// SPDX-License-Identifier: GPL-2.0
/*
 * Driver for the Texas Instruments DP83848 PHY
 *
 * Copyright (C) 2015-2016 Texas Instruments Incorporated - http://www.ti.com/
 */

#include <linux/module.h>
#include <linux/phy.h>

#define TI_DP83848C_PHY_ID              0x20005ca0
#define TI_DP83620_PHY_ID               0x20005ce0
#define NS_DP83848C_PHY_ID              0x20005c90
#define TLK10X_PHY_ID                   0x2000a210

/* Registers */
#define DP83848_MICR                    0x11 /* MII Interrupt Control Register */
#define DP83848_MISR                    0x12 /* MII Interrupt Status Register */

/* MICR Register Fields */
#define DP83848_MICR_INT_OE             BIT(0) /* Interrupt Output Enable */
#define DP83848_MICR_INTEN              BIT(1) /* Interrupt Enable */

/* MISR Register Fields */
#define DP83848_MISR_RHF_INT_EN         BIT(0) /* Receive Error Counter */
#define DP83848_MISR_FHF_INT_EN         BIT(1) /* False Carrier Counter */
#define DP83848_MISR_ANC_INT_EN         BIT(2) /* Auto-negotiation complete */
#define DP83848_MISR_DUP_INT_EN         BIT(3) /* Duplex Status */
#define DP83848_MISR_SPD_INT_EN         BIT(4) /* Speed status */
#define DP83848_MISR_LINK_INT_EN        BIT(5) /* Link status */
#define DP83848_MISR_ED_INT_EN          BIT(6) /* Energy detect */
#define DP83848_MISR_LQM_INT_EN         BIT(7) /* Link Quality Monitor */

#define DP83848_INT_EN_MASK             \
        (DP83848_MISR_ANC_INT_EN |      \
         DP83848_MISR_DUP_INT_EN |      \
         DP83848_MISR_SPD_INT_EN |      \
         DP83848_MISR_LINK_INT_EN)

#define DP83848_MISR_RHF_INT            BIT(8)
#define DP83848_MISR_FHF_INT            BIT(9)
#define DP83848_MISR_ANC_INT            BIT(10)
#define DP83848_MISR_DUP_INT            BIT(11)
#define DP83848_MISR_SPD_INT            BIT(12)
#define DP83848_MISR_LINK_INT           BIT(13)
#define DP83848_MISR_ED_INT             BIT(14)

#define DP83848_INT_MASK                \
        (DP83848_MISR_ANC_INT | \
         DP83848_MISR_DUP_INT | \
         DP83848_MISR_SPD_INT | \
         DP83848_MISR_LINK_INT)

static int dp83848_ack_interrupt(struct phy_device *phydev)
{
        int err = phy_read(phydev, DP83848_MISR);

        return err < 0 ? err : 0;
}

static int dp83848_config_intr(struct phy_device *phydev)
{
        int control, ret;

        control = phy_read(phydev, DP83848_MICR);
        if (control < 0)
                return control;

        if (phydev->interrupts == PHY_INTERRUPT_ENABLED) {
                ret = dp83848_ack_interrupt(phydev);
                if (ret)
                        return ret;

                control |= DP83848_MICR_INT_OE;
                control |= DP83848_MICR_INTEN;

                ret = phy_write(phydev, DP83848_MISR, DP83848_INT_EN_MASK);
                if (ret < 0)
                        return ret;

                ret = phy_write(phydev, DP83848_MICR, control);
        } else {
                control &= ~DP83848_MICR_INTEN;
                ret = phy_write(phydev, DP83848_MICR, control);
                if (ret)
                        return ret;

                ret = dp83848_ack_interrupt(phydev);
        }

        return ret;
}

static irqreturn_t dp83848_handle_interrupt(struct phy_device *phydev)
{
        int irq_status;

        irq_status = phy_read(phydev, DP83848_MISR);
        if (irq_status < 0) {
                phy_error(phydev);
                return IRQ_NONE;
        }

        if (!(irq_status & DP83848_INT_MASK))
                return IRQ_NONE;

        phy_trigger_machine(phydev);

        return IRQ_HANDLED;
}

static int dp83848_config_init(struct phy_device *phydev)
{
        int val;

        /* DP83620 always reports Auto Negotiation Ability on BMSR. Instead,
         * we check initial value of BMCR Auto negotiation enable bit
         */
        val = phy_read(phydev, MII_BMCR);
        if (!(val & BMCR_ANENABLE))
                phydev->autoneg = AUTONEG_DISABLE;

        return 0;
}

static const struct mdio_device_id __maybe_unused dp83848_tbl[] = {
        { TI_DP83848C_PHY_ID, 0xfffffff0 },
        { NS_DP83848C_PHY_ID, 0xfffffff0 },
        { TI_DP83620_PHY_ID, 0xfffffff0 },
        { TLK10X_PHY_ID, 0xfffffff0 },
        { }
};
MODULE_DEVICE_TABLE(mdio, dp83848_tbl);

#define DP83848_PHY_DRIVER(_id, _name, _config_init)            \
        {                                                       \
                .phy_id         = _id,                          \
                .phy_id_mask    = 0xfffffff0,                   \
                .name           = _name,                        \
                /* PHY_BASIC_FEATURES */                        \
                                                                \
                .soft_reset     = genphy_soft_reset,            \
                .config_init    = _config_init,                 \
                .suspend        = genphy_suspend,               \
                .resume         = genphy_resume,                \
                                                                \
                /* IRQ related */                               \
                .config_intr    = dp83848_config_intr,          \
                .handle_interrupt = dp83848_handle_interrupt,   \
                                                                \
                .flags          = PHY_RST_AFTER_CLK_EN,         \
        }

static struct phy_driver dp83848_driver[] = {
        DP83848_PHY_DRIVER(TI_DP83848C_PHY_ID, "TI DP83848C 10/100 Mbps PHY",
                           NULL),
        DP83848_PHY_DRIVER(NS_DP83848C_PHY_ID, "NS DP83848C 10/100 Mbps PHY",
                           NULL),
        DP83848_PHY_DRIVER(TI_DP83620_PHY_ID, "TI DP83620 10/100 Mbps PHY",
                           dp83848_config_init),
        DP83848_PHY_DRIVER(TLK10X_PHY_ID, "TI TLK10X 10/100 Mbps PHY",
                           NULL),
};
module_phy_driver(dp83848_driver);

MODULE_DESCRIPTION("Texas Instruments DP83848 PHY driver");
MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
MODULE_LICENSE("GPL v2");