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![Baoyou Xie](/assets/img/avatar_default.png)
We get 1 warning when building kernel with W=1: drivers/net/ethernet/arc/emac_mdio.c:107:5: warning: no previous prototype for 'arc_mdio_reset' [-Wmissing-prototypes] In fact, this function is only used in the file in which it is declared and don't need a declaration, but can be made static. so this patch marks this function with 'static'. Signed-off-by: Baoyou Xie <baoyou.xie@linaro.org> Signed-off-by: David S. Miller <davem@davemloft.net>
188 lines
4.4 KiB
C
188 lines
4.4 KiB
C
/*
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* Copyright (C) 2004-2013 Synopsys, Inc. (www.synopsys.com)
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*
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* MDIO implementation for ARC EMAC
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*/
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#include <linux/delay.h>
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#include <linux/of_mdio.h>
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#include <linux/platform_device.h>
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#include <linux/gpio/consumer.h>
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#include "emac.h"
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/* Number of seconds we wait for "MDIO complete" flag to appear */
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#define ARC_MDIO_COMPLETE_POLL_COUNT 1
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/**
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* arc_mdio_complete_wait - Waits until MDIO transaction is completed.
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* @priv: Pointer to ARC EMAC private data structure.
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*
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* returns: 0 on success, -ETIMEDOUT on a timeout.
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*/
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static int arc_mdio_complete_wait(struct arc_emac_priv *priv)
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{
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unsigned int i;
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for (i = 0; i < ARC_MDIO_COMPLETE_POLL_COUNT * 40; i++) {
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unsigned int status = arc_reg_get(priv, R_STATUS);
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status &= MDIO_MASK;
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if (status) {
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/* Reset "MDIO complete" flag */
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arc_reg_set(priv, R_STATUS, status);
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return 0;
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}
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msleep(25);
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}
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return -ETIMEDOUT;
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}
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/**
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* arc_mdio_read - MDIO interface read function.
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* @bus: Pointer to MII bus structure.
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* @phy_addr: Address of the PHY device.
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* @reg_num: PHY register to read.
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*
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* returns: The register contents on success, -ETIMEDOUT on a timeout.
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*
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* Reads the contents of the requested register from the requested PHY
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* address.
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*/
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static int arc_mdio_read(struct mii_bus *bus, int phy_addr, int reg_num)
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{
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struct arc_emac_priv *priv = bus->priv;
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unsigned int value;
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int error;
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arc_reg_set(priv, R_MDIO,
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0x60020000 | (phy_addr << 23) | (reg_num << 18));
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error = arc_mdio_complete_wait(priv);
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if (error < 0)
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return error;
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value = arc_reg_get(priv, R_MDIO) & 0xffff;
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dev_dbg(priv->dev, "arc_mdio_read(phy_addr=%i, reg_num=%x) = %x\n",
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phy_addr, reg_num, value);
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return value;
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}
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/**
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* arc_mdio_write - MDIO interface write function.
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* @bus: Pointer to MII bus structure.
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* @phy_addr: Address of the PHY device.
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* @reg_num: PHY register to write to.
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* @value: Value to be written into the register.
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*
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* returns: 0 on success, -ETIMEDOUT on a timeout.
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*
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* Writes the value to the requested register.
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*/
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static int arc_mdio_write(struct mii_bus *bus, int phy_addr,
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int reg_num, u16 value)
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{
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struct arc_emac_priv *priv = bus->priv;
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dev_dbg(priv->dev,
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"arc_mdio_write(phy_addr=%i, reg_num=%x, value=%x)\n",
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phy_addr, reg_num, value);
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arc_reg_set(priv, R_MDIO,
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0x50020000 | (phy_addr << 23) | (reg_num << 18) | value);
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return arc_mdio_complete_wait(priv);
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}
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/**
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* arc_mdio_reset
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* @bus: points to the mii_bus structure
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* Description: reset the MII bus
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*/
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static int arc_mdio_reset(struct mii_bus *bus)
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{
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struct arc_emac_priv *priv = bus->priv;
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struct arc_emac_mdio_bus_data *data = &priv->bus_data;
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if (data->reset_gpio) {
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gpiod_set_value_cansleep(data->reset_gpio, 1);
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msleep(data->msec);
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gpiod_set_value_cansleep(data->reset_gpio, 0);
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}
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return 0;
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}
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/**
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* arc_mdio_probe - MDIO probe function.
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* @priv: Pointer to ARC EMAC private data structure.
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*
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* returns: 0 on success, -ENOMEM when mdiobus_alloc
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* (to allocate memory for MII bus structure) fails.
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*
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* Sets up and registers the MDIO interface.
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*/
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int arc_mdio_probe(struct arc_emac_priv *priv)
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{
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struct arc_emac_mdio_bus_data *data = &priv->bus_data;
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struct device_node *np = priv->dev->of_node;
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struct mii_bus *bus;
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int error;
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bus = mdiobus_alloc();
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if (!bus)
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return -ENOMEM;
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priv->bus = bus;
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bus->priv = priv;
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bus->parent = priv->dev;
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bus->name = "Synopsys MII Bus";
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bus->read = &arc_mdio_read;
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bus->write = &arc_mdio_write;
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bus->reset = &arc_mdio_reset;
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/* optional reset-related properties */
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data->reset_gpio = devm_gpiod_get_optional(priv->dev, "phy-reset",
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GPIOD_OUT_LOW);
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if (IS_ERR(data->reset_gpio)) {
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error = PTR_ERR(data->reset_gpio);
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dev_err(priv->dev, "Failed to request gpio: %d\n", error);
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return error;
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}
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of_property_read_u32(np, "phy-reset-duration", &data->msec);
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/* A sane reset duration should not be longer than 1s */
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if (data->msec > 1000)
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data->msec = 1;
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snprintf(bus->id, MII_BUS_ID_SIZE, "%s", bus->name);
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error = of_mdiobus_register(bus, priv->dev->of_node);
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if (error) {
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dev_err(priv->dev, "cannot register MDIO bus %s\n", bus->name);
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mdiobus_free(bus);
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return error;
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}
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return 0;
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}
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/**
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* arc_mdio_remove - MDIO remove function.
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* @priv: Pointer to ARC EMAC private data structure.
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*
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* Unregisters the MDIO and frees any associate memory for MII bus.
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*/
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int arc_mdio_remove(struct arc_emac_priv *priv)
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{
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mdiobus_unregister(priv->bus);
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mdiobus_free(priv->bus);
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priv->bus = NULL;
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return 0;
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}
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