
+		if (devm_gpio_request(dev, bitbang->mdo, "mdo"))
+			goto out_free_bus;
+		gpio_direction_output(bitbang->mdo, 1);
+		gpio_direction_input(bitbang->mdio);
+	}
 
 	gpio_direction_output(bitbang->mdc, 0);
 
@@ -150,12 +185,8 @@ static struct mii_bus *mdio_gpio_bus_init(struct device *dev,
 
 	return new_bus;
 
-out_free_mdc:
-	gpio_free(bitbang->mdc);
 out_free_bus:
 	free_mdio_bitbang(new_bus);
-out_free_bitbang:
-	kfree(bitbang);
 out:
 	return NULL;
 }
@@ -163,13 +194,8 @@ out:
 static void mdio_gpio_bus_deinit(struct device *dev)
 {
 	struct mii_bus *bus = dev_get_drvdata(dev);
-	struct mdio_gpio_info *bitbang = bus->priv;
 
-	dev_set_drvdata(dev, NULL);
-	gpio_free(bitbang->mdio);
-	gpio_free(bitbang->mdc);
 	free_mdio_bitbang(bus);
-	kfree(bitbang);
 }
 
 static void mdio_gpio_bus_destroy(struct device *dev)
diff --git a/include/linux/mdio-gpio.h b/include/linux/mdio-gpio.h
index 7c9fe3c2be73..66c30a763b10 100644
--- a/include/linux/mdio-gpio.h
+++ b/include/linux/mdio-gpio.h
@@ -17,6 +17,11 @@ struct mdio_gpio_platform_data {
 	/* GPIO numbers for bus pins */
 	unsigned int mdc;
 	unsigned int mdio;
+	unsigned int mdo;
+
+	bool mdc_active_low;
+	bool mdio_active_low;
+	bool mdo_active_low;
 
 	unsigned int phy_mask;
 	int irqs[PHY_MAX_ADDR];