1 // SPDX-License-Identifier: GPL-2.0+
3  * Broadcom UniMAC MDIO bus controller driver
5  * Copyright (C) 2014-2017 Broadcom
17 #include <linux/platform_data/mdio-bcm-unimac.h>
50 	 * peripheral registers for CPU-native byte order.  in unimac_mdio_readl()
53 		return __raw_readl(priv->base + offset);  in unimac_mdio_readl()
55 		return readl_relaxed(priv->base + offset);  in unimac_mdio_readl()
62 		__raw_writel(val, priv->base + offset);  in unimac_mdio_writel()
64 		writel_relaxed(val, priv->base + offset);  in unimac_mdio_writel()
91 	} while (--timeout);  in unimac_mdio_poll()
93 	return -ETIMEDOUT;  in unimac_mdio_poll()
96 static int unimac_mdio_read(struct mii_bus *bus, int phy_id, int reg)  in unimac_mdio_read()  argument
98 	struct unimac_mdio_priv *priv = bus->priv;  in unimac_mdio_read()
106 	/* Start MDIO transaction */  in unimac_mdio_read()
109 	ret = priv->wait_func(priv->wait_func_data);  in unimac_mdio_read()
116 	 * turn-around, e.g: Broadcom BCM53125 external switches, so check for  in unimac_mdio_read()
117 	 * that condition here and ignore the MDIO controller read failure  in unimac_mdio_read()
120 	if (!(bus->phy_ignore_ta_mask & 1 << phy_id) && (cmd & MDIO_READ_FAIL))  in unimac_mdio_read()
121 		return -EIO;  in unimac_mdio_read()
126 static int unimac_mdio_write(struct mii_bus *bus, int phy_id,  in unimac_mdio_write()  argument
129 	struct unimac_mdio_priv *priv = bus->priv;  in unimac_mdio_write()
139 	return priv->wait_func(priv->wait_func_data);  in unimac_mdio_write()
143  * their internal MDIO management controller making them fail to successfully
150  * there (e.g: during system-wide power management).
152  * bus->reset is invoked before mdiobus_scan during mdiobus_register and is
154  * to read from non-existing PHYs, we either use bus->phy_mask or do a manual
157 static int unimac_mdio_reset(struct mii_bus *bus)  in unimac_mdio_reset()  argument
159 	struct device_node *np = bus->dev.of_node;  in unimac_mdio_reset()
165 		read_mask = ~bus->phy_mask;  in unimac_mdio_reset()
168 			addr = of_mdio_parse_addr(&bus->dev, child);  in unimac_mdio_reset()
178 			dev_dbg(&bus->dev, "Workaround for PHY @ %d\n", addr);  in unimac_mdio_reset()
179 			mdiobus_read(bus, addr, MII_BMSR);  in unimac_mdio_reset()
192 	if (!priv->clk_freq)  in unimac_mdio_clk_set()
195 	if (!priv->clk)  in unimac_mdio_clk_set()
198 		rate = clk_get_rate(priv->clk);  in unimac_mdio_clk_set()
200 	div = (rate / (2 * priv->clk_freq)) - 1;  in unimac_mdio_clk_set()
202 		pr_warn("Incorrect MDIO clock frequency, ignoring\n");  in unimac_mdio_clk_set()
206 	/* The MDIO clock is the reference clock (typically 250Mhz) divided by  in unimac_mdio_clk_set()
217 	struct unimac_mdio_pdata *pdata = pdev->dev.platform_data;  in unimac_mdio_probe()
220 	struct mii_bus *bus;  in unimac_mdio_probe()  local
224 	np = pdev->dev.of_node;  in unimac_mdio_probe()
226 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);  in unimac_mdio_probe()
228 		return -ENOMEM;  in unimac_mdio_probe()
232 		return -EINVAL;  in unimac_mdio_probe()
234 	/* Just ioremap, as this MDIO block is usually integrated into an  in unimac_mdio_probe()
237 	priv->base = devm_ioremap(&pdev->dev, r->start, resource_size(r));  in unimac_mdio_probe()
238 	if (!priv->base) {  in unimac_mdio_probe()
239 		dev_err(&pdev->dev, "failed to remap register\n");  in unimac_mdio_probe()
240 		return -ENOMEM;  in unimac_mdio_probe()
243 	priv->clk = devm_clk_get_optional(&pdev->dev, NULL);  in unimac_mdio_probe()
244 	if (IS_ERR(priv->clk))  in unimac_mdio_probe()
245 		return PTR_ERR(priv->clk);  in unimac_mdio_probe()
247 	ret = clk_prepare_enable(priv->clk);  in unimac_mdio_probe()
251 	if (of_property_read_u32(np, "clock-frequency", &priv->clk_freq))  in unimac_mdio_probe()
252 		priv->clk_freq = 0;  in unimac_mdio_probe()
256 	priv->mii_bus = mdiobus_alloc();  in unimac_mdio_probe()
257 	if (!priv->mii_bus) {  in unimac_mdio_probe()
258 		ret = -ENOMEM;  in unimac_mdio_probe()
262 	bus = priv->mii_bus;  in unimac_mdio_probe()
263 	bus->priv = priv;  in unimac_mdio_probe()
265 		bus->name = pdata->bus_name;  in unimac_mdio_probe()
266 		priv->wait_func = pdata->wait_func;  in unimac_mdio_probe()
267 		priv->wait_func_data = pdata->wait_func_data;  in unimac_mdio_probe()
268 		bus->phy_mask = ~pdata->phy_mask;  in unimac_mdio_probe()
270 		bus->name = "unimac MII bus";  in unimac_mdio_probe()
271 		priv->wait_func_data = priv;  in unimac_mdio_probe()
272 		priv->wait_func = unimac_mdio_poll;  in unimac_mdio_probe()
274 	bus->parent = &pdev->dev;  in unimac_mdio_probe()
275 	bus->read = unimac_mdio_read;  in unimac_mdio_probe()
276 	bus->write = unimac_mdio_write;  in unimac_mdio_probe()
277 	bus->reset = unimac_mdio_reset;  in unimac_mdio_probe()
278 	snprintf(bus->id, MII_BUS_ID_SIZE, "%s-%d", pdev->name, pdev->id);  in unimac_mdio_probe()
280 	ret = of_mdiobus_register(bus, np);  in unimac_mdio_probe()
282 		dev_err(&pdev->dev, "MDIO bus registration failed\n");  in unimac_mdio_probe()
288 	dev_info(&pdev->dev, "Broadcom UniMAC MDIO bus\n");  in unimac_mdio_probe()
293 	mdiobus_free(bus);  in unimac_mdio_probe()
295 	clk_disable_unprepare(priv->clk);  in unimac_mdio_probe()
303 	mdiobus_unregister(priv->mii_bus);  in unimac_mdio_remove()
304 	mdiobus_free(priv->mii_bus);  in unimac_mdio_remove()
305 	clk_disable_unprepare(priv->clk);  in unimac_mdio_remove()
314 	clk_disable_unprepare(priv->clk);  in unimac_mdio_suspend()
324 	ret = clk_prepare_enable(priv->clk);  in unimac_mdio_resume()
337 	{ .compatible = "brcm,genet-mdio-v5", },
338 	{ .compatible = "brcm,genet-mdio-v4", },
339 	{ .compatible = "brcm,genet-mdio-v3", },
340 	{ .compatible = "brcm,genet-mdio-v2", },
341 	{ .compatible = "brcm,genet-mdio-v1", },
342 	{ .compatible = "brcm,unimac-mdio", },
359 MODULE_DESCRIPTION("Broadcom UniMAC MDIO bus controller");