mvmdio.c 5.3 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
/*
 * Driver for the MDIO interface of Marvell network interfaces.
 *
 * Since the MDIO interface of Marvell network interfaces is shared
 * between all network interfaces, having a single driver allows to
 * handle concurrent accesses properly (you may have four Ethernet
 * ports, but they in fact share the same SMI interface to access the
 * MDIO bus). Moreover, this MDIO interface code is similar between
 * the mv643xx_eth driver and the mvneta driver. For now, it is only
 * used by the mvneta driver, but it could later be used by the
 * mv643xx_eth driver as well.
 *
 * Copyright (C) 2012 Marvell
 *
 * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
 *
 * This file is licensed under the terms of the GNU General Public
 * License version 2. This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 */

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/phy.h>
#include <linux/platform_device.h>
28
#include <linux/delay.h>
29 30
#include <linux/io.h>
#include <linux/of_mdio.h>
31 32 33 34 35 36 37 38 39 40 41 42 43 44

#define MVMDIO_SMI_DATA_SHIFT              0
#define MVMDIO_SMI_PHY_ADDR_SHIFT          16
#define MVMDIO_SMI_PHY_REG_SHIFT           21
#define MVMDIO_SMI_READ_OPERATION          BIT(26)
#define MVMDIO_SMI_WRITE_OPERATION         0
#define MVMDIO_SMI_READ_VALID              BIT(27)
#define MVMDIO_SMI_BUSY                    BIT(28)

struct orion_mdio_dev {
	struct mutex lock;
	void __iomem *smireg;
};

45
/* Wait for the SMI unit to be ready for another operation
46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143
 */
static int orion_mdio_wait_ready(struct mii_bus *bus)
{
	struct orion_mdio_dev *dev = bus->priv;
	int count;
	u32 val;

	count = 0;
	while (1) {
		val = readl(dev->smireg);
		if (!(val & MVMDIO_SMI_BUSY))
			break;

		if (count > 100) {
			dev_err(bus->parent, "Timeout: SMI busy for too long\n");
			return -ETIMEDOUT;
		}

		udelay(10);
		count++;
	}

	return 0;
}

static int orion_mdio_read(struct mii_bus *bus, int mii_id,
			   int regnum)
{
	struct orion_mdio_dev *dev = bus->priv;
	int count;
	u32 val;
	int ret;

	mutex_lock(&dev->lock);

	ret = orion_mdio_wait_ready(bus);
	if (ret < 0) {
		mutex_unlock(&dev->lock);
		return ret;
	}

	writel(((mii_id << MVMDIO_SMI_PHY_ADDR_SHIFT) |
		(regnum << MVMDIO_SMI_PHY_REG_SHIFT)  |
		MVMDIO_SMI_READ_OPERATION),
	       dev->smireg);

	/* Wait for the value to become available */
	count = 0;
	while (1) {
		val = readl(dev->smireg);
		if (val & MVMDIO_SMI_READ_VALID)
			break;

		if (count > 100) {
			dev_err(bus->parent, "Timeout when reading PHY\n");
			mutex_unlock(&dev->lock);
			return -ETIMEDOUT;
		}

		udelay(10);
		count++;
	}

	mutex_unlock(&dev->lock);

	return val & 0xFFFF;
}

static int orion_mdio_write(struct mii_bus *bus, int mii_id,
			    int regnum, u16 value)
{
	struct orion_mdio_dev *dev = bus->priv;
	int ret;

	mutex_lock(&dev->lock);

	ret = orion_mdio_wait_ready(bus);
	if (ret < 0) {
		mutex_unlock(&dev->lock);
		return ret;
	}

	writel(((mii_id << MVMDIO_SMI_PHY_ADDR_SHIFT) |
		(regnum << MVMDIO_SMI_PHY_REG_SHIFT)  |
		MVMDIO_SMI_WRITE_OPERATION            |
		(value << MVMDIO_SMI_DATA_SHIFT)),
	       dev->smireg);

	mutex_unlock(&dev->lock);

	return 0;
}

static int orion_mdio_reset(struct mii_bus *bus)
{
	return 0;
}

G
Greg KH 已提交
144
static int orion_mdio_probe(struct platform_device *pdev)
145
{
146
	struct resource *r;
147 148 149 150
	struct mii_bus *bus;
	struct orion_mdio_dev *dev;
	int i, ret;

151 152 153 154 155 156
	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!r) {
		dev_err(&pdev->dev, "No SMI register address given\n");
		return -ENODEV;
	}

157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180
	bus = mdiobus_alloc_size(sizeof(struct orion_mdio_dev));
	if (!bus) {
		dev_err(&pdev->dev, "Cannot allocate MDIO bus\n");
		return -ENOMEM;
	}

	bus->name = "orion_mdio_bus";
	bus->read = orion_mdio_read;
	bus->write = orion_mdio_write;
	bus->reset = orion_mdio_reset;
	snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii",
		 dev_name(&pdev->dev));
	bus->parent = &pdev->dev;

	bus->irq = kmalloc(sizeof(int) * PHY_MAX_ADDR, GFP_KERNEL);
	if (!bus->irq) {
		mdiobus_free(bus);
		return -ENOMEM;
	}

	for (i = 0; i < PHY_MAX_ADDR; i++)
		bus->irq[i] = PHY_POLL;

	dev = bus->priv;
181
	dev->smireg = devm_ioremap(&pdev->dev, r->start, resource_size(r));
182
	if (!dev->smireg) {
183
		dev_err(&pdev->dev, "Unable to remap SMI register\n");
184 185 186 187 188 189 190
		kfree(bus->irq);
		mdiobus_free(bus);
		return -ENODEV;
	}

	mutex_init(&dev->lock);

191 192 193 194
	if (pdev->dev.of_node)
		ret = of_mdiobus_register(bus, pdev->dev.of_node);
	else
		ret = mdiobus_register(bus);
195 196 197 198 199 200 201 202 203 204 205 206
	if (ret < 0) {
		dev_err(&pdev->dev, "Cannot register MDIO bus (%d)\n", ret);
		kfree(bus->irq);
		mdiobus_free(bus);
		return ret;
	}

	platform_set_drvdata(pdev, bus);

	return 0;
}

G
Greg KH 已提交
207
static int orion_mdio_remove(struct platform_device *pdev)
208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223
{
	struct mii_bus *bus = platform_get_drvdata(pdev);
	mdiobus_unregister(bus);
	kfree(bus->irq);
	mdiobus_free(bus);
	return 0;
}

static const struct of_device_id orion_mdio_match[] = {
	{ .compatible = "marvell,orion-mdio" },
	{ }
};
MODULE_DEVICE_TABLE(of, orion_mdio_match);

static struct platform_driver orion_mdio_driver = {
	.probe = orion_mdio_probe,
G
Greg KH 已提交
224
	.remove = orion_mdio_remove,
225 226 227 228 229 230 231 232 233 234 235
	.driver = {
		.name = "orion-mdio",
		.of_match_table = orion_mdio_match,
	},
};

module_platform_driver(orion_mdio_driver);

MODULE_DESCRIPTION("Marvell MDIO interface driver");
MODULE_AUTHOR("Thomas Petazzoni <thomas.petazzoni@free-electrons.com>");
MODULE_LICENSE("GPL");