- 根目录:
- 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 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 = 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;
bus->irq = devm_kmalloc_array(&pdev->dev, PHY_MAX_ADDR, sizeof(int),
GFP_KERNEL);
if (!bus->irq)
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 > 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");