diff options
Diffstat (limited to 'drivers/net/mdio/mdio-gpio.c')
| -rw-r--r-- | drivers/net/mdio/mdio-gpio.c | 225 |
1 files changed, 225 insertions, 0 deletions
diff --git a/drivers/net/mdio/mdio-gpio.c b/drivers/net/mdio/mdio-gpio.c new file mode 100644 index 000000000..0fb3c2de0 --- /dev/null +++ b/drivers/net/mdio/mdio-gpio.c @@ -0,0 +1,225 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * 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> + */ + +#include <linux/gpio/consumer.h> +#include <linux/interrupt.h> +#include <linux/mdio-bitbang.h> +#include <linux/mdio-gpio.h> +#include <linux/module.h> +#include <linux/of_mdio.h> +#include <linux/platform_data/mdio-gpio.h> +#include <linux/platform_device.h> +#include <linux/slab.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_cansleep(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_cansleep(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_cansleep(bitbang->mdo, what); + else + gpiod_set_value_cansleep(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_cansleep(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 mdio_gpio_platform_data *pdata = dev_get_platdata(dev); + 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); + + if (pdata) { + new_bus->phy_mask = pdata->phy_mask; + new_bus->phy_ignore_ta_mask = pdata->phy_ignore_ta_mask; + } + + if (dev->of_node && + of_device_is_compatible(dev->of_node, "microchip,mdio-smi0")) { + bitbang->ctrl.op_c22_read = 0; + bitbang->ctrl.op_c22_write = 0; + bitbang->ctrl.override_op_c22 = 1; + } + + 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; + + ret = of_mdiobus_register(new_bus, pdev->dev.of_node); + 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", }, + { .compatible = "microchip,mdio-smi0" }, + { /* 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 v2"); +MODULE_DESCRIPTION("Generic driver for MDIO bus emulation using GPIO"); |