blob: 578fc969051e1e51e6aa96344dc24b31d565df2f [file] [log] [blame] [edit]
/*
* pic32_mdio.c: PIC32 MDIO/MII driver, part of pic32_eth.c.
*
* Copyright 2015 Microchip Inc.
* Purna Chandra Mandal <purna.mandal@microchip.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <phy.h>
#include <miiphy.h>
#include <errno.h>
#include <wait_bit.h>
#include <asm/io.h>
#include "pic32_eth.h"
static int pic32_mdio_write(struct mii_dev *bus,
int addr, int dev_addr,
int reg, u16 value)
{
u32 v;
struct pic32_mii_regs *mii_regs = bus->priv;
/* Wait for the previous operation to finish */
wait_for_bit(__func__, &mii_regs->mind.raw, MIIMIND_BUSY,
false, CONFIG_SYS_HZ, true);
/* Put phyaddr and regaddr into MIIMADD */
v = (addr << MIIMADD_PHYADDR_SHIFT) | (reg & MIIMADD_REGADDR);
writel(v, &mii_regs->madr.raw);
/* Initiate a write command */
writel(value, &mii_regs->mwtd.raw);
/* Wait 30 clock cycles for busy flag to be set */
udelay(12);
/* Wait for write to complete */
wait_for_bit(__func__, &mii_regs->mind.raw, MIIMIND_BUSY,
false, CONFIG_SYS_HZ, true);
return 0;
}
static int pic32_mdio_read(struct mii_dev *bus, int addr, int devaddr, int reg)
{
u32 v;
struct pic32_mii_regs *mii_regs = bus->priv;
/* Wait for the previous operation to finish */
wait_for_bit(__func__, &mii_regs->mind.raw, MIIMIND_BUSY,
false, CONFIG_SYS_HZ, true);
/* Put phyaddr and regaddr into MIIMADD */
v = (addr << MIIMADD_PHYADDR_SHIFT) | (reg & MIIMADD_REGADDR);
writel(v, &mii_regs->madr.raw);
/* Initiate a read command */
writel(MIIMCMD_READ, &mii_regs->mcmd.raw);
/* Wait 30 clock cycles for busy flag to be set */
udelay(12);
/* Wait for read to complete */
wait_for_bit(__func__, &mii_regs->mind.raw,
MIIMIND_NOTVALID | MIIMIND_BUSY,
false, CONFIG_SYS_HZ, false);
/* Clear the command register */
writel(0, &mii_regs->mcmd.raw);
/* Grab the value read from the PHY */
v = readl(&mii_regs->mrdd.raw);
return v;
}
static int pic32_mdio_reset(struct mii_dev *bus)
{
struct pic32_mii_regs *mii_regs = bus->priv;
/* Reset MII (due to new addresses) */
writel(MIIMCFG_RSTMGMT, &mii_regs->mcfg.raw);
/* Wait for the operation to finish */
wait_for_bit(__func__, &mii_regs->mind.raw, MIIMIND_BUSY,
false, CONFIG_SYS_HZ, true);
/* Clear reset bit */
writel(0, &mii_regs->mcfg);
/* Wait for the operation to finish */
wait_for_bit(__func__, &mii_regs->mind.raw, MIIMIND_BUSY,
false, CONFIG_SYS_HZ, true);
/* Set the MII Management Clock (MDC) - no faster than 2.5 MHz */
writel(MIIMCFG_CLKSEL_DIV40, &mii_regs->mcfg.raw);
/* Wait for the operation to finish */
wait_for_bit(__func__, &mii_regs->mind.raw, MIIMIND_BUSY,
false, CONFIG_SYS_HZ, true);
return 0;
}
int pic32_mdio_init(const char *name, ulong ioaddr)
{
struct mii_dev *bus;
bus = mdio_alloc();
if (!bus) {
printf("Failed to allocate PIC32-MDIO bus\n");
return -ENOMEM;
}
bus->read = pic32_mdio_read;
bus->write = pic32_mdio_write;
bus->reset = pic32_mdio_reset;
strncpy(bus->name, name, sizeof(bus->name));
bus->priv = (void *)ioaddr;
return mdio_register(bus);
}