// SPDX-License-Identifier: GPL-2.0-only
/*
 * Rockchip usb PHY driver
 *
 * Copyright (C) 2014 Yunzhi Li <lyz@rock-chips.com>
 * Copyright (C) 2014 ROCKCHIP, Inc.
 */

#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/hw_bitfield.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
#include <linux/property.h>
#include <linux/regulator/consumer.h>
#include <linux/reset.h>
#include <linux/regmap.h>
#include <linux/mfd/syscon.h>
#include <linux/delay.h>

static int enable_usb_uart;

#define UOC_CON0                                        0x00
#define UOC_CON0_SIDDQ                                  BIT(13)
#define UOC_CON0_DISABLE                                BIT(4)
#define UOC_CON0_COMMON_ON_N                            BIT(0)

#define UOC_CON2                                        0x08
#define UOC_CON2_SOFT_CON_SEL                           BIT(2)

#define UOC_CON3                                        0x0c
/* bits present on rk3188 and rk3288 phys */
#define UOC_CON3_UTMI_TERMSEL_FULLSPEED                 BIT(5)
#define UOC_CON3_UTMI_XCVRSEELCT_FSTRANSC               1UL
#define UOC_CON3_UTMI_XCVRSEELCT_MASK                   GENMASK(4, 3)
#define UOC_CON3_UTMI_OPMODE_NODRIVING                  1UL
#define UOC_CON3_UTMI_OPMODE_MASK                       GENMASK(2, 1)
#define UOC_CON3_UTMI_SUSPENDN                          BIT(0)

struct rockchip_usb_phys {
        int reg;
        const char *pll_name;
};

struct rockchip_usb_phy_base;
struct rockchip_usb_phy_pdata {
        struct rockchip_usb_phys *phys;
        int (*init_usb_uart)(struct regmap *grf,
                             const struct rockchip_usb_phy_pdata *pdata);
        int usb_uart_phy;
};

struct rockchip_usb_phy_base {
        struct device *dev;
        struct regmap *reg_base;
        const struct rockchip_usb_phy_pdata *pdata;
};

struct rockchip_usb_phy {
        struct rockchip_usb_phy_base *base;
        struct device_node *np;
        unsigned int    reg_offset;
        struct clk      *clk;
        struct clk      *clk480m;
        struct clk_hw   clk480m_hw;
        struct phy      *phy;
        bool            uart_enabled;
        struct reset_control *reset;
        struct regulator *vbus;
};

static int rockchip_usb_phy_power(struct rockchip_usb_phy *phy,
                                           bool siddq)
{
        u32 val = FIELD_PREP_WM16(UOC_CON0_SIDDQ, siddq);

        return regmap_write(phy->base->reg_base, phy->reg_offset, val);
}

static unsigned long rockchip_usb_phy480m_recalc_rate(struct clk_hw *hw,
                                                unsigned long parent_rate)
{
        return 480000000;
}

static void rockchip_usb_phy480m_disable(struct clk_hw *hw)
{
        struct rockchip_usb_phy *phy = container_of(hw,
                                                    struct rockchip_usb_phy,
                                                    clk480m_hw);

        if (phy->vbus)
                regulator_disable(phy->vbus);

        /* Power down usb phy analog blocks by set siddq 1 */
        rockchip_usb_phy_power(phy, 1);
}

static int rockchip_usb_phy480m_enable(struct clk_hw *hw)
{
        struct rockchip_usb_phy *phy = container_of(hw,
                                                    struct rockchip_usb_phy,
                                                    clk480m_hw);

        /* Power up usb phy analog blocks by set siddq 0 */
        return rockchip_usb_phy_power(phy, 0);
}

static int rockchip_usb_phy480m_is_enabled(struct clk_hw *hw)
{
        struct rockchip_usb_phy *phy = container_of(hw,
                                                    struct rockchip_usb_phy,
                                                    clk480m_hw);
        int ret;
        u32 val;

        ret = regmap_read(phy->base->reg_base, phy->reg_offset, &val);
        if (ret < 0)
                return ret;

        return (val & UOC_CON0_SIDDQ) ? 0 : 1;
}

static const struct clk_ops rockchip_usb_phy480m_ops = {
        .enable = rockchip_usb_phy480m_enable,
        .disable = rockchip_usb_phy480m_disable,
        .is_enabled = rockchip_usb_phy480m_is_enabled,
        .recalc_rate = rockchip_usb_phy480m_recalc_rate,
};

static int rockchip_usb_phy_power_off(struct phy *_phy)
{
        struct rockchip_usb_phy *phy = phy_get_drvdata(_phy);

        if (phy->uart_enabled)
                return -EBUSY;

        clk_disable_unprepare(phy->clk480m);

        return 0;
}

static int rockchip_usb_phy_power_on(struct phy *_phy)
{
        struct rockchip_usb_phy *phy = phy_get_drvdata(_phy);

        if (phy->uart_enabled)
                return -EBUSY;

        if (phy->vbus) {
                int ret;

                ret = regulator_enable(phy->vbus);
                if (ret)
                        return ret;
        }

        return clk_prepare_enable(phy->clk480m);
}

static int rockchip_usb_phy_reset(struct phy *_phy)
{
        struct rockchip_usb_phy *phy = phy_get_drvdata(_phy);

        if (phy->reset) {
                reset_control_assert(phy->reset);
                udelay(10);
                reset_control_deassert(phy->reset);
        }

        return 0;
}

static const struct phy_ops ops = {
        .power_on       = rockchip_usb_phy_power_on,
        .power_off      = rockchip_usb_phy_power_off,
        .reset          = rockchip_usb_phy_reset,
        .owner          = THIS_MODULE,
};

static void rockchip_usb_phy_action(void *data)
{
        struct rockchip_usb_phy *rk_phy = data;

        if (!rk_phy->uart_enabled) {
                of_clk_del_provider(rk_phy->np);
                clk_unregister(rk_phy->clk480m);
        }

        if (rk_phy->clk)
                clk_put(rk_phy->clk);
}

static int rockchip_usb_phy_init(struct rockchip_usb_phy_base *base,
                                 struct device_node *child)
{
        struct rockchip_usb_phy *rk_phy;
        unsigned int reg_offset;
        const char *clk_name;
        struct clk_init_data init;
        int err, i;

        rk_phy = devm_kzalloc(base->dev, sizeof(*rk_phy), GFP_KERNEL);
        if (!rk_phy)
                return -ENOMEM;

        rk_phy->base = base;
        rk_phy->np = child;

        if (of_property_read_u32(child, "reg", &reg_offset)) {
                dev_err(base->dev, "missing reg property in node %pOFn\n",
                        child);
                return -EINVAL;
        }

        rk_phy->reset = of_reset_control_get(child, "phy-reset");
        if (IS_ERR(rk_phy->reset))
                rk_phy->reset = NULL;

        rk_phy->reg_offset = reg_offset;

        rk_phy->clk = of_clk_get_by_name(child, "phyclk");
        if (IS_ERR(rk_phy->clk))
                rk_phy->clk = NULL;

        i = 0;
        init.name = NULL;
        while (base->pdata->phys[i].reg) {
                if (base->pdata->phys[i].reg == reg_offset) {
                        init.name = base->pdata->phys[i].pll_name;
                        break;
                }
                i++;
        }

        if (!init.name) {
                dev_err(base->dev, "phy data not found\n");
                return -EINVAL;
        }

        if (enable_usb_uart && base->pdata->usb_uart_phy == i) {
                dev_dbg(base->dev, "phy%d used as uart output\n", i);
                rk_phy->uart_enabled = true;
        } else {
                if (rk_phy->clk) {
                        clk_name = __clk_get_name(rk_phy->clk);
                        init.flags = 0;
                        init.parent_names = &clk_name;
                        init.num_parents = 1;
                } else {
                        init.flags = 0;
                        init.parent_names = NULL;
                        init.num_parents = 0;
                }

                init.ops = &rockchip_usb_phy480m_ops;
                rk_phy->clk480m_hw.init = &init;

                rk_phy->clk480m = clk_register(base->dev, &rk_phy->clk480m_hw);
                if (IS_ERR(rk_phy->clk480m)) {
                        err = PTR_ERR(rk_phy->clk480m);
                        goto err_clk;
                }

                err = of_clk_add_provider(child, of_clk_src_simple_get,
                                        rk_phy->clk480m);
                if (err < 0)
                        goto err_clk_prov;
        }

        err = devm_add_action_or_reset(base->dev, rockchip_usb_phy_action,
                                       rk_phy);
        if (err)
                return err;

        rk_phy->phy = devm_phy_create(base->dev, child, &ops);
        if (IS_ERR(rk_phy->phy)) {
                dev_err(base->dev, "failed to create PHY\n");
                return PTR_ERR(rk_phy->phy);
        }
        phy_set_drvdata(rk_phy->phy, rk_phy);

        rk_phy->vbus = devm_regulator_get_optional(&rk_phy->phy->dev, "vbus");
        if (IS_ERR(rk_phy->vbus)) {
                if (PTR_ERR(rk_phy->vbus) == -EPROBE_DEFER)
                        return PTR_ERR(rk_phy->vbus);
                rk_phy->vbus = NULL;
        }

        /*
         * When acting as uart-pipe, just keep clock on otherwise
         * only power up usb phy when it use, so disable it when init
         */
        if (rk_phy->uart_enabled)
                return clk_prepare_enable(rk_phy->clk);
        else
                return rockchip_usb_phy_power(rk_phy, 1);

err_clk_prov:
        if (!rk_phy->uart_enabled)
                clk_unregister(rk_phy->clk480m);
err_clk:
        if (rk_phy->clk)
                clk_put(rk_phy->clk);
        return err;
}

static const struct rockchip_usb_phy_pdata rk3066a_pdata = {
        .phys = (struct rockchip_usb_phys[]){
                { .reg = 0x17c, .pll_name = "sclk_otgphy0_480m" },
                { .reg = 0x188, .pll_name = "sclk_otgphy1_480m" },
                { /* sentinel */ }
        },
};

static int __init rockchip_init_usb_uart_common(struct regmap *grf,
                                const struct rockchip_usb_phy_pdata *pdata)
{
        int regoffs = pdata->phys[pdata->usb_uart_phy].reg;
        int ret;
        u32 val;

        /*
         * COMMON_ON and DISABLE settings are described in the TRM,
         * but were not present in the original code.
         * Also disable the analog phy components to save power.
         */
        val = FIELD_PREP_WM16(UOC_CON0_COMMON_ON_N, 1) |
              FIELD_PREP_WM16(UOC_CON0_DISABLE, 1) |
              FIELD_PREP_WM16(UOC_CON0_SIDDQ, 1);
        ret = regmap_write(grf, regoffs + UOC_CON0, val);
        if (ret)
                return ret;

        val = FIELD_PREP_WM16(UOC_CON2_SOFT_CON_SEL, 1);
        ret = regmap_write(grf, regoffs + UOC_CON2, val);
        if (ret)
                return ret;

        val = FIELD_PREP_WM16(UOC_CON3_UTMI_SUSPENDN, 0) |
              FIELD_PREP_WM16(UOC_CON3_UTMI_OPMODE_MASK,
                           UOC_CON3_UTMI_OPMODE_NODRIVING) |
              FIELD_PREP_WM16(UOC_CON3_UTMI_XCVRSEELCT_MASK,
                           UOC_CON3_UTMI_XCVRSEELCT_FSTRANSC) |
              FIELD_PREP_WM16(UOC_CON3_UTMI_TERMSEL_FULLSPEED, 1);
        ret = regmap_write(grf, UOC_CON3, val);
        if (ret)
                return ret;

        return 0;
}

#define RK3188_UOC0_CON0                                0x10c
#define RK3188_UOC0_CON0_BYPASSSEL                      BIT(9)
#define RK3188_UOC0_CON0_BYPASSDMEN                     BIT(8)

/*
 * Enable the bypass of uart2 data through the otg usb phy.
 * See description of rk3288-variant for details.
 */
static int __init rk3188_init_usb_uart(struct regmap *grf,
                                const struct rockchip_usb_phy_pdata *pdata)
{
        u32 val;
        int ret;

        ret = rockchip_init_usb_uart_common(grf, pdata);
        if (ret)
                return ret;

        val = FIELD_PREP_WM16(RK3188_UOC0_CON0_BYPASSSEL, 1) |
              FIELD_PREP_WM16(RK3188_UOC0_CON0_BYPASSDMEN, 1);
        ret = regmap_write(grf, RK3188_UOC0_CON0, val);
        if (ret)
                return ret;

        return 0;
}

static const struct rockchip_usb_phy_pdata rk3188_pdata = {
        .phys = (struct rockchip_usb_phys[]){
                { .reg = 0x10c, .pll_name = "sclk_otgphy0_480m" },
                { .reg = 0x11c, .pll_name = "sclk_otgphy1_480m" },
                { /* sentinel */ }
        },
        .init_usb_uart = rk3188_init_usb_uart,
        .usb_uart_phy = 0,
};

#define RK3288_UOC0_CON3                                0x32c
#define RK3288_UOC0_CON3_BYPASSDMEN                     BIT(6)
#define RK3288_UOC0_CON3_BYPASSSEL                      BIT(7)

/*
 * Enable the bypass of uart2 data through the otg usb phy.
 * Original description in the TRM.
 * 1. Disable the OTG block by setting OTGDISABLE0 to 1’b1.
 * 2. Disable the pull-up resistance on the D+ line by setting
 *    OPMODE0[1:0] to 2’b01.
 * 3. To ensure that the XO, Bias, and PLL blocks are powered down in Suspend
 *    mode, set COMMONONN to 1’b1.
 * 4. Place the USB PHY in Suspend mode by setting SUSPENDM0 to 1’b0.
 * 5. Set BYPASSSEL0 to 1’b1.
 * 6. To transmit data, controls BYPASSDMEN0, and BYPASSDMDATA0.
 * To receive data, monitor FSVPLUS0.
 *
 * The actual code in the vendor kernel does some things differently.
 */
static int __init rk3288_init_usb_uart(struct regmap *grf,
                                const struct rockchip_usb_phy_pdata *pdata)
{
        u32 val;
        int ret;

        ret = rockchip_init_usb_uart_common(grf, pdata);
        if (ret)
                return ret;

        val = FIELD_PREP_WM16(RK3288_UOC0_CON3_BYPASSSEL, 1) |
              FIELD_PREP_WM16(RK3288_UOC0_CON3_BYPASSDMEN, 1);
        ret = regmap_write(grf, RK3288_UOC0_CON3, val);
        if (ret)
                return ret;

        return 0;
}

static const struct rockchip_usb_phy_pdata rk3288_pdata = {
        .phys = (struct rockchip_usb_phys[]){
                { .reg = 0x320, .pll_name = "sclk_otgphy0_480m" },
                { .reg = 0x334, .pll_name = "sclk_otgphy1_480m" },
                { .reg = 0x348, .pll_name = "sclk_otgphy2_480m" },
                { /* sentinel */ }
        },
        .init_usb_uart = rk3288_init_usb_uart,
        .usb_uart_phy = 0,
};

static int rockchip_usb_phy_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct rockchip_usb_phy_base *phy_base;
        struct phy_provider *phy_provider;
        int err;

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

        phy_base->pdata = device_get_match_data(dev);
        if (!phy_base->pdata) {
                dev_err(dev, "missing phy data\n");
                return -EINVAL;
        }

        phy_base->dev = dev;
        phy_base->reg_base = ERR_PTR(-ENODEV);
        if (dev->parent && dev->parent->of_node)
                phy_base->reg_base = syscon_node_to_regmap(
                                                dev->parent->of_node);
        if (IS_ERR(phy_base->reg_base))
                phy_base->reg_base = syscon_regmap_lookup_by_phandle(
                                                dev->of_node, "rockchip,grf");
        if (IS_ERR(phy_base->reg_base)) {
                dev_err(&pdev->dev, "Missing rockchip,grf property\n");
                return PTR_ERR(phy_base->reg_base);
        }

        for_each_available_child_of_node_scoped(dev->of_node, child) {
                err = rockchip_usb_phy_init(phy_base, child);
                if (err)
                        return err;
        }

        phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
        return PTR_ERR_OR_ZERO(phy_provider);
}

static const struct of_device_id rockchip_usb_phy_dt_ids[] = {
        { .compatible = "rockchip,rk3066a-usb-phy", .data = &rk3066a_pdata },
        { .compatible = "rockchip,rk3188-usb-phy", .data = &rk3188_pdata },
        { .compatible = "rockchip,rk3288-usb-phy", .data = &rk3288_pdata },
        {}
};

MODULE_DEVICE_TABLE(of, rockchip_usb_phy_dt_ids);

static struct platform_driver rockchip_usb_driver = {
        .probe          = rockchip_usb_phy_probe,
        .driver         = {
                .name   = "rockchip-usb-phy",
                .of_match_table = rockchip_usb_phy_dt_ids,
        },
};

module_platform_driver(rockchip_usb_driver);

#ifndef MODULE
static int __init rockchip_init_usb_uart(void)
{
        const struct of_device_id *match;
        const struct rockchip_usb_phy_pdata *data;
        struct device_node *np;
        struct regmap *grf;
        int ret;

        if (!enable_usb_uart)
                return 0;

        np = of_find_matching_node_and_match(NULL, rockchip_usb_phy_dt_ids,
                                             &match);
        if (!np) {
                pr_err("%s: failed to find usbphy node\n", __func__);
                return -ENOTSUPP;
        }

        pr_debug("%s: using settings for %s\n", __func__, match->compatible);
        data = match->data;

        if (!data->init_usb_uart) {
                pr_err("%s: usb-uart not available on %s\n",
                       __func__, match->compatible);
                return -ENOTSUPP;
        }

        grf = ERR_PTR(-ENODEV);
        if (np->parent)
                grf = syscon_node_to_regmap(np->parent);
        if (IS_ERR(grf))
                grf = syscon_regmap_lookup_by_phandle(np, "rockchip,grf");
        if (IS_ERR(grf)) {
                pr_err("%s: Missing rockchip,grf property, %lu\n",
                       __func__, PTR_ERR(grf));
                return PTR_ERR(grf);
        }

        ret = data->init_usb_uart(grf, data);
        if (ret) {
                pr_err("%s: could not init usb_uart, %d\n", __func__, ret);
                enable_usb_uart = 0;
                return ret;
        }

        return 0;
}
early_initcall(rockchip_init_usb_uart);

static int __init rockchip_usb_uart(char *buf)
{
        enable_usb_uart = true;
        return 0;
}
early_param("rockchip.usb_uart", rockchip_usb_uart);
#endif

MODULE_AUTHOR("Yunzhi Li <lyz@rock-chips.com>");
MODULE_DESCRIPTION("Rockchip USB 2.0 PHY driver");
MODULE_LICENSE("GPL v2");