root/drivers/phy/marvell/phy-armada38x-comphy.c
// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2018 Russell King, Deep Blue Solutions Ltd.
 *
 * Partly derived from CP110 comphy driver by Antoine Tenart
 * <antoine.tenart@bootlin.com>
 */
#include <linux/delay.h>
#include <linux/iopoll.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/phy/phy.h>
#include <linux/phy.h>
#include <linux/platform_device.h>

#define MAX_A38X_COMPHY 6
#define MAX_A38X_PORTS  3

#define COMPHY_CFG1             0x00
#define  COMPHY_CFG1_GEN_TX(x)          ((x) << 26)
#define  COMPHY_CFG1_GEN_TX_MSK         COMPHY_CFG1_GEN_TX(15)
#define  COMPHY_CFG1_GEN_RX(x)          ((x) << 22)
#define  COMPHY_CFG1_GEN_RX_MSK         COMPHY_CFG1_GEN_RX(15)
#define  GEN_SGMII_1_25GBPS             6
#define  GEN_SGMII_3_125GBPS            8

#define COMPHY_STAT1            0x18
#define  COMPHY_STAT1_PLL_RDY_TX        BIT(3)
#define  COMPHY_STAT1_PLL_RDY_RX        BIT(2)

#define COMPHY_SELECTOR         0xfc

struct a38x_comphy;

struct a38x_comphy_lane {
        void __iomem *base;
        struct a38x_comphy *priv;
        unsigned int n;

        int port;
};

struct a38x_comphy {
        void __iomem *base;
        void __iomem *conf;
        struct device *dev;
        struct a38x_comphy_lane lane[MAX_A38X_COMPHY];
};

/*
 * Map serdes lanes and gbe ports to serdes mux configuration values:
 * row index = serdes lane,
 * column index = gbe port number.
 */
static const u8 gbe_mux[MAX_A38X_COMPHY][MAX_A38X_PORTS] = {
        { 3, 0, 0 },
        { 4, 5, 0 },
        { 0, 4, 0 },
        { 0, 0, 4 },
        { 0, 3, 0 },
        { 0, 0, 3 },
};

static void a38x_set_conf(struct a38x_comphy_lane *lane, bool enable)
{
        struct a38x_comphy *priv = lane->priv;
        u32 conf;

        if (priv->conf) {
                conf = readl_relaxed(priv->conf);
                if (enable)
                        conf |= BIT(lane->port);
                else
                        conf &= ~BIT(lane->port);
                writel(conf, priv->conf);
        }
}

static void a38x_comphy_set_reg(struct a38x_comphy_lane *lane,
                                unsigned int offset, u32 mask, u32 value)
{
        u32 val;

        val = readl_relaxed(lane->base + offset) & ~mask;
        writel(val | value, lane->base + offset);
}

static void a38x_comphy_set_speed(struct a38x_comphy_lane *lane,
                                  unsigned int gen_tx, unsigned int gen_rx)
{
        a38x_comphy_set_reg(lane, COMPHY_CFG1,
                            COMPHY_CFG1_GEN_TX_MSK | COMPHY_CFG1_GEN_RX_MSK,
                            COMPHY_CFG1_GEN_TX(gen_tx) |
                            COMPHY_CFG1_GEN_RX(gen_rx));
}

static int a38x_comphy_poll(struct a38x_comphy_lane *lane,
                            unsigned int offset, u32 mask, u32 value)
{
        u32 val;
        int ret;

        ret = readl_relaxed_poll_timeout_atomic(lane->base + offset, val,
                                                (val & mask) == value,
                                                1000, 150000);

        if (ret)
                dev_err(lane->priv->dev,
                        "comphy%u: timed out waiting for status\n", lane->n);

        return ret;
}

/*
 * We only support changing the speed for comphys configured for GBE.
 * Since that is all we do, we only poll for PLL ready status.
 */
static int a38x_comphy_set_mode(struct phy *phy, enum phy_mode mode, int sub)
{
        struct a38x_comphy_lane *lane = phy_get_drvdata(phy);
        unsigned int gen;
        int ret;

        if (mode != PHY_MODE_ETHERNET)
                return -EINVAL;

        switch (sub) {
        case PHY_INTERFACE_MODE_SGMII:
        case PHY_INTERFACE_MODE_1000BASEX:
                gen = GEN_SGMII_1_25GBPS;
                break;

        case PHY_INTERFACE_MODE_2500BASEX:
                gen = GEN_SGMII_3_125GBPS;
                break;

        default:
                return -EINVAL;
        }

        a38x_set_conf(lane, false);

        a38x_comphy_set_speed(lane, gen, gen);

        ret = a38x_comphy_poll(lane, COMPHY_STAT1,
                               COMPHY_STAT1_PLL_RDY_TX |
                               COMPHY_STAT1_PLL_RDY_RX,
                               COMPHY_STAT1_PLL_RDY_TX |
                               COMPHY_STAT1_PLL_RDY_RX);

        if (ret == 0)
                a38x_set_conf(lane, true);

        return ret;
}

static const struct phy_ops a38x_comphy_ops = {
        .set_mode       = a38x_comphy_set_mode,
        .owner          = THIS_MODULE,
};

static struct phy *a38x_comphy_xlate(struct device *dev,
                                     const struct of_phandle_args *args)
{
        struct a38x_comphy_lane *lane;
        struct phy *phy;
        u32 val;

        if (WARN_ON(args->args[0] >= MAX_A38X_PORTS))
                return ERR_PTR(-EINVAL);

        phy = of_phy_simple_xlate(dev, args);
        if (IS_ERR(phy))
                return phy;

        lane = phy_get_drvdata(phy);
        if (lane->port >= 0)
                return ERR_PTR(-EBUSY);

        lane->port = args->args[0];

        val = readl_relaxed(lane->priv->base + COMPHY_SELECTOR);
        val = (val >> (4 * lane->n)) & 0xf;

        if (!gbe_mux[lane->n][lane->port] ||
            val != gbe_mux[lane->n][lane->port]) {
                dev_warn(lane->priv->dev,
                         "comphy%u: not configured for GBE\n", lane->n);
                phy = ERR_PTR(-EINVAL);
        }

        return phy;
}

static int a38x_comphy_probe(struct platform_device *pdev)
{
        struct phy_provider *provider;
        struct device_node *child;
        struct a38x_comphy *priv;
        struct resource *res;
        void __iomem *base;

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

        base = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(base))
                return PTR_ERR(base);

        priv->dev = &pdev->dev;
        priv->base = base;

        /* Optional */
        res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "conf");
        if (res) {
                priv->conf = devm_ioremap_resource(&pdev->dev, res);
                if (IS_ERR(priv->conf))
                        return PTR_ERR(priv->conf);
        }

        for_each_available_child_of_node(pdev->dev.of_node, child) {
                struct phy *phy;
                int ret;
                u32 val;

                ret = of_property_read_u32(child, "reg", &val);
                if (ret < 0) {
                        dev_err(&pdev->dev, "missing 'reg' property (%d)\n",
                                ret);
                        continue;
                }

                if (val >= MAX_A38X_COMPHY || priv->lane[val].base) {
                        dev_err(&pdev->dev, "invalid 'reg' property\n");
                        continue;
                }

                phy = devm_phy_create(&pdev->dev, child, &a38x_comphy_ops);
                if (IS_ERR(phy)) {
                        of_node_put(child);
                        return PTR_ERR(phy);
                }

                priv->lane[val].base = base + 0x28 * val;
                priv->lane[val].priv = priv;
                priv->lane[val].n = val;
                priv->lane[val].port = -1;
                phy_set_drvdata(phy, &priv->lane[val]);
        }

        dev_set_drvdata(&pdev->dev, priv);

        provider = devm_of_phy_provider_register(&pdev->dev, a38x_comphy_xlate);

        return PTR_ERR_OR_ZERO(provider);
}

static const struct of_device_id a38x_comphy_of_match_table[] = {
        { .compatible = "marvell,armada-380-comphy" },
        { },
};
MODULE_DEVICE_TABLE(of, a38x_comphy_of_match_table);

static struct platform_driver a38x_comphy_driver = {
        .probe  = a38x_comphy_probe,
        .driver = {
                .name = "armada-38x-comphy",
                .of_match_table = a38x_comphy_of_match_table,
        },
};
module_platform_driver(a38x_comphy_driver);

MODULE_AUTHOR("Russell King <rmk+kernel@armlinux.org.uk>");
MODULE_DESCRIPTION("Common PHY driver for Armada 38x SoCs");
MODULE_LICENSE("GPL v2");