root/drivers/usb/musb/mediatek.c
// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2019 MediaTek Inc.
 *
 * Author:
 *  Min Guo <min.guo@mediatek.com>
 *  Yonglong Wu <yonglong.wu@mediatek.com>
 */

#include <linux/clk.h>
#include <linux/dma-mapping.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/usb/role.h>
#include <linux/usb/usb_phy_generic.h>
#include "musb_core.h"
#include "musb_dma.h"

#define USB_L1INTS              0x00a0
#define USB_L1INTM              0x00a4
#define MTK_MUSB_TXFUNCADDR     0x0480

/* MediaTek controller toggle enable and status reg */
#define MUSB_RXTOG              0x80
#define MUSB_RXTOGEN            0x82
#define MUSB_TXTOG              0x84
#define MUSB_TXTOGEN            0x86
#define MTK_TOGGLE_EN           GENMASK(15, 0)

#define TX_INT_STATUS           BIT(0)
#define RX_INT_STATUS           BIT(1)
#define USBCOM_INT_STATUS       BIT(2)
#define DMA_INT_STATUS          BIT(3)

#define DMA_INTR_STATUS_MSK     GENMASK(7, 0)
#define DMA_INTR_UNMASK_SET_MSK GENMASK(31, 24)

#define MTK_MUSB_CLKS_NUM       3

struct mtk_glue {
        struct device *dev;
        struct musb *musb;
        struct platform_device *musb_pdev;
        struct platform_device *usb_phy;
        struct phy *phy;
        struct usb_phy *xceiv;
        enum phy_mode phy_mode;
        struct clk_bulk_data clks[MTK_MUSB_CLKS_NUM];
        enum usb_role role;
        struct usb_role_switch *role_sw;
};

static int mtk_musb_clks_get(struct mtk_glue *glue)
{
        struct device *dev = glue->dev;

        glue->clks[0].id = "main";
        glue->clks[1].id = "mcu";
        glue->clks[2].id = "univpll";

        return devm_clk_bulk_get(dev, MTK_MUSB_CLKS_NUM, glue->clks);
}

static int mtk_otg_switch_set(struct mtk_glue *glue, enum usb_role role)
{
        struct musb *musb = glue->musb;
        u8 devctl = readb(musb->mregs + MUSB_DEVCTL);
        enum usb_role new_role;

        if (role == glue->role)
                return 0;

        switch (role) {
        case USB_ROLE_HOST:
                musb->xceiv->otg->state = OTG_STATE_A_WAIT_VRISE;
                glue->phy_mode = PHY_MODE_USB_HOST;
                new_role = USB_ROLE_HOST;
                if (glue->role == USB_ROLE_NONE)
                        phy_power_on(glue->phy);

                devctl |= MUSB_DEVCTL_SESSION;
                musb_writeb(musb->mregs, MUSB_DEVCTL, devctl);
                MUSB_HST_MODE(musb);
                break;
        case USB_ROLE_DEVICE:
                musb->xceiv->otg->state = OTG_STATE_B_IDLE;
                glue->phy_mode = PHY_MODE_USB_DEVICE;
                new_role = USB_ROLE_DEVICE;
                devctl &= ~MUSB_DEVCTL_SESSION;
                musb_writeb(musb->mregs, MUSB_DEVCTL, devctl);
                if (glue->role == USB_ROLE_NONE)
                        phy_power_on(glue->phy);

                MUSB_DEV_MODE(musb);
                break;
        case USB_ROLE_NONE:
                glue->phy_mode = PHY_MODE_USB_OTG;
                new_role = USB_ROLE_NONE;
                devctl &= ~MUSB_DEVCTL_SESSION;
                musb_writeb(musb->mregs, MUSB_DEVCTL, devctl);
                if (glue->role != USB_ROLE_NONE)
                        phy_power_off(glue->phy);

                break;
        default:
                dev_err(glue->dev, "Invalid State\n");
                return -EINVAL;
        }

        glue->role = new_role;
        phy_set_mode(glue->phy, glue->phy_mode);

        return 0;
}

static int musb_usb_role_sx_set(struct usb_role_switch *sw, enum usb_role role)
{
        return mtk_otg_switch_set(usb_role_switch_get_drvdata(sw), role);
}

static enum usb_role musb_usb_role_sx_get(struct usb_role_switch *sw)
{
        struct mtk_glue *glue = usb_role_switch_get_drvdata(sw);

        return glue->role;
}

static int mtk_otg_switch_init(struct mtk_glue *glue)
{
        struct usb_role_switch_desc role_sx_desc = { 0 };

        role_sx_desc.set = musb_usb_role_sx_set;
        role_sx_desc.get = musb_usb_role_sx_get;
        role_sx_desc.allow_userspace_control = true;
        role_sx_desc.fwnode = dev_fwnode(glue->dev);
        role_sx_desc.driver_data = glue;
        glue->role_sw = usb_role_switch_register(glue->dev, &role_sx_desc);

        return PTR_ERR_OR_ZERO(glue->role_sw);
}

static void mtk_otg_switch_exit(struct mtk_glue *glue)
{
        return usb_role_switch_unregister(glue->role_sw);
}

static irqreturn_t generic_interrupt(int irq, void *__hci)
{
        unsigned long flags;
        irqreturn_t retval = IRQ_NONE;
        struct musb *musb = __hci;

        spin_lock_irqsave(&musb->lock, flags);
        musb->int_usb = musb_clearb(musb->mregs, MUSB_INTRUSB);
        musb->int_rx = musb_clearw(musb->mregs, MUSB_INTRRX);
        musb->int_tx = musb_clearw(musb->mregs, MUSB_INTRTX);

        if ((musb->int_usb & MUSB_INTR_RESET) && !is_host_active(musb)) {
                /* ep0 FADDR must be 0 when (re)entering peripheral mode */
                musb_ep_select(musb->mregs, 0);
                musb_writeb(musb->mregs, MUSB_FADDR, 0);
        }

        if (musb->int_usb || musb->int_tx || musb->int_rx)
                retval = musb_interrupt(musb);

        spin_unlock_irqrestore(&musb->lock, flags);

        return retval;
}

static irqreturn_t mtk_musb_interrupt(int irq, void *dev_id)
{
        irqreturn_t retval = IRQ_NONE;
        struct musb *musb = (struct musb *)dev_id;
        u32 l1_ints;

        l1_ints = musb_readl(musb->mregs, USB_L1INTS) &
                        musb_readl(musb->mregs, USB_L1INTM);

        if (l1_ints & (TX_INT_STATUS | RX_INT_STATUS | USBCOM_INT_STATUS))
                retval = generic_interrupt(irq, musb);

#if defined(CONFIG_USB_INVENTRA_DMA)
        if (l1_ints & DMA_INT_STATUS)
                retval = dma_controller_irq(irq, musb->dma_controller);
#endif
        return retval;
}

static u32 mtk_musb_busctl_offset(u8 epnum, u16 offset)
{
        return MTK_MUSB_TXFUNCADDR + offset + 8 * epnum;
}

static u8 mtk_musb_clearb(void __iomem *addr, unsigned int offset)
{
        u8 data;

        /* W1C */
        data = musb_readb(addr, offset);
        musb_writeb(addr, offset, data);
        return data;
}

static u16 mtk_musb_clearw(void __iomem *addr, unsigned int offset)
{
        u16 data;

        /* W1C */
        data = musb_readw(addr, offset);
        musb_writew(addr, offset, data);
        return data;
}

static int mtk_musb_set_mode(struct musb *musb, u8 mode)
{
        struct device *dev = musb->controller;
        struct mtk_glue *glue = dev_get_drvdata(dev->parent);
        enum phy_mode new_mode;
        enum usb_role new_role;

        switch (mode) {
        case MUSB_HOST:
                new_mode = PHY_MODE_USB_HOST;
                new_role = USB_ROLE_HOST;
                break;
        case MUSB_PERIPHERAL:
                new_mode = PHY_MODE_USB_DEVICE;
                new_role = USB_ROLE_DEVICE;
                break;
        case MUSB_OTG:
                new_mode = PHY_MODE_USB_OTG;
                new_role = USB_ROLE_NONE;
                break;
        default:
                dev_err(glue->dev, "Invalid mode request\n");
                return -EINVAL;
        }

        if (glue->phy_mode == new_mode)
                return 0;

        if (musb->port_mode != MUSB_OTG) {
                dev_err(glue->dev, "Does not support changing modes\n");
                return -EINVAL;
        }

        mtk_otg_switch_set(glue, new_role);
        return 0;
}

static int mtk_musb_init(struct musb *musb)
{
        struct device *dev = musb->controller;
        struct mtk_glue *glue = dev_get_drvdata(dev->parent);
        int ret;

        glue->musb = musb;
        musb->phy = glue->phy;
        musb->xceiv = glue->xceiv;
        musb->is_host = false;
        musb->isr = mtk_musb_interrupt;

        /* Set TX/RX toggle enable */
        musb_writew(musb->mregs, MUSB_TXTOGEN, MTK_TOGGLE_EN);
        musb_writew(musb->mregs, MUSB_RXTOGEN, MTK_TOGGLE_EN);

        if (musb->port_mode == MUSB_OTG) {
                ret = mtk_otg_switch_init(glue);
                if (ret)
                        return ret;
        }

        ret = phy_init(glue->phy);
        if (ret)
                goto err_phy_init;

        ret = phy_power_on(glue->phy);
        if (ret)
                goto err_phy_power_on;

        phy_set_mode(glue->phy, glue->phy_mode);

#if defined(CONFIG_USB_INVENTRA_DMA)
        musb_writel(musb->mregs, MUSB_HSDMA_INTR,
                    DMA_INTR_STATUS_MSK | DMA_INTR_UNMASK_SET_MSK);
#endif
        musb_writel(musb->mregs, USB_L1INTM, TX_INT_STATUS | RX_INT_STATUS |
                    USBCOM_INT_STATUS | DMA_INT_STATUS);
        return 0;

err_phy_power_on:
        phy_exit(glue->phy);
err_phy_init:
        if (musb->port_mode == MUSB_OTG)
                mtk_otg_switch_exit(glue);
        return ret;
}

static u16 mtk_musb_get_toggle(struct musb_qh *qh, int is_out)
{
        struct musb *musb = qh->hw_ep->musb;
        u8 epnum = qh->hw_ep->epnum;
        u16 toggle;

        toggle = musb_readw(musb->mregs, is_out ? MUSB_TXTOG : MUSB_RXTOG);
        return toggle & (1 << epnum);
}

static u16 mtk_musb_set_toggle(struct musb_qh *qh, int is_out, struct urb *urb)
{
        struct musb *musb = qh->hw_ep->musb;
        u8 epnum = qh->hw_ep->epnum;
        u16 value, toggle;

        toggle = usb_gettoggle(urb->dev, qh->epnum, is_out);

        if (is_out) {
                value = musb_readw(musb->mregs, MUSB_TXTOG);
                value |= toggle << epnum;
                musb_writew(musb->mregs, MUSB_TXTOG, value);
        } else {
                value = musb_readw(musb->mregs, MUSB_RXTOG);
                value |= toggle << epnum;
                musb_writew(musb->mregs, MUSB_RXTOG, value);
        }

        return 0;
}

static int mtk_musb_exit(struct musb *musb)
{
        struct device *dev = musb->controller;
        struct mtk_glue *glue = dev_get_drvdata(dev->parent);

        mtk_otg_switch_exit(glue);
        phy_power_off(glue->phy);
        phy_exit(glue->phy);
        clk_bulk_disable_unprepare(MTK_MUSB_CLKS_NUM, glue->clks);

        pm_runtime_put_sync(dev);
        pm_runtime_disable(dev);
        return 0;
}

static const struct musb_platform_ops mtk_musb_ops = {
        .quirks = MUSB_DMA_INVENTRA,
        .init = mtk_musb_init,
        .get_toggle = mtk_musb_get_toggle,
        .set_toggle = mtk_musb_set_toggle,
        .exit = mtk_musb_exit,
#ifdef CONFIG_USB_INVENTRA_DMA
        .dma_init = musbhs_dma_controller_create_noirq,
        .dma_exit = musbhs_dma_controller_destroy,
#endif
        .clearb = mtk_musb_clearb,
        .clearw = mtk_musb_clearw,
        .busctl_offset = mtk_musb_busctl_offset,
        .set_mode = mtk_musb_set_mode,
};

#define MTK_MUSB_MAX_EP_NUM     8
#define MTK_MUSB_RAM_BITS       11

static const struct musb_fifo_cfg mtk_musb_mode_cfg[] = {
        { .hw_ep_num = 1, .style = FIFO_TX, .maxpacket = 512, },
        { .hw_ep_num = 1, .style = FIFO_RX, .maxpacket = 512, },
        { .hw_ep_num = 2, .style = FIFO_TX, .maxpacket = 512, },
        { .hw_ep_num = 2, .style = FIFO_RX, .maxpacket = 512, },
        { .hw_ep_num = 3, .style = FIFO_TX, .maxpacket = 512, },
        { .hw_ep_num = 3, .style = FIFO_RX, .maxpacket = 512, },
        { .hw_ep_num = 4, .style = FIFO_TX, .maxpacket = 512, },
        { .hw_ep_num = 4, .style = FIFO_RX, .maxpacket = 512, },
        { .hw_ep_num = 5, .style = FIFO_TX, .maxpacket = 512, },
        { .hw_ep_num = 5, .style = FIFO_RX, .maxpacket = 512, },
        { .hw_ep_num = 6, .style = FIFO_TX, .maxpacket = 1024, },
        { .hw_ep_num = 6, .style = FIFO_RX, .maxpacket = 1024, },
        { .hw_ep_num = 7, .style = FIFO_TX, .maxpacket = 512, },
        { .hw_ep_num = 7, .style = FIFO_RX, .maxpacket = 64, },
};

static const struct musb_hdrc_config mtk_musb_hdrc_config = {
        .fifo_cfg = mtk_musb_mode_cfg,
        .fifo_cfg_size = ARRAY_SIZE(mtk_musb_mode_cfg),
        .multipoint = true,
        .dyn_fifo = true,
        .num_eps = MTK_MUSB_MAX_EP_NUM,
        .ram_bits = MTK_MUSB_RAM_BITS,
};

static const struct platform_device_info mtk_dev_info = {
        .name = "musb-hdrc",
        .id = PLATFORM_DEVID_AUTO,
        .dma_mask = DMA_BIT_MASK(32),
};

static int mtk_musb_probe(struct platform_device *pdev)
{
        struct musb_hdrc_platform_data *pdata;
        struct mtk_glue *glue;
        struct platform_device_info pinfo;
        struct device *dev = &pdev->dev;
        struct device_node *np = dev->of_node;
        int ret;

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

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

        ret = of_platform_populate(np, NULL, NULL, dev);
        if (ret)
                return dev_err_probe(dev, ret,
                                "failed to create child devices at %p\n", np);

        ret = mtk_musb_clks_get(glue);
        if (ret)
                return ret;

        pdata->config = &mtk_musb_hdrc_config;
        pdata->platform_ops = &mtk_musb_ops;
        pdata->mode = usb_get_dr_mode(dev);

        if (IS_ENABLED(CONFIG_USB_MUSB_HOST))
                pdata->mode = USB_DR_MODE_HOST;
        else if (IS_ENABLED(CONFIG_USB_MUSB_GADGET))
                pdata->mode = USB_DR_MODE_PERIPHERAL;

        switch (pdata->mode) {
        case USB_DR_MODE_HOST:
                glue->phy_mode = PHY_MODE_USB_HOST;
                glue->role = USB_ROLE_HOST;
                break;
        case USB_DR_MODE_PERIPHERAL:
                glue->phy_mode = PHY_MODE_USB_DEVICE;
                glue->role = USB_ROLE_DEVICE;
                break;
        case USB_DR_MODE_OTG:
                glue->phy_mode = PHY_MODE_USB_OTG;
                glue->role = USB_ROLE_NONE;
                break;
        default:
                return dev_err_probe(&pdev->dev, -EINVAL,
                                "Error 'dr_mode' property\n");
        }

        glue->phy = devm_of_phy_get_by_index(dev, np, 0);
        if (IS_ERR(glue->phy))
                return dev_err_probe(dev, PTR_ERR(glue->phy),
                                "fail to getting phy\n");

        glue->usb_phy = usb_phy_generic_register();
        if (IS_ERR(glue->usb_phy))
                return dev_err_probe(dev, PTR_ERR(glue->usb_phy),
                                "fail to registering usb-phy\n");

        glue->xceiv = devm_usb_get_phy(dev, USB_PHY_TYPE_USB2);
        if (IS_ERR(glue->xceiv)) {
                ret = PTR_ERR(glue->xceiv);
                dev_err(dev, "fail to getting usb-phy %d\n", ret);
                goto err_unregister_usb_phy;
        }

        platform_set_drvdata(pdev, glue);
        pm_runtime_enable(dev);
        pm_runtime_get_sync(dev);

        ret = clk_bulk_prepare_enable(MTK_MUSB_CLKS_NUM, glue->clks);
        if (ret)
                goto err_enable_clk;

        pinfo = mtk_dev_info;
        pinfo.parent = dev;
        pinfo.res = pdev->resource;
        pinfo.num_res = pdev->num_resources;
        pinfo.data = pdata;
        pinfo.size_data = sizeof(*pdata);
        pinfo.fwnode = of_fwnode_handle(np);
        pinfo.of_node_reused = true;

        glue->musb_pdev = platform_device_register_full(&pinfo);
        if (IS_ERR(glue->musb_pdev)) {
                ret = PTR_ERR(glue->musb_pdev);
                dev_err(dev, "failed to register musb device: %d\n", ret);
                goto err_device_register;
        }

        return 0;

err_device_register:
        clk_bulk_disable_unprepare(MTK_MUSB_CLKS_NUM, glue->clks);
err_enable_clk:
        pm_runtime_put_sync(dev);
        pm_runtime_disable(dev);
err_unregister_usb_phy:
        usb_phy_generic_unregister(glue->usb_phy);
        return ret;
}

static void mtk_musb_remove(struct platform_device *pdev)
{
        struct mtk_glue *glue = platform_get_drvdata(pdev);
        struct platform_device *usb_phy = glue->usb_phy;

        platform_device_unregister(glue->musb_pdev);
        usb_phy_generic_unregister(usb_phy);
}

#ifdef CONFIG_OF
static const struct of_device_id mtk_musb_match[] = {
        {.compatible = "mediatek,mtk-musb",},
        {},
};
MODULE_DEVICE_TABLE(of, mtk_musb_match);
#endif

static struct platform_driver mtk_musb_driver = {
        .probe = mtk_musb_probe,
        .remove = mtk_musb_remove,
        .driver = {
                   .name = "musb-mtk",
                   .of_match_table = of_match_ptr(mtk_musb_match),
        },
};

module_platform_driver(mtk_musb_driver);

MODULE_DESCRIPTION("MediaTek MUSB Glue Layer");
MODULE_AUTHOR("Min Guo <min.guo@mediatek.com>");
MODULE_LICENSE("GPL v2");