--- /dev/null
+/*
+ * 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/davinci_emac.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 (0xff)
+
+ 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];
+};
+
+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;
+ }
+ 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;
+}
+
+static int __devinit davinci_mdio_probe(struct platform_device *pdev)
+{
+ struct mdio_platform_data *pdata = pdev->dev.platform_data;
+ 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) {
+ dev_err(dev, "failed to alloc device data\n");
+ return -ENOMEM;
+ }
+
+ data->pdata = pdata ? (*pdata) : default_pdata;
+
+ data->bus = mdiobus_alloc();
+ if (!data->bus) {
+ dev_err(dev, "failed to alloc mii bus\n");
+ ret = -ENOMEM;
+ goto bail_out;
+ }
+
+ 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;
+ snprintf(data->bus->id, MII_BUS_ID_SIZE, "%x", pdev->id);
+
+ data->clk = clk_get(dev, NULL);
+ if (IS_ERR(data->clk)) {
+ data->clk = NULL;
+ dev_err(dev, "failed to get device clock\n");
+ ret = PTR_ERR(data->clk);
+ goto bail_out;
+ }
+
+ clk_enable(data->clk);
+
+ 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_disable(data->clk);
+ clk_put(data->clk);
+ }
+
+ kfree(data);
+
+ return ret;
+}
+
+static int __devexit davinci_mdio_remove(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct davinci_mdio_data *data = dev_get_drvdata(dev);
+
+ if (data->bus)
+ mdiobus_free(data->bus);
+
+ if (data->clk) {
+ clk_disable(data->clk);
+ clk_put(data->clk);
+ }
+
+ dev_set_drvdata(dev, NULL);
+
+ 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);
+
+ if (data->clk)
+ clk_disable(data->clk);
+
+ data->suspended = true;
+ spin_unlock(&data->lock);
+
+ return 0;
+}
+
+static int davinci_mdio_resume(struct device *dev)
+{
+ struct davinci_mdio_data *data = dev_get_drvdata(dev);
+ u32 ctrl;
+
+ spin_lock(&data->lock);
+ if (data->clk)
+ clk_enable(data->clk);
+
+ /* restart the scan state machine */
+ ctrl = __raw_readl(&data->regs->control);
+ ctrl |= CONTROL_ENABLE;
+ __raw_writel(ctrl, &data->regs->control);
+
+ data->suspended = false;
+ spin_unlock(&data->lock);
+
+ return 0;
+}
+
+static const struct dev_pm_ops davinci_mdio_pm_ops = {
+ .suspend = davinci_mdio_suspend,
+ .resume = davinci_mdio_resume,
+};
+
+static struct platform_driver davinci_mdio_driver = {
+ .driver = {
+ .name = "davinci_mdio",
+ .owner = THIS_MODULE,
+ .pm = &davinci_mdio_pm_ops,
+ },
+ .probe = davinci_mdio_probe,
+ .remove = __devexit_p(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");
git.openpandora.org / pandora-kernel.git / commitdiff