[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). This driver is currently used by the mvneta and
 * mv643xx_eth drivers.
 *
 * 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/clk.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

/*
 * SMI Timeout measurements:
 * - Kirkwood 88F6281 (Globalscale Dreamplug): 45us to 95us (Interrupt)
 * - Armada 370       (Globalscale Mirabox):   41us to 43us (Polled)
 */
#define MVMDIO_SMI_TIMEOUT		   1000 /* 1000us = 1ms */
#define MVMDIO_SMI_POLL_INTERVAL_MIN	   45
#define MVMDIO_SMI_POLL_INTERVAL_MAX	   55

struct orion_mdio_dev {
	struct mutex lock;
	void __iomem *regs;
	struct clk *clk;
	/*
	 * 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;
	unsigned long timeout = usecs_to_jiffies(MVMDIO_SMI_TIMEOUT);
	unsigned long end = jiffies + timeout;
	int timedout = 0;

	while (1) {
	        if (orion_mdio_smi_is_done(dev))
			return 0;
	        else if (timedout)
			break;

	        if (dev->err_interrupt <= 0) {
			usleep_range(MVMDIO_SMI_POLL_INTERVAL_MIN,
				     MVMDIO_SMI_POLL_INTERVAL_MAX);

			if (time_is_before_jiffies(end))
				++timedout;
	        } else {
			/* wait_event_timeout does not guarantee a delay of at
			 * least one whole jiffie, so timeout must be no less
			 * than two.
			 */
			if (timeout < 2)
				timeout = 2;
			wait_event_timeout(dev->smi_busy_wait,
				           orion_mdio_smi_is_done(dev),
				           timeout);

			++timedout;
	        }
	}

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

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

	mutex_lock(&dev->lock);

	ret = orion_mdio_wait_ready(bus);
	if (ret < 0)
		goto out;

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

	ret = orion_mdio_wait_ready(bus);
	if (ret < 0)
		goto out;

	val = readl(dev->regs);
	if (!(val & MVMDIO_SMI_READ_VALID)) {
		dev_err(bus->parent, "SMI bus read not valid\n");
		ret = -ENODEV;
		goto out;
	}

	ret = val & 0xFFFF;
out:
	mutex_unlock(&dev->lock);
	return ret;
}

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)
		goto out;

	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);

out:
	mutex_unlock(&dev->lock);
	return ret;
}

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->clk = devm_clk_get(&pdev->dev, NULL);
	if (!IS_ERR(dev->clk))
		clk_prepare_enable(dev->clk);

	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:
	if (!IS_ERR(dev->clk))
		clk_disable_unprepare(dev->clk);
	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);
	if (!IS_ERR(dev->clk))
		clk_disable_unprepare(dev->clk);

	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");
MODULE_ALIAS("platform:orion-mdio");
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
d4a0acb8 LB	7	* ports, but they in fact share the same SMI interface to access
	8	* the MDIO bus). This driver is currently used by the mvneta and
	9	* mv643xx_eth drivers.
fc8f5ade TP	10	*
	11	* Copyright (C) 2012 Marvell
	12	*
	13	* Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
	14	*
	15	* This file is licensed under the terms of the GNU General Public
	16	* License version 2. This program is licensed "as is" without any
	17	* warranty of any kind, whether express or implied.
	18	*/
	19
	20	#include <linux/init.h>
	21	#include <linux/kernel.h>
	22	#include <linux/module.h>
	23	#include <linux/mutex.h>
	24	#include <linux/phy.h>
2ec98521	25	#include <linux/interrupt.h>
fc8f5ade	26	#include <linux/platform_device.h>
d98a80f5	27	#include <linux/delay.h>
7111b717	28	#include <linux/io.h>
3d604da1	29	#include <linux/clk.h>
7111b717	30	#include <linux/of_mdio.h>
2ec98521 FF	31	#include <linux/sched.h>
2ec98521 FF	32	#include <linux/wait.h>
fc8f5ade TP	33
	34	#define MVMDIO_SMI_DATA_SHIFT 0
	35	#define MVMDIO_SMI_PHY_ADDR_SHIFT 16
	36	#define MVMDIO_SMI_PHY_REG_SHIFT 21
	37	#define MVMDIO_SMI_READ_OPERATION BIT(26)
	38	#define MVMDIO_SMI_WRITE_OPERATION 0
	39	#define MVMDIO_SMI_READ_VALID BIT(27)
	40	#define MVMDIO_SMI_BUSY BIT(28)
2ec98521 FF	41	#define MVMDIO_ERR_INT_CAUSE 0x007C
	42	#define MVMDIO_ERR_INT_SMI_DONE 0x00000010
	43	#define MVMDIO_ERR_INT_MASK 0x0080
fc8f5ade	44
b70cd1c1 LB	45	/*
	46	* SMI Timeout measurements:
	47	* - Kirkwood 88F6281 (Globalscale Dreamplug): 45us to 95us (Interrupt)
	48	* - Armada 370 (Globalscale Mirabox): 41us to 43us (Polled)
	49	*/
	50	#define MVMDIO_SMI_TIMEOUT 1000 /* 1000us = 1ms */
	51	#define MVMDIO_SMI_POLL_INTERVAL_MIN 45
	52	#define MVMDIO_SMI_POLL_INTERVAL_MAX 55
	53
fc8f5ade TP	54	struct orion_mdio_dev {
fc8f5ade TP	55	struct mutex lock;
3712b717	56	void __iomem *regs;
3d604da1	57	struct clk *clk;
2ec98521 FF	58	/*
	59	* If we have access to the error interrupt pin (which is
	60	* somewhat misnamed as it not only reflects internal errors
	61	* but also reflects SMI completion), use that to wait for
	62	* SMI access completion instead of polling the SMI busy bit.
	63	*/
	64	int err_interrupt;
	65	wait_queue_head_t smi_busy_wait;
fc8f5ade TP	66	};
fc8f5ade TP	67
2ec98521 FF	68	static int orion_mdio_smi_is_done(struct orion_mdio_dev *dev)
	69	{
	70	return !(readl(dev->regs) & MVMDIO_SMI_BUSY);
	71	}
	72
b07812f1	73	/* Wait for the SMI unit to be ready for another operation
fc8f5ade TP	74	*/
	75	static int orion_mdio_wait_ready(struct mii_bus *bus)
	76	{
	77	struct orion_mdio_dev *dev = bus->priv;
b70cd1c1 LB	78	unsigned long timeout = usecs_to_jiffies(MVMDIO_SMI_TIMEOUT);
	79	unsigned long end = jiffies + timeout;
	80	int timedout = 0;
fc8f5ade	81
b70cd1c1 LB	82	while (1) {
	83	if (orion_mdio_smi_is_done(dev))
	84	return 0;
	85	else if (timedout)
	86	break;
fc8f5ade	87
b70cd1c1 LB	88	if (dev->err_interrupt <= 0) {
	89	usleep_range(MVMDIO_SMI_POLL_INTERVAL_MIN,
	90	MVMDIO_SMI_POLL_INTERVAL_MAX);
fc8f5ade	91
b70cd1c1 LB	92	if (time_is_before_jiffies(end))
	93	++timedout;
	94	} else {
1a1f20bc LB	95	/* wait_event_timeout does not guarantee a delay of at
	96	* least one whole jiffie, so timeout must be no less
	97	* than two.
	98	*/
	99	if (timeout < 2)
	100	timeout = 2;
2ec98521	101	wait_event_timeout(dev->smi_busy_wait,
b70cd1c1 LB	102	orion_mdio_smi_is_done(dev),
	103	timeout);
	104
	105	++timedout;
	106	}
fc8f5ade TP	107	}
fc8f5ade TP	108
b70cd1c1 LB	109	dev_err(bus->parent, "Timeout: SMI busy for too long\n");
b70cd1c1 LB	110	return -ETIMEDOUT;
fc8f5ade TP	111	}
	112
	113	static int orion_mdio_read(struct mii_bus *bus, int mii_id,
	114	int regnum)
	115	{
	116	struct orion_mdio_dev *dev = bus->priv;
fc8f5ade TP	117	u32 val;
	118	int ret;
	119
	120	mutex_lock(&dev->lock);
	121
	122	ret = orion_mdio_wait_ready(bus);
839f46bb LB	123	if (ret < 0)
839f46bb LB	124	goto out;
fc8f5ade TP	125
	126	writel(((mii_id << MVMDIO_SMI_PHY_ADDR_SHIFT) \|
	127	(regnum << MVMDIO_SMI_PHY_REG_SHIFT) \|
	128	MVMDIO_SMI_READ_OPERATION),
3712b717	129	dev->regs);
fc8f5ade	130
839f46bb LB	131	ret = orion_mdio_wait_ready(bus);
	132	if (ret < 0)
	133	goto out;
	134
	135	val = readl(dev->regs);
	136	if (!(val & MVMDIO_SMI_READ_VALID)) {
	137	dev_err(bus->parent, "SMI bus read not valid\n");
	138	ret = -ENODEV;
	139	goto out;
fc8f5ade TP	140	}
fc8f5ade TP	141
839f46bb LB	142	ret = val & 0xFFFF;
839f46bb LB	143	out:
fc8f5ade	144	mutex_unlock(&dev->lock);
839f46bb	145	return ret;
fc8f5ade TP	146	}
	147
	148	static int orion_mdio_write(struct mii_bus *bus, int mii_id,
	149	int regnum, u16 value)
	150	{
	151	struct orion_mdio_dev *dev = bus->priv;
	152	int ret;
	153
	154	mutex_lock(&dev->lock);
	155
	156	ret = orion_mdio_wait_ready(bus);
526edcf5 LB	157	if (ret < 0)
526edcf5 LB	158	goto out;
fc8f5ade TP	159
	160	writel(((mii_id << MVMDIO_SMI_PHY_ADDR_SHIFT) \|
	161	(regnum << MVMDIO_SMI_PHY_REG_SHIFT) \|
	162	MVMDIO_SMI_WRITE_OPERATION \|
	163	(value << MVMDIO_SMI_DATA_SHIFT)),
3712b717	164	dev->regs);
fc8f5ade	165
526edcf5	166	out:
fc8f5ade	167	mutex_unlock(&dev->lock);
526edcf5	168	return ret;
fc8f5ade TP	169	}
	170
	171	static int orion_mdio_reset(struct mii_bus *bus)
	172	{
	173	return 0;
	174	}
	175
2ec98521 FF	176	static irqreturn_t orion_mdio_err_irq(int irq, void *dev_id)
	177	{
	178	struct orion_mdio_dev *dev = dev_id;
	179
	180	if (readl(dev->regs + MVMDIO_ERR_INT_CAUSE) &
	181	MVMDIO_ERR_INT_SMI_DONE) {
	182	writel(~MVMDIO_ERR_INT_SMI_DONE,
	183	dev->regs + MVMDIO_ERR_INT_CAUSE);
	184	wake_up(&dev->smi_busy_wait);
	185	return IRQ_HANDLED;
	186	}
	187
	188	return IRQ_NONE;
	189	}
	190
03ce758e	191	static int orion_mdio_probe(struct platform_device *pdev)
fc8f5ade	192	{
7111b717	193	struct resource *r;
fc8f5ade TP	194	struct mii_bus *bus;
	195	struct orion_mdio_dev *dev;
	196	int i, ret;
	197
7111b717 FF	198	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	199	if (!r) {
	200	dev_err(&pdev->dev, "No SMI register address given\n");
	201	return -ENODEV;
	202	}
	203
fc8f5ade TP	204	bus = mdiobus_alloc_size(sizeof(struct orion_mdio_dev));
	205	if (!bus) {
	206	dev_err(&pdev->dev, "Cannot allocate MDIO bus\n");
	207	return -ENOMEM;
	208	}
	209
	210	bus->name = "orion_mdio_bus";
	211	bus->read = orion_mdio_read;
	212	bus->write = orion_mdio_write;
	213	bus->reset = orion_mdio_reset;
	214	snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii",
	215	dev_name(&pdev->dev));
	216	bus->parent = &pdev->dev;
	217
	218	bus->irq = kmalloc(sizeof(int) * PHY_MAX_ADDR, GFP_KERNEL);
	219	if (!bus->irq) {
fc8f5ade TP	220	mdiobus_free(bus);
	221	return -ENOMEM;
	222	}
	223
	224	for (i = 0; i < PHY_MAX_ADDR; i++)
	225	bus->irq[i] = PHY_POLL;
	226
	227	dev = bus->priv;
3712b717 FF	228	dev->regs = devm_ioremap(&pdev->dev, r->start, resource_size(r));
3712b717 FF	229	if (!dev->regs) {
7111b717	230	dev_err(&pdev->dev, "Unable to remap SMI register\n");
2ec98521 FF	231	ret = -ENODEV;
	232	goto out_mdio;
	233	}
	234
	235	init_waitqueue_head(&dev->smi_busy_wait);
	236
3d604da1 SH	237	dev->clk = devm_clk_get(&pdev->dev, NULL);
	238	if (!IS_ERR(dev->clk))
	239	clk_prepare_enable(dev->clk);
	240
2ec98521 FF	241	dev->err_interrupt = platform_get_irq(pdev, 0);
	242	if (dev->err_interrupt != -ENXIO) {
	243	ret = devm_request_irq(&pdev->dev, dev->err_interrupt,
	244	orion_mdio_err_irq,
	245	IRQF_SHARED, pdev->name, dev);
	246	if (ret)
	247	goto out_mdio;
	248
	249	writel(MVMDIO_ERR_INT_SMI_DONE,
	250	dev->regs + MVMDIO_ERR_INT_MASK);
fc8f5ade TP	251	}
	252
	253	mutex_init(&dev->lock);
	254
7111b717 FF	255	if (pdev->dev.of_node)
	256	ret = of_mdiobus_register(bus, pdev->dev.of_node);
	257	else
	258	ret = mdiobus_register(bus);
fc8f5ade TP	259	if (ret < 0) {
fc8f5ade TP	260	dev_err(&pdev->dev, "Cannot register MDIO bus (%d)\n", ret);
2ec98521	261	goto out_mdio;
fc8f5ade TP	262	}
	263
	264	platform_set_drvdata(pdev, bus);
	265
	266	return 0;
2ec98521 FF	267
2ec98521 FF	268	out_mdio:
3d604da1 SH	269	if (!IS_ERR(dev->clk))
3d604da1 SH	270	clk_disable_unprepare(dev->clk);
2ec98521 FF	271	kfree(bus->irq);
	272	mdiobus_free(bus);
	273	return ret;
fc8f5ade TP	274	}
fc8f5ade TP	275
03ce758e	276	static int orion_mdio_remove(struct platform_device *pdev)
fc8f5ade TP	277	{
fc8f5ade TP	278	struct mii_bus *bus = platform_get_drvdata(pdev);
2ec98521 FF	279	struct orion_mdio_dev *dev = bus->priv;
	280
	281	writel(0, dev->regs + MVMDIO_ERR_INT_MASK);
fc8f5ade TP	282	mdiobus_unregister(bus);
	283	kfree(bus->irq);
	284	mdiobus_free(bus);
3d604da1 SH	285	if (!IS_ERR(dev->clk))
	286	clk_disable_unprepare(dev->clk);
	287
fc8f5ade TP	288	return 0;
	289	}
	290
	291	static const struct of_device_id orion_mdio_match[] = {
	292	{ .compatible = "marvell,orion-mdio" },
	293	{ }
	294	};
	295	MODULE_DEVICE_TABLE(of, orion_mdio_match);
	296
	297	static struct platform_driver orion_mdio_driver = {
	298	.probe = orion_mdio_probe,
03ce758e	299	.remove = orion_mdio_remove,
fc8f5ade TP	300	.driver = {
	301	.name = "orion-mdio",
	302	.of_match_table = orion_mdio_match,
	303	},
	304	};
	305
	306	module_platform_driver(orion_mdio_driver);
	307
	308	MODULE_DESCRIPTION("Marvell MDIO interface driver");
	309	MODULE_AUTHOR("Thomas Petazzoni <thomas.petazzoni@free-electrons.com>");
	310	MODULE_LICENSE("GPL");
404b8bed	311	MODULE_ALIAS("platform:orion-mdio");