// SPDX-License-Identifier: GPL-1.0+
/*
 * OHCI HCD (Host Controller Driver) for USB.
 *
 *  Copyright (C) 2004 SAN People (Pty) Ltd.
 *  Copyright (C) 2005 Thibaut VARENE <varenet@parisc-linux.org>
 *
 * AT91 Bus Glue
 *
 * Based on fragments of 2.4 driver by Rick Bronson.
 * Based on ohci-omap.c
 *
 * This file is licenced under the GPL.
 */

#include <linux/clk.h>
#include <linux/dma-mapping.h>
#include <linux/gpio/consumer.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/platform_data/atmel.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>
#include <linux/usb.h>
#include <linux/usb/hcd.h>
#include <soc/at91/atmel-sfr.h>

#include "ohci.h"

#define valid_port(index)       ((index) >= 0 && (index) < AT91_MAX_USBH_PORTS)
#define at91_for_each_port(index)       \
                for ((index) = 0; (index) < AT91_MAX_USBH_PORTS; (index)++)

/* interface, function and usb clocks; sometimes also an AHB clock */
#define hcd_to_ohci_at91_priv(h) \
        ((struct ohci_at91_priv *)hcd_to_ohci(h)->priv)

#define AT91_MAX_USBH_PORTS     3
struct at91_usbh_data {
        struct gpio_desc *vbus_pin[AT91_MAX_USBH_PORTS];
        struct gpio_desc *overcurrent_pin[AT91_MAX_USBH_PORTS];
        u8 ports;                               /* number of ports on root hub */
        u8 overcurrent_supported;
        u8 overcurrent_status[AT91_MAX_USBH_PORTS];
        u8 overcurrent_changed[AT91_MAX_USBH_PORTS];
};

struct ohci_at91_priv {
        struct clk *iclk;
        struct clk *fclk;
        struct clk *hclk;
        bool clocked;
        bool wakeup;            /* Saved wake-up state for resume */
        struct regmap *sfr_regmap;
};
/* interface and function clocks; sometimes also an AHB clock */

#define DRIVER_DESC "OHCI Atmel driver"

static const char hcd_name[] = "ohci-atmel";

static struct hc_driver __read_mostly ohci_at91_hc_driver;

static const struct ohci_driver_overrides ohci_at91_drv_overrides __initconst = {
        .extra_priv_size = sizeof(struct ohci_at91_priv),
};

/*-------------------------------------------------------------------------*/

static void at91_start_clock(struct ohci_at91_priv *ohci_at91)
{
        if (ohci_at91->clocked)
                return;

        clk_set_rate(ohci_at91->fclk, 48000000);
        clk_prepare_enable(ohci_at91->hclk);
        clk_prepare_enable(ohci_at91->iclk);
        clk_prepare_enable(ohci_at91->fclk);
        ohci_at91->clocked = true;
}

static void at91_stop_clock(struct ohci_at91_priv *ohci_at91)
{
        if (!ohci_at91->clocked)
                return;

        clk_disable_unprepare(ohci_at91->fclk);
        clk_disable_unprepare(ohci_at91->iclk);
        clk_disable_unprepare(ohci_at91->hclk);
        ohci_at91->clocked = false;
}

static void at91_start_hc(struct platform_device *pdev)
{
        struct usb_hcd *hcd = platform_get_drvdata(pdev);
        struct ohci_regs __iomem *regs = hcd->regs;
        struct ohci_at91_priv *ohci_at91 = hcd_to_ohci_at91_priv(hcd);

        dev_dbg(&pdev->dev, "start\n");

        /*
         * Start the USB clocks.
         */
        at91_start_clock(ohci_at91);

        /*
         * The USB host controller must remain in reset.
         */
        writel(0, &regs->control);
}

static void at91_stop_hc(struct platform_device *pdev)
{
        struct usb_hcd *hcd = platform_get_drvdata(pdev);
        struct ohci_regs __iomem *regs = hcd->regs;
        struct ohci_at91_priv *ohci_at91 = hcd_to_ohci_at91_priv(hcd);

        dev_dbg(&pdev->dev, "stop\n");

        /*
         * Put the USB host controller into reset.
         */
        writel(0, &regs->control);

        /*
         * Stop the USB clocks.
         */
        at91_stop_clock(ohci_at91);
}


/*-------------------------------------------------------------------------*/

static void usb_hcd_at91_remove (struct usb_hcd *, struct platform_device *);

static struct regmap *at91_dt_syscon_sfr(void)
{
        struct regmap *regmap;

        regmap = syscon_regmap_lookup_by_compatible("atmel,sama5d2-sfr");
        if (IS_ERR(regmap))
                regmap = NULL;

        return regmap;
}

/* configure so an HC device and id are always provided */
/* always called with process context; sleeping is OK */


/**
 * usb_hcd_at91_probe - initialize AT91-based HCDs
 * Context: !in_interrupt()
 *
 * Allocates basic resources for this USB host controller, and
 * then invokes the start() method for the HCD associated with it
 * through the hotplug entry's driver_data.
 */
static int usb_hcd_at91_probe(const struct hc_driver *driver,
                        struct platform_device *pdev)
{
        struct at91_usbh_data *board;
        struct ohci_hcd *ohci;
        int retval;
        struct usb_hcd *hcd;
        struct ohci_at91_priv *ohci_at91;
        struct device *dev = &pdev->dev;
        struct resource *res;
        int irq;

        irq = platform_get_irq(pdev, 0);
        if (irq < 0) {
                dev_dbg(dev, "hcd probe: missing irq resource\n");
                return irq;
        }

        hcd = usb_create_hcd(driver, dev, "at91");
        if (!hcd)
                return -ENOMEM;
        ohci_at91 = hcd_to_ohci_at91_priv(hcd);

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        hcd->regs = devm_ioremap_resource(dev, res);
        if (IS_ERR(hcd->regs)) {
                retval = PTR_ERR(hcd->regs);
                goto err;
        }
        hcd->rsrc_start = res->start;
        hcd->rsrc_len = resource_size(res);

        ohci_at91->iclk = devm_clk_get(dev, "ohci_clk");
        if (IS_ERR(ohci_at91->iclk)) {
                dev_err(dev, "failed to get ohci_clk\n");
                retval = PTR_ERR(ohci_at91->iclk);
                goto err;
        }
        ohci_at91->fclk = devm_clk_get(dev, "uhpck");
        if (IS_ERR(ohci_at91->fclk)) {
                dev_err(dev, "failed to get uhpck\n");
                retval = PTR_ERR(ohci_at91->fclk);
                goto err;
        }
        ohci_at91->hclk = devm_clk_get(dev, "hclk");
        if (IS_ERR(ohci_at91->hclk)) {
                dev_err(dev, "failed to get hclk\n");
                retval = PTR_ERR(ohci_at91->hclk);
                goto err;
        }

        ohci_at91->sfr_regmap = at91_dt_syscon_sfr();
        if (!ohci_at91->sfr_regmap)
                dev_warn(dev, "failed to find sfr node\n");

        board = hcd->self.controller->platform_data;
        ohci = hcd_to_ohci(hcd);
        ohci->num_ports = board->ports;
        at91_start_hc(pdev);

        /*
         * The RemoteWakeupConnected bit has to be set explicitly
         * before calling ohci_run. The reset value of this bit is 0.
         */
        ohci->hc_control = OHCI_CTRL_RWC;

        retval = usb_add_hcd(hcd, irq, IRQF_SHARED);
        if (retval == 0) {
                device_wakeup_enable(hcd->self.controller);
                return retval;
        }

        /* Error handling */
        at91_stop_hc(pdev);

 err:
        usb_put_hcd(hcd);
        return retval;
}


/* may be called with controller, bus, and devices active */

/**
 * usb_hcd_at91_remove - shutdown processing for AT91-based HCDs
 * @dev: USB Host Controller being removed
 * Context: !in_interrupt()
 *
 * Reverses the effect of usb_hcd_at91_probe(), first invoking
 * the HCD's stop() method.  It is always called from a thread
 * context, "rmmod" or something similar.
 *
 */
static void usb_hcd_at91_remove(struct usb_hcd *hcd,
                                struct platform_device *pdev)
{
        usb_remove_hcd(hcd);
        at91_stop_hc(pdev);
        usb_put_hcd(hcd);
}

/*-------------------------------------------------------------------------*/
static void ohci_at91_usb_set_power(struct at91_usbh_data *pdata, int port, int enable)
{
        if (!valid_port(port))
                return;

        gpiod_set_value(pdata->vbus_pin[port], enable);
}

static int ohci_at91_usb_get_power(struct at91_usbh_data *pdata, int port)
{
        if (!valid_port(port))
                return -EINVAL;

        return gpiod_get_value(pdata->vbus_pin[port]);
}

/*
 * Update the status data from the hub with the over-current indicator change.
 */
static int ohci_at91_hub_status_data(struct usb_hcd *hcd, char *buf)
{
        struct at91_usbh_data *pdata = hcd->self.controller->platform_data;
        int length = ohci_hub_status_data(hcd, buf);
        int port;

        at91_for_each_port(port) {
                if (pdata->overcurrent_changed[port]) {
                        if (!length)
                                length = 1;
                        buf[0] |= 1 << (port + 1);
                }
        }

        return length;
}

static int ohci_at91_port_suspend(struct regmap *regmap, u8 set)
{
        u32 regval;
        int ret;

        if (!regmap)
                return 0;

        ret = regmap_read(regmap, AT91_SFR_OHCIICR, &regval);
        if (ret)
                return ret;

        if (set)
                regval |= AT91_OHCIICR_USB_SUSPEND;
        else
                regval &= ~AT91_OHCIICR_USB_SUSPEND;

        regmap_write(regmap, AT91_SFR_OHCIICR, regval);

        return 0;
}

/*
 * Look at the control requests to the root hub and see if we need to override.
 */
static int ohci_at91_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
                                 u16 wIndex, char *buf, u16 wLength)
{
        struct at91_usbh_data *pdata = dev_get_platdata(hcd->self.controller);
        struct ohci_at91_priv *ohci_at91 = hcd_to_ohci_at91_priv(hcd);
        struct usb_hub_descriptor *desc;
        int ret = -EINVAL;
        u32 *data = (u32 *)buf;

        dev_dbg(hcd->self.controller,
                "ohci_at91_hub_control(%p,0x%04x,0x%04x,0x%04x,%p,%04x)\n",
                hcd, typeReq, wValue, wIndex, buf, wLength);

        wIndex--;

        switch (typeReq) {
        case SetPortFeature:
                switch (wValue) {
                case USB_PORT_FEAT_POWER:
                        dev_dbg(hcd->self.controller, "SetPortFeat: POWER\n");
                        if (valid_port(wIndex)) {
                                ohci_at91_usb_set_power(pdata, wIndex, 1);
                                ret = 0;
                        }

                        goto out;

                case USB_PORT_FEAT_SUSPEND:
                        dev_dbg(hcd->self.controller, "SetPortFeat: SUSPEND\n");
                        if (valid_port(wIndex) && ohci_at91->sfr_regmap) {
                                ohci_at91_port_suspend(ohci_at91->sfr_regmap,
                                                       1);
                                return 0;
                        }
                        break;
                }
                break;

        case ClearPortFeature:
                switch (wValue) {
                case USB_PORT_FEAT_C_OVER_CURRENT:
                        dev_dbg(hcd->self.controller,
                                "ClearPortFeature: C_OVER_CURRENT\n");

                        if (valid_port(wIndex)) {
                                pdata->overcurrent_changed[wIndex] = 0;
                                pdata->overcurrent_status[wIndex] = 0;
                        }

                        goto out;

                case USB_PORT_FEAT_OVER_CURRENT:
                        dev_dbg(hcd->self.controller,
                                "ClearPortFeature: OVER_CURRENT\n");

                        if (valid_port(wIndex))
                                pdata->overcurrent_status[wIndex] = 0;

                        goto out;

                case USB_PORT_FEAT_POWER:
                        dev_dbg(hcd->self.controller,
                                "ClearPortFeature: POWER\n");

                        if (valid_port(wIndex)) {
                                ohci_at91_usb_set_power(pdata, wIndex, 0);
                                return 0;
                        }
                        break;

                case USB_PORT_FEAT_SUSPEND:
                        dev_dbg(hcd->self.controller, "ClearPortFeature: SUSPEND\n");
                        if (valid_port(wIndex) && ohci_at91->sfr_regmap) {
                                ohci_at91_port_suspend(ohci_at91->sfr_regmap,
                                                       0);
                                return 0;
                        }
                        break;
                }
                break;
        }

        ret = ohci_hub_control(hcd, typeReq, wValue, wIndex + 1, buf, wLength);
        if (ret)
                goto out;

        switch (typeReq) {
        case GetHubDescriptor:

                /* update the hub's descriptor */

                desc = (struct usb_hub_descriptor *)buf;

                dev_dbg(hcd->self.controller, "wHubCharacteristics 0x%04x\n",
                        desc->wHubCharacteristics);

                /* remove the old configurations for power-switching, and
                 * over-current protection, and insert our new configuration
                 */

                desc->wHubCharacteristics &= ~cpu_to_le16(HUB_CHAR_LPSM);
                desc->wHubCharacteristics |=
                        cpu_to_le16(HUB_CHAR_INDV_PORT_LPSM);

                if (pdata->overcurrent_supported) {
                        desc->wHubCharacteristics &= ~cpu_to_le16(HUB_CHAR_OCPM);
                        desc->wHubCharacteristics |=
                                cpu_to_le16(HUB_CHAR_INDV_PORT_OCPM);
                }

                dev_dbg(hcd->self.controller, "wHubCharacteristics after 0x%04x\n",
                        desc->wHubCharacteristics);

                return ret;

        case GetPortStatus:
                /* check port status */

                dev_dbg(hcd->self.controller, "GetPortStatus(%d)\n", wIndex);

                if (valid_port(wIndex)) {
                        if (!ohci_at91_usb_get_power(pdata, wIndex))
                                *data &= ~cpu_to_le32(RH_PS_PPS);

                        if (pdata->overcurrent_changed[wIndex])
                                *data |= cpu_to_le32(RH_PS_OCIC);

                        if (pdata->overcurrent_status[wIndex])
                                *data |= cpu_to_le32(RH_PS_POCI);
                }
        }

 out:
        return ret;
}

/*-------------------------------------------------------------------------*/

static irqreturn_t ohci_hcd_at91_overcurrent_irq(int irq, void *data)
{
        struct platform_device *pdev = data;
        struct at91_usbh_data *pdata = dev_get_platdata(&pdev->dev);
        int val, port;

        /* From the GPIO notifying the over-current situation, find
         * out the corresponding port */
        at91_for_each_port(port) {
                if (gpiod_to_irq(pdata->overcurrent_pin[port]) == irq)
                        break;
        }

        if (port == AT91_MAX_USBH_PORTS) {
                dev_err(& pdev->dev, "overcurrent interrupt from unknown GPIO\n");
                return IRQ_HANDLED;
        }

        val = gpiod_get_value(pdata->overcurrent_pin[port]);

        /* When notified of an over-current situation, disable power
           on the corresponding port, and mark this port in
           over-current. */
        if (!val) {
                ohci_at91_usb_set_power(pdata, port, 0);
                pdata->overcurrent_status[port]  = 1;
                pdata->overcurrent_changed[port] = 1;
        }

        dev_dbg(& pdev->dev, "overcurrent situation %s\n",
                val ? "exited" : "notified");

        return IRQ_HANDLED;
}

static const struct of_device_id at91_ohci_dt_ids[] = {
        { .compatible = "atmel,at91rm9200-ohci" },
        { /* sentinel */ }
};

MODULE_DEVICE_TABLE(of, at91_ohci_dt_ids);

/*-------------------------------------------------------------------------*/

static int ohci_hcd_at91_drv_probe(struct platform_device *pdev)
{
        struct device_node *np = pdev->dev.of_node;
        struct at91_usbh_data   *pdata;
        int                     i;
        int                     ret;
        int                     err;
        u32                     ports;

        /* Right now device-tree probed devices don't get dma_mask set.
         * Since shared usb code relies on it, set it here for now.
         * Once we have dma capability bindings this can go away.
         */
        ret = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
        if (ret)
                return ret;

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

        pdev->dev.platform_data = pdata;

        if (!of_property_read_u32(np, "num-ports", &ports))
                pdata->ports = ports;

        at91_for_each_port(i) {
                if (i >= pdata->ports)
                        break;

                pdata->vbus_pin[i] =
                        devm_gpiod_get_index_optional(&pdev->dev, "atmel,vbus",
                                                      i, GPIOD_OUT_HIGH);
                if (IS_ERR(pdata->vbus_pin[i])) {
                        err = PTR_ERR(pdata->vbus_pin[i]);
                        dev_err(&pdev->dev, "unable to claim gpio \"vbus\": %d\n", err);
                        continue;
                }
        }

        at91_for_each_port(i) {
                if (i >= pdata->ports)
                        break;

                pdata->overcurrent_pin[i] =
                        devm_gpiod_get_index_optional(&pdev->dev, "atmel,oc",
                                                      i, GPIOD_IN);
                if (IS_ERR(pdata->overcurrent_pin[i])) {
                        err = PTR_ERR(pdata->overcurrent_pin[i]);
                        dev_err(&pdev->dev, "unable to claim gpio \"overcurrent\": %d\n", err);
                        continue;
                }

                ret = devm_request_irq(&pdev->dev,
                                       gpiod_to_irq(pdata->overcurrent_pin[i]),
                                       ohci_hcd_at91_overcurrent_irq,
                                       IRQF_SHARED,
                                       "ohci_overcurrent", pdev);
                if (ret)
                        dev_info(&pdev->dev, "failed to request gpio \"overcurrent\" IRQ\n");
        }

        device_init_wakeup(&pdev->dev, 1);
        return usb_hcd_at91_probe(&ohci_at91_hc_driver, pdev);
}

static int ohci_hcd_at91_drv_remove(struct platform_device *pdev)
{
        struct at91_usbh_data   *pdata = dev_get_platdata(&pdev->dev);
        int                     i;

        if (pdata) {
                at91_for_each_port(i)
                        ohci_at91_usb_set_power(pdata, i, 0);
        }

        device_init_wakeup(&pdev->dev, 0);
        usb_hcd_at91_remove(platform_get_drvdata(pdev), pdev);
        return 0;
}

static int __maybe_unused
ohci_hcd_at91_drv_suspend(struct device *dev)
{
        struct usb_hcd  *hcd = dev_get_drvdata(dev);
        struct ohci_hcd *ohci = hcd_to_ohci(hcd);
        struct ohci_at91_priv *ohci_at91 = hcd_to_ohci_at91_priv(hcd);
        int             ret;

        /*
         * Disable wakeup if we are going to sleep with slow clock mode
         * enabled.
         */
        ohci_at91->wakeup = device_may_wakeup(dev)
                        && !at91_suspend_entering_slow_clock();

        if (ohci_at91->wakeup)
                enable_irq_wake(hcd->irq);

        ohci_at91_port_suspend(ohci_at91->sfr_regmap, 1);

        ret = ohci_suspend(hcd, ohci_at91->wakeup);
        if (ret) {
                if (ohci_at91->wakeup)
                        disable_irq_wake(hcd->irq);
                return ret;
        }
        /*
         * The integrated transceivers seem unable to notice disconnect,
         * reconnect, or wakeup without the 48 MHz clock active.  so for
         * correctness, always discard connection state (using reset).
         *
         * REVISIT: some boards will be able to turn VBUS off...
         */
        if (!ohci_at91->wakeup) {
                ohci->rh_state = OHCI_RH_HALTED;

                /* flush the writes */
                (void) ohci_readl (ohci, &ohci->regs->control);
                at91_stop_clock(ohci_at91);
        }

        return ret;
}

static int __maybe_unused
ohci_hcd_at91_drv_resume(struct device *dev)
{
        struct usb_hcd  *hcd = dev_get_drvdata(dev);
        struct ohci_at91_priv *ohci_at91 = hcd_to_ohci_at91_priv(hcd);

        if (ohci_at91->wakeup)
                disable_irq_wake(hcd->irq);

        at91_start_clock(ohci_at91);

        ohci_resume(hcd, false);

        ohci_at91_port_suspend(ohci_at91->sfr_regmap, 0);

        return 0;
}

static SIMPLE_DEV_PM_OPS(ohci_hcd_at91_pm_ops, ohci_hcd_at91_drv_suspend,
                                        ohci_hcd_at91_drv_resume);

static struct platform_driver ohci_hcd_at91_driver = {
        .probe          = ohci_hcd_at91_drv_probe,
        .remove         = ohci_hcd_at91_drv_remove,
        .shutdown       = usb_hcd_platform_shutdown,
        .driver         = {
                .name   = "at91_ohci",
                .pm     = &ohci_hcd_at91_pm_ops,
                .of_match_table = at91_ohci_dt_ids,
        },
};

static int __init ohci_at91_init(void)
{
        if (usb_disabled())
                return -ENODEV;

        pr_info("%s: " DRIVER_DESC "\n", hcd_name);
        ohci_init_driver(&ohci_at91_hc_driver, &ohci_at91_drv_overrides);

        /*
         * The Atmel HW has some unusual quirks, which require Atmel-specific
         * workarounds. We override certain hc_driver functions here to
         * achieve that. We explicitly do not enhance ohci_driver_overrides to
         * allow this more easily, since this is an unusual case, and we don't
         * want to encourage others to override these functions by making it
         * too easy.
         */

        ohci_at91_hc_driver.hub_status_data     = ohci_at91_hub_status_data;
        ohci_at91_hc_driver.hub_control         = ohci_at91_hub_control;

        return platform_driver_register(&ohci_hcd_at91_driver);
}
module_init(ohci_at91_init);

static void __exit ohci_at91_cleanup(void)
{
        platform_driver_unregister(&ohci_hcd_at91_driver);
}
module_exit(ohci_at91_cleanup);

MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:at91_ohci");