diff options
Diffstat (limited to 'kernel/drivers/net/ethernet/ti/davinci_mdio.c')
| -rw-r--r-- | kernel/drivers/net/ethernet/ti/davinci_mdio.c | 505 |
1 files changed, 505 insertions, 0 deletions
diff --git a/kernel/drivers/net/ethernet/ti/davinci_mdio.c b/kernel/drivers/net/ethernet/ti/davinci_mdio.c new file mode 100644 index 000000000..c00084d68 --- /dev/null +++ b/kernel/drivers/net/ethernet/ti/davinci_mdio.c @@ -0,0 +1,505 @@ +/* + * 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/of_mdio.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 */ + /* Indicates that driver shouldn't modify phy_mask in case + * if MDIO bus is registered from DT. + */ + bool skip_scan; +}; + +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); + + if (data->skip_scan) + return 0; + + /* 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)) { + dev_err(&pdev->dev, "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 = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->bus = devm_mdiobus_alloc(dev); + if (!data->bus) { + dev_err(dev, "failed to alloc mii bus\n"); + return -ENOMEM; + } + + 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; + + pm_runtime_enable(&pdev->dev); + pm_runtime_get_sync(&pdev->dev); + data->clk = devm_clk_get(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); + data->regs = devm_ioremap_resource(dev, res); + if (IS_ERR(data->regs)) { + ret = PTR_ERR(data->regs); + goto bail_out; + } + + /* register the mii bus + * Create PHYs from DT only in case if PHY child nodes are explicitly + * defined to support backward compatibility with DTs which assume that + * Davinci MDIO will always scan the bus for PHYs detection. + */ + if (dev->of_node && of_get_child_count(dev->of_node)) { + data->skip_scan = true; + ret = of_mdiobus_register(data->bus, dev->of_node); + } else { + 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: + pm_runtime_put_sync(&pdev->dev); + pm_runtime_disable(&pdev->dev); + + 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); + + pm_runtime_put_sync(&pdev->dev); + pm_runtime_disable(&pdev->dev); + + return 0; +} + +#ifdef CONFIG_PM_SLEEP +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; +} +#endif + +static const struct dev_pm_ops davinci_mdio_pm_ops = { + SET_LATE_SYSTEM_SLEEP_PM_OPS(davinci_mdio_suspend, 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", + .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"); |