[deliverable/linux.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/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 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 ret;

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

	bus = devm_mdiobus_alloc_size(&pdev->dev,
				      sizeof(struct orion_mdio_dev));
	if (!bus)
		return -ENOMEM;

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

	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 > 0) {
		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);

	} else if (dev->err_interrupt == -EPROBE_DEFER) {
		return -EPROBE_DEFER;
	}

	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);
	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);
	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
fc8f5ade TP	20	#include <linux/kernel.h>
	21	#include <linux/module.h>
	22	#include <linux/mutex.h>
	23	#include <linux/phy.h>
2ec98521	24	#include <linux/interrupt.h>
fc8f5ade	25	#include <linux/platform_device.h>
d98a80f5	26	#include <linux/delay.h>
7111b717	27	#include <linux/io.h>
3d604da1	28	#include <linux/clk.h>
7111b717	29	#include <linux/of_mdio.h>
2ec98521 FF	30	#include <linux/sched.h>
2ec98521 FF	31	#include <linux/wait.h>
fc8f5ade TP	32
	33	#define MVMDIO_SMI_DATA_SHIFT 0
	34	#define MVMDIO_SMI_PHY_ADDR_SHIFT 16
	35	#define MVMDIO_SMI_PHY_REG_SHIFT 21
	36	#define MVMDIO_SMI_READ_OPERATION BIT(26)
	37	#define MVMDIO_SMI_WRITE_OPERATION 0
	38	#define MVMDIO_SMI_READ_VALID BIT(27)
	39	#define MVMDIO_SMI_BUSY BIT(28)
2ec98521 FF	40	#define MVMDIO_ERR_INT_CAUSE 0x007C
	41	#define MVMDIO_ERR_INT_SMI_DONE 0x00000010
	42	#define MVMDIO_ERR_INT_MASK 0x0080
fc8f5ade	43
b70cd1c1 LB	44	/*
	45	* SMI Timeout measurements:
	46	* - Kirkwood 88F6281 (Globalscale Dreamplug): 45us to 95us (Interrupt)
	47	* - Armada 370 (Globalscale Mirabox): 41us to 43us (Polled)
	48	*/
	49	#define MVMDIO_SMI_TIMEOUT 1000 /* 1000us = 1ms */
	50	#define MVMDIO_SMI_POLL_INTERVAL_MIN 45
	51	#define MVMDIO_SMI_POLL_INTERVAL_MAX 55
	52
fc8f5ade TP	53	struct orion_mdio_dev {
fc8f5ade TP	54	struct mutex lock;
3712b717	55	void __iomem *regs;
3d604da1	56	struct clk *clk;
2ec98521 FF	57	/*
	58	* If we have access to the error interrupt pin (which is
	59	* somewhat misnamed as it not only reflects internal errors
	60	* but also reflects SMI completion), use that to wait for
	61	* SMI access completion instead of polling the SMI busy bit.
	62	*/
	63	int err_interrupt;
	64	wait_queue_head_t smi_busy_wait;
fc8f5ade TP	65	};
fc8f5ade TP	66
2ec98521 FF	67	static int orion_mdio_smi_is_done(struct orion_mdio_dev *dev)
	68	{
	69	return !(readl(dev->regs) & MVMDIO_SMI_BUSY);
	70	}
	71
b07812f1	72	/* Wait for the SMI unit to be ready for another operation
fc8f5ade TP	73	*/
	74	static int orion_mdio_wait_ready(struct mii_bus *bus)
	75	{
	76	struct orion_mdio_dev *dev = bus->priv;
b70cd1c1 LB	77	unsigned long timeout = usecs_to_jiffies(MVMDIO_SMI_TIMEOUT);
	78	unsigned long end = jiffies + timeout;
	79	int timedout = 0;
fc8f5ade	80
b70cd1c1 LB	81	while (1) {
	82	if (orion_mdio_smi_is_done(dev))
	83	return 0;
	84	else if (timedout)
	85	break;
fc8f5ade	86
b70cd1c1 LB	87	if (dev->err_interrupt <= 0) {
	88	usleep_range(MVMDIO_SMI_POLL_INTERVAL_MIN,
	89	MVMDIO_SMI_POLL_INTERVAL_MAX);
fc8f5ade	90
b70cd1c1 LB	91	if (time_is_before_jiffies(end))
	92	++timedout;
	93	} else {
1a1f20bc LB	94	/* wait_event_timeout does not guarantee a delay of at
	95	* least one whole jiffie, so timeout must be no less
	96	* than two.
	97	*/
	98	if (timeout < 2)
	99	timeout = 2;
2ec98521	100	wait_event_timeout(dev->smi_busy_wait,
b70cd1c1 LB	101	orion_mdio_smi_is_done(dev),
	102	timeout);
	103
	104	++timedout;
	105	}
fc8f5ade TP	106	}
fc8f5ade TP	107
b70cd1c1 LB	108	dev_err(bus->parent, "Timeout: SMI busy for too long\n");
b70cd1c1 LB	109	return -ETIMEDOUT;
fc8f5ade TP	110	}
	111
	112	static int orion_mdio_read(struct mii_bus *bus, int mii_id,
	113	int regnum)
	114	{
	115	struct orion_mdio_dev *dev = bus->priv;
fc8f5ade TP	116	u32 val;
	117	int ret;
	118
	119	mutex_lock(&dev->lock);
	120
	121	ret = orion_mdio_wait_ready(bus);
839f46bb LB	122	if (ret < 0)
839f46bb LB	123	goto out;
fc8f5ade TP	124
	125	writel(((mii_id << MVMDIO_SMI_PHY_ADDR_SHIFT) \|
	126	(regnum << MVMDIO_SMI_PHY_REG_SHIFT) \|
	127	MVMDIO_SMI_READ_OPERATION),
3712b717	128	dev->regs);
fc8f5ade	129
839f46bb LB	130	ret = orion_mdio_wait_ready(bus);
	131	if (ret < 0)
	132	goto out;
	133
	134	val = readl(dev->regs);
	135	if (!(val & MVMDIO_SMI_READ_VALID)) {
	136	dev_err(bus->parent, "SMI bus read not valid\n");
	137	ret = -ENODEV;
	138	goto out;
fc8f5ade TP	139	}
fc8f5ade TP	140
839f46bb LB	141	ret = val & 0xFFFF;
839f46bb LB	142	out:
fc8f5ade	143	mutex_unlock(&dev->lock);
839f46bb	144	return ret;
fc8f5ade TP	145	}
	146
	147	static int orion_mdio_write(struct mii_bus *bus, int mii_id,
	148	int regnum, u16 value)
	149	{
	150	struct orion_mdio_dev *dev = bus->priv;
	151	int ret;
	152
	153	mutex_lock(&dev->lock);
	154
	155	ret = orion_mdio_wait_ready(bus);
526edcf5 LB	156	if (ret < 0)
526edcf5 LB	157	goto out;
fc8f5ade TP	158
	159	writel(((mii_id << MVMDIO_SMI_PHY_ADDR_SHIFT) \|
	160	(regnum << MVMDIO_SMI_PHY_REG_SHIFT) \|
	161	MVMDIO_SMI_WRITE_OPERATION \|
	162	(value << MVMDIO_SMI_DATA_SHIFT)),
3712b717	163	dev->regs);
fc8f5ade	164
526edcf5	165	out:
fc8f5ade	166	mutex_unlock(&dev->lock);
526edcf5	167	return ret;
fc8f5ade TP	168	}
fc8f5ade TP	169
2ec98521 FF	170	static irqreturn_t orion_mdio_err_irq(int irq, void *dev_id)
	171	{
	172	struct orion_mdio_dev *dev = dev_id;
	173
	174	if (readl(dev->regs + MVMDIO_ERR_INT_CAUSE) &
	175	MVMDIO_ERR_INT_SMI_DONE) {
	176	writel(~MVMDIO_ERR_INT_SMI_DONE,
	177	dev->regs + MVMDIO_ERR_INT_CAUSE);
	178	wake_up(&dev->smi_busy_wait);
	179	return IRQ_HANDLED;
	180	}
	181
	182	return IRQ_NONE;
	183	}
	184
03ce758e	185	static int orion_mdio_probe(struct platform_device *pdev)
fc8f5ade	186	{
7111b717	187	struct resource *r;
fc8f5ade TP	188	struct mii_bus *bus;
fc8f5ade TP	189	struct orion_mdio_dev *dev;
e7f4dc35	190	int ret;
fc8f5ade	191
7111b717 FF	192	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	193	if (!r) {
	194	dev_err(&pdev->dev, "No SMI register address given\n");
	195	return -ENODEV;
	196	}
	197
56ecd2cc EG	198	bus = devm_mdiobus_alloc_size(&pdev->dev,
	199	sizeof(struct orion_mdio_dev));
	200	if (!bus)
fc8f5ade	201	return -ENOMEM;
fc8f5ade TP	202
	203	bus->name = "orion_mdio_bus";
	204	bus->read = orion_mdio_read;
	205	bus->write = orion_mdio_write;
fc8f5ade TP	206	snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii",
	207	dev_name(&pdev->dev));
	208	bus->parent = &pdev->dev;
	209
fc8f5ade	210	dev = bus->priv;
3712b717 FF	211	dev->regs = devm_ioremap(&pdev->dev, r->start, resource_size(r));
3712b717 FF	212	if (!dev->regs) {
7111b717	213	dev_err(&pdev->dev, "Unable to remap SMI register\n");
2ec98521 FF	214	ret = -ENODEV;
	215	goto out_mdio;
	216	}
	217
	218	init_waitqueue_head(&dev->smi_busy_wait);
	219
3d604da1 SH	220	dev->clk = devm_clk_get(&pdev->dev, NULL);
	221	if (!IS_ERR(dev->clk))
	222	clk_prepare_enable(dev->clk);
	223
2ec98521	224	dev->err_interrupt = platform_get_irq(pdev, 0);
39076b04	225	if (dev->err_interrupt > 0) {
2ec98521 FF	226	ret = devm_request_irq(&pdev->dev, dev->err_interrupt,
	227	orion_mdio_err_irq,
	228	IRQF_SHARED, pdev->name, dev);
	229	if (ret)
	230	goto out_mdio;
	231
	232	writel(MVMDIO_ERR_INT_SMI_DONE,
	233	dev->regs + MVMDIO_ERR_INT_MASK);
39076b04 EG	234
	235	} else if (dev->err_interrupt == -EPROBE_DEFER) {
	236	return -EPROBE_DEFER;
fc8f5ade TP	237	}
	238
	239	mutex_init(&dev->lock);
	240
7111b717 FF	241	if (pdev->dev.of_node)
	242	ret = of_mdiobus_register(bus, pdev->dev.of_node);
	243	else
	244	ret = mdiobus_register(bus);
fc8f5ade TP	245	if (ret < 0) {
fc8f5ade TP	246	dev_err(&pdev->dev, "Cannot register MDIO bus (%d)\n", ret);
2ec98521	247	goto out_mdio;
fc8f5ade TP	248	}
	249
	250	platform_set_drvdata(pdev, bus);
	251
	252	return 0;
2ec98521 FF	253
2ec98521 FF	254	out_mdio:
3d604da1 SH	255	if (!IS_ERR(dev->clk))
3d604da1 SH	256	clk_disable_unprepare(dev->clk);
2ec98521	257	return ret;
fc8f5ade TP	258	}
fc8f5ade TP	259
03ce758e	260	static int orion_mdio_remove(struct platform_device *pdev)
fc8f5ade TP	261	{
fc8f5ade TP	262	struct mii_bus *bus = platform_get_drvdata(pdev);
2ec98521 FF	263	struct orion_mdio_dev *dev = bus->priv;
	264
	265	writel(0, dev->regs + MVMDIO_ERR_INT_MASK);
fc8f5ade	266	mdiobus_unregister(bus);
3d604da1 SH	267	if (!IS_ERR(dev->clk))
	268	clk_disable_unprepare(dev->clk);
	269
fc8f5ade TP	270	return 0;
	271	}
	272
	273	static const struct of_device_id orion_mdio_match[] = {
	274	{ .compatible = "marvell,orion-mdio" },
	275	{ }
	276	};
	277	MODULE_DEVICE_TABLE(of, orion_mdio_match);
	278
	279	static struct platform_driver orion_mdio_driver = {
	280	.probe = orion_mdio_probe,
03ce758e	281	.remove = orion_mdio_remove,
fc8f5ade TP	282	.driver = {
	283	.name = "orion-mdio",
	284	.of_match_table = orion_mdio_match,
	285	},
	286	};
	287
	288	module_platform_driver(orion_mdio_driver);
	289
	290	MODULE_DESCRIPTION("Marvell MDIO interface driver");
	291	MODULE_AUTHOR("Thomas Petazzoni <thomas.petazzoni@free-electrons.com>");
	292	MODULE_LICENSE("GPL");
404b8bed	293	MODULE_ALIAS("platform:orion-mdio");