root/drivers/phy/amlogic/phy-meson8b-usb2.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Meson8, Meson8b and GXBB USB2 PHY driver
 *
 * Copyright (C) 2016 Martin Blumenstingl <martin.blumenstingl@googlemail.com>
 */

#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/property.h>
#include <linux/regmap.h>
#include <linux/reset.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
#include <linux/usb/of.h>

#define REG_CONFIG                                      0x00
        #define REG_CONFIG_CLK_EN                       BIT(0)
        #define REG_CONFIG_CLK_SEL_MASK                 GENMASK(3, 1)
        #define REG_CONFIG_CLK_DIV_MASK                 GENMASK(10, 4)
        #define REG_CONFIG_CLK_32k_ALTSEL               BIT(15)
        #define REG_CONFIG_TEST_TRIG                    BIT(31)

#define REG_CTRL                                        0x04
        #define REG_CTRL_SOFT_PRST                      BIT(0)
        #define REG_CTRL_SOFT_HRESET                    BIT(1)
        #define REG_CTRL_SS_SCALEDOWN_MODE_MASK         GENMASK(3, 2)
        #define REG_CTRL_CLK_DET_RST                    BIT(4)
        #define REG_CTRL_INTR_SEL                       BIT(5)
        #define REG_CTRL_CLK_DETECTED                   BIT(8)
        #define REG_CTRL_SOF_SENT_RCVD_TGL              BIT(9)
        #define REG_CTRL_SOF_TOGGLE_OUT                 BIT(10)
        #define REG_CTRL_POWER_ON_RESET                 BIT(15)
        #define REG_CTRL_SLEEPM                         BIT(16)
        #define REG_CTRL_TX_BITSTUFF_ENN_H              BIT(17)
        #define REG_CTRL_TX_BITSTUFF_ENN                BIT(18)
        #define REG_CTRL_COMMON_ON                      BIT(19)
        #define REG_CTRL_REF_CLK_SEL_MASK               GENMASK(21, 20)
        #define REG_CTRL_FSEL_MASK                      GENMASK(24, 22)
        #define REG_CTRL_PORT_RESET                     BIT(25)
        #define REG_CTRL_THREAD_ID_MASK                 GENMASK(31, 26)

#define REG_ENDP_INTR                                   0x08

/* bits [31:26], [24:21] and [15:3] seem to be read-only */
#define REG_ADP_BC                                      0x0c
        #define REG_ADP_BC_VBUS_VLD_EXT_SEL             BIT(0)
        #define REG_ADP_BC_VBUS_VLD_EXT                 BIT(1)
        #define REG_ADP_BC_OTG_DISABLE                  BIT(2)
        #define REG_ADP_BC_ID_PULLUP                    BIT(3)
        #define REG_ADP_BC_DRV_VBUS                     BIT(4)
        #define REG_ADP_BC_ADP_PRB_EN                   BIT(5)
        #define REG_ADP_BC_ADP_DISCHARGE                BIT(6)
        #define REG_ADP_BC_ADP_CHARGE                   BIT(7)
        #define REG_ADP_BC_SESS_END                     BIT(8)
        #define REG_ADP_BC_DEVICE_SESS_VLD              BIT(9)
        #define REG_ADP_BC_B_VALID                      BIT(10)
        #define REG_ADP_BC_A_VALID                      BIT(11)
        #define REG_ADP_BC_ID_DIG                       BIT(12)
        #define REG_ADP_BC_VBUS_VALID                   BIT(13)
        #define REG_ADP_BC_ADP_PROBE                    BIT(14)
        #define REG_ADP_BC_ADP_SENSE                    BIT(15)
        #define REG_ADP_BC_ACA_ENABLE                   BIT(16)
        #define REG_ADP_BC_DCD_ENABLE                   BIT(17)
        #define REG_ADP_BC_VDAT_DET_EN_B                BIT(18)
        #define REG_ADP_BC_VDAT_SRC_EN_B                BIT(19)
        #define REG_ADP_BC_CHARGE_SEL                   BIT(20)
        #define REG_ADP_BC_CHARGE_DETECT                BIT(21)
        #define REG_ADP_BC_ACA_PIN_RANGE_C              BIT(22)
        #define REG_ADP_BC_ACA_PIN_RANGE_B              BIT(23)
        #define REG_ADP_BC_ACA_PIN_RANGE_A              BIT(24)
        #define REG_ADP_BC_ACA_PIN_GND                  BIT(25)
        #define REG_ADP_BC_ACA_PIN_FLOAT                BIT(26)

#define REG_DBG_UART                                    0x10
        #define REG_DBG_UART_BYPASS_SEL                 BIT(0)
        #define REG_DBG_UART_BYPASS_DM_EN               BIT(1)
        #define REG_DBG_UART_BYPASS_DP_EN               BIT(2)
        #define REG_DBG_UART_BYPASS_DM_DATA             BIT(3)
        #define REG_DBG_UART_BYPASS_DP_DATA             BIT(4)
        #define REG_DBG_UART_FSV_MINUS                  BIT(5)
        #define REG_DBG_UART_FSV_PLUS                   BIT(6)
        #define REG_DBG_UART_FSV_BURN_IN_TEST           BIT(7)
        #define REG_DBG_UART_LOOPBACK_EN_B              BIT(8)
        #define REG_DBG_UART_SET_IDDQ                   BIT(9)
        #define REG_DBG_UART_ATE_RESET                  BIT(10)

#define REG_TEST                                        0x14
        #define REG_TEST_DATA_IN_MASK                   GENMASK(3, 0)
        #define REG_TEST_EN_MASK                        GENMASK(7, 4)
        #define REG_TEST_ADDR_MASK                      GENMASK(11, 8)
        #define REG_TEST_DATA_OUT_SEL                   BIT(12)
        #define REG_TEST_CLK                            BIT(13)
        #define REG_TEST_VA_TEST_EN_B_MASK              GENMASK(15, 14)
        #define REG_TEST_DATA_OUT_MASK                  GENMASK(19, 16)
        #define REG_TEST_DISABLE_ID_PULLUP              BIT(20)

#define REG_TUNE                                        0x18
        #define REG_TUNE_TX_RES_TUNE_MASK               GENMASK(1, 0)
        #define REG_TUNE_TX_HSXV_TUNE_MASK              GENMASK(3, 2)
        #define REG_TUNE_TX_VREF_TUNE_MASK              GENMASK(7, 4)
        #define REG_TUNE_TX_RISE_TUNE_MASK              GENMASK(9, 8)
        #define REG_TUNE_TX_PREEMP_PULSE_TUNE           BIT(10)
        #define REG_TUNE_TX_PREEMP_AMP_TUNE_MASK        GENMASK(12, 11)
        #define REG_TUNE_TX_FSLS_TUNE_MASK              GENMASK(16, 13)
        #define REG_TUNE_SQRX_TUNE_MASK                 GENMASK(19, 17)
        #define REG_TUNE_OTG_TUNE                       GENMASK(22, 20)
        #define REG_TUNE_COMP_DIS_TUNE                  GENMASK(25, 23)
        #define REG_TUNE_HOST_DM_PULLDOWN               BIT(26)
        #define REG_TUNE_HOST_DP_PULLDOWN               BIT(27)

#define RESET_COMPLETE_TIME                             500
#define ACA_ENABLE_COMPLETE_TIME                        50

struct phy_meson8b_usb2_match_data {
        bool                    host_enable_aca;
};

struct phy_meson8b_usb2_priv {
        struct regmap                                   *regmap;
        enum usb_dr_mode                                dr_mode;
        struct clk                                      *clk_usb_general;
        struct clk                                      *clk_usb;
        struct reset_control                            *reset;
        const struct phy_meson8b_usb2_match_data        *match;
};

static const struct regmap_config phy_meson8b_usb2_regmap_conf = {
        .reg_bits = 8,
        .val_bits = 32,
        .reg_stride = 4,
        .max_register = REG_TUNE,
};

static int phy_meson8b_usb2_power_on(struct phy *phy)
{
        struct phy_meson8b_usb2_priv *priv = phy_get_drvdata(phy);
        u32 reg;
        int ret;

        if (!IS_ERR_OR_NULL(priv->reset)) {
                ret = reset_control_reset(priv->reset);
                if (ret) {
                        dev_err(&phy->dev, "Failed to trigger USB reset\n");
                        return ret;
                }
        }

        ret = clk_prepare_enable(priv->clk_usb_general);
        if (ret) {
                dev_err(&phy->dev, "Failed to enable USB general clock\n");
                reset_control_rearm(priv->reset);
                return ret;
        }

        ret = clk_prepare_enable(priv->clk_usb);
        if (ret) {
                dev_err(&phy->dev, "Failed to enable USB DDR clock\n");
                clk_disable_unprepare(priv->clk_usb_general);
                reset_control_rearm(priv->reset);
                return ret;
        }

        regmap_set_bits(priv->regmap, REG_CONFIG, REG_CONFIG_CLK_32k_ALTSEL);

        regmap_update_bits(priv->regmap, REG_CTRL, REG_CTRL_REF_CLK_SEL_MASK,
                           FIELD_PREP(REG_CTRL_REF_CLK_SEL_MASK, 0x2));

        regmap_update_bits(priv->regmap, REG_CTRL, REG_CTRL_FSEL_MASK,
                           FIELD_PREP(REG_CTRL_FSEL_MASK, 0x5));

        /* reset the PHY */
        regmap_set_bits(priv->regmap, REG_CTRL, REG_CTRL_POWER_ON_RESET);
        udelay(RESET_COMPLETE_TIME);
        regmap_clear_bits(priv->regmap, REG_CTRL, REG_CTRL_POWER_ON_RESET);
        udelay(RESET_COMPLETE_TIME);

        regmap_set_bits(priv->regmap, REG_CTRL, REG_CTRL_SOF_TOGGLE_OUT);

        if (priv->dr_mode == USB_DR_MODE_HOST) {
                regmap_clear_bits(priv->regmap, REG_DBG_UART,
                                  REG_DBG_UART_SET_IDDQ);

                if (priv->match->host_enable_aca) {
                        regmap_set_bits(priv->regmap, REG_ADP_BC,
                                        REG_ADP_BC_ACA_ENABLE);

                        udelay(ACA_ENABLE_COMPLETE_TIME);

                        regmap_read(priv->regmap, REG_ADP_BC, &reg);
                        if (reg & REG_ADP_BC_ACA_PIN_FLOAT) {
                                dev_warn(&phy->dev, "USB ID detect failed!\n");
                                clk_disable_unprepare(priv->clk_usb);
                                clk_disable_unprepare(priv->clk_usb_general);
                                reset_control_rearm(priv->reset);
                                return -EINVAL;
                        }
                }
        }

        return 0;
}

static int phy_meson8b_usb2_power_off(struct phy *phy)
{
        struct phy_meson8b_usb2_priv *priv = phy_get_drvdata(phy);

        if (priv->dr_mode == USB_DR_MODE_HOST)
                regmap_set_bits(priv->regmap, REG_DBG_UART,
                                REG_DBG_UART_SET_IDDQ);

        clk_disable_unprepare(priv->clk_usb);
        clk_disable_unprepare(priv->clk_usb_general);
        reset_control_rearm(priv->reset);

        /* power off the PHY by putting it into reset mode */
        regmap_set_bits(priv->regmap, REG_CTRL, REG_CTRL_POWER_ON_RESET);

        return 0;
}

static const struct phy_ops phy_meson8b_usb2_ops = {
        .power_on       = phy_meson8b_usb2_power_on,
        .power_off      = phy_meson8b_usb2_power_off,
        .owner          = THIS_MODULE,
};

static int phy_meson8b_usb2_probe(struct platform_device *pdev)
{
        struct phy_meson8b_usb2_priv *priv;
        struct phy *phy;
        struct phy_provider *phy_provider;
        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->match = device_get_match_data(&pdev->dev);
        if (!priv->match)
                return -ENODEV;

        priv->regmap = devm_regmap_init_mmio(&pdev->dev, base,
                                             &phy_meson8b_usb2_regmap_conf);
        if (IS_ERR(priv->regmap))
                return PTR_ERR(priv->regmap);

        priv->clk_usb_general = devm_clk_get(&pdev->dev, "usb_general");
        if (IS_ERR(priv->clk_usb_general))
                return PTR_ERR(priv->clk_usb_general);

        priv->clk_usb = devm_clk_get(&pdev->dev, "usb");
        if (IS_ERR(priv->clk_usb))
                return PTR_ERR(priv->clk_usb);

        priv->reset = devm_reset_control_get_optional_shared(&pdev->dev, NULL);
        if (IS_ERR(priv->reset))
                return dev_err_probe(&pdev->dev, PTR_ERR(priv->reset),
                                     "Failed to get the reset line");

        priv->dr_mode = of_usb_get_dr_mode_by_phy(pdev->dev.of_node, -1);
        if (priv->dr_mode == USB_DR_MODE_UNKNOWN) {
                dev_err(&pdev->dev,
                        "missing dual role configuration of the controller\n");
                return -EINVAL;
        }

        phy = devm_phy_create(&pdev->dev, NULL, &phy_meson8b_usb2_ops);
        if (IS_ERR(phy)) {
                return dev_err_probe(&pdev->dev, PTR_ERR(phy),
                                     "failed to create PHY\n");
        }

        phy_set_drvdata(phy, priv);

        phy_provider =
                devm_of_phy_provider_register(&pdev->dev, of_phy_simple_xlate);

        return PTR_ERR_OR_ZERO(phy_provider);
}

static const struct phy_meson8b_usb2_match_data phy_meson8_usb2_match_data = {
        .host_enable_aca = false,
};

static const struct phy_meson8b_usb2_match_data phy_meson8b_usb2_match_data = {
        .host_enable_aca = true,
};

static const struct of_device_id phy_meson8b_usb2_of_match[] = {
        {
                .compatible = "amlogic,meson8-usb2-phy",
                .data = &phy_meson8_usb2_match_data
        },
        {
                .compatible = "amlogic,meson8b-usb2-phy",
                .data = &phy_meson8b_usb2_match_data
        },
        {
                .compatible = "amlogic,meson8m2-usb2-phy",
                .data = &phy_meson8b_usb2_match_data
        },
        {
                .compatible = "amlogic,meson-gxbb-usb2-phy",
                .data = &phy_meson8b_usb2_match_data
        },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, phy_meson8b_usb2_of_match);

static struct platform_driver phy_meson8b_usb2_driver = {
        .probe  = phy_meson8b_usb2_probe,
        .driver = {
                .name           = "phy-meson-usb2",
                .of_match_table = phy_meson8b_usb2_of_match,
        },
};
module_platform_driver(phy_meson8b_usb2_driver);

MODULE_AUTHOR("Martin Blumenstingl <martin.blumenstingl@googlemail.com>");
MODULE_DESCRIPTION("Meson8, Meson8b, Meson8m2 and GXBB USB2 PHY driver");
MODULE_LICENSE("GPL");