Merge tag 'block-5.11-2021-01-10' of git://git.kernel.dk/linux-block

[linux/fpc-iii.git] / drivers / net / phy / at803x.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * drivers/net/phy/at803x.c
 *
 * Driver for Qualcomm Atheros AR803x PHY
 *
 * Author: Matus Ujhelyi <ujhelyi.m@gmail.com>
 */

#include <linux/phy.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/ethtool_netlink.h>
#include <linux/of_gpio.h>
#include <linux/bitfield.h>
#include <linux/gpio/consumer.h>
#include <linux/regulator/of_regulator.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/consumer.h>
#include <dt-bindings/net/qca-ar803x.h>

#define AT803X_SPECIFIC_FUNCTION_CONTROL        0x10
#define AT803X_SFC_ASSERT_CRS                   BIT(11)
#define AT803X_SFC_FORCE_LINK                   BIT(10)
#define AT803X_SFC_MDI_CROSSOVER_MODE_M         GENMASK(6, 5)
#define AT803X_SFC_AUTOMATIC_CROSSOVER          0x3
#define AT803X_SFC_MANUAL_MDIX                  0x1
#define AT803X_SFC_MANUAL_MDI                   0x0
#define AT803X_SFC_SQE_TEST                     BIT(2)
#define AT803X_SFC_POLARITY_REVERSAL            BIT(1)
#define AT803X_SFC_DISABLE_JABBER               BIT(0)

#define AT803X_SPECIFIC_STATUS                  0x11
#define AT803X_SS_SPEED_MASK                    (3 << 14)
#define AT803X_SS_SPEED_1000                    (2 << 14)
#define AT803X_SS_SPEED_100                     (1 << 14)
#define AT803X_SS_SPEED_10                      (0 << 14)
#define AT803X_SS_DUPLEX                        BIT(13)
#define AT803X_SS_SPEED_DUPLEX_RESOLVED         BIT(11)
#define AT803X_SS_MDIX                          BIT(6)

#define AT803X_INTR_ENABLE                      0x12
#define AT803X_INTR_ENABLE_AUTONEG_ERR          BIT(15)
#define AT803X_INTR_ENABLE_SPEED_CHANGED        BIT(14)
#define AT803X_INTR_ENABLE_DUPLEX_CHANGED       BIT(13)
#define AT803X_INTR_ENABLE_PAGE_RECEIVED        BIT(12)
#define AT803X_INTR_ENABLE_LINK_FAIL            BIT(11)
#define AT803X_INTR_ENABLE_LINK_SUCCESS         BIT(10)
#define AT803X_INTR_ENABLE_WIRESPEED_DOWNGRADE  BIT(5)
#define AT803X_INTR_ENABLE_POLARITY_CHANGED     BIT(1)
#define AT803X_INTR_ENABLE_WOL                  BIT(0)

#define AT803X_INTR_STATUS                      0x13

#define AT803X_SMART_SPEED                      0x14
#define AT803X_SMART_SPEED_ENABLE               BIT(5)
#define AT803X_SMART_SPEED_RETRY_LIMIT_MASK     GENMASK(4, 2)
#define AT803X_SMART_SPEED_BYPASS_TIMER         BIT(1)
#define AT803X_CDT                              0x16
#define AT803X_CDT_MDI_PAIR_MASK                GENMASK(9, 8)
#define AT803X_CDT_ENABLE_TEST                  BIT(0)
#define AT803X_CDT_STATUS                       0x1c
#define AT803X_CDT_STATUS_STAT_NORMAL           0
#define AT803X_CDT_STATUS_STAT_SHORT            1
#define AT803X_CDT_STATUS_STAT_OPEN             2
#define AT803X_CDT_STATUS_STAT_FAIL             3
#define AT803X_CDT_STATUS_STAT_MASK             GENMASK(9, 8)
#define AT803X_CDT_STATUS_DELTA_TIME_MASK       GENMASK(7, 0)
#define AT803X_LED_CONTROL                      0x18

#define AT803X_DEVICE_ADDR                      0x03
#define AT803X_LOC_MAC_ADDR_0_15_OFFSET         0x804C
#define AT803X_LOC_MAC_ADDR_16_31_OFFSET        0x804B
#define AT803X_LOC_MAC_ADDR_32_47_OFFSET        0x804A
#define AT803X_REG_CHIP_CONFIG                  0x1f
#define AT803X_BT_BX_REG_SEL                    0x8000

#define AT803X_DEBUG_ADDR                       0x1D
#define AT803X_DEBUG_DATA                       0x1E

#define AT803X_MODE_CFG_MASK                    0x0F
#define AT803X_MODE_CFG_SGMII                   0x01

#define AT803X_PSSR                     0x11    /*PHY-Specific Status Register*/
#define AT803X_PSSR_MR_AN_COMPLETE      0x0200

#define AT803X_DEBUG_REG_0                      0x00
#define AT803X_DEBUG_RX_CLK_DLY_EN              BIT(15)

#define AT803X_DEBUG_REG_5                      0x05
#define AT803X_DEBUG_TX_CLK_DLY_EN              BIT(8)

#define AT803X_DEBUG_REG_1F                     0x1F
#define AT803X_DEBUG_PLL_ON                     BIT(2)
#define AT803X_DEBUG_RGMII_1V8                  BIT(3)

/* AT803x supports either the XTAL input pad, an internal PLL or the
 * DSP as clock reference for the clock output pad. The XTAL reference
 * is only used for 25 MHz output, all other frequencies need the PLL.
 * The DSP as a clock reference is used in synchronous ethernet
 * applications.
 *
 * By default the PLL is only enabled if there is a link. Otherwise
 * the PHY will go into low power state and disabled the PLL. You can
 * set the PLL_ON bit (see debug register 0x1f) to keep the PLL always
 * enabled.
 */
#define AT803X_MMD7_CLK25M                      0x8016
#define AT803X_CLK_OUT_MASK                     GENMASK(4, 2)
#define AT803X_CLK_OUT_25MHZ_XTAL               0
#define AT803X_CLK_OUT_25MHZ_DSP                1
#define AT803X_CLK_OUT_50MHZ_PLL                2
#define AT803X_CLK_OUT_50MHZ_DSP                3
#define AT803X_CLK_OUT_62_5MHZ_PLL              4
#define AT803X_CLK_OUT_62_5MHZ_DSP              5
#define AT803X_CLK_OUT_125MHZ_PLL               6
#define AT803X_CLK_OUT_125MHZ_DSP               7

/* The AR8035 has another mask which is compatible with the AR8031/AR8033 mask
 * but doesn't support choosing between XTAL/PLL and DSP.
 */
#define AT8035_CLK_OUT_MASK                     GENMASK(4, 3)

#define AT803X_CLK_OUT_STRENGTH_MASK            GENMASK(8, 7)
#define AT803X_CLK_OUT_STRENGTH_FULL            0
#define AT803X_CLK_OUT_STRENGTH_HALF            1
#define AT803X_CLK_OUT_STRENGTH_QUARTER         2

#define AT803X_DEFAULT_DOWNSHIFT 5
#define AT803X_MIN_DOWNSHIFT 2
#define AT803X_MAX_DOWNSHIFT 9

#define ATH9331_PHY_ID 0x004dd041
#define ATH8030_PHY_ID 0x004dd076
#define ATH8031_PHY_ID 0x004dd074
#define ATH8032_PHY_ID 0x004dd023
#define ATH8035_PHY_ID 0x004dd072
#define AT8030_PHY_ID_MASK                      0xffffffef

MODULE_DESCRIPTION("Qualcomm Atheros AR803x PHY driver");
MODULE_AUTHOR("Matus Ujhelyi");
MODULE_LICENSE("GPL");

struct at803x_priv {
        int flags;
#define AT803X_KEEP_PLL_ENABLED BIT(0)  /* don't turn off internal PLL */
        u16 clk_25m_reg;
        u16 clk_25m_mask;
        struct regulator_dev *vddio_rdev;
        struct regulator_dev *vddh_rdev;
        struct regulator *vddio;
};

struct at803x_context {
        u16 bmcr;
        u16 advertise;
        u16 control1000;
        u16 int_enable;
        u16 smart_speed;
        u16 led_control;
};

static int at803x_debug_reg_read(struct phy_device *phydev, u16 reg)
{
        int ret;

        ret = phy_write(phydev, AT803X_DEBUG_ADDR, reg);
        if (ret < 0)
                return ret;

        return phy_read(phydev, AT803X_DEBUG_DATA);
}

static int at803x_debug_reg_mask(struct phy_device *phydev, u16 reg,
                                 u16 clear, u16 set)
{
        u16 val;
        int ret;

        ret = at803x_debug_reg_read(phydev, reg);
        if (ret < 0)
                return ret;

        val = ret & 0xffff;
        val &= ~clear;
        val |= set;

        return phy_write(phydev, AT803X_DEBUG_DATA, val);
}

static int at803x_enable_rx_delay(struct phy_device *phydev)
{
        return at803x_debug_reg_mask(phydev, AT803X_DEBUG_REG_0, 0,
                                     AT803X_DEBUG_RX_CLK_DLY_EN);
}

static int at803x_enable_tx_delay(struct phy_device *phydev)
{
        return at803x_debug_reg_mask(phydev, AT803X_DEBUG_REG_5, 0,
                                     AT803X_DEBUG_TX_CLK_DLY_EN);
}

static int at803x_disable_rx_delay(struct phy_device *phydev)
{
        return at803x_debug_reg_mask(phydev, AT803X_DEBUG_REG_0,
                                     AT803X_DEBUG_RX_CLK_DLY_EN, 0);
}

static int at803x_disable_tx_delay(struct phy_device *phydev)
{
        return at803x_debug_reg_mask(phydev, AT803X_DEBUG_REG_5,
                                     AT803X_DEBUG_TX_CLK_DLY_EN, 0);
}

/* save relevant PHY registers to private copy */
static void at803x_context_save(struct phy_device *phydev,
                                struct at803x_context *context)
{
        context->bmcr = phy_read(phydev, MII_BMCR);
        context->advertise = phy_read(phydev, MII_ADVERTISE);
        context->control1000 = phy_read(phydev, MII_CTRL1000);
        context->int_enable = phy_read(phydev, AT803X_INTR_ENABLE);
        context->smart_speed = phy_read(phydev, AT803X_SMART_SPEED);
        context->led_control = phy_read(phydev, AT803X_LED_CONTROL);
}

/* restore relevant PHY registers from private copy */
static void at803x_context_restore(struct phy_device *phydev,
                                   const struct at803x_context *context)
{
        phy_write(phydev, MII_BMCR, context->bmcr);
        phy_write(phydev, MII_ADVERTISE, context->advertise);
        phy_write(phydev, MII_CTRL1000, context->control1000);
        phy_write(phydev, AT803X_INTR_ENABLE, context->int_enable);
        phy_write(phydev, AT803X_SMART_SPEED, context->smart_speed);
        phy_write(phydev, AT803X_LED_CONTROL, context->led_control);
}

static int at803x_set_wol(struct phy_device *phydev,
                          struct ethtool_wolinfo *wol)
{
        struct net_device *ndev = phydev->attached_dev;
        const u8 *mac;
        int ret;
        u32 value;
        unsigned int i, offsets[] = {
                AT803X_LOC_MAC_ADDR_32_47_OFFSET,
                AT803X_LOC_MAC_ADDR_16_31_OFFSET,
                AT803X_LOC_MAC_ADDR_0_15_OFFSET,
        };

        if (!ndev)
                return -ENODEV;

        if (wol->wolopts & WAKE_MAGIC) {
                mac = (const u8 *) ndev->dev_addr;

                if (!is_valid_ether_addr(mac))
                        return -EINVAL;

                for (i = 0; i < 3; i++)
                        phy_write_mmd(phydev, AT803X_DEVICE_ADDR, offsets[i],
                                      mac[(i * 2) + 1] | (mac[(i * 2)] << 8));

                value = phy_read(phydev, AT803X_INTR_ENABLE);
                value |= AT803X_INTR_ENABLE_WOL;
                ret = phy_write(phydev, AT803X_INTR_ENABLE, value);
                if (ret)
                        return ret;
                value = phy_read(phydev, AT803X_INTR_STATUS);
        } else {
                value = phy_read(phydev, AT803X_INTR_ENABLE);
                value &= (~AT803X_INTR_ENABLE_WOL);
                ret = phy_write(phydev, AT803X_INTR_ENABLE, value);
                if (ret)
                        return ret;
                value = phy_read(phydev, AT803X_INTR_STATUS);
        }

        return ret;
}

static void at803x_get_wol(struct phy_device *phydev,
                           struct ethtool_wolinfo *wol)
{
        u32 value;

        wol->supported = WAKE_MAGIC;
        wol->wolopts = 0;

        value = phy_read(phydev, AT803X_INTR_ENABLE);
        if (value & AT803X_INTR_ENABLE_WOL)
                wol->wolopts |= WAKE_MAGIC;
}

static int at803x_suspend(struct phy_device *phydev)
{
        int value;
        int wol_enabled;

        value = phy_read(phydev, AT803X_INTR_ENABLE);
        wol_enabled = value & AT803X_INTR_ENABLE_WOL;

        if (wol_enabled)
                value = BMCR_ISOLATE;
        else
                value = BMCR_PDOWN;

        phy_modify(phydev, MII_BMCR, 0, value);

        return 0;
}

static int at803x_resume(struct phy_device *phydev)
{
        return phy_modify(phydev, MII_BMCR, BMCR_PDOWN | BMCR_ISOLATE, 0);
}

static int at803x_rgmii_reg_set_voltage_sel(struct regulator_dev *rdev,
                                            unsigned int selector)
{
        struct phy_device *phydev = rdev_get_drvdata(rdev);

        if (selector)
                return at803x_debug_reg_mask(phydev, AT803X_DEBUG_REG_1F,
                                             0, AT803X_DEBUG_RGMII_1V8);
        else
                return at803x_debug_reg_mask(phydev, AT803X_DEBUG_REG_1F,
                                             AT803X_DEBUG_RGMII_1V8, 0);
}

static int at803x_rgmii_reg_get_voltage_sel(struct regulator_dev *rdev)
{
        struct phy_device *phydev = rdev_get_drvdata(rdev);
        int val;

        val = at803x_debug_reg_read(phydev, AT803X_DEBUG_REG_1F);
        if (val < 0)
                return val;

        return (val & AT803X_DEBUG_RGMII_1V8) ? 1 : 0;
}

static const struct regulator_ops vddio_regulator_ops = {
        .list_voltage = regulator_list_voltage_table,
        .set_voltage_sel = at803x_rgmii_reg_set_voltage_sel,
        .get_voltage_sel = at803x_rgmii_reg_get_voltage_sel,
};

static const unsigned int vddio_voltage_table[] = {
        1500000,
        1800000,
};

static const struct regulator_desc vddio_desc = {
        .name = "vddio",
        .of_match = of_match_ptr("vddio-regulator"),
        .n_voltages = ARRAY_SIZE(vddio_voltage_table),
        .volt_table = vddio_voltage_table,
        .ops = &vddio_regulator_ops,
        .type = REGULATOR_VOLTAGE,
        .owner = THIS_MODULE,
};

static const struct regulator_ops vddh_regulator_ops = {
};

static const struct regulator_desc vddh_desc = {
        .name = "vddh",
        .of_match = of_match_ptr("vddh-regulator"),
        .n_voltages = 1,
        .fixed_uV = 2500000,
        .ops = &vddh_regulator_ops,
        .type = REGULATOR_VOLTAGE,
        .owner = THIS_MODULE,
};

static int at8031_register_regulators(struct phy_device *phydev)
{
        struct at803x_priv *priv = phydev->priv;
        struct device *dev = &phydev->mdio.dev;
        struct regulator_config config = { };

        config.dev = dev;
        config.driver_data = phydev;

        priv->vddio_rdev = devm_regulator_register(dev, &vddio_desc, &config);
        if (IS_ERR(priv->vddio_rdev)) {
                phydev_err(phydev, "failed to register VDDIO regulator\n");
                return PTR_ERR(priv->vddio_rdev);
        }

        priv->vddh_rdev = devm_regulator_register(dev, &vddh_desc, &config);
        if (IS_ERR(priv->vddh_rdev)) {
                phydev_err(phydev, "failed to register VDDH regulator\n");
                return PTR_ERR(priv->vddh_rdev);
        }

        return 0;
}

static bool at803x_match_phy_id(struct phy_device *phydev, u32 phy_id)
{
        return (phydev->phy_id & phydev->drv->phy_id_mask)
                == (phy_id & phydev->drv->phy_id_mask);
}

static int at803x_parse_dt(struct phy_device *phydev)
{
        struct device_node *node = phydev->mdio.dev.of_node;
        struct at803x_priv *priv = phydev->priv;
        u32 freq, strength;
        unsigned int sel;
        int ret;

        if (!IS_ENABLED(CONFIG_OF_MDIO))
                return 0;

        ret = of_property_read_u32(node, "qca,clk-out-frequency", &freq);
        if (!ret) {
                switch (freq) {
                case 25000000:
                        sel = AT803X_CLK_OUT_25MHZ_XTAL;
                        break;
                case 50000000:
                        sel = AT803X_CLK_OUT_50MHZ_PLL;
                        break;
                case 62500000:
                        sel = AT803X_CLK_OUT_62_5MHZ_PLL;
                        break;
                case 125000000:
                        sel = AT803X_CLK_OUT_125MHZ_PLL;
                        break;
                default:
                        phydev_err(phydev, "invalid qca,clk-out-frequency\n");
                        return -EINVAL;
                }

                priv->clk_25m_reg |= FIELD_PREP(AT803X_CLK_OUT_MASK, sel);
                priv->clk_25m_mask |= AT803X_CLK_OUT_MASK;

                /* Fixup for the AR8030/AR8035. This chip has another mask and
                 * doesn't support the DSP reference. Eg. the lowest bit of the
                 * mask. The upper two bits select the same frequencies. Mask
                 * the lowest bit here.
                 *
                 * Warning:
                 *   There was no datasheet for the AR8030 available so this is
                 *   just a guess. But the AR8035 is listed as pin compatible
                 *   to the AR8030 so there might be a good chance it works on
                 *   the AR8030 too.
                 */
                if (at803x_match_phy_id(phydev, ATH8030_PHY_ID) ||
                    at803x_match_phy_id(phydev, ATH8035_PHY_ID)) {
                        priv->clk_25m_reg &= AT8035_CLK_OUT_MASK;
                        priv->clk_25m_mask &= AT8035_CLK_OUT_MASK;
                }
        }

        ret = of_property_read_u32(node, "qca,clk-out-strength", &strength);
        if (!ret) {
                priv->clk_25m_mask |= AT803X_CLK_OUT_STRENGTH_MASK;
                switch (strength) {
                case AR803X_STRENGTH_FULL:
                        priv->clk_25m_reg |= AT803X_CLK_OUT_STRENGTH_FULL;
                        break;
                case AR803X_STRENGTH_HALF:
                        priv->clk_25m_reg |= AT803X_CLK_OUT_STRENGTH_HALF;
                        break;
                case AR803X_STRENGTH_QUARTER:
                        priv->clk_25m_reg |= AT803X_CLK_OUT_STRENGTH_QUARTER;
                        break;
                default:
                        phydev_err(phydev, "invalid qca,clk-out-strength\n");
                        return -EINVAL;
                }
        }

        /* Only supported on AR8031/AR8033, the AR8030/AR8035 use strapping
         * options.
         */
        if (at803x_match_phy_id(phydev, ATH8031_PHY_ID)) {
                if (of_property_read_bool(node, "qca,keep-pll-enabled"))
                        priv->flags |= AT803X_KEEP_PLL_ENABLED;

                ret = at8031_register_regulators(phydev);
                if (ret < 0)
                        return ret;

                priv->vddio = devm_regulator_get_optional(&phydev->mdio.dev,
                                                          "vddio");
                if (IS_ERR(priv->vddio)) {
                        phydev_err(phydev, "failed to get VDDIO regulator\n");
                        return PTR_ERR(priv->vddio);
                }

                ret = regulator_enable(priv->vddio);
                if (ret < 0)
                        return ret;
        }

        return 0;
}

static int at803x_probe(struct phy_device *phydev)
{
        struct device *dev = &phydev->mdio.dev;
        struct at803x_priv *priv;

        priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
        if (!priv)
                return -ENOMEM;

        phydev->priv = priv;

        return at803x_parse_dt(phydev);
}

static void at803x_remove(struct phy_device *phydev)
{
        struct at803x_priv *priv = phydev->priv;

        if (priv->vddio)
                regulator_disable(priv->vddio);
}

static int at803x_clk_out_config(struct phy_device *phydev)
{
        struct at803x_priv *priv = phydev->priv;
        int val;

        if (!priv->clk_25m_mask)
                return 0;

        val = phy_read_mmd(phydev, MDIO_MMD_AN, AT803X_MMD7_CLK25M);
        if (val < 0)
                return val;

        val &= ~priv->clk_25m_mask;
        val |= priv->clk_25m_reg;

        return phy_write_mmd(phydev, MDIO_MMD_AN, AT803X_MMD7_CLK25M, val);
}

static int at8031_pll_config(struct phy_device *phydev)
{
        struct at803x_priv *priv = phydev->priv;

        /* The default after hardware reset is PLL OFF. After a soft reset, the
         * values are retained.
         */
        if (priv->flags & AT803X_KEEP_PLL_ENABLED)
                return at803x_debug_reg_mask(phydev, AT803X_DEBUG_REG_1F,
                                             0, AT803X_DEBUG_PLL_ON);
        else
                return at803x_debug_reg_mask(phydev, AT803X_DEBUG_REG_1F,
                                             AT803X_DEBUG_PLL_ON, 0);
}

static int at803x_config_init(struct phy_device *phydev)
{
        int ret;

        /* The RX and TX delay default is:
         *   after HW reset: RX delay enabled and TX delay disabled
         *   after SW reset: RX delay enabled, while TX delay retains the
         *   value before reset.
         */
        if (phydev->interface == PHY_INTERFACE_MODE_RGMII_ID ||
            phydev->interface == PHY_INTERFACE_MODE_RGMII_RXID)
                ret = at803x_enable_rx_delay(phydev);
        else
                ret = at803x_disable_rx_delay(phydev);
        if (ret < 0)
                return ret;

        if (phydev->interface == PHY_INTERFACE_MODE_RGMII_ID ||
            phydev->interface == PHY_INTERFACE_MODE_RGMII_TXID)
                ret = at803x_enable_tx_delay(phydev);
        else
                ret = at803x_disable_tx_delay(phydev);
        if (ret < 0)
                return ret;

        ret = at803x_clk_out_config(phydev);
        if (ret < 0)
                return ret;

        if (at803x_match_phy_id(phydev, ATH8031_PHY_ID)) {
                ret = at8031_pll_config(phydev);
                if (ret < 0)
                        return ret;
        }

        return 0;
}

static int at803x_ack_interrupt(struct phy_device *phydev)
{
        int err;

        err = phy_read(phydev, AT803X_INTR_STATUS);

        return (err < 0) ? err : 0;
}

static int at803x_config_intr(struct phy_device *phydev)
{
        int err;
        int value;

        value = phy_read(phydev, AT803X_INTR_ENABLE);

        if (phydev->interrupts == PHY_INTERRUPT_ENABLED) {
                /* Clear any pending interrupts */
                err = at803x_ack_interrupt(phydev);
                if (err)
                        return err;

                value |= AT803X_INTR_ENABLE_AUTONEG_ERR;
                value |= AT803X_INTR_ENABLE_SPEED_CHANGED;
                value |= AT803X_INTR_ENABLE_DUPLEX_CHANGED;
                value |= AT803X_INTR_ENABLE_LINK_FAIL;
                value |= AT803X_INTR_ENABLE_LINK_SUCCESS;

                err = phy_write(phydev, AT803X_INTR_ENABLE, value);
        } else {
                err = phy_write(phydev, AT803X_INTR_ENABLE, 0);
                if (err)
                        return err;

                /* Clear any pending interrupts */
                err = at803x_ack_interrupt(phydev);
        }

        return err;
}

static irqreturn_t at803x_handle_interrupt(struct phy_device *phydev)
{
        int irq_status, int_enabled;

        irq_status = phy_read(phydev, AT803X_INTR_STATUS);
        if (irq_status < 0) {
                phy_error(phydev);
                return IRQ_NONE;
        }

        /* Read the current enabled interrupts */
        int_enabled = phy_read(phydev, AT803X_INTR_ENABLE);
        if (int_enabled < 0) {
                phy_error(phydev);
                return IRQ_NONE;
        }

        /* See if this was one of our enabled interrupts */
        if (!(irq_status & int_enabled))
                return IRQ_NONE;

        phy_trigger_machine(phydev);

        return IRQ_HANDLED;
}

static void at803x_link_change_notify(struct phy_device *phydev)
{
        /*
         * Conduct a hardware reset for AT8030 every time a link loss is
         * signalled. This is necessary to circumvent a hardware bug that
         * occurs when the cable is unplugged while TX packets are pending
         * in the FIFO. In such cases, the FIFO enters an error mode it
         * cannot recover from by software.
         */
        if (phydev->state == PHY_NOLINK && phydev->mdio.reset_gpio) {
                struct at803x_context context;

                at803x_context_save(phydev, &context);

                phy_device_reset(phydev, 1);
                msleep(1);
                phy_device_reset(phydev, 0);
                msleep(1);

                at803x_context_restore(phydev, &context);

                phydev_dbg(phydev, "%s(): phy was reset\n", __func__);
        }
}

static int at803x_aneg_done(struct phy_device *phydev)
{
        int ccr;

        int aneg_done = genphy_aneg_done(phydev);
        if (aneg_done != BMSR_ANEGCOMPLETE)
                return aneg_done;

        /*
         * in SGMII mode, if copper side autoneg is successful,
         * also check SGMII side autoneg result
         */
        ccr = phy_read(phydev, AT803X_REG_CHIP_CONFIG);
        if ((ccr & AT803X_MODE_CFG_MASK) != AT803X_MODE_CFG_SGMII)
                return aneg_done;

        /* switch to SGMII/fiber page */
        phy_write(phydev, AT803X_REG_CHIP_CONFIG, ccr & ~AT803X_BT_BX_REG_SEL);

        /* check if the SGMII link is OK. */
        if (!(phy_read(phydev, AT803X_PSSR) & AT803X_PSSR_MR_AN_COMPLETE)) {
                phydev_warn(phydev, "803x_aneg_done: SGMII link is not ok\n");
                aneg_done = 0;
        }
        /* switch back to copper page */
        phy_write(phydev, AT803X_REG_CHIP_CONFIG, ccr | AT803X_BT_BX_REG_SEL);

        return aneg_done;
}

static int at803x_read_status(struct phy_device *phydev)
{
        int ss, err, old_link = phydev->link;

        /* Update the link, but return if there was an error */
        err = genphy_update_link(phydev);
        if (err)
                return err;

        /* why bother the PHY if nothing can have changed */
        if (phydev->autoneg == AUTONEG_ENABLE && old_link && phydev->link)
                return 0;

        phydev->speed = SPEED_UNKNOWN;
        phydev->duplex = DUPLEX_UNKNOWN;
        phydev->pause = 0;
        phydev->asym_pause = 0;

        err = genphy_read_lpa(phydev);
        if (err < 0)
                return err;

        /* Read the AT8035 PHY-Specific Status register, which indicates the
         * speed and duplex that the PHY is actually using, irrespective of
         * whether we are in autoneg mode or not.
         */
        ss = phy_read(phydev, AT803X_SPECIFIC_STATUS);
        if (ss < 0)
                return ss;

        if (ss & AT803X_SS_SPEED_DUPLEX_RESOLVED) {
                int sfc;

                sfc = phy_read(phydev, AT803X_SPECIFIC_FUNCTION_CONTROL);
                if (sfc < 0)
                        return sfc;

                switch (ss & AT803X_SS_SPEED_MASK) {
                case AT803X_SS_SPEED_10:
                        phydev->speed = SPEED_10;
                        break;
                case AT803X_SS_SPEED_100:
                        phydev->speed = SPEED_100;
                        break;
                case AT803X_SS_SPEED_1000:
                        phydev->speed = SPEED_1000;
                        break;
                }
                if (ss & AT803X_SS_DUPLEX)
                        phydev->duplex = DUPLEX_FULL;
                else
                        phydev->duplex = DUPLEX_HALF;

                if (ss & AT803X_SS_MDIX)
                        phydev->mdix = ETH_TP_MDI_X;
                else
                        phydev->mdix = ETH_TP_MDI;

                switch (FIELD_GET(AT803X_SFC_MDI_CROSSOVER_MODE_M, sfc)) {
                case AT803X_SFC_MANUAL_MDI:
                        phydev->mdix_ctrl = ETH_TP_MDI;
                        break;
                case AT803X_SFC_MANUAL_MDIX:
                        phydev->mdix_ctrl = ETH_TP_MDI_X;
                        break;
                case AT803X_SFC_AUTOMATIC_CROSSOVER:
                        phydev->mdix_ctrl = ETH_TP_MDI_AUTO;
                        break;
                }
        }

        if (phydev->autoneg == AUTONEG_ENABLE && phydev->autoneg_complete)
                phy_resolve_aneg_pause(phydev);

        return 0;
}

static int at803x_config_mdix(struct phy_device *phydev, u8 ctrl)
{
        u16 val;

        switch (ctrl) {
        case ETH_TP_MDI:
                val = AT803X_SFC_MANUAL_MDI;
                break;
        case ETH_TP_MDI_X:
                val = AT803X_SFC_MANUAL_MDIX;
                break;
        case ETH_TP_MDI_AUTO:
                val = AT803X_SFC_AUTOMATIC_CROSSOVER;
                break;
        default:
                return 0;
        }

        return phy_modify_changed(phydev, AT803X_SPECIFIC_FUNCTION_CONTROL,
                          AT803X_SFC_MDI_CROSSOVER_MODE_M,
                          FIELD_PREP(AT803X_SFC_MDI_CROSSOVER_MODE_M, val));
}

static int at803x_config_aneg(struct phy_device *phydev)
{
        int ret;

        ret = at803x_config_mdix(phydev, phydev->mdix_ctrl);
        if (ret < 0)
                return ret;

        /* Changes of the midx bits are disruptive to the normal operation;
         * therefore any changes to these registers must be followed by a
         * software reset to take effect.
         */
        if (ret == 1) {
                ret = genphy_soft_reset(phydev);
                if (ret < 0)
                        return ret;
        }

        return genphy_config_aneg(phydev);
}

static int at803x_get_downshift(struct phy_device *phydev, u8 *d)
{
        int val;

        val = phy_read(phydev, AT803X_SMART_SPEED);
        if (val < 0)
                return val;

        if (val & AT803X_SMART_SPEED_ENABLE)
                *d = FIELD_GET(AT803X_SMART_SPEED_RETRY_LIMIT_MASK, val) + 2;
        else
                *d = DOWNSHIFT_DEV_DISABLE;

        return 0;
}

static int at803x_set_downshift(struct phy_device *phydev, u8 cnt)
{
        u16 mask, set;
        int ret;

        switch (cnt) {
        case DOWNSHIFT_DEV_DEFAULT_COUNT:
                cnt = AT803X_DEFAULT_DOWNSHIFT;
                fallthrough;
        case AT803X_MIN_DOWNSHIFT ... AT803X_MAX_DOWNSHIFT:
                set = AT803X_SMART_SPEED_ENABLE |
                      AT803X_SMART_SPEED_BYPASS_TIMER |
                      FIELD_PREP(AT803X_SMART_SPEED_RETRY_LIMIT_MASK, cnt - 2);
                mask = AT803X_SMART_SPEED_RETRY_LIMIT_MASK;
                break;
        case DOWNSHIFT_DEV_DISABLE:
                set = 0;
                mask = AT803X_SMART_SPEED_ENABLE |
                       AT803X_SMART_SPEED_BYPASS_TIMER;
                break;
        default:
                return -EINVAL;
        }

        ret = phy_modify_changed(phydev, AT803X_SMART_SPEED, mask, set);

        /* After changing the smart speed settings, we need to perform a
         * software reset, use phy_init_hw() to make sure we set the
         * reapply any values which might got lost during software reset.
         */
        if (ret == 1)
                ret = phy_init_hw(phydev);

        return ret;
}

static int at803x_get_tunable(struct phy_device *phydev,
                              struct ethtool_tunable *tuna, void *data)
{
        switch (tuna->id) {
        case ETHTOOL_PHY_DOWNSHIFT:
                return at803x_get_downshift(phydev, data);
        default:
                return -EOPNOTSUPP;
        }
}

static int at803x_set_tunable(struct phy_device *phydev,
                              struct ethtool_tunable *tuna, const void *data)
{
        switch (tuna->id) {
        case ETHTOOL_PHY_DOWNSHIFT:
                return at803x_set_downshift(phydev, *(const u8 *)data);
        default:
                return -EOPNOTSUPP;
        }
}

static int at803x_cable_test_result_trans(u16 status)
{
        switch (FIELD_GET(AT803X_CDT_STATUS_STAT_MASK, status)) {
        case AT803X_CDT_STATUS_STAT_NORMAL:
                return ETHTOOL_A_CABLE_RESULT_CODE_OK;
        case AT803X_CDT_STATUS_STAT_SHORT:
                return ETHTOOL_A_CABLE_RESULT_CODE_SAME_SHORT;
        case AT803X_CDT_STATUS_STAT_OPEN:
                return ETHTOOL_A_CABLE_RESULT_CODE_OPEN;
        case AT803X_CDT_STATUS_STAT_FAIL:
        default:
                return ETHTOOL_A_CABLE_RESULT_CODE_UNSPEC;
        }
}

static bool at803x_cdt_test_failed(u16 status)
{
        return FIELD_GET(AT803X_CDT_STATUS_STAT_MASK, status) ==
                AT803X_CDT_STATUS_STAT_FAIL;
}

static bool at803x_cdt_fault_length_valid(u16 status)
{
        switch (FIELD_GET(AT803X_CDT_STATUS_STAT_MASK, status)) {
        case AT803X_CDT_STATUS_STAT_OPEN:
        case AT803X_CDT_STATUS_STAT_SHORT:
                return true;
        }
        return false;
}

static int at803x_cdt_fault_length(u16 status)
{
        int dt;

        /* According to the datasheet the distance to the fault is
         * DELTA_TIME * 0.824 meters.
         *
         * The author suspect the correct formula is:
         *
         *   fault_distance = DELTA_TIME * (c * VF) / 125MHz / 2
         *
         * where c is the speed of light, VF is the velocity factor of
         * the twisted pair cable, 125MHz the counter frequency and
         * we need to divide by 2 because the hardware will measure the
         * round trip time to the fault and back to the PHY.
         *
         * With a VF of 0.69 we get the factor 0.824 mentioned in the
         * datasheet.
         */
        dt = FIELD_GET(AT803X_CDT_STATUS_DELTA_TIME_MASK, status);

        return (dt * 824) / 10;
}

static int at803x_cdt_start(struct phy_device *phydev, int pair)
{
        u16 cdt;

        cdt = FIELD_PREP(AT803X_CDT_MDI_PAIR_MASK, pair) |
              AT803X_CDT_ENABLE_TEST;

        return phy_write(phydev, AT803X_CDT, cdt);
}

static int at803x_cdt_wait_for_completion(struct phy_device *phydev)
{
        int val, ret;

        /* One test run takes about 25ms */
        ret = phy_read_poll_timeout(phydev, AT803X_CDT, val,
                                    !(val & AT803X_CDT_ENABLE_TEST),
                                    30000, 100000, true);

        return ret < 0 ? ret : 0;
}

static int at803x_cable_test_one_pair(struct phy_device *phydev, int pair)
{
        static const int ethtool_pair[] = {
                ETHTOOL_A_CABLE_PAIR_A,
                ETHTOOL_A_CABLE_PAIR_B,
                ETHTOOL_A_CABLE_PAIR_C,
                ETHTOOL_A_CABLE_PAIR_D,
        };
        int ret, val;

        ret = at803x_cdt_start(phydev, pair);
        if (ret)
                return ret;

        ret = at803x_cdt_wait_for_completion(phydev);
        if (ret)
                return ret;

        val = phy_read(phydev, AT803X_CDT_STATUS);
        if (val < 0)
                return val;

        if (at803x_cdt_test_failed(val))
                return 0;

        ethnl_cable_test_result(phydev, ethtool_pair[pair],
                                at803x_cable_test_result_trans(val));

        if (at803x_cdt_fault_length_valid(val))
                ethnl_cable_test_fault_length(phydev, ethtool_pair[pair],
                                              at803x_cdt_fault_length(val));

        return 1;
}

static int at803x_cable_test_get_status(struct phy_device *phydev,
                                        bool *finished)
{
        unsigned long pair_mask;
        int retries = 20;
        int pair, ret;

        if (phydev->phy_id == ATH9331_PHY_ID ||
            phydev->phy_id == ATH8032_PHY_ID)
                pair_mask = 0x3;
        else
                pair_mask = 0xf;

        *finished = false;

        /* According to the datasheet the CDT can be performed when
         * there is no link partner or when the link partner is
         * auto-negotiating. Starting the test will restart the AN
         * automatically. It seems that doing this repeatedly we will
         * get a slot where our link partner won't disturb our
         * measurement.
         */
        while (pair_mask && retries--) {
                for_each_set_bit(pair, &pair_mask, 4) {
                        ret = at803x_cable_test_one_pair(phydev, pair);
                        if (ret < 0)
                                return ret;
                        if (ret)
                                clear_bit(pair, &pair_mask);
                }
                if (pair_mask)
                        msleep(250);
        }

        *finished = true;

        return 0;
}

static int at803x_cable_test_start(struct phy_device *phydev)
{
        /* Enable auto-negotiation, but advertise no capabilities, no link
         * will be established. A restart of the auto-negotiation is not
         * required, because the cable test will automatically break the link.
         */
        phy_write(phydev, MII_BMCR, BMCR_ANENABLE);
        phy_write(phydev, MII_ADVERTISE, ADVERTISE_CSMA);
        if (phydev->phy_id != ATH9331_PHY_ID &&
            phydev->phy_id != ATH8032_PHY_ID)
                phy_write(phydev, MII_CTRL1000, 0);

        /* we do all the (time consuming) work later */
        return 0;
}

static struct phy_driver at803x_driver[] = {
{
        /* Qualcomm Atheros AR8035 */
        PHY_ID_MATCH_EXACT(ATH8035_PHY_ID),
        .name                   = "Qualcomm Atheros AR8035",
        .flags                  = PHY_POLL_CABLE_TEST,
        .probe                  = at803x_probe,
        .remove                 = at803x_remove,
        .config_aneg            = at803x_config_aneg,
        .config_init            = at803x_config_init,
        .soft_reset             = genphy_soft_reset,
        .set_wol                = at803x_set_wol,
        .get_wol                = at803x_get_wol,
        .suspend                = at803x_suspend,
        .resume                 = at803x_resume,
        /* PHY_GBIT_FEATURES */
        .read_status            = at803x_read_status,
        .config_intr            = at803x_config_intr,
        .handle_interrupt       = at803x_handle_interrupt,
        .get_tunable            = at803x_get_tunable,
        .set_tunable            = at803x_set_tunable,
        .cable_test_start       = at803x_cable_test_start,
        .cable_test_get_status  = at803x_cable_test_get_status,
}, {
        /* Qualcomm Atheros AR8030 */
        .phy_id                 = ATH8030_PHY_ID,
        .name                   = "Qualcomm Atheros AR8030",
        .phy_id_mask            = AT8030_PHY_ID_MASK,
        .probe                  = at803x_probe,
        .remove                 = at803x_remove,
        .config_init            = at803x_config_init,
        .link_change_notify     = at803x_link_change_notify,
        .set_wol                = at803x_set_wol,
        .get_wol                = at803x_get_wol,
        .suspend                = at803x_suspend,
        .resume                 = at803x_resume,
        /* PHY_BASIC_FEATURES */
        .config_intr            = at803x_config_intr,
        .handle_interrupt       = at803x_handle_interrupt,
}, {
        /* Qualcomm Atheros AR8031/AR8033 */
        PHY_ID_MATCH_EXACT(ATH8031_PHY_ID),
        .name                   = "Qualcomm Atheros AR8031/AR8033",
        .flags                  = PHY_POLL_CABLE_TEST,
        .probe                  = at803x_probe,
        .remove                 = at803x_remove,
        .config_init            = at803x_config_init,
        .soft_reset             = genphy_soft_reset,
        .set_wol                = at803x_set_wol,
        .get_wol                = at803x_get_wol,
        .suspend                = at803x_suspend,
        .resume                 = at803x_resume,
        /* PHY_GBIT_FEATURES */
        .read_status            = at803x_read_status,
        .aneg_done              = at803x_aneg_done,
        .config_intr            = &at803x_config_intr,
        .handle_interrupt       = at803x_handle_interrupt,
        .get_tunable            = at803x_get_tunable,
        .set_tunable            = at803x_set_tunable,
        .cable_test_start       = at803x_cable_test_start,
        .cable_test_get_status  = at803x_cable_test_get_status,
}, {
        /* Qualcomm Atheros AR8032 */
        PHY_ID_MATCH_EXACT(ATH8032_PHY_ID),
        .name                   = "Qualcomm Atheros AR8032",
        .probe                  = at803x_probe,
        .remove                 = at803x_remove,
        .flags                  = PHY_POLL_CABLE_TEST,
        .config_init            = at803x_config_init,
        .link_change_notify     = at803x_link_change_notify,
        .set_wol                = at803x_set_wol,
        .get_wol                = at803x_get_wol,
        .suspend                = at803x_suspend,
        .resume                 = at803x_resume,
        /* PHY_BASIC_FEATURES */
        .config_intr            = at803x_config_intr,
        .handle_interrupt       = at803x_handle_interrupt,
        .cable_test_start       = at803x_cable_test_start,
        .cable_test_get_status  = at803x_cable_test_get_status,
}, {
        /* ATHEROS AR9331 */
        PHY_ID_MATCH_EXACT(ATH9331_PHY_ID),
        .name                   = "Qualcomm Atheros AR9331 built-in PHY",
        .suspend                = at803x_suspend,
        .resume                 = at803x_resume,
        .flags                  = PHY_POLL_CABLE_TEST,
        /* PHY_BASIC_FEATURES */
        .config_intr            = &at803x_config_intr,
        .handle_interrupt       = at803x_handle_interrupt,
        .cable_test_start       = at803x_cable_test_start,
        .cable_test_get_status  = at803x_cable_test_get_status,
        .read_status            = at803x_read_status,
        .soft_reset             = genphy_soft_reset,
        .config_aneg            = at803x_config_aneg,
} };

module_phy_driver(at803x_driver);

static struct mdio_device_id __maybe_unused atheros_tbl[] = {
        { ATH8030_PHY_ID, AT8030_PHY_ID_MASK },
        { PHY_ID_MATCH_EXACT(ATH8031_PHY_ID) },
        { PHY_ID_MATCH_EXACT(ATH8032_PHY_ID) },
        { PHY_ID_MATCH_EXACT(ATH8035_PHY_ID) },
        { PHY_ID_MATCH_EXACT(ATH9331_PHY_ID) },
        { }
};

MODULE_DEVICE_TABLE(mdio, atheros_tbl);