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Release 4.11 drivers/net/ethernet/marvell/mvmdio.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/kernel.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/phy.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/clk.h>
#include <linux/of_mdio.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 {
	
struct mutex lock;
	
void __iomem *regs;
	
struct clk *clk;
	/*
         * 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;
};


static int orion_mdio_smi_is_done(struct orion_mdio_dev *dev) { return !(readl(dev->regs) & MVMDIO_SMI_BUSY); }

Contributors

PersonTokensPropCommitsCommitProp
Florian Fainelli24100.00%1100.00%
Total24100.00%1100.00%

/* Wait for the SMI unit to be ready for another operation */
static int orion_mdio_wait_ready(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 (orion_mdio_smi_is_done(dev)) return 0; else if (timedout) break; if (dev->err_interrupt <= 0) { usleep_range(MVMDIO_SMI_POLL_INTERVAL_MIN, MVMDIO_SMI_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, orion_mdio_smi_is_done(dev), timeout); ++timedout; } } dev_err(bus->parent, "Timeout: SMI busy for too long\n"); return -ETIMEDOUT; }

Contributors

PersonTokensPropCommitsCommitProp
Leigh Brown6648.89%250.00%
Thomas Petazzoni4432.59%125.00%
Florian Fainelli2518.52%125.00%
Total135100.00%4100.00%


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; mutex_lock(&dev->lock); ret = orion_mdio_wait_ready(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(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 & 0xFFFF; out: mutex_unlock(&dev->lock); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Petazzoni11576.16%133.33%
Leigh Brown3422.52%133.33%
Florian Fainelli21.32%133.33%
Total151100.00%3100.00%


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; mutex_lock(&dev->lock); ret = orion_mdio_wait_ready(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: mutex_unlock(&dev->lock); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Petazzoni9192.86%133.33%
Leigh Brown66.12%133.33%
Florian Fainelli11.02%133.33%
Total98100.00%3100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Florian Fainelli61100.00%1100.00%
Total61100.00%1100.00%


static int orion_mdio_probe(struct platform_device *pdev) { struct resource *r; struct mii_bus *bus; struct orion_mdio_dev *dev; int 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); dev->clk = devm_clk_get(&pdev->dev, NULL); if (!IS_ERR(dev->clk)) clk_prepare_enable(dev->clk); dev->err_interrupt = platform_get_irq(pdev, 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; } mutex_init(&dev->lock); 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 (!IS_ERR(dev->clk)) clk_disable_unprepare(dev->clk); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Petazzoni17043.37%112.50%
Florian Fainelli14837.76%337.50%
Sebastian Hesselbarth4812.24%112.50%
Ezequiel García246.12%225.00%
Alexey Khoroshilov20.51%112.50%
Total392100.00%8100.00%


static int orion_mdio_remove(struct platform_device *pdev) { struct mii_bus *bus = platform_get_drvdata(pdev); struct orion_mdio_dev *dev = bus->priv; writel(0, dev->regs + MVMDIO_ERR_INT_MASK); mdiobus_unregister(bus); if (!IS_ERR(dev->clk)) clk_disable_unprepare(dev->clk); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Petazzoni2943.94%133.33%
Florian Fainelli2030.30%133.33%
Sebastian Hesselbarth1725.76%133.33%
Total66100.00%3100.00%

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");

Overall Contributors

PersonTokensPropCommitsCommitProp
Thomas Petazzoni58852.17%213.33%
Florian Fainelli31427.86%320.00%
Leigh Brown12110.74%533.33%
Sebastian Hesselbarth736.48%16.67%
Ezequiel García242.13%213.33%
Simon Baatz50.44%16.67%
Alexey Khoroshilov20.18%16.67%
Total1127100.00%15100.00%
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