/*
* DaVinci MDIO Module driver
*
* Copyright (C) 2010 Texas Instruments.
*
* Shamelessly ripped out of davinci_emac.c, original copyrights follow:
*
* Copyright (C) 2009 Texas Instruments.
*
* ---------------------------------------------------------------------------
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
* ---------------------------------------------------------------------------
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/phy.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/pm_runtime.h>
#include <linux/davinci_emac.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/pinctrl/consumer.h>
/*
* This timeout definition is a worst-case ultra defensive measure against
* unexpected controller lock ups. Ideally, we should never ever hit this
* scenario in practice.
*/
#define MDIO_TIMEOUT 100 /* msecs */
#define PHY_REG_MASK 0x1f
#define PHY_ID_MASK 0x1f
#define DEF_OUT_FREQ 2200000 /* 2.2 MHz */
struct davinci_mdio_regs {
u32 version;
u32 control;
#define CONTROL_IDLE BIT(31)
#define CONTROL_ENABLE BIT(30)
#define CONTROL_MAX_DIV (0xffff)
u32 alive;
u32 link;
u32 linkintraw;
u32 linkintmasked;
u32 __reserved_0[2];
u32 userintraw;
u32 userintmasked;
u32 userintmaskset;
u32 userintmaskclr;
u32 __reserved_1[20];
struct {
u32 access;
#define USERACCESS_GO BIT(31)
#define USERACCESS_WRITE BIT(30)
#define USERACCESS_ACK BIT(29)
#define USERACCESS_READ (0)
#define USERACCESS_DATA (0xffff)
u32 physel;
} user[0];
};
static const struct mdio_platform_data default_pdata = {
.bus_freq = DEF_OUT_FREQ,
};
struct davinci_mdio_data {
struct mdio_platform_data pdata;
struct davinci_mdio_regs __iomem *regs;
spinlock_t lock;
struct clk *clk;
struct device *dev;
struct mii_bus *bus;
bool suspended;
unsigned long access_time; /* jiffies */
};
static void __davinci_mdio_reset(struct davinci_mdio_data *data)
{
u32 mdio_in, div, mdio_out_khz, access_time;
mdio_in = clk_get_rate(data->clk);
div = (mdio_in / data->pdata.bus_freq) - 1;
if (div > CONTROL_MAX_DIV)
div = CONTROL_MAX_DIV;
/* set enable and clock divider */
__raw_writel(div | CONTROL_ENABLE, &data->regs->control);
/*
* One mdio transaction consists of:
* 32 bits of preamble
* 32 bits of transferred data
* 24 bits of bus yield (not needed unless shared?)
*/
mdio_out_khz = mdio_in / (1000 * (div + 1));
access_time = (88 * 1000) / mdio_out_khz;
/*
* In the worst case, we could be kicking off a user-access immediately
* after the mdio bus scan state-machine triggered its own read. If
* so, our request could get deferred by one access cycle. We
* defensively allow for 4 access cycles.
*/
data->access_time = usecs_to_jiffies(access_time * 4);
if (!data->access_time)
data->access_time = 1;
}
static int davinci_mdio_reset(struct mii_bus *bus)
{
struct davinci_mdio_data *data = bus->priv;
u32 phy_mask, ver;
__davinci_mdio_reset(data);
/* wait for scan logic to settle */
msleep(PHY_MAX_ADDR * data->access_time);
/* dump hardware version info */
ver = __raw_readl(&data->regs->version);
dev_info(data->dev, "davinci mdio revision %d.%d\n",
(ver >> 8) & 0xff, ver & 0xff);
/* get phy mask from the alive register */
phy_mask = __raw_readl(&data->regs->alive);
if (phy_mask) {
/* restrict mdio bus to live phys only */
dev_info(data->dev, "detected phy mask %x\n", ~phy_mask);
phy_mask = ~phy_mask;
} else {
/* desperately scan all phys */
dev_warn(data->dev, "no live phy, scanning all\n");
phy_mask = 0;
}
data->bus->phy_mask = phy_mask;
return 0;
}
/* wait until hardware is ready for another user access */
static inline int wait_for_user_access(struct davinci_mdio_data *data)
{
struct davinci_mdio_regs __iomem *regs = data->regs;
unsigned long timeout = jiffies + msecs_to_jiffies(MDIO_TIMEOUT);
u32 reg;
while (time_after(timeout, jiffies)) {
reg = __raw_readl(®s->user[0].access);
if ((reg & USERACCESS_GO) == 0)
return 0;
reg = __raw_readl(®s->control);
if ((reg & CONTROL_IDLE) == 0)
continue;
/*
* An emac soft_reset may have clobbered the mdio controller's
* state machine. We need to reset and retry the current
* operation
*/
dev_warn(data->dev, "resetting idled controller\n");
__davinci_mdio_reset(data);
return -EAGAIN;
}
reg = __raw_readl(®s->user[0].access);
if ((reg & USERACCESS_GO) == 0)
return 0;
dev_err(data->dev, "timed out waiting for user access\n");
return -ETIMEDOUT;
}
/* wait until hardware state machine is idle */
static inline int wait_for_idle(struct davinci_mdio_data *data)
{
struct davinci_mdio_regs __iomem *regs = data->regs;
unsigned long timeout = jiffies + msecs_to_jiffies(MDIO_TIMEOUT);
while (time_after(timeout, jiffies)) {
if (__raw_readl(®s->control) & CONTROL_IDLE)
return 0;
}
dev_err(data->dev, "timed out waiting for idle\n");
return -ETIMEDOUT;
}
static int davinci_mdio_read(struct mii_bus *bus, int phy_id, int phy_reg)
{
struct davinci_mdio_data *data = bus->priv;
u32 reg;
int ret;
if (phy_reg & ~PHY_REG_MASK || phy_id & ~PHY_ID_MASK)
return -EINVAL;
spin_lock(&data->lock);
if (data->suspended) {
spin_unlock(&data->lock);
return -ENODEV;
}
reg = (USERACCESS_GO | USERACCESS_READ | (phy_reg << 21) |
(phy_id << 16));
while (1) {
ret = wait_for_user_access(data);
if (ret == -EAGAIN)
continue;
if (ret < 0)
break;
__raw_writel(reg, &data->regs->user[0].access);
ret = wait_for_user_access(data);
if (ret == -EAGAIN)
continue;
if (ret < 0)
break;
reg = __raw_readl(&data->regs->user[0].access);
ret = (reg & USERACCESS_ACK) ? (reg & USERACCESS_DATA) : -EIO;
break;
}
spin_unlock(&data->lock);
return ret;
}
static int davinci_mdio_write(struct mii_bus *bus, int phy_id,
int phy_reg, u16 phy_data)
{
struct davinci_mdio_data *data = bus->priv;
u32 reg;
int ret;
if (phy_reg & ~PHY_REG_MASK || phy_id & ~PHY_ID_MASK)
return -EINVAL;
spin_lock(&data->lock);
if (data->suspended) {
spin_unlock(&data->lock);
return -ENODEV;
}
reg = (USERACCESS_GO | USERACCESS_WRITE | (phy_reg << 21) |
(phy_id << 16) | (phy_data & USERACCESS_DATA));
while (1) {
ret = wait_for_user_access(data);
if (ret == -EAGAIN)
continue;
if (ret < 0)
break;
__raw_writel(reg, &data->regs->user[0].access);
ret = wait_for_user_access(data);
if (ret == -EAGAIN)
continue;
break;
}
spin_unlock(&data->lock);
return 0;
}
#if IS_ENABLED(CONFIG_OF)
static int davinci_mdio_probe_dt(struct mdio_platform_data *data,
struct platform_device *pdev)
{
struct device_node *node = pdev->dev.of_node;
u32 prop;
if (!node)
return -EINVAL;
if (of_property_read_u32(node, "bus_freq", &prop)) {
pr_err("Missing bus_freq property in the DT.\n");
return -EINVAL;
}
data->bus_freq = prop;
return 0;
}
#endif
static int davinci_mdio_probe(struct platform_device *pdev)
{
struct mdio_platform_data *pdata = dev_get_platdata(&pdev->dev);
struct device *dev = &pdev->dev;
struct davinci_mdio_data *data;
struct resource *res;
struct phy_device *phy;
int ret, addr;
data = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
data->bus = mdiobus_alloc();
if (!data->bus) {
dev_err(dev, "failed to alloc mii bus\n");
ret = -ENOMEM;
goto bail_out;
}
if (dev->of_node) {
if (davinci_mdio_probe_dt(&data->pdata, pdev))
data->pdata = default_pdata;
snprintf(data->bus->id, MII_BUS_ID_SIZE, "%s", pdev->name);
} else {
data->pdata = pdata ? (*pdata) : default_pdata;
snprintf(data->bus->id, MII_BUS_ID_SIZE, "%s-%x",
pdev->name, pdev->id);
}
data->bus->name = dev_name(dev);
data->bus->read = davinci_mdio_read,
data->bus->write = davinci_mdio_write,
data->bus->reset = davinci_mdio_reset,
data->bus->parent = dev;
data->bus->priv = data;
/* Select default pin state */
pinctrl_pm_select_default_state(&pdev->dev);
pm_runtime_enable(&pdev->dev);
pm_runtime_get_sync(&pdev->dev);
data->clk = clk_get(&pdev->dev, "fck");
if (IS_ERR(data->clk)) {
dev_err(dev, "failed to get device clock\n");
ret = PTR_ERR(data->clk);
data->clk = NULL;
goto bail_out;
}
dev_set_drvdata(dev, data);
data->dev = dev;
spin_lock_init(&data->lock);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
dev_err(dev, "could not find register map resource\n");
ret = -ENOENT;
goto bail_out;
}
res = devm_request_mem_region(dev, res->start, resource_size(res),
dev_name(dev));
if (!res) {
dev_err(dev, "could not allocate register map resource\n");
ret = -ENXIO;
goto bail_out;
}
data->regs = devm_ioremap_nocache(dev, res->start, resource_size(res));
if (!data->regs) {
dev_err(dev, "could not map mdio registers\n");
ret = -ENOMEM;
goto bail_out;
}
/* register the mii bus */
ret = mdiobus_register(data->bus);
if (ret)
goto bail_out;
/* scan and dump the bus */
for (addr = 0; addr < PHY_MAX_ADDR; addr++) {
phy = data->bus->phy_map[addr];
if (phy) {
dev_info(dev, "phy[%d]: device %s, driver %s\n",
phy->addr, dev_name(&phy->dev),
phy->drv ? phy->drv->name : "unknown");
}
}
return 0;
bail_out:
if (data->bus)
mdiobus_free(data->bus);
if (data->clk)
clk_put(data->clk);
pm_runtime_put_sync(&pdev->dev);
pm_runtime_disable(&pdev->dev);
kfree(data);
return ret;
}
static int davinci_mdio_remove(struct platform_device *pdev)
{
struct davinci_mdio_data *data = platform_get_drvdata(pdev);
if (data->bus) {
mdiobus_unregister(data->bus);
mdiobus_free(data->bus);
}
if (data->clk)
clk_put(data->clk);
pm_runtime_put_sync(&pdev->dev);
pm_runtime_disable(&pdev->dev);
kfree(data);
return 0;
}
static int davinci_mdio_suspend(struct device *dev)
{
struct davinci_mdio_data *data = dev_get_drvdata(dev);
u32 ctrl;
spin_lock(&data->lock);
/* shutdown the scan state machine */
ctrl = __raw_readl(&data->regs->control);
ctrl &= ~CONTROL_ENABLE;
__raw_writel(ctrl, &data->regs->control);
wait_for_idle(data);
data->suspended = true;
spin_unlock(&data->lock);
pm_runtime_put_sync(data->dev);
/* Select sleep pin state */
pinctrl_pm_select_sleep_state(dev);
return 0;
}
static int davinci_mdio_resume(struct device *dev)
{
struct davinci_mdio_data *data = dev_get_drvdata(dev);
/* Select default pin state */
pinctrl_pm_select_default_state(dev);
pm_runtime_get_sync(data->dev);
spin_lock(&data->lock);
/* restart the scan state machine */
__davinci_mdio_reset(data);
data->suspended = false;
spin_unlock(&data->lock);
return 0;
}
static const struct dev_pm_ops davinci_mdio_pm_ops = {
.suspend_late = davinci_mdio_suspend,
.resume_early = davinci_mdio_resume,
};
#if IS_ENABLED(CONFIG_OF)
static const struct of_device_id davinci_mdio_of_mtable[] = {
{ .compatible = "ti,davinci_mdio", },
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, davinci_mdio_of_mtable);
#endif
static struct platform_driver davinci_mdio_driver = {
.driver = {
.name = "davinci_mdio",
.owner = THIS_MODULE,
.pm = &davinci_mdio_pm_ops,
.of_match_table = of_match_ptr(davinci_mdio_of_mtable),
},
.probe = davinci_mdio_probe,
.remove = davinci_mdio_remove,
};
static int __init davinci_mdio_init(void)
{
return platform_driver_register(&davinci_mdio_driver);
}
device_initcall(davinci_mdio_init);
static void __exit davinci_mdio_exit(void)
{
platform_driver_unregister(&davinci_mdio_driver);
}
module_exit(davinci_mdio_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("DaVinci MDIO driver");