1 // SPDX-License-Identifier: GPL-2.0
3  * GPIO based MDIO bitbang driver.
7  *  by Laurent Pinchart <laurentp@cse-semaphore.com>
20 #include <linux/gpio/consumer.h>
22 #include <linux/mdio-bitbang.h>
23 #include <linux/mdio-gpio.h>
26 #include <linux/platform_data/mdio-gpio.h>
31 	struct mdiobb_ctrl ctrl;  member
38 	bitbang->mdc = devm_gpiod_get_index(dev, NULL, MDIO_GPIO_MDC,  in mdio_gpio_get_data()
40 	if (IS_ERR(bitbang->mdc))  in mdio_gpio_get_data()
41 		return PTR_ERR(bitbang->mdc);  in mdio_gpio_get_data()
43 	bitbang->mdio = devm_gpiod_get_index(dev, NULL, MDIO_GPIO_MDIO,  in mdio_gpio_get_data()
45 	if (IS_ERR(bitbang->mdio))  in mdio_gpio_get_data()
46 		return PTR_ERR(bitbang->mdio);  in mdio_gpio_get_data()
48 	bitbang->mdo = devm_gpiod_get_index_optional(dev, NULL, MDIO_GPIO_MDO,  in mdio_gpio_get_data()
50 	return PTR_ERR_OR_ZERO(bitbang->mdo);  in mdio_gpio_get_data()
53 static void mdio_dir(struct mdiobb_ctrl *ctrl, int dir)  in mdio_dir()  argument
56 		container_of(ctrl, struct mdio_gpio_info, ctrl);  in mdio_dir()
58 	if (bitbang->mdo) {  in mdio_dir()
61 		 * assume the pin serves as pull-up. If direction is  in mdio_dir()
64 		gpiod_set_value_cansleep(bitbang->mdo, 1);  in mdio_dir()
69 		gpiod_direction_output(bitbang->mdio, 1);  in mdio_dir()
71 		gpiod_direction_input(bitbang->mdio);  in mdio_dir()
74 static int mdio_get(struct mdiobb_ctrl *ctrl)  in mdio_get()  argument
77 		container_of(ctrl, struct mdio_gpio_info, ctrl);  in mdio_get()
79 	return gpiod_get_value_cansleep(bitbang->mdio);  in mdio_get()
82 static void mdio_set(struct mdiobb_ctrl *ctrl, int what)  in mdio_set()  argument
85 		container_of(ctrl, struct mdio_gpio_info, ctrl);  in mdio_set()
87 	if (bitbang->mdo)  in mdio_set()
88 		gpiod_set_value_cansleep(bitbang->mdo, what);  in mdio_set()
90 		gpiod_set_value_cansleep(bitbang->mdio, what);  in mdio_set()
93 static void mdc_set(struct mdiobb_ctrl *ctrl, int what)  in mdc_set()  argument
96 		container_of(ctrl, struct mdio_gpio_info, ctrl);  in mdc_set()
98 	gpiod_set_value_cansleep(bitbang->mdc, what);  in mdc_set()
116 	bitbang->ctrl.ops = &mdio_gpio_ops;  in mdio_gpio_bus_init()
118 	new_bus = alloc_mdio_bitbang(&bitbang->ctrl);  in mdio_gpio_bus_init()
122 	new_bus->name = "GPIO Bitbanged MDIO";  in mdio_gpio_bus_init()
123 	new_bus->parent = dev;  in mdio_gpio_bus_init()
125 	if (bus_id != -1)  in mdio_gpio_bus_init()
126 		snprintf(new_bus->id, MII_BUS_ID_SIZE, "gpio-%x", bus_id);  in mdio_gpio_bus_init()
128 		strncpy(new_bus->id, "gpio", MII_BUS_ID_SIZE);  in mdio_gpio_bus_init()
131 		new_bus->phy_mask = pdata->phy_mask;  in mdio_gpio_bus_init()
132 		new_bus->phy_ignore_ta_mask = pdata->phy_ignore_ta_mask;  in mdio_gpio_bus_init()
161 	bitbang = devm_kzalloc(&pdev->dev, sizeof(*bitbang), GFP_KERNEL);  in mdio_gpio_probe()
163 		return -ENOMEM;  in mdio_gpio_probe()
165 	ret = mdio_gpio_get_data(&pdev->dev, bitbang);  in mdio_gpio_probe()
169 	if (pdev->dev.of_node) {  in mdio_gpio_probe()
170 		bus_id = of_alias_get_id(pdev->dev.of_node, "mdio-gpio");  in mdio_gpio_probe()
172 			dev_warn(&pdev->dev, "failed to get alias id\n");  in mdio_gpio_probe()
176 		bus_id = pdev->id;  in mdio_gpio_probe()
179 	new_bus = mdio_gpio_bus_init(&pdev->dev, bitbang, bus_id);  in mdio_gpio_probe()
181 		return -ENODEV;  in mdio_gpio_probe()
183 	ret = of_mdiobus_register(new_bus, pdev->dev.of_node);  in mdio_gpio_probe()
185 		mdio_gpio_bus_deinit(&pdev->dev);  in mdio_gpio_probe()
192 	mdio_gpio_bus_destroy(&pdev->dev);  in mdio_gpio_remove()
198 	{ .compatible = "virtual,mdio-gpio", },
207 		.name	= "mdio-gpio",
214 MODULE_ALIAS("platform:mdio-gpio");
217 MODULE_DESCRIPTION("Generic driver for MDIO bus emulation using GPIO");