/*
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* pic32_mdio.c: PIC32 MDIO/MII driver, part of pic32_eth.c.
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*
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* Copyright 2015 Microchip Inc.
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* Purna Chandra Mandal <purna.mandal@microchip.com>
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*
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* SPDX-License-Identifier: GPL-2.0+
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*/
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#include <common.h>
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#include <phy.h>
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#include <miiphy.h>
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#include <errno.h>
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#include <wait_bit.h>
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#include <asm/io.h>
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#include "pic32_eth.h"
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static int pic32_mdio_write(struct mii_dev *bus,
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int addr, int dev_addr,
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int reg, u16 value)
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{
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u32 v;
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struct pic32_mii_regs *mii_regs = bus->priv;
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/* Wait for the previous operation to finish */
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wait_for_bit_le32(&mii_regs->mind.raw, MIIMIND_BUSY,
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false, CONFIG_SYS_HZ, true);
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/* Put phyaddr and regaddr into MIIMADD */
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v = (addr << MIIMADD_PHYADDR_SHIFT) | (reg & MIIMADD_REGADDR);
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writel(v, &mii_regs->madr.raw);
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/* Initiate a write command */
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writel(value, &mii_regs->mwtd.raw);
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/* Wait 30 clock cycles for busy flag to be set */
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udelay(12);
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/* Wait for write to complete */
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wait_for_bit_le32(&mii_regs->mind.raw, MIIMIND_BUSY,
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false, CONFIG_SYS_HZ, true);
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return 0;
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}
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static int pic32_mdio_read(struct mii_dev *bus, int addr, int devaddr, int reg)
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{
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u32 v;
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struct pic32_mii_regs *mii_regs = bus->priv;
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/* Wait for the previous operation to finish */
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wait_for_bit_le32(&mii_regs->mind.raw, MIIMIND_BUSY,
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false, CONFIG_SYS_HZ, true);
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/* Put phyaddr and regaddr into MIIMADD */
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v = (addr << MIIMADD_PHYADDR_SHIFT) | (reg & MIIMADD_REGADDR);
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writel(v, &mii_regs->madr.raw);
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/* Initiate a read command */
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writel(MIIMCMD_READ, &mii_regs->mcmd.raw);
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/* Wait 30 clock cycles for busy flag to be set */
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udelay(12);
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/* Wait for read to complete */
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wait_for_bit_le32(&mii_regs->mind.raw,
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MIIMIND_NOTVALID | MIIMIND_BUSY,
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false, CONFIG_SYS_HZ, false);
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/* Clear the command register */
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writel(0, &mii_regs->mcmd.raw);
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/* Grab the value read from the PHY */
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v = readl(&mii_regs->mrdd.raw);
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return v;
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}
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static int pic32_mdio_reset(struct mii_dev *bus)
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{
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struct pic32_mii_regs *mii_regs = bus->priv;
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/* Reset MII (due to new addresses) */
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writel(MIIMCFG_RSTMGMT, &mii_regs->mcfg.raw);
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/* Wait for the operation to finish */
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wait_for_bit_le32(&mii_regs->mind.raw, MIIMIND_BUSY,
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false, CONFIG_SYS_HZ, true);
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/* Clear reset bit */
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writel(0, &mii_regs->mcfg);
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/* Wait for the operation to finish */
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wait_for_bit_le32(&mii_regs->mind.raw, MIIMIND_BUSY,
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false, CONFIG_SYS_HZ, true);
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/* Set the MII Management Clock (MDC) - no faster than 2.5 MHz */
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writel(MIIMCFG_CLKSEL_DIV40, &mii_regs->mcfg.raw);
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/* Wait for the operation to finish */
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wait_for_bit_le32(&mii_regs->mind.raw, MIIMIND_BUSY,
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false, CONFIG_SYS_HZ, true);
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return 0;
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}
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int pic32_mdio_init(const char *name, ulong ioaddr)
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{
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struct mii_dev *bus;
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bus = mdio_alloc();
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if (!bus) {
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printf("Failed to allocate PIC32-MDIO bus\n");
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return -ENOMEM;
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}
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bus->read = pic32_mdio_read;
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bus->write = pic32_mdio_write;
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bus->reset = pic32_mdio_reset;
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strncpy(bus->name, name, sizeof(bus->name));
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bus->priv = (void *)ioaddr;
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return mdio_register(bus);
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}
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