diff options
Diffstat (limited to 'drivers/net/ethernet/freescale/enetc/enetc_mdio.c')
| -rw-r--r-- | drivers/net/ethernet/freescale/enetc/enetc_mdio.c | 199 |
1 files changed, 199 insertions, 0 deletions
diff --git a/drivers/net/ethernet/freescale/enetc/enetc_mdio.c b/drivers/net/ethernet/freescale/enetc/enetc_mdio.c new file mode 100644 index 000000000000..77b9cd10ba2b --- /dev/null +++ b/drivers/net/ethernet/freescale/enetc/enetc_mdio.c @@ -0,0 +1,199 @@ +// SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause) +/* Copyright 2019 NXP */ + +#include <linux/mdio.h> +#include <linux/of_mdio.h> +#include <linux/iopoll.h> +#include <linux/of.h> + +#include "enetc_pf.h" + +struct enetc_mdio_regs { + u32 mdio_cfg; /* MDIO configuration and status */ + u32 mdio_ctl; /* MDIO control */ + u32 mdio_data; /* MDIO data */ + u32 mdio_addr; /* MDIO address */ +}; + +#define bus_to_enetc_regs(bus) (struct enetc_mdio_regs __iomem *)((bus)->priv) + +#define ENETC_MDIO_REG_OFFSET 0x1c00 +#define ENETC_MDC_DIV 258 + +#define MDIO_CFG_CLKDIV(x) ((((x) >> 1) & 0xff) << 8) +#define MDIO_CFG_BSY BIT(0) +#define MDIO_CFG_RD_ER BIT(1) +#define MDIO_CFG_ENC45 BIT(6) + /* external MDIO only - driven on neg MDC edge */ +#define MDIO_CFG_NEG BIT(23) + +#define MDIO_CTL_DEV_ADDR(x) ((x) & 0x1f) +#define MDIO_CTL_PORT_ADDR(x) (((x) & 0x1f) << 5) +#define MDIO_CTL_READ BIT(15) +#define MDIO_DATA(x) ((x) & 0xffff) + +#define TIMEOUT 1000 +static int enetc_mdio_wait_complete(struct enetc_mdio_regs __iomem *regs) +{ + u32 val; + + return readx_poll_timeout(enetc_rd_reg, ®s->mdio_cfg, val, + !(val & MDIO_CFG_BSY), 10, 10 * TIMEOUT); +} + +static int enetc_mdio_write(struct mii_bus *bus, int phy_id, int regnum, + u16 value) +{ + struct enetc_mdio_regs __iomem *regs = bus_to_enetc_regs(bus); + u32 mdio_ctl, mdio_cfg; + u16 dev_addr; + int ret; + + mdio_cfg = MDIO_CFG_CLKDIV(ENETC_MDC_DIV) | MDIO_CFG_NEG; + if (regnum & MII_ADDR_C45) { + dev_addr = (regnum >> 16) & 0x1f; + mdio_cfg |= MDIO_CFG_ENC45; + } else { + /* clause 22 (ie 1G) */ + dev_addr = regnum & 0x1f; + mdio_cfg &= ~MDIO_CFG_ENC45; + } + + enetc_wr_reg(®s->mdio_cfg, mdio_cfg); + + ret = enetc_mdio_wait_complete(regs); + if (ret) + return ret; + + /* set port and dev addr */ + mdio_ctl = MDIO_CTL_PORT_ADDR(phy_id) | MDIO_CTL_DEV_ADDR(dev_addr); + enetc_wr_reg(®s->mdio_ctl, mdio_ctl); + + /* set the register address */ + if (regnum & MII_ADDR_C45) { + enetc_wr_reg(®s->mdio_addr, regnum & 0xffff); + + ret = enetc_mdio_wait_complete(regs); + if (ret) + return ret; + } + + /* write the value */ + enetc_wr_reg(®s->mdio_data, MDIO_DATA(value)); + + ret = enetc_mdio_wait_complete(regs); + if (ret) + return ret; + + return 0; +} + +static int enetc_mdio_read(struct mii_bus *bus, int phy_id, int regnum) +{ + struct enetc_mdio_regs __iomem *regs = bus_to_enetc_regs(bus); + u32 mdio_ctl, mdio_cfg; + u16 dev_addr, value; + int ret; + + mdio_cfg = MDIO_CFG_CLKDIV(ENETC_MDC_DIV) | MDIO_CFG_NEG; + if (regnum & MII_ADDR_C45) { + dev_addr = (regnum >> 16) & 0x1f; + mdio_cfg |= MDIO_CFG_ENC45; + } else { + dev_addr = regnum & 0x1f; + mdio_cfg &= ~MDIO_CFG_ENC45; + } + + enetc_wr_reg(®s->mdio_cfg, mdio_cfg); + + ret = enetc_mdio_wait_complete(regs); + if (ret) + return ret; + + /* set port and device addr */ + mdio_ctl = MDIO_CTL_PORT_ADDR(phy_id) | MDIO_CTL_DEV_ADDR(dev_addr); + enetc_wr_reg(®s->mdio_ctl, mdio_ctl); + + /* set the register address */ + if (regnum & MII_ADDR_C45) { + enetc_wr_reg(®s->mdio_addr, regnum & 0xffff); + + ret = enetc_mdio_wait_complete(regs); + if (ret) + return ret; + } + + /* initiate the read */ + enetc_wr_reg(®s->mdio_ctl, mdio_ctl | MDIO_CTL_READ); + + ret = enetc_mdio_wait_complete(regs); + if (ret) + return ret; + + /* return all Fs if nothing was there */ + if (enetc_rd_reg(®s->mdio_cfg) & MDIO_CFG_RD_ER) { + dev_dbg(&bus->dev, + "Error while reading PHY%d reg at %d.%hhu\n", + phy_id, dev_addr, regnum); + return 0xffff; + } + + value = enetc_rd_reg(®s->mdio_data) & 0xffff; + + return value; +} + +int enetc_mdio_probe(struct enetc_pf *pf) +{ + struct device *dev = &pf->si->pdev->dev; + struct enetc_mdio_regs __iomem *regs; + struct device_node *np; + struct mii_bus *bus; + int ret; + + bus = mdiobus_alloc_size(sizeof(regs)); + if (!bus) + return -ENOMEM; + + bus->name = "Freescale ENETC MDIO Bus"; + bus->read = enetc_mdio_read; + bus->write = enetc_mdio_write; + bus->parent = dev; + snprintf(bus->id, MII_BUS_ID_SIZE, "%s", dev_name(dev)); + + /* store the enetc mdio base address for this bus */ + regs = pf->si->hw.port + ENETC_MDIO_REG_OFFSET; + bus->priv = regs; + + np = of_get_child_by_name(dev->of_node, "mdio"); + if (!np) { + dev_err(dev, "MDIO node missing\n"); + ret = -EINVAL; + goto err_registration; + } + + ret = of_mdiobus_register(bus, np); + if (ret) { + of_node_put(np); + dev_err(dev, "cannot register MDIO bus\n"); + goto err_registration; + } + + of_node_put(np); + pf->mdio = bus; + + return 0; + +err_registration: + mdiobus_free(bus); + + return ret; +} + +void enetc_mdio_remove(struct enetc_pf *pf) +{ + if (pf->mdio) { + mdiobus_unregister(pf->mdio); + mdiobus_free(pf->mdio); + } +} |