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/*
* GPIO based MDIO bitbang driver.
* Supports OpenFirmware.
*
* Copyright (c) 2008 CSE Semaphore Belgium.
* by Laurent Pinchart <laurentp@cse-semaphore.com>
*
* Copyright (C) 2008, Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
*
* Based on earlier work by
*
* Copyright (c) 2003 Intracom S.A.
* by Pantelis Antoniou <panto@intracom.gr>
*
* 2005 (c) MontaVista Software, Inc.
* Vitaly Bordug <vbordug@ru.mvista.com>
*
* This file is licensed under the terms of the GNU General Public License
* version 2. This program is licensed "as is" without any warranty of any
* kind, whether express or implied.
*/
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/mdio-bitbang.h>
#include <linux/mdio-gpio.h>
#include <linux/gpio.h>
#include <linux/gpio/consumer.h>
#include <linux/of_gpio.h>
#include <linux/of_mdio.h>
struct mdio_gpio_info {
struct mdiobb_ctrl ctrl;
struct gpio_desc *mdc, *mdio, *mdo;
};
static int mdio_gpio_get_data(struct device *dev,
struct mdio_gpio_info *bitbang)
{
bitbang->mdc = devm_gpiod_get_index(dev, NULL, MDIO_GPIO_MDC,
GPIOD_OUT_LOW);
if (IS_ERR(bitbang->mdc))
return PTR_ERR(bitbang->mdc);
bitbang->mdio = devm_gpiod_get_index(dev, NULL, MDIO_GPIO_MDIO,
GPIOD_IN);
if (IS_ERR(bitbang->mdio))
return PTR_ERR(bitbang->mdio);
bitbang->mdo = devm_gpiod_get_index_optional(dev, NULL, MDIO_GPIO_MDO,
GPIOD_OUT_LOW);
return PTR_ERR_OR_ZERO(bitbang->mdo);
}
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.
*/
gpiod_set_value(bitbang->mdo, 1);
return;
}
if (dir)
gpiod_direction_output(bitbang->mdio, 1);
else
gpiod_direction_input(bitbang->mdio);
}
static int mdio_get(struct mdiobb_ctrl *ctrl)
{
struct mdio_gpio_info *bitbang =
container_of(ctrl, struct mdio_gpio_info, ctrl);
return gpiod_get_value(bitbang->mdio);
}
static void mdio_set(struct mdiobb_ctrl *ctrl, int what)
{
struct mdio_gpio_info *bitbang =
container_of(ctrl, struct mdio_gpio_info, ctrl);
if (bitbang->mdo)
gpiod_set_value(bitbang->mdo, what);
else
gpiod_set_value(bitbang->mdio, what);
}
static void mdc_set(struct mdiobb_ctrl *ctrl, int what)
{
struct mdio_gpio_info *bitbang =
container_of(ctrl, struct mdio_gpio_info, ctrl);
gpiod_set_value(bitbang->mdc, what);
}
static const struct mdiobb_ops mdio_gpio_ops = {
.owner = THIS_MODULE,
.set_mdc = mdc_set,
.set_mdio_dir = mdio_dir,
.set_mdio_data = mdio_set,
.get_mdio_data = mdio_get,
};
static struct mii_bus *mdio_gpio_bus_init(struct device *dev,
struct mdio_gpio_info *bitbang,
int bus_id)
{
struct mii_bus *new_bus;
bitbang->ctrl.ops = &mdio_gpio_ops;
new_bus = alloc_mdio_bitbang(&bitbang->ctrl);
if (!new_bus)
return NULL;
new_bus->name = "GPIO Bitbanged MDIO";
new_bus->parent = dev;
if (bus_id != -1)
snprintf(new_bus->id, MII_BUS_ID_SIZE, "gpio-%x", bus_id);
else
strncpy(new_bus->id, "gpio", MII_BUS_ID_SIZE);
dev_set_drvdata(dev, new_bus);
return new_bus;
}
static void mdio_gpio_bus_deinit(struct device *dev)
{
struct mii_bus *bus = dev_get_drvdata(dev);
free_mdio_bitbang(bus);
}
static void mdio_gpio_bus_destroy(struct device *dev)
{
struct mii_bus *bus = dev_get_drvdata(dev);
mdiobus_unregister(bus);
mdio_gpio_bus_deinit(dev);
}
static int mdio_gpio_probe(struct platform_device *pdev)
{
struct mdio_gpio_info *bitbang;
struct mii_bus *new_bus;
int ret, bus_id;
bitbang = devm_kzalloc(&pdev->dev, sizeof(*bitbang), GFP_KERNEL);
if (!bitbang)
return -ENOMEM;
ret = mdio_gpio_get_data(&pdev->dev, bitbang);
if (ret)
return ret;
if (pdev->dev.of_node) {
bus_id = of_alias_get_id(pdev->dev.of_node, "mdio-gpio");
if (bus_id < 0) {
dev_warn(&pdev->dev, "failed to get alias id\n");
bus_id = 0;
}
} else {
bus_id = pdev->id;
}
new_bus = mdio_gpio_bus_init(&pdev->dev, bitbang, bus_id);
if (!new_bus)
return -ENODEV;
if (pdev->dev.of_node)
ret = of_mdiobus_register(new_bus, pdev->dev.of_node);
else
ret = mdiobus_register(new_bus);
if (ret)
mdio_gpio_bus_deinit(&pdev->dev);
return ret;
}
static int mdio_gpio_remove(struct platform_device *pdev)
{
mdio_gpio_bus_destroy(&pdev->dev);
return 0;
}
static const struct of_device_id mdio_gpio_of_match[] = {
{ .compatible = "virtual,mdio-gpio", },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, mdio_gpio_of_match);
static struct platform_driver mdio_gpio_driver = {
.probe = mdio_gpio_probe,
.remove = mdio_gpio_remove,
.driver = {
.name = "mdio-gpio",
.of_match_table = mdio_gpio_of_match,
},
};
module_platform_driver(mdio_gpio_driver);
MODULE_ALIAS("platform:mdio-gpio");
MODULE_AUTHOR("Laurent Pinchart, Paulius Zaleckas");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Generic driver for MDIO bus emulation using GPIO");
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