linux-stable/drivers/net/ethernet/marvell/mvmdio.c
Antoine Ténart 1955796640 net: mvmdio: put the poll intervals in the ops structure
Put the two poll intervals (min and max) in the driver's ops
structure. This is needed to add the xmdio support later.

Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-16 12:27:11 -04:00

318 lines
7.8 KiB
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/clk.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of_mdio.h>
#include <linux/phy.h>
#include <linux/platform_device.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 {
void __iomem *regs;
struct clk *clk[3];
/*
* 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;
};
struct orion_mdio_ops {
int (*is_done)(struct orion_mdio_dev *);
unsigned int poll_interval_min;
unsigned int poll_interval_max;
};
/* Wait for the SMI unit to be ready for another operation
*/
static int orion_mdio_wait_ready(const struct orion_mdio_ops *ops,
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 (ops->is_done(dev))
return 0;
else if (timedout)
break;
if (dev->err_interrupt <= 0) {
usleep_range(ops->poll_interval_min,
ops->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,
ops->is_done(dev), timeout);
++timedout;
}
}
dev_err(bus->parent, "Timeout: SMI busy for too long\n");
return -ETIMEDOUT;
}
static int orion_mdio_smi_is_done(struct orion_mdio_dev *dev)
{
return !(readl(dev->regs) & MVMDIO_SMI_BUSY);
}
static const struct orion_mdio_ops orion_mdio_smi_ops = {
.is_done = orion_mdio_smi_is_done,
.poll_interval_min = MVMDIO_SMI_POLL_INTERVAL_MIN,
.poll_interval_max = MVMDIO_SMI_POLL_INTERVAL_MAX,
};
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;
ret = orion_mdio_wait_ready(&orion_mdio_smi_ops, 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(&orion_mdio_smi_ops, 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 & GENMASK(15, 0);
out:
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;
ret = orion_mdio_wait_ready(&orion_mdio_smi_ops, 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:
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;
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");
return -ENODEV;
}
init_waitqueue_head(&dev->smi_busy_wait);
for (i = 0; i < ARRAY_SIZE(dev->clk); i++) {
dev->clk[i] = of_clk_get(pdev->dev.of_node, i);
if (IS_ERR(dev->clk[i]))
break;
clk_prepare_enable(dev->clk[i]);
}
dev->err_interrupt = platform_get_irq(pdev, 0);
if (dev->err_interrupt > 0 &&
resource_size(r) < MVMDIO_ERR_INT_MASK + 4) {
dev_err(&pdev->dev,
"disabling interrupt, resource size is too small\n");
dev->err_interrupt = 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;
}
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 (dev->err_interrupt > 0)
writel(0, dev->regs + MVMDIO_ERR_INT_MASK);
for (i = 0; i < ARRAY_SIZE(dev->clk); i++) {
if (IS_ERR(dev->clk[i]))
break;
clk_disable_unprepare(dev->clk[i]);
clk_put(dev->clk[i]);
}
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;
int i;
if (dev->err_interrupt > 0)
writel(0, dev->regs + MVMDIO_ERR_INT_MASK);
mdiobus_unregister(bus);
for (i = 0; i < ARRAY_SIZE(dev->clk); i++) {
if (IS_ERR(dev->clk[i]))
break;
clk_disable_unprepare(dev->clk[i]);
clk_put(dev->clk[i]);
}
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");