| /* |
| * 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_device.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 |
| |
| #define MVMDIO_XSMI_MGNT_REG 0x0 |
| #define MVMDIO_XSMI_PHYADDR_SHIFT 16 |
| #define MVMDIO_XSMI_DEVADDR_SHIFT 21 |
| #define MVMDIO_XSMI_WRITE_OPERATION (0x5 << 26) |
| #define MVMDIO_XSMI_READ_OPERATION (0x7 << 26) |
| #define MVMDIO_XSMI_READ_VALID BIT(29) |
| #define MVMDIO_XSMI_BUSY BIT(30) |
| #define MVMDIO_XSMI_ADDR_REG 0x8 |
| |
| /* |
| * 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 |
| |
| #define MVMDIO_XSMI_POLL_INTERVAL_MIN 150 |
| #define MVMDIO_XSMI_POLL_INTERVAL_MAX 160 |
| |
| struct orion_mdio_dev { |
| void __iomem *regs; |
| struct clk *clk[4]; |
| /* |
| * 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; |
| }; |
| |
| enum orion_mdio_bus_type { |
| BUS_TYPE_SMI, |
| BUS_TYPE_XSMI |
| }; |
| |
| 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_smi_read(struct mii_bus *bus, int mii_id, |
| int regnum) |
| { |
| struct orion_mdio_dev *dev = bus->priv; |
| u32 val; |
| int ret; |
| |
| if (regnum & MII_ADDR_C45) |
| return -EOPNOTSUPP; |
| |
| ret = orion_mdio_wait_ready(&orion_mdio_smi_ops, bus); |
| if (ret < 0) |
| return ret; |
| |
| 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) |
| return ret; |
| |
| val = readl(dev->regs); |
| if (!(val & MVMDIO_SMI_READ_VALID)) { |
| dev_err(bus->parent, "SMI bus read not valid\n"); |
| return -ENODEV; |
| } |
| |
| return val & GENMASK(15, 0); |
| } |
| |
| static int orion_mdio_smi_write(struct mii_bus *bus, int mii_id, |
| int regnum, u16 value) |
| { |
| struct orion_mdio_dev *dev = bus->priv; |
| int ret; |
| |
| if (regnum & MII_ADDR_C45) |
| return -EOPNOTSUPP; |
| |
| ret = orion_mdio_wait_ready(&orion_mdio_smi_ops, bus); |
| if (ret < 0) |
| return ret; |
| |
| 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); |
| |
| return 0; |
| } |
| |
| static int orion_mdio_xsmi_is_done(struct orion_mdio_dev *dev) |
| { |
| return !(readl(dev->regs + MVMDIO_XSMI_MGNT_REG) & MVMDIO_XSMI_BUSY); |
| } |
| |
| static const struct orion_mdio_ops orion_mdio_xsmi_ops = { |
| .is_done = orion_mdio_xsmi_is_done, |
| .poll_interval_min = MVMDIO_XSMI_POLL_INTERVAL_MIN, |
| .poll_interval_max = MVMDIO_XSMI_POLL_INTERVAL_MAX, |
| }; |
| |
| static int orion_mdio_xsmi_read(struct mii_bus *bus, int mii_id, |
| int regnum) |
| { |
| struct orion_mdio_dev *dev = bus->priv; |
| u16 dev_addr = (regnum >> 16) & GENMASK(4, 0); |
| int ret; |
| |
| if (!(regnum & MII_ADDR_C45)) |
| return -EOPNOTSUPP; |
| |
| ret = orion_mdio_wait_ready(&orion_mdio_xsmi_ops, bus); |
| if (ret < 0) |
| return ret; |
| |
| writel(regnum & GENMASK(15, 0), dev->regs + MVMDIO_XSMI_ADDR_REG); |
| writel((mii_id << MVMDIO_XSMI_PHYADDR_SHIFT) | |
| (dev_addr << MVMDIO_XSMI_DEVADDR_SHIFT) | |
| MVMDIO_XSMI_READ_OPERATION, |
| dev->regs + MVMDIO_XSMI_MGNT_REG); |
| |
| ret = orion_mdio_wait_ready(&orion_mdio_xsmi_ops, bus); |
| if (ret < 0) |
| return ret; |
| |
| if (!(readl(dev->regs + MVMDIO_XSMI_MGNT_REG) & |
| MVMDIO_XSMI_READ_VALID)) { |
| dev_err(bus->parent, "XSMI bus read not valid\n"); |
| return -ENODEV; |
| } |
| |
| return readl(dev->regs + MVMDIO_XSMI_MGNT_REG) & GENMASK(15, 0); |
| } |
| |
| static int orion_mdio_xsmi_write(struct mii_bus *bus, int mii_id, |
| int regnum, u16 value) |
| { |
| struct orion_mdio_dev *dev = bus->priv; |
| u16 dev_addr = (regnum >> 16) & GENMASK(4, 0); |
| int ret; |
| |
| if (!(regnum & MII_ADDR_C45)) |
| return -EOPNOTSUPP; |
| |
| ret = orion_mdio_wait_ready(&orion_mdio_xsmi_ops, bus); |
| if (ret < 0) |
| return ret; |
| |
| writel(regnum & GENMASK(15, 0), dev->regs + MVMDIO_XSMI_ADDR_REG); |
| writel((mii_id << MVMDIO_XSMI_PHYADDR_SHIFT) | |
| (dev_addr << MVMDIO_XSMI_DEVADDR_SHIFT) | |
| MVMDIO_XSMI_WRITE_OPERATION | value, |
| dev->regs + MVMDIO_XSMI_MGNT_REG); |
| |
| return 0; |
| } |
| |
| 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) |
| { |
| enum orion_mdio_bus_type type; |
| struct resource *r; |
| struct mii_bus *bus; |
| struct orion_mdio_dev *dev; |
| int i, ret; |
| |
| type = (enum orion_mdio_bus_type)of_device_get_match_data(&pdev->dev); |
| |
| 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; |
| |
| switch (type) { |
| case BUS_TYPE_SMI: |
| bus->read = orion_mdio_smi_read; |
| bus->write = orion_mdio_smi_write; |
| break; |
| case BUS_TYPE_XSMI: |
| bus->read = orion_mdio_xsmi_read; |
| bus->write = orion_mdio_xsmi_write; |
| break; |
| } |
| |
| bus->name = "orion_mdio_bus"; |
| 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); |
| |
| if (pdev->dev.of_node) { |
| for (i = 0; i < ARRAY_SIZE(dev->clk); i++) { |
| dev->clk[i] = of_clk_get(pdev->dev.of_node, i); |
| if (PTR_ERR(dev->clk[i]) == -EPROBE_DEFER) { |
| ret = -EPROBE_DEFER; |
| goto out_clk; |
| } |
| if (IS_ERR(dev->clk[i])) |
| break; |
| clk_prepare_enable(dev->clk[i]); |
| } |
| } else { |
| dev->clk[0] = clk_get(&pdev->dev, NULL); |
| if (PTR_ERR(dev->clk[0]) == -EPROBE_DEFER) { |
| ret = -EPROBE_DEFER; |
| goto out_clk; |
| } |
| if (!IS_ERR(dev->clk[0])) |
| clk_prepare_enable(dev->clk[0]); |
| } |
| |
| 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) { |
| ret = -EPROBE_DEFER; |
| goto out_mdio; |
| } |
| |
| 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); |
| |
| out_clk: |
| 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", .data = (void *)BUS_TYPE_SMI }, |
| { .compatible = "marvell,xmdio", .data = (void *)BUS_TYPE_XSMI }, |
| { } |
| }; |
| 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"); |