/*
 * 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/platform_device.h>
#include <linux/of_platform.h>
#include <linux/of_gpio.h>
#include <linux/platform_data/atmel.h>

#include <mach/hardware.h>
#include <asm/gpio.h>

#include <mach/cpu.h>

#ifndef CONFIG_ARCH_AT91
#error "CONFIG_ARCH_AT91 must be defined."
#endif

#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 and function clocks; sometimes also an AHB clock */
static struct clk *iclk, *fclk, *hclk;
static int clocked;

extern int usb_disabled(void);

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

static void at91_start_clock(void)
{
        clk_enable(hclk);
        clk_enable(iclk);
        clk_enable(fclk);
        clocked = 1;
}

static void at91_stop_clock(void)
{
        clk_disable(fclk);
        clk_disable(iclk);
        clk_disable(hclk);
        clocked = 0;
}

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

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

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

        /*
         * 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;

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

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

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


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

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

/* 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)
{
        int retval;
        struct usb_hcd *hcd = NULL;

        if (pdev->num_resources != 2) {
                pr_debug("hcd probe: invalid num_resources");
                return -ENODEV;
        }

        if ((pdev->resource[0].flags != IORESOURCE_MEM)
                        || (pdev->resource[1].flags != IORESOURCE_IRQ)) {
                pr_debug("hcd probe: invalid resource type\n");
                return -ENODEV;
        }

        hcd = usb_create_hcd(driver, &pdev->dev, "at91");
        if (!hcd)
                return -ENOMEM;
        hcd->rsrc_start = pdev->resource[0].start;
        hcd->rsrc_len = resource_size(&pdev->resource[0]);

        if (!request_mem_region(hcd->rsrc_start, hcd->rsrc_len, hcd_name)) {
                pr_debug("request_mem_region failed\n");
                retval = -EBUSY;
                goto err1;
        }

        hcd->regs = ioremap(hcd->rsrc_start, hcd->rsrc_len);
        if (!hcd->regs) {
                pr_debug("ioremap failed\n");
                retval = -EIO;
                goto err2;
        }

        iclk = clk_get(&pdev->dev, "ohci_clk");
        if (IS_ERR(iclk)) {
                dev_err(&pdev->dev, "failed to get ohci_clk\n");
                retval = PTR_ERR(iclk);
                goto err3;
        }
        fclk = clk_get(&pdev->dev, "uhpck");
        if (IS_ERR(fclk)) {
                dev_err(&pdev->dev, "failed to get uhpck\n");
                retval = PTR_ERR(fclk);
                goto err4;
        }
        hclk = clk_get(&pdev->dev, "hclk");
        if (IS_ERR(hclk)) {
                dev_err(&pdev->dev, "failed to get hclk\n");
                retval = PTR_ERR(hclk);
                goto err5;
        }

        at91_start_hc(pdev);
        ohci_hcd_init(hcd_to_ohci(hcd));

        retval = usb_add_hcd(hcd, pdev->resource[1].start, IRQF_SHARED);
        if (retval == 0)
                return retval;

        /* Error handling */
        at91_stop_hc(pdev);

        clk_put(hclk);
 err5:
        clk_put(fclk);
 err4:
        clk_put(iclk);

 err3:
        iounmap(hcd->regs);

 err2:
        release_mem_region(hcd->rsrc_start, hcd->rsrc_len);

 err1:
        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);
        iounmap(hcd->regs);
        release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
        usb_put_hcd(hcd);

        clk_put(hclk);
        clk_put(fclk);
        clk_put(iclk);
        fclk = iclk = hclk = NULL;

        dev_set_drvdata(&pdev->dev, NULL);
}

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

static int
ohci_at91_reset (struct usb_hcd *hcd)
{
        struct at91_usbh_data   *board = hcd->self.controller->platform_data;
        struct ohci_hcd         *ohci = hcd_to_ohci (hcd);
        int                     ret;

        if ((ret = ohci_init(ohci)) < 0)
                return ret;

        ohci->num_ports = board->ports;
        return 0;
}

static int
ohci_at91_start (struct usb_hcd *hcd)
{
        struct ohci_hcd         *ohci = hcd_to_ohci (hcd);
        int                     ret;

        if ((ret = ohci_run(ohci)) < 0) {
                dev_err(hcd->self.controller, "can't start %s\n",
                        hcd->self.bus_name);
                ohci_stop(hcd);
                return ret;
        }
        return 0;
}

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

        if (!gpio_is_valid(pdata->vbus_pin[port]))
                return;

        gpio_set_value(pdata->vbus_pin[port],
                       pdata->vbus_pin_active_low[port] ^ enable);
}

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

        if (!gpio_is_valid(pdata->vbus_pin[port]))
                return -EINVAL;

        return gpio_get_value(pdata->vbus_pin[port]) ^
                pdata->vbus_pin_active_low[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;
}

/*
 * 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 = hcd->self.controller->platform_data;
        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:
                if (wValue == 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;
                }
                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;
        }

        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(0x0001);

                if (pdata->overcurrent_supported) {
                        desc->wHubCharacteristics &= ~cpu_to_le16(HUB_CHAR_OCPM);
                        desc->wHubCharacteristics |=  cpu_to_le16(0x0008|0x0001);
                }

                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 const struct hc_driver ohci_at91_hc_driver = {
        .description =          hcd_name,
        .product_desc =         "AT91 OHCI",
        .hcd_priv_size =        sizeof(struct ohci_hcd),

        /*
         * generic hardware linkage
         */
        .irq =                  ohci_irq,
        .flags =                HCD_USB11 | HCD_MEMORY,

        /*
         * basic lifecycle operations
         */
        .reset =                ohci_at91_reset,
        .start =                ohci_at91_start,
        .stop =                 ohci_stop,
        .shutdown =             ohci_shutdown,

        /*
         * managing i/o requests and associated device resources
         */
        .urb_enqueue =          ohci_urb_enqueue,
        .urb_dequeue =          ohci_urb_dequeue,
        .endpoint_disable =     ohci_endpoint_disable,

        /*
         * scheduling support
         */
        .get_frame_number =     ohci_get_frame,

        /*
         * root hub support
         */
        .hub_status_data =      ohci_at91_hub_status_data,
        .hub_control =          ohci_at91_hub_control,
#ifdef CONFIG_PM
        .bus_suspend =          ohci_bus_suspend,
        .bus_resume =           ohci_bus_resume,
#endif
        .start_port_reset =     ohci_start_port_reset,
};

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

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

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

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

        val = gpio_get_value(gpio);

        /* 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;
}

#ifdef CONFIG_OF
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_at91_of_init(struct platform_device *pdev)
{
        struct device_node *np = pdev->dev.of_node;
        int i, gpio;
        enum of_gpio_flags flags;
        struct at91_usbh_data   *pdata;
        u32 ports;

        if (!np)
                return 0;

        /* 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.
         */
        if (!pdev->dev.dma_mask)
                pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
        if (!pdev->dev.coherent_dma_mask)
                pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);

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

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

        at91_for_each_port(i) {
                gpio = of_get_named_gpio_flags(np, "atmel,vbus-gpio", i, &flags);
                pdata->vbus_pin[i] = gpio;
                if (!gpio_is_valid(gpio))
                        continue;
                pdata->vbus_pin_active_low[i] = flags & OF_GPIO_ACTIVE_LOW;
        }

        at91_for_each_port(i)
                pdata->overcurrent_pin[i] =
                        of_get_named_gpio_flags(np, "atmel,oc-gpio", i, &flags);

        pdev->dev.platform_data = pdata;

        return 0;
}
#else
static int ohci_at91_of_init(struct platform_device *pdev)
{
        return 0;
}
#endif

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

static int ohci_hcd_at91_drv_probe(struct platform_device *pdev)
{
        struct at91_usbh_data   *pdata;
        int                     i;
        int                     gpio;
        int                     ret;

        ret = ohci_at91_of_init(pdev);
        if (ret)
                return ret;

        pdata = pdev->dev.platform_data;

        if (pdata) {
                at91_for_each_port(i) {
                        /*
                         * do not configure PIO if not in relation with
                         * real USB port on board
                         */
                        if (i >= pdata->ports) {
                                pdata->vbus_pin[i] = -EINVAL;
                                pdata->overcurrent_pin[i] = -EINVAL;
                                break;
                        }

                        if (!gpio_is_valid(pdata->vbus_pin[i]))
                                continue;
                        gpio = pdata->vbus_pin[i];

                        ret = gpio_request(gpio, "ohci_vbus");
                        if (ret) {
                                dev_err(&pdev->dev,
                                        "can't request vbus gpio %d\n", gpio);
                                continue;
                        }
                        ret = gpio_direction_output(gpio,
                                                !pdata->vbus_pin_active_low[i]);
                        if (ret) {
                                dev_err(&pdev->dev,
                                        "can't put vbus gpio %d as output %d\n",
                                        gpio, !pdata->vbus_pin_active_low[i]);
                                gpio_free(gpio);
                                continue;
                        }

                        ohci_at91_usb_set_power(pdata, i, 1);
                }

                at91_for_each_port(i) {
                        if (!gpio_is_valid(pdata->overcurrent_pin[i]))
                                continue;
                        gpio = pdata->overcurrent_pin[i];

                        ret = gpio_request(gpio, "ohci_overcurrent");
                        if (ret) {
                                dev_err(&pdev->dev,
                                        "can't request overcurrent gpio %d\n",
                                        gpio);
                                continue;
                        }

                        ret = gpio_direction_input(gpio);
                        if (ret) {
                                dev_err(&pdev->dev,
                                        "can't configure overcurrent gpio %d as input\n",
                                        gpio);
                                gpio_free(gpio);
                                continue;
                        }

                        ret = request_irq(gpio_to_irq(gpio),
                                          ohci_hcd_at91_overcurrent_irq,
                                          IRQF_SHARED, "ohci_overcurrent", pdev);
                        if (ret) {
                                gpio_free(gpio);
                                dev_err(&pdev->dev,
                                        "can't get gpio IRQ for overcurrent\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 = pdev->dev.platform_data;
        int                     i;

        if (pdata) {
                at91_for_each_port(i) {
                        if (!gpio_is_valid(pdata->vbus_pin[i]))
                                continue;
                        ohci_at91_usb_set_power(pdata, i, 0);
                        gpio_free(pdata->vbus_pin[i]);
                }

                at91_for_each_port(i) {
                        if (!gpio_is_valid(pdata->overcurrent_pin[i]))
                                continue;
                        free_irq(gpio_to_irq(pdata->overcurrent_pin[i]), pdev);
                        gpio_free(pdata->overcurrent_pin[i]);
                }
        }

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

#ifdef CONFIG_PM

static int
ohci_hcd_at91_drv_suspend(struct platform_device *pdev, pm_message_t mesg)
{
        struct usb_hcd  *hcd = platform_get_drvdata(pdev);
        struct ohci_hcd *ohci = hcd_to_ohci(hcd);

        if (device_may_wakeup(&pdev->dev))
                enable_irq_wake(hcd->irq);

        /*
         * 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 (at91_suspend_entering_slow_clock()) {
                ohci_usb_reset (ohci);
                /* flush the writes */
                (void) ohci_readl (ohci, &ohci->regs->control);
                at91_stop_clock();
        }

        return 0;
}

static int ohci_hcd_at91_drv_resume(struct platform_device *pdev)
{
        struct usb_hcd  *hcd = platform_get_drvdata(pdev);

        if (device_may_wakeup(&pdev->dev))
                disable_irq_wake(hcd->irq);

        if (!clocked)
                at91_start_clock();

        ohci_resume(hcd, false);
        return 0;
}
#else
#define ohci_hcd_at91_drv_suspend NULL
#define ohci_hcd_at91_drv_resume  NULL
#endif

MODULE_ALIAS("platform:at91_ohci");

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,
        .suspend        = ohci_hcd_at91_drv_suspend,
        .resume         = ohci_hcd_at91_drv_resume,
        .driver         = {
                .name   = "at91_ohci",
                .owner  = THIS_MODULE,
                .of_match_table = of_match_ptr(at91_ohci_dt_ids),
        },
};