1 // SPDX-License-Identifier: GPL-2.0-only
3  * Copyright (C) 2006-2007 PA Semi, Inc
9  * Based on drivers/net/fs_enet/mii-bitbang.c.
25 #define DELAY 1  macro
34 #define MDC_PIN(bus)	(((struct gpio_priv *)bus->priv)->mdc_pin)
35 #define MDIO_PIN(bus)	(((struct gpio_priv *)bus->priv)->mdio_pin)
78 	udelay(DELAY);  in clock_out()
80 	udelay(DELAY);  in clock_out()
84 /* Utility to send the preamble, address, and register (common to read and write). */
85 static void bitbang_pre(struct mii_bus *bus, int read, u8 addr, u8 reg)  in bitbang_pre()  argument
95 	/* send the start bit (01) and the read opcode (10) or write (10) */  in bitbang_pre()
99 	clock_out(bus, read);  in bitbang_pre()
100 	clock_out(bus, !read);  in bitbang_pre()
124 	/* tri-state our MDIO I/O pin so we can read */  in gpio_mdio_read()
126 	udelay(DELAY);  in gpio_mdio_read()
128 	udelay(DELAY);  in gpio_mdio_read()
131 	/* read 16 bits of register data, MSB first */  in gpio_mdio_read()
135 		udelay(DELAY);  in gpio_mdio_read()
137 		udelay(DELAY);  in gpio_mdio_read()
139 		udelay(DELAY);  in gpio_mdio_read()
145 	udelay(DELAY);  in gpio_mdio_read()
147 	udelay(DELAY);  in gpio_mdio_read()
167 	udelay(DELAY);  in gpio_mdio_write()
169 	udelay(DELAY);  in gpio_mdio_write()
172 	udelay(DELAY);  in gpio_mdio_write()
174 	udelay(DELAY);  in gpio_mdio_write()
183 		udelay(DELAY);  in gpio_mdio_write()
185 		udelay(DELAY);  in gpio_mdio_write()
190 	 * Tri-state the MDIO line.  in gpio_mdio_write()
194 	udelay(DELAY);  in gpio_mdio_write()
196 	udelay(DELAY);  in gpio_mdio_write()
202 	/*nothing here - dunno how to reset it*/  in gpio_mdio_reset()
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()
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()
281 		.compatible      = "gpio-mdio",
292 		.name = "gpio-mdio-bitbang",
301 	np = of_find_compatible_node(NULL, NULL, "1682m-gpio");  in gpio_mdio_init()
304 					     "pasemi,pwrficient-gpio");  in gpio_mdio_init()
306 		return -ENODEV;  in gpio_mdio_init()
311 		return -ENODEV;  in gpio_mdio_init()
327 MODULE_DESCRIPTION("Driver for MDIO over GPIO on PA Semi PWRficient-based boards");