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