121 lines
3 KiB
C
121 lines
3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* MDIO bus driver for the Xilinx TEMAC device
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*
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* Copyright (c) 2009 Secret Lab Technologies, Ltd.
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*/
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#include <linux/io.h>
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#include <linux/netdevice.h>
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#include <linux/mutex.h>
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#include <linux/phy.h>
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#include <linux/of.h>
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#include <linux/of_device.h>
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#include <linux/of_address.h>
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#include <linux/slab.h>
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#include <linux/of_mdio.h>
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#include "ll_temac.h"
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/* ---------------------------------------------------------------------
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* MDIO Bus functions
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*/
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static int temac_mdio_read(struct mii_bus *bus, int phy_id, int reg)
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{
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struct temac_local *lp = bus->priv;
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u32 rc;
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/* Write the PHY address to the MIIM Access Initiator register.
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* When the transfer completes, the PHY register value will appear
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* in the LSW0 register */
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mutex_lock(&lp->indirect_mutex);
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temac_iow(lp, XTE_LSW0_OFFSET, (phy_id << 5) | reg);
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rc = temac_indirect_in32(lp, XTE_MIIMAI_OFFSET);
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mutex_unlock(&lp->indirect_mutex);
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dev_dbg(lp->dev, "temac_mdio_read(phy_id=%i, reg=%x) == %x\n",
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phy_id, reg, rc);
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return rc;
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}
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static int temac_mdio_write(struct mii_bus *bus, int phy_id, int reg, u16 val)
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{
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struct temac_local *lp = bus->priv;
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dev_dbg(lp->dev, "temac_mdio_write(phy_id=%i, reg=%x, val=%x)\n",
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phy_id, reg, val);
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/* First write the desired value into the write data register
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* and then write the address into the access initiator register
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*/
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mutex_lock(&lp->indirect_mutex);
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temac_indirect_out32(lp, XTE_MGTDR_OFFSET, val);
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temac_indirect_out32(lp, XTE_MIIMAI_OFFSET, (phy_id << 5) | reg);
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mutex_unlock(&lp->indirect_mutex);
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return 0;
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}
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int temac_mdio_setup(struct temac_local *lp, struct device_node *np)
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{
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struct mii_bus *bus;
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u32 bus_hz;
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int clk_div;
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int rc;
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struct resource res;
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/* Calculate a reasonable divisor for the clock rate */
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clk_div = 0x3f; /* worst-case default setting */
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if (of_property_read_u32(np, "clock-frequency", &bus_hz) == 0) {
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clk_div = bus_hz / (2500 * 1000 * 2) - 1;
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if (clk_div < 1)
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clk_div = 1;
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if (clk_div > 0x3f)
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clk_div = 0x3f;
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}
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/* Enable the MDIO bus by asserting the enable bit and writing
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* in the clock config */
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mutex_lock(&lp->indirect_mutex);
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temac_indirect_out32(lp, XTE_MC_OFFSET, 1 << 6 | clk_div);
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mutex_unlock(&lp->indirect_mutex);
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bus = mdiobus_alloc();
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if (!bus)
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return -ENOMEM;
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of_address_to_resource(np, 0, &res);
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snprintf(bus->id, MII_BUS_ID_SIZE, "%.8llx",
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(unsigned long long)res.start);
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bus->priv = lp;
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bus->name = "Xilinx TEMAC MDIO";
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bus->read = temac_mdio_read;
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bus->write = temac_mdio_write;
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bus->parent = lp->dev;
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lp->mii_bus = bus;
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rc = of_mdiobus_register(bus, np);
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if (rc)
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goto err_register;
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mutex_lock(&lp->indirect_mutex);
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dev_dbg(lp->dev, "MDIO bus registered; MC:%x\n",
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temac_indirect_in32(lp, XTE_MC_OFFSET));
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mutex_unlock(&lp->indirect_mutex);
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return 0;
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err_register:
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mdiobus_free(bus);
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return rc;
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}
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void temac_mdio_teardown(struct temac_local *lp)
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{
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mdiobus_unregister(lp->mii_bus);
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mdiobus_free(lp->mii_bus);
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lp->mii_bus = NULL;
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}
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