// SPDX-License-Identifier: GPL-2.0
/**
 * cdns_ti-ti.c - TI specific Glue layer for Cadence USB Controller
 *
 * Copyright (C) 2019 Texas Instruments Incorporated - http://www.ti.com
 */

#include <common.h>
#include <asm-generic/io.h>
#include <clk.h>
#include <dm.h>
#include <dm/device_compat.h>
#include <linux/bitops.h>
#include <linux/io.h>
#include <linux/usb/otg.h>
#include <malloc.h>

#include "core.h"

/* USB Wrapper register offsets */
#define USBSS_PID               0x0
#define USBSS_W1                0x4
#define USBSS_STATIC_CONFIG     0x8
#define USBSS_PHY_TEST          0xc
#define USBSS_DEBUG_CTRL        0x10
#define USBSS_DEBUG_INFO        0x14
#define USBSS_DEBUG_LINK_STATE  0x18
#define USBSS_DEVICE_CTRL       0x1c

/* Wrapper 1 register bits */
#define USBSS_W1_PWRUP_RST              BIT(0)
#define USBSS_W1_OVERCURRENT_SEL        BIT(8)
#define USBSS_W1_MODESTRAP_SEL          BIT(9)
#define USBSS_W1_OVERCURRENT            BIT(16)
#define USBSS_W1_MODESTRAP_MASK         GENMASK(18, 17)
#define USBSS_W1_MODESTRAP_SHIFT        17
#define USBSS_W1_USB2_ONLY              BIT(19)

/* Static config register bits */
#define USBSS1_STATIC_PLL_REF_SEL_MASK  GENMASK(8, 5)
#define USBSS1_STATIC_PLL_REF_SEL_SHIFT 5
#define USBSS1_STATIC_LOOPBACK_MODE_MASK        GENMASK(4, 3)
#define USBSS1_STATIC_LOOPBACK_MODE_SHIFT       3
#define USBSS1_STATIC_VBUS_SEL_MASK     GENMASK(2, 1)
#define USBSS1_STATIC_VBUS_SEL_SHIFT    1
#define USBSS1_STATIC_LANE_REVERSE      BIT(0)

/* Modestrap modes */
enum modestrap_mode { USBSS_MODESTRAP_MODE_NONE,
                      USBSS_MODESTRAP_MODE_HOST,
                      USBSS_MODESTRAP_MODE_PERIPHERAL};

struct cdns_ti {
        struct udevice *dev;
        void __iomem *usbss;
        int usb2_only:1;
        int vbus_divider:1;
        struct clk *usb2_refclk;
        struct clk *lpm_clk;
};

static const int cdns_ti_rate_table[] = {       /* in KHZ */
        9600,
        10000,
        12000,
        19200,
        20000,
        24000,
        25000,
        26000,
        38400,
        40000,
        58000,
        50000,
        52000,
};

static inline u32 cdns_ti_readl(struct cdns_ti *data, u32 offset)
{
        return readl(data->usbss + offset);
}

static inline void cdns_ti_writel(struct cdns_ti *data, u32 offset, u32 value)
{
        writel(value, data->usbss + offset);
}

static int cdns_ti_probe(struct udevice *dev)
{
        struct cdns_ti *data = dev_get_plat(dev);
        struct clk usb2_refclk;
        int modestrap_mode;
        unsigned long rate;
        int rate_code, i;
        u32 reg;
        int ret;

        data->dev = dev;

        data->usbss = dev_remap_addr_index(dev, 0);
        if (!data->usbss)
                return -EINVAL;

        ret = clk_get_by_name(dev, "ref", &usb2_refclk);
        if (ret) {
                dev_err(dev, "Failed to get usb2_refclk\n");
                return ret;
        }

        rate = clk_get_rate(&usb2_refclk);
        rate /= 1000;   /* To KHz */
        for (i = 0; i < ARRAY_SIZE(cdns_ti_rate_table); i++) {
                if (cdns_ti_rate_table[i] == rate)
                        break;
        }

        if (i == ARRAY_SIZE(cdns_ti_rate_table)) {
                dev_err(dev, "unsupported usb2_refclk rate: %lu KHz\n", rate);
                return -EINVAL;
        }

        rate_code = i;

        /* assert RESET */
        reg = cdns_ti_readl(data, USBSS_W1);
        reg &= ~USBSS_W1_PWRUP_RST;
        cdns_ti_writel(data, USBSS_W1, reg);

        /* set static config */
        reg = cdns_ti_readl(data, USBSS_STATIC_CONFIG);
        reg &= ~USBSS1_STATIC_PLL_REF_SEL_MASK;
        reg |= rate_code << USBSS1_STATIC_PLL_REF_SEL_SHIFT;

        reg &= ~USBSS1_STATIC_VBUS_SEL_MASK;
        data->vbus_divider = dev_read_bool(dev, "ti,vbus-divider");
        if (data->vbus_divider)
                reg |= 1 << USBSS1_STATIC_VBUS_SEL_SHIFT;

        cdns_ti_writel(data, USBSS_STATIC_CONFIG, reg);
        reg = cdns_ti_readl(data, USBSS_STATIC_CONFIG);

        /* set USB2_ONLY mode if requested */
        reg = cdns_ti_readl(data, USBSS_W1);
        data->usb2_only = dev_read_bool(dev, "ti,usb2-only");
        if (data->usb2_only)
                reg |= USBSS_W1_USB2_ONLY;

        /* set modestrap  */
        if (dev_read_bool(dev, "ti,modestrap-host"))
                modestrap_mode = USBSS_MODESTRAP_MODE_HOST;
        else if (dev_read_bool(dev, "ti,modestrap-peripheral"))
                modestrap_mode = USBSS_MODESTRAP_MODE_PERIPHERAL;
        else
                modestrap_mode = USBSS_MODESTRAP_MODE_NONE;

        reg |= USBSS_W1_MODESTRAP_SEL;
        reg &= ~USBSS_W1_MODESTRAP_MASK;
        reg |= modestrap_mode << USBSS_W1_MODESTRAP_SHIFT;
        cdns_ti_writel(data, USBSS_W1, reg);

        /* de-assert RESET */
        reg |= USBSS_W1_PWRUP_RST;
        cdns_ti_writel(data, USBSS_W1, reg);

        return 0;
}

static int cdns_ti_remove(struct udevice *dev)
{
        struct cdns_ti *data = dev_get_plat(dev);
        u32 reg;

        /* put device back to RESET*/
        reg = cdns_ti_readl(data, USBSS_W1);
        reg &= ~USBSS_W1_PWRUP_RST;
        cdns_ti_writel(data, USBSS_W1, reg);

        return 0;
}

static const struct udevice_id cdns_ti_of_match[] = {
        { .compatible = "ti,j721e-usb", },
        {},
};

U_BOOT_DRIVER(cdns_ti) = {
        .name = "cdns-ti",
        .id = UCLASS_NOP,
        .of_match = cdns_ti_of_match,
        .bind = cdns3_bind,
        .probe = cdns_ti_probe,
        .remove = cdns_ti_remove,
        .plat_auto      = sizeof(struct cdns_ti),
        .flags = DM_FLAG_OS_PREPARE,
};