root/drivers/usb/dwc3/dwc3-omap.c
// SPDX-License-Identifier: GPL-2.0
/*
 * dwc3-omap.c - OMAP Specific Glue layer
 *
 * Copyright (C) 2010-2011 Texas Instruments Incorporated - https://www.ti.com
 *
 * Authors: Felipe Balbi <balbi@ti.com>,
 *          Sebastian Andrzej Siewior <bigeasy@linutronix.de>
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/dma-mapping.h>
#include <linux/ioport.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/extcon.h>
#include <linux/regulator/consumer.h>

#include <linux/usb/otg.h>

/*
 * All these registers belong to OMAP's Wrapper around the
 * DesignWare USB3 Core.
 */

#define USBOTGSS_REVISION                       0x0000
#define USBOTGSS_SYSCONFIG                      0x0010
#define USBOTGSS_IRQ_EOI                        0x0020
#define USBOTGSS_EOI_OFFSET                     0x0008
#define USBOTGSS_IRQSTATUS_RAW_0                0x0024
#define USBOTGSS_IRQSTATUS_0                    0x0028
#define USBOTGSS_IRQENABLE_SET_0                0x002c
#define USBOTGSS_IRQENABLE_CLR_0                0x0030
#define USBOTGSS_IRQ0_OFFSET                    0x0004
#define USBOTGSS_IRQSTATUS_RAW_1                0x0030
#define USBOTGSS_IRQSTATUS_1                    0x0034
#define USBOTGSS_IRQENABLE_SET_1                0x0038
#define USBOTGSS_IRQENABLE_CLR_1                0x003c
#define USBOTGSS_IRQSTATUS_RAW_2                0x0040
#define USBOTGSS_IRQSTATUS_2                    0x0044
#define USBOTGSS_IRQENABLE_SET_2                0x0048
#define USBOTGSS_IRQENABLE_CLR_2                0x004c
#define USBOTGSS_IRQSTATUS_RAW_3                0x0050
#define USBOTGSS_IRQSTATUS_3                    0x0054
#define USBOTGSS_IRQENABLE_SET_3                0x0058
#define USBOTGSS_IRQENABLE_CLR_3                0x005c
#define USBOTGSS_IRQSTATUS_EOI_MISC             0x0030
#define USBOTGSS_IRQSTATUS_RAW_MISC             0x0034
#define USBOTGSS_IRQSTATUS_MISC                 0x0038
#define USBOTGSS_IRQENABLE_SET_MISC             0x003c
#define USBOTGSS_IRQENABLE_CLR_MISC             0x0040
#define USBOTGSS_IRQMISC_OFFSET                 0x03fc
#define USBOTGSS_UTMI_OTG_STATUS                0x0080
#define USBOTGSS_UTMI_OTG_CTRL                  0x0084
#define USBOTGSS_UTMI_OTG_OFFSET                0x0480
#define USBOTGSS_TXFIFO_DEPTH                   0x0508
#define USBOTGSS_RXFIFO_DEPTH                   0x050c
#define USBOTGSS_MMRAM_OFFSET                   0x0100
#define USBOTGSS_FLADJ                          0x0104
#define USBOTGSS_DEBUG_CFG                      0x0108
#define USBOTGSS_DEBUG_DATA                     0x010c
#define USBOTGSS_DEV_EBC_EN                     0x0110
#define USBOTGSS_DEBUG_OFFSET                   0x0600

/* SYSCONFIG REGISTER */
#define USBOTGSS_SYSCONFIG_DMADISABLE           BIT(16)

/* IRQ_EOI REGISTER */
#define USBOTGSS_IRQ_EOI_LINE_NUMBER            BIT(0)

/* IRQS0 BITS */
#define USBOTGSS_IRQO_COREIRQ_ST                BIT(0)

/* IRQMISC BITS */
#define USBOTGSS_IRQMISC_DMADISABLECLR          BIT(17)
#define USBOTGSS_IRQMISC_OEVT                   BIT(16)
#define USBOTGSS_IRQMISC_DRVVBUS_RISE           BIT(13)
#define USBOTGSS_IRQMISC_CHRGVBUS_RISE          BIT(12)
#define USBOTGSS_IRQMISC_DISCHRGVBUS_RISE       BIT(11)
#define USBOTGSS_IRQMISC_IDPULLUP_RISE          BIT(8)
#define USBOTGSS_IRQMISC_DRVVBUS_FALL           BIT(5)
#define USBOTGSS_IRQMISC_CHRGVBUS_FALL          BIT(4)
#define USBOTGSS_IRQMISC_DISCHRGVBUS_FALL               BIT(3)
#define USBOTGSS_IRQMISC_IDPULLUP_FALL          BIT(0)

/* UTMI_OTG_STATUS REGISTER */
#define USBOTGSS_UTMI_OTG_STATUS_DRVVBUS        BIT(5)
#define USBOTGSS_UTMI_OTG_STATUS_CHRGVBUS       BIT(4)
#define USBOTGSS_UTMI_OTG_STATUS_DISCHRGVBUS    BIT(3)
#define USBOTGSS_UTMI_OTG_STATUS_IDPULLUP       BIT(0)

/* UTMI_OTG_CTRL REGISTER */
#define USBOTGSS_UTMI_OTG_CTRL_SW_MODE          BIT(31)
#define USBOTGSS_UTMI_OTG_CTRL_POWERPRESENT     BIT(9)
#define USBOTGSS_UTMI_OTG_CTRL_TXBITSTUFFENABLE BIT(8)
#define USBOTGSS_UTMI_OTG_CTRL_IDDIG            BIT(4)
#define USBOTGSS_UTMI_OTG_CTRL_SESSEND          BIT(3)
#define USBOTGSS_UTMI_OTG_CTRL_SESSVALID        BIT(2)
#define USBOTGSS_UTMI_OTG_CTRL_VBUSVALID        BIT(1)

enum dwc3_omap_utmi_mode {
        DWC3_OMAP_UTMI_MODE_UNKNOWN = 0,
        DWC3_OMAP_UTMI_MODE_HW,
        DWC3_OMAP_UTMI_MODE_SW,
};

struct dwc3_omap {
        struct device           *dev;

        int                     irq;
        void __iomem            *base;

        u32                     utmi_otg_ctrl;
        u32                     utmi_otg_offset;
        u32                     irqmisc_offset;
        u32                     irq_eoi_offset;
        u32                     debug_offset;
        u32                     irq0_offset;

        struct extcon_dev       *edev;
        struct notifier_block   vbus_nb;
        struct notifier_block   id_nb;

        struct regulator        *vbus_reg;
};

enum omap_dwc3_vbus_id_status {
        OMAP_DWC3_ID_FLOAT,
        OMAP_DWC3_ID_GROUND,
        OMAP_DWC3_VBUS_OFF,
        OMAP_DWC3_VBUS_VALID,
};

static inline u32 dwc3_omap_readl(void __iomem *base, u32 offset)
{
        return readl(base + offset);
}

static inline void dwc3_omap_writel(void __iomem *base, u32 offset, u32 value)
{
        writel(value, base + offset);
}

static u32 dwc3_omap_read_utmi_ctrl(struct dwc3_omap *omap)
{
        return dwc3_omap_readl(omap->base, USBOTGSS_UTMI_OTG_CTRL +
                                                        omap->utmi_otg_offset);
}

static void dwc3_omap_write_utmi_ctrl(struct dwc3_omap *omap, u32 value)
{
        dwc3_omap_writel(omap->base, USBOTGSS_UTMI_OTG_CTRL +
                                        omap->utmi_otg_offset, value);

}

static u32 dwc3_omap_read_irq0_status(struct dwc3_omap *omap)
{
        return dwc3_omap_readl(omap->base, USBOTGSS_IRQSTATUS_RAW_0 -
                                                omap->irq0_offset);
}

static void dwc3_omap_write_irq0_status(struct dwc3_omap *omap, u32 value)
{
        dwc3_omap_writel(omap->base, USBOTGSS_IRQSTATUS_0 -
                                                omap->irq0_offset, value);

}

static u32 dwc3_omap_read_irqmisc_status(struct dwc3_omap *omap)
{
        return dwc3_omap_readl(omap->base, USBOTGSS_IRQSTATUS_RAW_MISC +
                                                omap->irqmisc_offset);
}

static void dwc3_omap_write_irqmisc_status(struct dwc3_omap *omap, u32 value)
{
        dwc3_omap_writel(omap->base, USBOTGSS_IRQSTATUS_MISC +
                                        omap->irqmisc_offset, value);

}

static void dwc3_omap_write_irqmisc_set(struct dwc3_omap *omap, u32 value)
{
        dwc3_omap_writel(omap->base, USBOTGSS_IRQENABLE_SET_MISC +
                                                omap->irqmisc_offset, value);

}

static void dwc3_omap_write_irq0_set(struct dwc3_omap *omap, u32 value)
{
        dwc3_omap_writel(omap->base, USBOTGSS_IRQENABLE_SET_0 -
                                                omap->irq0_offset, value);
}

static void dwc3_omap_write_irqmisc_clr(struct dwc3_omap *omap, u32 value)
{
        dwc3_omap_writel(omap->base, USBOTGSS_IRQENABLE_CLR_MISC +
                                                omap->irqmisc_offset, value);
}

static void dwc3_omap_write_irq0_clr(struct dwc3_omap *omap, u32 value)
{
        dwc3_omap_writel(omap->base, USBOTGSS_IRQENABLE_CLR_0 -
                                                omap->irq0_offset, value);
}

static void dwc3_omap_set_mailbox(struct dwc3_omap *omap,
        enum omap_dwc3_vbus_id_status status)
{
        int     ret;
        u32     val;

        switch (status) {
        case OMAP_DWC3_ID_GROUND:
                if (omap->vbus_reg) {
                        ret = regulator_enable(omap->vbus_reg);
                        if (ret) {
                                dev_err(omap->dev, "regulator enable failed\n");
                                return;
                        }
                }

                val = dwc3_omap_read_utmi_ctrl(omap);
                val &= ~USBOTGSS_UTMI_OTG_CTRL_IDDIG;
                dwc3_omap_write_utmi_ctrl(omap, val);
                break;

        case OMAP_DWC3_VBUS_VALID:
                val = dwc3_omap_read_utmi_ctrl(omap);
                val &= ~USBOTGSS_UTMI_OTG_CTRL_SESSEND;
                val |= USBOTGSS_UTMI_OTG_CTRL_VBUSVALID
                                | USBOTGSS_UTMI_OTG_CTRL_SESSVALID;
                dwc3_omap_write_utmi_ctrl(omap, val);
                break;

        case OMAP_DWC3_ID_FLOAT:
                if (omap->vbus_reg && regulator_is_enabled(omap->vbus_reg))
                        regulator_disable(omap->vbus_reg);
                val = dwc3_omap_read_utmi_ctrl(omap);
                val |= USBOTGSS_UTMI_OTG_CTRL_IDDIG;
                dwc3_omap_write_utmi_ctrl(omap, val);
                break;

        case OMAP_DWC3_VBUS_OFF:
                val = dwc3_omap_read_utmi_ctrl(omap);
                val &= ~(USBOTGSS_UTMI_OTG_CTRL_SESSVALID
                                | USBOTGSS_UTMI_OTG_CTRL_VBUSVALID);
                val |= USBOTGSS_UTMI_OTG_CTRL_SESSEND;
                dwc3_omap_write_utmi_ctrl(omap, val);
                break;

        default:
                dev_WARN(omap->dev, "invalid state\n");
        }
}

static void dwc3_omap_enable_irqs(struct dwc3_omap *omap);
static void dwc3_omap_disable_irqs(struct dwc3_omap *omap);

static irqreturn_t dwc3_omap_interrupt(int irq, void *_omap)
{
        struct dwc3_omap        *omap = _omap;

        if (dwc3_omap_read_irqmisc_status(omap) ||
            dwc3_omap_read_irq0_status(omap)) {
                /* mask irqs */
                dwc3_omap_disable_irqs(omap);
                return IRQ_WAKE_THREAD;
        }

        return IRQ_NONE;
}

static irqreturn_t dwc3_omap_interrupt_thread(int irq, void *_omap)
{
        struct dwc3_omap        *omap = _omap;
        u32                     reg;

        /* clear irq status flags */
        reg = dwc3_omap_read_irqmisc_status(omap);
        dwc3_omap_write_irqmisc_status(omap, reg);

        reg = dwc3_omap_read_irq0_status(omap);
        dwc3_omap_write_irq0_status(omap, reg);

        /* unmask irqs */
        dwc3_omap_enable_irqs(omap);

        return IRQ_HANDLED;
}

static void dwc3_omap_enable_irqs(struct dwc3_omap *omap)
{
        u32                     reg;

        /* enable all IRQs */
        reg = USBOTGSS_IRQO_COREIRQ_ST;
        dwc3_omap_write_irq0_set(omap, reg);

        reg = (USBOTGSS_IRQMISC_OEVT |
                        USBOTGSS_IRQMISC_DRVVBUS_RISE |
                        USBOTGSS_IRQMISC_CHRGVBUS_RISE |
                        USBOTGSS_IRQMISC_DISCHRGVBUS_RISE |
                        USBOTGSS_IRQMISC_IDPULLUP_RISE |
                        USBOTGSS_IRQMISC_DRVVBUS_FALL |
                        USBOTGSS_IRQMISC_CHRGVBUS_FALL |
                        USBOTGSS_IRQMISC_DISCHRGVBUS_FALL |
                        USBOTGSS_IRQMISC_IDPULLUP_FALL);

        dwc3_omap_write_irqmisc_set(omap, reg);
}

static void dwc3_omap_disable_irqs(struct dwc3_omap *omap)
{
        u32                     reg;

        /* disable all IRQs */
        reg = USBOTGSS_IRQO_COREIRQ_ST;
        dwc3_omap_write_irq0_clr(omap, reg);

        reg = (USBOTGSS_IRQMISC_OEVT |
                        USBOTGSS_IRQMISC_DRVVBUS_RISE |
                        USBOTGSS_IRQMISC_CHRGVBUS_RISE |
                        USBOTGSS_IRQMISC_DISCHRGVBUS_RISE |
                        USBOTGSS_IRQMISC_IDPULLUP_RISE |
                        USBOTGSS_IRQMISC_DRVVBUS_FALL |
                        USBOTGSS_IRQMISC_CHRGVBUS_FALL |
                        USBOTGSS_IRQMISC_DISCHRGVBUS_FALL |
                        USBOTGSS_IRQMISC_IDPULLUP_FALL);

        dwc3_omap_write_irqmisc_clr(omap, reg);
}

static int dwc3_omap_id_notifier(struct notifier_block *nb,
        unsigned long event, void *ptr)
{
        struct dwc3_omap *omap = container_of(nb, struct dwc3_omap, id_nb);

        if (event)
                dwc3_omap_set_mailbox(omap, OMAP_DWC3_ID_GROUND);
        else
                dwc3_omap_set_mailbox(omap, OMAP_DWC3_ID_FLOAT);

        return NOTIFY_DONE;
}

static int dwc3_omap_vbus_notifier(struct notifier_block *nb,
        unsigned long event, void *ptr)
{
        struct dwc3_omap *omap = container_of(nb, struct dwc3_omap, vbus_nb);

        if (event)
                dwc3_omap_set_mailbox(omap, OMAP_DWC3_VBUS_VALID);
        else
                dwc3_omap_set_mailbox(omap, OMAP_DWC3_VBUS_OFF);

        return NOTIFY_DONE;
}

static void dwc3_omap_map_offset(struct dwc3_omap *omap)
{
        struct device_node      *node = omap->dev->of_node;

        /*
         * Differentiate between OMAP5 and AM437x.
         *
         * For OMAP5(ES2.0) and AM437x wrapper revision is same, even
         * though there are changes in wrapper register offsets.
         *
         * Using dt compatible to differentiate AM437x.
         */
        if (of_device_is_compatible(node, "ti,am437x-dwc3")) {
                omap->irq_eoi_offset = USBOTGSS_EOI_OFFSET;
                omap->irq0_offset = USBOTGSS_IRQ0_OFFSET;
                omap->irqmisc_offset = USBOTGSS_IRQMISC_OFFSET;
                omap->utmi_otg_offset = USBOTGSS_UTMI_OTG_OFFSET;
                omap->debug_offset = USBOTGSS_DEBUG_OFFSET;
        }
}

static void dwc3_omap_set_utmi_mode(struct dwc3_omap *omap)
{
        u32                     reg;
        struct device_node      *node = omap->dev->of_node;
        u32                     utmi_mode = 0;

        reg = dwc3_omap_read_utmi_ctrl(omap);

        of_property_read_u32(node, "utmi-mode", &utmi_mode);

        switch (utmi_mode) {
        case DWC3_OMAP_UTMI_MODE_SW:
                reg |= USBOTGSS_UTMI_OTG_CTRL_SW_MODE;
                break;
        case DWC3_OMAP_UTMI_MODE_HW:
                reg &= ~USBOTGSS_UTMI_OTG_CTRL_SW_MODE;
                break;
        default:
                dev_WARN(omap->dev, "UNKNOWN utmi mode %d\n", utmi_mode);
        }

        dwc3_omap_write_utmi_ctrl(omap, reg);
}

static int dwc3_omap_extcon_register(struct dwc3_omap *omap)
{
        int                     ret;
        struct device_node      *node = omap->dev->of_node;
        struct extcon_dev       *edev;

        if (of_property_present(node, "extcon")) {
                edev = extcon_get_edev_by_phandle(omap->dev, 0);
                if (IS_ERR(edev)) {
                        dev_vdbg(omap->dev, "couldn't get extcon device\n");
                        return -EPROBE_DEFER;
                }

                omap->vbus_nb.notifier_call = dwc3_omap_vbus_notifier;
                ret = devm_extcon_register_notifier(omap->dev, edev,
                                                EXTCON_USB, &omap->vbus_nb);
                if (ret < 0)
                        dev_vdbg(omap->dev, "failed to register notifier for USB\n");

                omap->id_nb.notifier_call = dwc3_omap_id_notifier;
                ret = devm_extcon_register_notifier(omap->dev, edev,
                                                EXTCON_USB_HOST, &omap->id_nb);
                if (ret < 0)
                        dev_vdbg(omap->dev, "failed to register notifier for USB-HOST\n");

                if (extcon_get_state(edev, EXTCON_USB) == true)
                        dwc3_omap_set_mailbox(omap, OMAP_DWC3_VBUS_VALID);
                else
                        dwc3_omap_set_mailbox(omap, OMAP_DWC3_VBUS_OFF);

                if (extcon_get_state(edev, EXTCON_USB_HOST) == true)
                        dwc3_omap_set_mailbox(omap, OMAP_DWC3_ID_GROUND);
                else
                        dwc3_omap_set_mailbox(omap, OMAP_DWC3_ID_FLOAT);

                omap->edev = edev;
        }

        return 0;
}

static int dwc3_omap_probe(struct platform_device *pdev)
{
        struct device_node      *node = pdev->dev.of_node;

        struct dwc3_omap        *omap;
        struct device           *dev = &pdev->dev;
        struct regulator        *vbus_reg;

        int                     ret;
        int                     irq;

        void __iomem            *base;

        if (!node) {
                dev_err(dev, "device node not found\n");
                return -EINVAL;
        }

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

        platform_set_drvdata(pdev, omap);

        irq = platform_get_irq(pdev, 0);
        if (irq < 0)
                return irq;

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

        vbus_reg = devm_regulator_get_optional(dev, "vbus");
        if (IS_ERR(vbus_reg)) {
                if (PTR_ERR(vbus_reg) != -ENODEV)
                        return dev_err_probe(dev, PTR_ERR(vbus_reg), "vbus init failed\n");
                vbus_reg = NULL;
        }

        omap->dev       = dev;
        omap->irq       = irq;
        omap->base      = base;
        omap->vbus_reg  = vbus_reg;

        pm_runtime_enable(dev);
        ret = pm_runtime_get_sync(dev);
        if (ret < 0) {
                dev_err(dev, "get_sync failed with err %d\n", ret);
                goto err1;
        }

        dwc3_omap_map_offset(omap);
        dwc3_omap_set_utmi_mode(omap);

        ret = dwc3_omap_extcon_register(omap);
        if (ret < 0)
                goto err1;

        ret = of_platform_populate(node, NULL, NULL, dev);
        if (ret) {
                dev_err(&pdev->dev, "failed to create dwc3 core\n");
                goto err1;
        }

        ret = devm_request_threaded_irq(dev, omap->irq, dwc3_omap_interrupt,
                                        dwc3_omap_interrupt_thread, IRQF_SHARED,
                                        "dwc3-omap", omap);
        if (ret) {
                dev_err(dev, "failed to request IRQ #%d --> %d\n",
                        omap->irq, ret);
                goto err2;
        }
        dwc3_omap_enable_irqs(omap);
        return 0;

err2:
        of_platform_depopulate(dev);
err1:
        pm_runtime_put_sync(dev);
        pm_runtime_disable(dev);

        return ret;
}

static void dwc3_omap_remove(struct platform_device *pdev)
{
        struct dwc3_omap        *omap = platform_get_drvdata(pdev);

        dwc3_omap_disable_irqs(omap);
        disable_irq(omap->irq);
        of_platform_depopulate(omap->dev);
        pm_runtime_put_sync(&pdev->dev);
        pm_runtime_disable(&pdev->dev);
}

static const struct of_device_id of_dwc3_match[] = {
        {
                .compatible =   "ti,dwc3"
        },
        {
                .compatible =   "ti,am437x-dwc3"
        },
        { },
};
MODULE_DEVICE_TABLE(of, of_dwc3_match);

#ifdef CONFIG_PM_SLEEP
static int dwc3_omap_suspend(struct device *dev)
{
        struct dwc3_omap        *omap = dev_get_drvdata(dev);

        omap->utmi_otg_ctrl = dwc3_omap_read_utmi_ctrl(omap);
        dwc3_omap_disable_irqs(omap);

        return 0;
}

static int dwc3_omap_resume(struct device *dev)
{
        struct dwc3_omap        *omap = dev_get_drvdata(dev);

        dwc3_omap_write_utmi_ctrl(omap, omap->utmi_otg_ctrl);
        dwc3_omap_enable_irqs(omap);

        pm_runtime_disable(dev);
        pm_runtime_set_active(dev);
        pm_runtime_enable(dev);

        return 0;
}

static void dwc3_omap_complete(struct device *dev)
{
        struct dwc3_omap        *omap = dev_get_drvdata(dev);

        if (extcon_get_state(omap->edev, EXTCON_USB))
                dwc3_omap_set_mailbox(omap, OMAP_DWC3_VBUS_VALID);
        else
                dwc3_omap_set_mailbox(omap, OMAP_DWC3_VBUS_OFF);

        if (extcon_get_state(omap->edev, EXTCON_USB_HOST))
                dwc3_omap_set_mailbox(omap, OMAP_DWC3_ID_GROUND);
        else
                dwc3_omap_set_mailbox(omap, OMAP_DWC3_ID_FLOAT);
}

static const struct dev_pm_ops dwc3_omap_dev_pm_ops = {

        SET_SYSTEM_SLEEP_PM_OPS(dwc3_omap_suspend, dwc3_omap_resume)
        .complete = dwc3_omap_complete,
};

#define DEV_PM_OPS      (&dwc3_omap_dev_pm_ops)
#else
#define DEV_PM_OPS      NULL
#endif /* CONFIG_PM_SLEEP */

static struct platform_driver dwc3_omap_driver = {
        .probe          = dwc3_omap_probe,
        .remove         = dwc3_omap_remove,
        .driver         = {
                .name   = "omap-dwc3",
                .of_match_table = of_dwc3_match,
                .pm     = DEV_PM_OPS,
        },
};

module_platform_driver(dwc3_omap_driver);

MODULE_ALIAS("platform:omap-dwc3");
MODULE_AUTHOR("Felipe Balbi <balbi@ti.com>");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("DesignWare USB3 OMAP Glue Layer");