Commit c3206e6f authored by David S. Miller's avatar David S. Miller
Browse files

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: default avatarDavid S. Miller <davem@davemloft.net>
parents bc383ea5 f1d54c47

drivers/net/phy/mdio-gpio.c

+47 −21
Original line number Diff line number Diff line
@@ -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)

include/linux/mdio-gpio.h

+5 −0
Original line number Diff line number Diff line
@@ -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];

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