[linux-2.6-block.git] / drivers / net / ethernet / marvell / mvmdio.c

/*
 * 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/interrupt.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/of_mdio.h>
#include <linux/sched.h>
#include <linux/wait.h>

#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)
#define MVMDIO_ERR_INT_CAUSE		   0x007C
#define  MVMDIO_ERR_INT_SMI_DONE	   0x00000010
#define MVMDIO_ERR_INT_MASK		   0x0080

struct orion_mdio_dev {
	struct mutex lock;
	void __iomem *regs;
	/*
	 * If we have access to the error interrupt pin (which is
	 * somewhat misnamed as it not only reflects internal errors
	 * but also reflects SMI completion), use that to wait for
	 * SMI access completion instead of polling the SMI busy bit.
	 */
	int err_interrupt;
	wait_queue_head_t smi_busy_wait;
};

static int orion_mdio_smi_is_done(struct orion_mdio_dev *dev)
{
	return !(readl(dev->regs) & MVMDIO_SMI_BUSY);
}

/* Wait for the SMI unit to be ready for another operation
 */
static int orion_mdio_wait_ready(struct mii_bus *bus)
{
	struct orion_mdio_dev *dev = bus->priv;
	int count;

	if (dev->err_interrupt <= 0) {
		count = 0;
		while (1) {
			if (orion_mdio_smi_is_done(dev))
				break;

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

			udelay(10);
			count++;
		}
	} else {
		if (!orion_mdio_smi_is_done(dev)) {
			wait_event_timeout(dev->smi_busy_wait,
				orion_mdio_smi_is_done(dev),
				msecs_to_jiffies(100));
			if (!orion_mdio_smi_is_done(dev))
				return -ETIMEDOUT;
		}
	}

	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->regs);

	/* Wait for the value to become available */
	count = 0;
	while (1) {
		val = readl(dev->regs);
		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->regs);

	mutex_unlock(&dev->lock);

	return 0;
}

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

static irqreturn_t orion_mdio_err_irq(int irq, void *dev_id)
{
	struct orion_mdio_dev *dev = dev_id;

	if (readl(dev->regs + MVMDIO_ERR_INT_CAUSE) &
			MVMDIO_ERR_INT_SMI_DONE) {
		writel(~MVMDIO_ERR_INT_SMI_DONE,
				dev->regs + MVMDIO_ERR_INT_CAUSE);
		wake_up(&dev->smi_busy_wait);
		return IRQ_HANDLED;
	}

	return IRQ_NONE;
}

static int orion_mdio_probe(struct platform_device *pdev)
{
	struct resource *r;
	struct mii_bus *bus;
	struct orion_mdio_dev *dev;
	int i, ret;

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

	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;
	dev->regs = devm_ioremap(&pdev->dev, r->start, resource_size(r));
	if (!dev->regs) {
		dev_err(&pdev->dev, "Unable to remap SMI register\n");
		ret = -ENODEV;
		goto out_mdio;
	}

	init_waitqueue_head(&dev->smi_busy_wait);

	dev->err_interrupt = platform_get_irq(pdev, 0);
	if (dev->err_interrupt != -ENXIO) {
		ret = devm_request_irq(&pdev->dev, dev->err_interrupt,
					orion_mdio_err_irq,
					IRQF_SHARED, pdev->name, dev);
		if (ret)
			goto out_mdio;

		writel(MVMDIO_ERR_INT_SMI_DONE,
			dev->regs + MVMDIO_ERR_INT_MASK);
	}

	mutex_init(&dev->lock);

	if (pdev->dev.of_node)
		ret = of_mdiobus_register(bus, pdev->dev.of_node);
	else
		ret = mdiobus_register(bus);
	if (ret < 0) {
		dev_err(&pdev->dev, "Cannot register MDIO bus (%d)\n", ret);
		goto out_mdio;
	}

	platform_set_drvdata(pdev, bus);

	return 0;

out_mdio:
	kfree(bus->irq);
	mdiobus_free(bus);
	return ret;
}

static int orion_mdio_remove(struct platform_device *pdev)
{
	struct mii_bus *bus = platform_get_drvdata(pdev);
	struct orion_mdio_dev *dev = bus->priv;

	writel(0, dev->regs + MVMDIO_ERR_INT_MASK);
	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,
	.remove = orion_mdio_remove,
	.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");
Commit	Line	Data
fc8f5ade TP	1	/*
	2	* Driver for the MDIO interface of Marvell network interfaces.
	3	*
	4	* Since the MDIO interface of Marvell network interfaces is shared
	5	* between all network interfaces, having a single driver allows to
	6	* handle concurrent accesses properly (you may have four Ethernet
	7	* ports, but they in fact share the same SMI interface to access the
	8	* MDIO bus). Moreover, this MDIO interface code is similar between
	9	* the mv643xx_eth driver and the mvneta driver. For now, it is only
	10	* used by the mvneta driver, but it could later be used by the
	11	* mv643xx_eth driver as well.
	12	*
	13	* Copyright (C) 2012 Marvell
	14	*
	15	* Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
	16	*
	17	* This file is licensed under the terms of the GNU General Public
	18	* License version 2. This program is licensed "as is" without any
	19	* warranty of any kind, whether express or implied.
	20	*/
	21
	22	#include <linux/init.h>
	23	#include <linux/kernel.h>
	24	#include <linux/module.h>
	25	#include <linux/mutex.h>
	26	#include <linux/phy.h>
2ec98521	27	#include <linux/interrupt.h>
fc8f5ade	28	#include <linux/platform_device.h>
d98a80f5	29	#include <linux/delay.h>
7111b717 FF	30	#include <linux/io.h>
7111b717 FF	31	#include <linux/of_mdio.h>
2ec98521 FF	32	#include <linux/sched.h>
2ec98521 FF	33	#include <linux/wait.h>
fc8f5ade TP	34
	35	#define MVMDIO_SMI_DATA_SHIFT 0
	36	#define MVMDIO_SMI_PHY_ADDR_SHIFT 16
	37	#define MVMDIO_SMI_PHY_REG_SHIFT 21
	38	#define MVMDIO_SMI_READ_OPERATION BIT(26)
	39	#define MVMDIO_SMI_WRITE_OPERATION 0
	40	#define MVMDIO_SMI_READ_VALID BIT(27)
	41	#define MVMDIO_SMI_BUSY BIT(28)
2ec98521 FF	42	#define MVMDIO_ERR_INT_CAUSE 0x007C
	43	#define MVMDIO_ERR_INT_SMI_DONE 0x00000010
	44	#define MVMDIO_ERR_INT_MASK 0x0080
fc8f5ade TP	45
	46	struct orion_mdio_dev {
	47	struct mutex lock;
3712b717	48	void __iomem *regs;
2ec98521 FF	49	/*
	50	* If we have access to the error interrupt pin (which is
	51	* somewhat misnamed as it not only reflects internal errors
	52	* but also reflects SMI completion), use that to wait for
	53	* SMI access completion instead of polling the SMI busy bit.
	54	*/
	55	int err_interrupt;
	56	wait_queue_head_t smi_busy_wait;
fc8f5ade TP	57	};
fc8f5ade TP	58
2ec98521 FF	59	static int orion_mdio_smi_is_done(struct orion_mdio_dev *dev)
	60	{
	61	return !(readl(dev->regs) & MVMDIO_SMI_BUSY);
	62	}
	63
b07812f1	64	/* Wait for the SMI unit to be ready for another operation
fc8f5ade TP	65	*/
	66	static int orion_mdio_wait_ready(struct mii_bus *bus)
	67	{
	68	struct orion_mdio_dev *dev = bus->priv;
	69	int count;
fc8f5ade	70
2ec98521 FF	71	if (dev->err_interrupt <= 0) {
	72	count = 0;
	73	while (1) {
	74	if (orion_mdio_smi_is_done(dev))
	75	break;
fc8f5ade	76
2ec98521 FF	77	if (count > 100) {
	78	dev_err(bus->parent,
	79	"Timeout: SMI busy for too long\n");
	80	return -ETIMEDOUT;
	81	}
fc8f5ade	82
2ec98521 FF	83	udelay(10);
	84	count++;
	85	}
	86	} else {
	87	if (!orion_mdio_smi_is_done(dev)) {
	88	wait_event_timeout(dev->smi_busy_wait,
	89	orion_mdio_smi_is_done(dev),
	90	msecs_to_jiffies(100));
	91	if (!orion_mdio_smi_is_done(dev))
	92	return -ETIMEDOUT;
	93	}
fc8f5ade TP	94	}
	95
	96	return 0;
	97	}
	98
	99	static int orion_mdio_read(struct mii_bus *bus, int mii_id,
	100	int regnum)
	101	{
	102	struct orion_mdio_dev *dev = bus->priv;
	103	int count;
	104	u32 val;
	105	int ret;
	106
	107	mutex_lock(&dev->lock);
	108
	109	ret = orion_mdio_wait_ready(bus);
	110	if (ret < 0) {
	111	mutex_unlock(&dev->lock);
	112	return ret;
	113	}
	114
	115	writel(((mii_id << MVMDIO_SMI_PHY_ADDR_SHIFT) \|
	116	(regnum << MVMDIO_SMI_PHY_REG_SHIFT) \|
	117	MVMDIO_SMI_READ_OPERATION),
3712b717	118	dev->regs);
fc8f5ade TP	119
	120	/* Wait for the value to become available */
	121	count = 0;
	122	while (1) {
3712b717	123	val = readl(dev->regs);
fc8f5ade TP	124	if (val & MVMDIO_SMI_READ_VALID)
	125	break;
	126
	127	if (count > 100) {
	128	dev_err(bus->parent, "Timeout when reading PHY\n");
	129	mutex_unlock(&dev->lock);
	130	return -ETIMEDOUT;
	131	}
	132
	133	udelay(10);
	134	count++;
	135	}
	136
	137	mutex_unlock(&dev->lock);
	138
	139	return val & 0xFFFF;
	140	}
	141
	142	static int orion_mdio_write(struct mii_bus *bus, int mii_id,
	143	int regnum, u16 value)
	144	{
	145	struct orion_mdio_dev *dev = bus->priv;
	146	int ret;
	147
	148	mutex_lock(&dev->lock);
	149
	150	ret = orion_mdio_wait_ready(bus);
	151	if (ret < 0) {
	152	mutex_unlock(&dev->lock);
	153	return ret;
	154	}
	155
	156	writel(((mii_id << MVMDIO_SMI_PHY_ADDR_SHIFT) \|
	157	(regnum << MVMDIO_SMI_PHY_REG_SHIFT) \|
	158	MVMDIO_SMI_WRITE_OPERATION \|
	159	(value << MVMDIO_SMI_DATA_SHIFT)),
3712b717	160	dev->regs);
fc8f5ade TP	161
	162	mutex_unlock(&dev->lock);
	163
	164	return 0;
	165	}
	166
	167	static int orion_mdio_reset(struct mii_bus *bus)
	168	{
	169	return 0;
	170	}
	171
2ec98521 FF	172	static irqreturn_t orion_mdio_err_irq(int irq, void *dev_id)
	173	{
	174	struct orion_mdio_dev *dev = dev_id;
	175
	176	if (readl(dev->regs + MVMDIO_ERR_INT_CAUSE) &
	177	MVMDIO_ERR_INT_SMI_DONE) {
	178	writel(~MVMDIO_ERR_INT_SMI_DONE,
	179	dev->regs + MVMDIO_ERR_INT_CAUSE);
	180	wake_up(&dev->smi_busy_wait);
	181	return IRQ_HANDLED;
	182	}
	183
	184	return IRQ_NONE;
	185	}
	186
03ce758e	187	static int orion_mdio_probe(struct platform_device *pdev)
fc8f5ade	188	{
7111b717	189	struct resource *r;
fc8f5ade TP	190	struct mii_bus *bus;
	191	struct orion_mdio_dev *dev;
	192	int i, ret;
	193
7111b717 FF	194	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	195	if (!r) {
	196	dev_err(&pdev->dev, "No SMI register address given\n");
	197	return -ENODEV;
	198	}
	199
fc8f5ade TP	200	bus = mdiobus_alloc_size(sizeof(struct orion_mdio_dev));
	201	if (!bus) {
	202	dev_err(&pdev->dev, "Cannot allocate MDIO bus\n");
	203	return -ENOMEM;
	204	}
	205
	206	bus->name = "orion_mdio_bus";
	207	bus->read = orion_mdio_read;
	208	bus->write = orion_mdio_write;
	209	bus->reset = orion_mdio_reset;
	210	snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii",
	211	dev_name(&pdev->dev));
	212	bus->parent = &pdev->dev;
	213
	214	bus->irq = kmalloc(sizeof(int) * PHY_MAX_ADDR, GFP_KERNEL);
	215	if (!bus->irq) {
fc8f5ade TP	216	mdiobus_free(bus);
	217	return -ENOMEM;
	218	}
	219
	220	for (i = 0; i < PHY_MAX_ADDR; i++)
	221	bus->irq[i] = PHY_POLL;
	222
	223	dev = bus->priv;
3712b717 FF	224	dev->regs = devm_ioremap(&pdev->dev, r->start, resource_size(r));
3712b717 FF	225	if (!dev->regs) {
7111b717	226	dev_err(&pdev->dev, "Unable to remap SMI register\n");
2ec98521 FF	227	ret = -ENODEV;
	228	goto out_mdio;
	229	}
	230
	231	init_waitqueue_head(&dev->smi_busy_wait);
	232
	233	dev->err_interrupt = platform_get_irq(pdev, 0);
	234	if (dev->err_interrupt != -ENXIO) {
	235	ret = devm_request_irq(&pdev->dev, dev->err_interrupt,
	236	orion_mdio_err_irq,
	237	IRQF_SHARED, pdev->name, dev);
	238	if (ret)
	239	goto out_mdio;
	240
	241	writel(MVMDIO_ERR_INT_SMI_DONE,
	242	dev->regs + MVMDIO_ERR_INT_MASK);
fc8f5ade TP	243	}
	244
	245	mutex_init(&dev->lock);
	246
7111b717 FF	247	if (pdev->dev.of_node)
	248	ret = of_mdiobus_register(bus, pdev->dev.of_node);
	249	else
	250	ret = mdiobus_register(bus);
fc8f5ade TP	251	if (ret < 0) {
fc8f5ade TP	252	dev_err(&pdev->dev, "Cannot register MDIO bus (%d)\n", ret);
2ec98521	253	goto out_mdio;
fc8f5ade TP	254	}
	255
	256	platform_set_drvdata(pdev, bus);
	257
	258	return 0;
2ec98521 FF	259
	260	out_mdio:
	261	kfree(bus->irq);
	262	mdiobus_free(bus);
	263	return ret;
fc8f5ade TP	264	}
fc8f5ade TP	265
03ce758e	266	static int orion_mdio_remove(struct platform_device *pdev)
fc8f5ade TP	267	{
fc8f5ade TP	268	struct mii_bus *bus = platform_get_drvdata(pdev);
2ec98521 FF	269	struct orion_mdio_dev *dev = bus->priv;
	270
	271	writel(0, dev->regs + MVMDIO_ERR_INT_MASK);
fc8f5ade TP	272	mdiobus_unregister(bus);
	273	kfree(bus->irq);
	274	mdiobus_free(bus);
	275	return 0;
	276	}
	277
	278	static const struct of_device_id orion_mdio_match[] = {
	279	{ .compatible = "marvell,orion-mdio" },
	280	{ }
	281	};
	282	MODULE_DEVICE_TABLE(of, orion_mdio_match);
	283
	284	static struct platform_driver orion_mdio_driver = {
	285	.probe = orion_mdio_probe,
03ce758e	286	.remove = orion_mdio_remove,
fc8f5ade TP	287	.driver = {
	288	.name = "orion-mdio",
	289	.of_match_table = orion_mdio_match,
	290	},
	291	};
	292
	293	module_platform_driver(orion_mdio_driver);
	294
	295	MODULE_DESCRIPTION("Marvell MDIO interface driver");
	296	MODULE_AUTHOR("Thomas Petazzoni <thomas.petazzoni@free-electrons.com>");
	297	MODULE_LICENSE("GPL");