root/drivers/phy/amlogic/phy-meson-axg-mipi-pcie-analog.c
// SPDX-License-Identifier: GPL-2.0
/*
 * Amlogic AXG MIPI + PCIE analog PHY driver
 *
 * Copyright (C) 2019 Remi Pommarel <repk@triplefau.lt>
 */
#include <linux/bitfield.h>
#include <linux/bitops.h>
#include <linux/module.h>
#include <linux/phy/phy.h>
#include <linux/regmap.h>
#include <linux/delay.h>
#include <linux/mfd/syscon.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <dt-bindings/phy/phy.h>

#define HHI_MIPI_CNTL0 0x00
#define         HHI_MIPI_CNTL0_COMMON_BLOCK     GENMASK(31, 28)
#define         HHI_MIPI_CNTL0_ENABLE           BIT(29)
#define         HHI_MIPI_CNTL0_BANDGAP          BIT(26)
#define         HHI_MIPI_CNTL0_DIF_REF_CTL1     GENMASK(25, 16)
#define         HHI_MIPI_CNTL0_DIF_REF_CTL0     GENMASK(15, 0)

#define HHI_MIPI_CNTL1 0x04
#define         HHI_MIPI_CNTL1_CH0_CML_PDR_EN   BIT(12)
#define         HHI_MIPI_CNTL1_LP_ABILITY       GENMASK(5, 4)
#define         HHI_MIPI_CNTL1_LP_RESISTER      BIT(3)
#define         HHI_MIPI_CNTL1_INPUT_SETTING    BIT(2)
#define         HHI_MIPI_CNTL1_INPUT_SEL        BIT(1)
#define         HHI_MIPI_CNTL1_PRBS7_EN         BIT(0)

#define HHI_MIPI_CNTL2 0x08
#define         HHI_MIPI_CNTL2_CH_PU            GENMASK(31, 25)
#define         HHI_MIPI_CNTL2_CH_CTL           GENMASK(24, 19)
#define         HHI_MIPI_CNTL2_CH0_DIGDR_EN     BIT(18)
#define         HHI_MIPI_CNTL2_CH_DIGDR_EN      BIT(17)
#define         HHI_MIPI_CNTL2_LPULPS_EN        BIT(16)
#define         HHI_MIPI_CNTL2_CH_EN            GENMASK(15, 11)
#define         HHI_MIPI_CNTL2_CH0_LP_CTL       GENMASK(10, 1)

#define DSI_LANE_0              BIT(4)
#define DSI_LANE_1              BIT(3)
#define DSI_LANE_CLK            BIT(2)
#define DSI_LANE_2              BIT(1)
#define DSI_LANE_3              BIT(0)

struct phy_axg_mipi_pcie_analog_priv {
        struct phy *phy;
        struct regmap *regmap;
        bool dsi_configured;
        bool dsi_enabled;
        bool powered;
        struct phy_configure_opts_mipi_dphy config;
};

static void phy_bandgap_enable(struct phy_axg_mipi_pcie_analog_priv *priv)
{
        regmap_update_bits(priv->regmap, HHI_MIPI_CNTL0,
                        HHI_MIPI_CNTL0_BANDGAP, HHI_MIPI_CNTL0_BANDGAP);

        regmap_update_bits(priv->regmap, HHI_MIPI_CNTL0,
                        HHI_MIPI_CNTL0_ENABLE, HHI_MIPI_CNTL0_ENABLE);
}

static void phy_bandgap_disable(struct phy_axg_mipi_pcie_analog_priv *priv)
{
        regmap_update_bits(priv->regmap, HHI_MIPI_CNTL0,
                        HHI_MIPI_CNTL0_BANDGAP, 0);
        regmap_update_bits(priv->regmap, HHI_MIPI_CNTL0,
                        HHI_MIPI_CNTL0_ENABLE, 0);
}

static void phy_dsi_analog_enable(struct phy_axg_mipi_pcie_analog_priv *priv)
{
        u32 reg;

        regmap_update_bits(priv->regmap, HHI_MIPI_CNTL0,
                           HHI_MIPI_CNTL0_DIF_REF_CTL1,
                           FIELD_PREP(HHI_MIPI_CNTL0_DIF_REF_CTL1, 0x1b8));
        regmap_update_bits(priv->regmap, HHI_MIPI_CNTL0,
                           BIT(31), BIT(31));
        regmap_update_bits(priv->regmap, HHI_MIPI_CNTL0,
                           HHI_MIPI_CNTL0_DIF_REF_CTL0,
                           FIELD_PREP(HHI_MIPI_CNTL0_DIF_REF_CTL0, 0x8));

        regmap_write(priv->regmap, HHI_MIPI_CNTL1, 0x001e);

        regmap_write(priv->regmap, HHI_MIPI_CNTL2,
                     (0x26e0 << 16) | (0x459 << 0));

        reg = DSI_LANE_CLK;
        switch (priv->config.lanes) {
        case 4:
                reg |= DSI_LANE_3;
                fallthrough;
        case 3:
                reg |= DSI_LANE_2;
                fallthrough;
        case 2:
                reg |= DSI_LANE_1;
                fallthrough;
        case 1:
                reg |= DSI_LANE_0;
                break;
        default:
                reg = 0;
        }

        regmap_update_bits(priv->regmap, HHI_MIPI_CNTL2,
                           HHI_MIPI_CNTL2_CH_EN,
                           FIELD_PREP(HHI_MIPI_CNTL2_CH_EN, reg));

        priv->dsi_enabled = true;
}

static void phy_dsi_analog_disable(struct phy_axg_mipi_pcie_analog_priv *priv)
{
        regmap_update_bits(priv->regmap, HHI_MIPI_CNTL0,
                        HHI_MIPI_CNTL0_DIF_REF_CTL1,
                        FIELD_PREP(HHI_MIPI_CNTL0_DIF_REF_CTL1, 0));
        regmap_update_bits(priv->regmap, HHI_MIPI_CNTL0, BIT(31), 0);
        regmap_update_bits(priv->regmap, HHI_MIPI_CNTL0,
                        HHI_MIPI_CNTL0_DIF_REF_CTL1, 0);

        regmap_write(priv->regmap, HHI_MIPI_CNTL1, 0x6);

        regmap_write(priv->regmap, HHI_MIPI_CNTL2, 0x00200000);

        priv->dsi_enabled = false;
}

static int phy_axg_mipi_pcie_analog_configure(struct phy *phy,
                                              union phy_configure_opts *opts)
{
        struct phy_axg_mipi_pcie_analog_priv *priv = phy_get_drvdata(phy);
        int ret;

        ret = phy_mipi_dphy_config_validate(&opts->mipi_dphy);
        if (ret)
                return ret;

        memcpy(&priv->config, opts, sizeof(priv->config));

        priv->dsi_configured = true;

        /* If PHY was already powered on, setup the DSI analog part */
        if (priv->powered) {
                /* If reconfiguring, disable & reconfigure */
                if (priv->dsi_enabled)
                        phy_dsi_analog_disable(priv);

                usleep_range(100, 200);

                phy_dsi_analog_enable(priv);
        }

        return 0;
}

static int phy_axg_mipi_pcie_analog_power_on(struct phy *phy)
{
        struct phy_axg_mipi_pcie_analog_priv *priv = phy_get_drvdata(phy);

        phy_bandgap_enable(priv);

        if (priv->dsi_configured)
                phy_dsi_analog_enable(priv);

        priv->powered = true;

        return 0;
}

static int phy_axg_mipi_pcie_analog_power_off(struct phy *phy)
{
        struct phy_axg_mipi_pcie_analog_priv *priv = phy_get_drvdata(phy);

        phy_bandgap_disable(priv);

        if (priv->dsi_enabled)
                phy_dsi_analog_disable(priv);

        priv->powered = false;

        return 0;
}

static const struct phy_ops phy_axg_mipi_pcie_analog_ops = {
        .configure = phy_axg_mipi_pcie_analog_configure,
        .power_on = phy_axg_mipi_pcie_analog_power_on,
        .power_off = phy_axg_mipi_pcie_analog_power_off,
        .owner = THIS_MODULE,
};

static int phy_axg_mipi_pcie_analog_probe(struct platform_device *pdev)
{
        struct phy_provider *phy;
        struct device *dev = &pdev->dev;
        struct phy_axg_mipi_pcie_analog_priv *priv;
        struct device_node *np = dev->of_node, *parent_np;
        struct regmap *map;

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

        /* Get the hhi system controller node */
        parent_np = of_get_parent(dev->of_node);
        map = syscon_node_to_regmap(parent_np);
        of_node_put(parent_np);
        if (IS_ERR(map)) {
                dev_err(dev,
                        "failed to get HHI regmap\n");
                return PTR_ERR(map);
        }

        priv->regmap = map;

        priv->phy = devm_phy_create(dev, np, &phy_axg_mipi_pcie_analog_ops);
        if (IS_ERR(priv->phy))
                return dev_err_probe(dev, PTR_ERR(priv->phy),
                                     "failed to create PHY\n");

        phy_set_drvdata(priv->phy, priv);
        dev_set_drvdata(dev, priv);

        phy = devm_of_phy_provider_register(dev, of_phy_simple_xlate);

        return PTR_ERR_OR_ZERO(phy);
}

static const struct of_device_id phy_axg_mipi_pcie_analog_of_match[] = {
        {
                .compatible = "amlogic,axg-mipi-pcie-analog-phy",
        },
        { },
};
MODULE_DEVICE_TABLE(of, phy_axg_mipi_pcie_analog_of_match);

static struct platform_driver phy_axg_mipi_pcie_analog_driver = {
        .probe = phy_axg_mipi_pcie_analog_probe,
        .driver = {
                .name = "phy-axg-mipi-pcie-analog",
                .of_match_table = phy_axg_mipi_pcie_analog_of_match,
        },
};
module_platform_driver(phy_axg_mipi_pcie_analog_driver);

MODULE_AUTHOR("Remi Pommarel <repk@triplefau.lt>");
MODULE_DESCRIPTION("Amlogic AXG MIPI + PCIE analog PHY driver");
MODULE_LICENSE("GPL v2");