blob: e77a2ff0a742f4d6641be367e24ef3f3c73aa79f [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0+
/*
* CPSW MDIO generic driver for TI AMxx/K2x/EMAC devices.
*
* Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
*/
#include <common.h>
#include <log.h>
#include <malloc.h>
#include <asm/io.h>
#include <miiphy.h>
#include <wait_bit.h>
#include <linux/delay.h>
struct cpsw_mdio_regs {
u32 version;
u32 control;
#define CONTROL_IDLE BIT(31)
#define CONTROL_ENABLE BIT(30)
#define CONTROL_FAULT BIT(19)
#define CONTROL_FAULT_ENABLE BIT(18)
#define CONTROL_DIV_MASK GENMASK(15, 0)
u32 alive;
u32 link;
u32 linkintraw;
u32 linkintmasked;
u32 __reserved_0[2];
u32 userintraw;
u32 userintmasked;
u32 userintmaskset;
u32 userintmaskclr;
u32 __reserved_1[20];
struct {
u32 access;
u32 physel;
#define USERACCESS_GO BIT(31)
#define USERACCESS_WRITE BIT(30)
#define USERACCESS_ACK BIT(29)
#define USERACCESS_READ (0)
#define USERACCESS_PHY_REG_SHIFT (21)
#define USERACCESS_PHY_ADDR_SHIFT (16)
#define USERACCESS_DATA GENMASK(15, 0)
} user[0];
};
#define CPSW_MDIO_DIV_DEF 0xff
#define PHY_REG_MASK 0x1f
#define PHY_ID_MASK 0x1f
/*
* This timeout definition is a worst-case ultra defensive measure against
* unexpected controller lock ups. Ideally, we should never ever hit this
* scenario in practice.
*/
#define CPSW_MDIO_TIMEOUT 100 /* msecs */
struct cpsw_mdio {
struct cpsw_mdio_regs *regs;
struct mii_dev *bus;
int div;
};
/* wait until hardware is ready for another user access */
static int cpsw_mdio_wait_for_user_access(struct cpsw_mdio *mdio)
{
return wait_for_bit_le32(&mdio->regs->user[0].access,
USERACCESS_GO, false,
CPSW_MDIO_TIMEOUT, false);
}
static int cpsw_mdio_read(struct mii_dev *bus, int phy_id,
int dev_addr, int phy_reg)
{
struct cpsw_mdio *mdio = bus->priv;
int data, ret;
u32 reg;
if (phy_reg & ~PHY_REG_MASK || phy_id & ~PHY_ID_MASK)
return -EINVAL;
ret = cpsw_mdio_wait_for_user_access(mdio);
if (ret)
return ret;
reg = (USERACCESS_GO | USERACCESS_READ |
(phy_reg << USERACCESS_PHY_REG_SHIFT) |
(phy_id << USERACCESS_PHY_ADDR_SHIFT));
writel(reg, &mdio->regs->user[0].access);
ret = cpsw_mdio_wait_for_user_access(mdio);
if (ret)
return ret;
reg = readl(&mdio->regs->user[0].access);
data = (reg & USERACCESS_ACK) ? (reg & USERACCESS_DATA) : -1;
return data;
}
static int cpsw_mdio_write(struct mii_dev *bus, int phy_id, int dev_addr,
int phy_reg, u16 data)
{
struct cpsw_mdio *mdio = bus->priv;
u32 reg;
int ret;
if (phy_reg & ~PHY_REG_MASK || phy_id & ~PHY_ID_MASK)
return -EINVAL;
ret = cpsw_mdio_wait_for_user_access(mdio);
if (ret)
return ret;
reg = (USERACCESS_GO | USERACCESS_WRITE |
(phy_reg << USERACCESS_PHY_REG_SHIFT) |
(phy_id << USERACCESS_PHY_ADDR_SHIFT) |
(data & USERACCESS_DATA));
writel(reg, &mdio->regs->user[0].access);
return cpsw_mdio_wait_for_user_access(mdio);
}
u32 cpsw_mdio_get_alive(struct mii_dev *bus)
{
struct cpsw_mdio *mdio = bus->priv;
u32 val;
val = readl(&mdio->regs->control);
return val & GENMASK(15, 0);
}
struct mii_dev *cpsw_mdio_init(const char *name, phys_addr_t mdio_base,
u32 bus_freq, int fck_freq)
{
struct cpsw_mdio *cpsw_mdio;
int ret;
cpsw_mdio = calloc(1, sizeof(*cpsw_mdio));
if (!cpsw_mdio) {
debug("failed to alloc cpsw_mdio\n");
return NULL;
}
cpsw_mdio->bus = mdio_alloc();
if (!cpsw_mdio->bus) {
debug("failed to alloc mii bus\n");
free(cpsw_mdio);
return NULL;
}
cpsw_mdio->regs = (struct cpsw_mdio_regs *)(uintptr_t)mdio_base;
if (!bus_freq || !fck_freq)
cpsw_mdio->div = CPSW_MDIO_DIV_DEF;
else
cpsw_mdio->div = (fck_freq / bus_freq) - 1;
cpsw_mdio->div &= CONTROL_DIV_MASK;
/* set enable and clock divider */
writel(cpsw_mdio->div | CONTROL_ENABLE | CONTROL_FAULT |
CONTROL_FAULT_ENABLE, &cpsw_mdio->regs->control);
wait_for_bit_le32(&cpsw_mdio->regs->control,
CONTROL_IDLE, false, CPSW_MDIO_TIMEOUT, true);
/*
* wait for scan logic to settle:
* the scan time consists of (a) a large fixed component, and (b) a
* small component that varies with the mii bus frequency. These
* were estimated using measurements at 1.1 and 2.2 MHz on tnetv107x
* silicon. Since the effect of (b) was found to be largely
* negligible, we keep things simple here.
*/
mdelay(1);
cpsw_mdio->bus->read = cpsw_mdio_read;
cpsw_mdio->bus->write = cpsw_mdio_write;
cpsw_mdio->bus->priv = cpsw_mdio;
snprintf(cpsw_mdio->bus->name, sizeof(cpsw_mdio->bus->name), name);
ret = mdio_register(cpsw_mdio->bus);
if (ret < 0) {
debug("failed to register mii bus\n");
goto free_bus;
}
return cpsw_mdio->bus;
free_bus:
mdio_free(cpsw_mdio->bus);
free(cpsw_mdio);
return NULL;
}
void cpsw_mdio_free(struct mii_dev *bus)
{
struct cpsw_mdio *mdio = bus->priv;
u32 reg;
/* disable mdio */
reg = readl(&mdio->regs->control);
reg &= ~CONTROL_ENABLE;
writel(reg, &mdio->regs->control);
mdio_unregister(bus);
mdio_free(bus);
free(mdio);
}