1 // SPDX-License-Identifier: GPL-2.0-only
3  * Copyright (C) 2006-2007 PA Semi, Inc
5  * Author: Olof Johansson, PA Semi
9  * Based on drivers/net/fs_enet/mii-bitbang.c.
27 static void __iomem *gpio_regs;
34 #define MDC_PIN(bus)	(((struct gpio_priv *)bus->priv)->mdc_pin)
35 #define MDIO_PIN(bus)	(((struct gpio_priv *)bus->priv)->mdio_pin)
37 static inline void mdio_lo(struct mii_bus *bus)  in mdio_lo()
42 static inline void mdio_hi(struct mii_bus *bus)  in mdio_hi()
47 static inline void mdc_lo(struct mii_bus *bus)  in mdc_lo()
52 static inline void mdc_hi(struct mii_bus *bus)  in mdc_hi()
57 static inline void mdio_active(struct mii_bus *bus)  in mdio_active()
62 static inline void mdio_tristate(struct mii_bus *bus)  in mdio_tristate()
67 static inline int mdio_read(struct mii_bus *bus)  in mdio_read()
72 static void clock_out(struct mii_bus *bus, int bit)  in clock_out()
85 static void bitbang_pre(struct mii_bus *bus, int read, u8 addr, u8 reg)  in bitbang_pre()
115 static int gpio_mdio_read(struct mii_bus *bus, int phy_id, int location)  in gpio_mdio_read()
124 	/* tri-state our MDIO I/O pin so we can read */  in gpio_mdio_read()
154 static int gpio_mdio_write(struct mii_bus *bus, int phy_id, int location, u16 val)  in gpio_mdio_write()
190 	 * Tri-state the MDIO line.  in gpio_mdio_write()
200 static int gpio_mdio_reset(struct mii_bus *bus)  in gpio_mdio_reset()
202 	/*nothing here - dunno how to reset it*/  in gpio_mdio_reset()
207 static int gpio_mdio_probe(struct platform_device *ofdev)  in gpio_mdio_probe()
209 	struct device *dev = &ofdev->dev;  in gpio_mdio_probe()
210 	struct device_node *np = ofdev->dev.of_node;  in gpio_mdio_probe()
216 	err = -ENOMEM;  in gpio_mdio_probe()
226 	new_bus->name = "pasemi gpio mdio bus";  in gpio_mdio_probe()
227 	new_bus->read = &gpio_mdio_read;  in gpio_mdio_probe()
228 	new_bus->write = &gpio_mdio_write;  in gpio_mdio_probe()
229 	new_bus->reset = &gpio_mdio_reset;  in gpio_mdio_probe()
232 	snprintf(new_bus->id, MII_BUS_ID_SIZE, "%x", *prop);  in gpio_mdio_probe()
233 	new_bus->priv = priv;  in gpio_mdio_probe()
235 	prop = of_get_property(np, "mdc-pin", NULL);  in gpio_mdio_probe()
236 	priv->mdc_pin = *prop;  in gpio_mdio_probe()
238 	prop = of_get_property(np, "mdio-pin", NULL);  in gpio_mdio_probe()
239 	priv->mdio_pin = *prop;  in gpio_mdio_probe()
241 	new_bus->parent = dev;  in gpio_mdio_probe()
248 				new_bus->name, err);  in gpio_mdio_probe()
263 static void gpio_mdio_remove(struct platform_device *dev)  in gpio_mdio_remove()
265 	struct mii_bus *bus = dev_get_drvdata(&dev->dev);  in gpio_mdio_remove()
269 	dev_set_drvdata(&dev->dev, NULL);  in gpio_mdio_remove()
271 	kfree(bus->priv);  in gpio_mdio_remove()
272 	bus->priv = NULL;  in gpio_mdio_remove()
276 static const struct of_device_id gpio_mdio_match[] =
279 		.compatible      = "gpio-mdio",
285 static struct platform_driver gpio_mdio_driver =
290 		.name = "gpio-mdio-bitbang",
295 static int __init gpio_mdio_init(void)  in gpio_mdio_init()
299 	np = of_find_compatible_node(NULL, NULL, "1682m-gpio");  in gpio_mdio_init()
302 					     "pasemi,pwrficient-gpio");  in gpio_mdio_init()
304 		return -ENODEV;  in gpio_mdio_init()
309 		return -ENODEV;  in gpio_mdio_init()
315 static void __exit gpio_mdio_exit(void)  in gpio_mdio_exit()
325 MODULE_DESCRIPTION("Driver for MDIO over GPIO on PA Semi PWRficient-based boards");