root/drivers/phy/broadcom/phy-bcm-sr-usb.c
// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2016-2018 Broadcom
 */

#include <linux/delay.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>

enum bcm_usb_phy_version {
        BCM_SR_USB_COMBO_PHY,
        BCM_SR_USB_HS_PHY,
};

enum bcm_usb_phy_reg {
        PLL_CTRL,
        PHY_CTRL,
        PHY_PLL_CTRL,
};

/* USB PHY registers */

static const u8 bcm_usb_combo_phy_ss[] = {
        [PLL_CTRL]              = 0x18,
        [PHY_CTRL]              = 0x14,
};

static const u8 bcm_usb_combo_phy_hs[] = {
        [PLL_CTRL]      = 0x0c,
        [PHY_CTRL]      = 0x10,
};

static const u8 bcm_usb_hs_phy[] = {
        [PLL_CTRL]      = 0x8,
        [PHY_CTRL]      = 0xc,
};

enum pll_ctrl_bits {
        PLL_RESETB,
        SSPLL_SUSPEND_EN,
        PLL_SEQ_START,
        PLL_LOCK,
};

static const u8 u3pll_ctrl[] = {
        [PLL_RESETB]            = 0,
        [SSPLL_SUSPEND_EN]      = 1,
        [PLL_SEQ_START]         = 2,
        [PLL_LOCK]              = 3,
};

#define HSPLL_PDIV_MASK         0xF
#define HSPLL_PDIV_VAL          0x1

static const u8 u2pll_ctrl[] = {
        [PLL_RESETB]    = 5,
        [PLL_LOCK]      = 6,
};

enum bcm_usb_phy_ctrl_bits {
        CORERDY,
        PHY_RESETB,
        PHY_PCTL,
};

#define PHY_PCTL_MASK   0xffff
#define SSPHY_PCTL_VAL  0x0006

static const u8 u3phy_ctrl[] = {
        [PHY_RESETB]    = 1,
        [PHY_PCTL]      = 2,
};

static const u8 u2phy_ctrl[] = {
        [CORERDY]               = 0,
        [PHY_RESETB]            = 5,
        [PHY_PCTL]              = 6,
};

struct bcm_usb_phy_cfg {
        uint32_t type;
        uint32_t version;
        void __iomem *regs;
        struct phy *phy;
        const u8 *offset;
};

#define PLL_LOCK_RETRY_COUNT    1000

enum bcm_usb_phy_type {
        USB_HS_PHY,
        USB_SS_PHY,
};

#define NUM_BCM_SR_USB_COMBO_PHYS       2

static inline void bcm_usb_reg32_clrbits(void __iomem *addr, uint32_t clear)
{
        writel(readl(addr) & ~clear, addr);
}

static inline void bcm_usb_reg32_setbits(void __iomem *addr, uint32_t set)
{
        writel(readl(addr) | set, addr);
}

static int bcm_usb_pll_lock_check(void __iomem *addr, u32 bit)
{
        u32 data;
        int ret;

        ret = readl_poll_timeout_atomic(addr, data, (data & bit), 1,
                                        PLL_LOCK_RETRY_COUNT);
        if (ret)
                pr_err("%s: FAIL\n", __func__);

        return ret;
}

static int bcm_usb_ss_phy_init(struct bcm_usb_phy_cfg *phy_cfg)
{
        int ret = 0;
        void __iomem *regs = phy_cfg->regs;
        const u8 *offset;
        u32 rd_data;

        offset = phy_cfg->offset;

        /* Set pctl with mode and soft reset */
        rd_data = readl(regs + offset[PHY_CTRL]);
        rd_data &= ~(PHY_PCTL_MASK << u3phy_ctrl[PHY_PCTL]);
        rd_data |= (SSPHY_PCTL_VAL << u3phy_ctrl[PHY_PCTL]);
        writel(rd_data, regs + offset[PHY_CTRL]);

        bcm_usb_reg32_clrbits(regs + offset[PLL_CTRL],
                              BIT(u3pll_ctrl[SSPLL_SUSPEND_EN]));
        bcm_usb_reg32_setbits(regs + offset[PLL_CTRL],
                              BIT(u3pll_ctrl[PLL_SEQ_START]));
        bcm_usb_reg32_setbits(regs + offset[PLL_CTRL],
                              BIT(u3pll_ctrl[PLL_RESETB]));

        /* Maximum timeout for PLL reset done */
        msleep(30);

        ret = bcm_usb_pll_lock_check(regs + offset[PLL_CTRL],
                                     BIT(u3pll_ctrl[PLL_LOCK]));

        return ret;
}

static int bcm_usb_hs_phy_init(struct bcm_usb_phy_cfg *phy_cfg)
{
        int ret = 0;
        void __iomem *regs = phy_cfg->regs;
        const u8 *offset;

        offset = phy_cfg->offset;

        bcm_usb_reg32_clrbits(regs + offset[PLL_CTRL],
                              BIT(u2pll_ctrl[PLL_RESETB]));
        bcm_usb_reg32_setbits(regs + offset[PLL_CTRL],
                              BIT(u2pll_ctrl[PLL_RESETB]));

        ret = bcm_usb_pll_lock_check(regs + offset[PLL_CTRL],
                                     BIT(u2pll_ctrl[PLL_LOCK]));

        return ret;
}

static int bcm_usb_phy_reset(struct phy *phy)
{
        struct bcm_usb_phy_cfg *phy_cfg = phy_get_drvdata(phy);
        void __iomem *regs = phy_cfg->regs;
        const u8 *offset;

        offset = phy_cfg->offset;

        if (phy_cfg->type == USB_HS_PHY) {
                bcm_usb_reg32_clrbits(regs + offset[PHY_CTRL],
                                      BIT(u2phy_ctrl[CORERDY]));
                bcm_usb_reg32_setbits(regs + offset[PHY_CTRL],
                                      BIT(u2phy_ctrl[CORERDY]));
        }

        return 0;
}

static int bcm_usb_phy_init(struct phy *phy)
{
        struct bcm_usb_phy_cfg *phy_cfg = phy_get_drvdata(phy);
        int ret = -EINVAL;

        if (phy_cfg->type == USB_SS_PHY)
                ret = bcm_usb_ss_phy_init(phy_cfg);
        else if (phy_cfg->type == USB_HS_PHY)
                ret = bcm_usb_hs_phy_init(phy_cfg);

        return ret;
}

static const struct phy_ops sr_phy_ops = {
        .init           = bcm_usb_phy_init,
        .reset          = bcm_usb_phy_reset,
        .owner          = THIS_MODULE,
};

static struct phy *bcm_usb_phy_xlate(struct device *dev,
                                     const struct of_phandle_args *args)
{
        struct bcm_usb_phy_cfg *phy_cfg;
        int phy_idx;

        phy_cfg = dev_get_drvdata(dev);
        if (!phy_cfg)
                return ERR_PTR(-EINVAL);

        if (phy_cfg->version == BCM_SR_USB_COMBO_PHY) {
                phy_idx = args->args[0];

                if (WARN_ON(phy_idx > 1))
                        return ERR_PTR(-ENODEV);

                return phy_cfg[phy_idx].phy;
        } else
                return phy_cfg->phy;
}

static int bcm_usb_phy_create(struct device *dev, struct device_node *node,
                              void __iomem *regs, uint32_t version)
{
        struct bcm_usb_phy_cfg *phy_cfg;
        int idx;

        if (version == BCM_SR_USB_COMBO_PHY) {
                phy_cfg = devm_kzalloc(dev, NUM_BCM_SR_USB_COMBO_PHYS *
                                       sizeof(struct bcm_usb_phy_cfg),
                                       GFP_KERNEL);
                if (!phy_cfg)
                        return -ENOMEM;

                for (idx = 0; idx < NUM_BCM_SR_USB_COMBO_PHYS; idx++) {
                        phy_cfg[idx].regs = regs;
                        phy_cfg[idx].version = version;
                        if (idx == 0) {
                                phy_cfg[idx].offset = bcm_usb_combo_phy_hs;
                                phy_cfg[idx].type = USB_HS_PHY;
                        } else {
                                phy_cfg[idx].offset = bcm_usb_combo_phy_ss;
                                phy_cfg[idx].type = USB_SS_PHY;
                        }
                        phy_cfg[idx].phy = devm_phy_create(dev, node,
                                                           &sr_phy_ops);
                        if (IS_ERR(phy_cfg[idx].phy))
                                return PTR_ERR(phy_cfg[idx].phy);

                        phy_set_drvdata(phy_cfg[idx].phy, &phy_cfg[idx]);
                }
        } else if (version == BCM_SR_USB_HS_PHY) {
                phy_cfg = devm_kzalloc(dev, sizeof(struct bcm_usb_phy_cfg),
                                       GFP_KERNEL);
                if (!phy_cfg)
                        return -ENOMEM;

                phy_cfg->regs = regs;
                phy_cfg->version = version;
                phy_cfg->offset = bcm_usb_hs_phy;
                phy_cfg->type = USB_HS_PHY;
                phy_cfg->phy = devm_phy_create(dev, node, &sr_phy_ops);
                if (IS_ERR(phy_cfg->phy))
                        return PTR_ERR(phy_cfg->phy);

                phy_set_drvdata(phy_cfg->phy, phy_cfg);
        } else
                return -ENODEV;

        dev_set_drvdata(dev, phy_cfg);

        return 0;
}

static const struct of_device_id bcm_usb_phy_of_match[] = {
        {
                .compatible = "brcm,sr-usb-combo-phy",
                .data = (void *)BCM_SR_USB_COMBO_PHY,
        },
        {
                .compatible = "brcm,sr-usb-hs-phy",
                .data = (void *)BCM_SR_USB_HS_PHY,
        },
        { /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, bcm_usb_phy_of_match);

static int bcm_usb_phy_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct device_node *dn = dev->of_node;
        const struct of_device_id *of_id;
        void __iomem *regs;
        int ret;
        enum bcm_usb_phy_version version;
        struct phy_provider *phy_provider;

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

        of_id = of_match_node(bcm_usb_phy_of_match, dn);
        if (of_id)
                version = (uintptr_t)of_id->data;
        else
                return -ENODEV;

        ret = bcm_usb_phy_create(dev, dn, regs, version);
        if (ret)
                return ret;

        phy_provider = devm_of_phy_provider_register(dev, bcm_usb_phy_xlate);

        return PTR_ERR_OR_ZERO(phy_provider);
}

static struct platform_driver bcm_usb_phy_driver = {
        .driver = {
                .name = "phy-bcm-sr-usb",
                .of_match_table = bcm_usb_phy_of_match,
        },
        .probe = bcm_usb_phy_probe,
};
module_platform_driver(bcm_usb_phy_driver);

MODULE_AUTHOR("Broadcom");
MODULE_DESCRIPTION("Broadcom stingray USB Phy driver");
MODULE_LICENSE("GPL v2");