core.c

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#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/io.h>
#include <linux/list.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/of.h>

#include <linux/usb/otg.h>
#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>

#include "core.h"
#include "gadget.h"
#include "io.h"

#include "debug.h"

static char *maximum_speed = "super";
module_param(maximum_speed, charp, 0);
MODULE_PARM_DESC(maximum_speed, "Maximum supported speed.");

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

#define DWC3_DEVS_POSSIBLE  32

static DECLARE_BITMAP(dwc3_devs, DWC3_DEVS_POSSIBLE);

int dwc3_get_device_id(void)
{
    int     id;

again:
    id = find_first_zero_bit(dwc3_devs, DWC3_DEVS_POSSIBLE);
    if (id < DWC3_DEVS_POSSIBLE) {
        int old;

        old = test_and_set_bit(id, dwc3_devs);
        if (old)
            goto again;
    } else {
        pr_err("dwc3: no space for new device\n");
        id = -ENOMEM;
    }

    return id;
}
EXPORT_SYMBOL_GPL(dwc3_get_device_id);

void dwc3_put_device_id(int id)
{
    int         ret;

    if (id < 0)
        return;

    ret = test_bit(id, dwc3_devs);
    WARN(!ret, "dwc3: ID %d not in use\n", id);
    smp_mb__before_clear_bit();
    clear_bit(id, dwc3_devs);
}
EXPORT_SYMBOL_GPL(dwc3_put_device_id);

void dwc3_set_mode(struct dwc3 *dwc, u32 mode)
{
    u32 reg;

    reg = dwc3_readl(dwc->regs, DWC3_GCTL);
    reg &= ~(DWC3_GCTL_PRTCAPDIR(DWC3_GCTL_PRTCAP_OTG));
    reg |= DWC3_GCTL_PRTCAPDIR(mode);
    dwc3_writel(dwc->regs, DWC3_GCTL, reg);
}

static void dwc3_core_soft_reset(struct dwc3 *dwc)
{
    u32     reg;

    /* Before Resetting PHY, put Core in Reset */
    reg = dwc3_readl(dwc->regs, DWC3_GCTL);
    reg |= DWC3_GCTL_CORESOFTRESET;
    dwc3_writel(dwc->regs, DWC3_GCTL, reg);

    /* Assert USB3 PHY reset */
    reg = dwc3_readl(dwc->regs, DWC3_GUSB3PIPECTL(0));
    reg |= DWC3_GUSB3PIPECTL_PHYSOFTRST;
    dwc3_writel(dwc->regs, DWC3_GUSB3PIPECTL(0), reg);

    /* Assert USB2 PHY reset */
    reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
    reg |= DWC3_GUSB2PHYCFG_PHYSOFTRST;
    dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);

    usb_phy_init(dwc->usb2_phy);
    usb_phy_init(dwc->usb3_phy);
    mdelay(100);

    /* Clear USB3 PHY reset */
    reg = dwc3_readl(dwc->regs, DWC3_GUSB3PIPECTL(0));
    reg &= ~DWC3_GUSB3PIPECTL_PHYSOFTRST;
    dwc3_writel(dwc->regs, DWC3_GUSB3PIPECTL(0), reg);

    /* Clear USB2 PHY reset */
    reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
    reg &= ~DWC3_GUSB2PHYCFG_PHYSOFTRST;
    dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);

    mdelay(100);

    /* After PHYs are stable we can take Core out of reset state */
    reg = dwc3_readl(dwc->regs, DWC3_GCTL);
    reg &= ~DWC3_GCTL_CORESOFTRESET;
    dwc3_writel(dwc->regs, DWC3_GCTL, reg);
}

static void dwc3_free_one_event_buffer(struct dwc3 *dwc,
        struct dwc3_event_buffer *evt)
{
    dma_free_coherent(dwc->dev, evt->length, evt->buf, evt->dma);
    kfree(evt);
}

static struct dwc3_event_buffer *__devinit
dwc3_alloc_one_event_buffer(struct dwc3 *dwc, unsigned length)
{
    struct dwc3_event_buffer    *evt;

    evt = kzalloc(sizeof(*evt), GFP_KERNEL);
    if (!evt)
        return ERR_PTR(-ENOMEM);

    evt->dwc    = dwc;
    evt->length = length;
    evt->buf    = dma_alloc_coherent(dwc->dev, length,
            &evt->dma, GFP_KERNEL);
    if (!evt->buf) {
        kfree(evt);
        return ERR_PTR(-ENOMEM);
    }

    return evt;
}

static void dwc3_free_event_buffers(struct dwc3 *dwc)
{
    struct dwc3_event_buffer    *evt;
    int i;

    for (i = 0; i < dwc->num_event_buffers; i++) {
        evt = dwc->ev_buffs[i];
        if (evt)
            dwc3_free_one_event_buffer(dwc, evt);
    }

    kfree(dwc->ev_buffs);
}

static int __devinit dwc3_alloc_event_buffers(struct dwc3 *dwc, unsigned length)
{
    int         num;
    int         i;

    num = DWC3_NUM_INT(dwc->hwparams.hwparams1);
    dwc->num_event_buffers = num;

    dwc->ev_buffs = kzalloc(sizeof(*dwc->ev_buffs) * num, GFP_KERNEL);
    if (!dwc->ev_buffs) {
        dev_err(dwc->dev, "can't allocate event buffers array\n");
        return -ENOMEM;
    }

    for (i = 0; i < num; i++) {
        struct dwc3_event_buffer    *evt;

        evt = dwc3_alloc_one_event_buffer(dwc, length);
        if (IS_ERR(evt)) {
            dev_err(dwc->dev, "can't allocate event buffer\n");
            return PTR_ERR(evt);
        }
        dwc->ev_buffs[i] = evt;
    }

    return 0;
}

static int dwc3_event_buffers_setup(struct dwc3 *dwc)
{
    struct dwc3_event_buffer    *evt;
    int             n;

    for (n = 0; n < dwc->num_event_buffers; n++) {
        evt = dwc->ev_buffs[n];
        dev_dbg(dwc->dev, "Event buf %p dma %08llx length %d\n",
                evt->buf, (unsigned long long) evt->dma,
                evt->length);

        evt->lpos = 0;

        dwc3_writel(dwc->regs, DWC3_GEVNTADRLO(n),
                lower_32_bits(evt->dma));
        dwc3_writel(dwc->regs, DWC3_GEVNTADRHI(n),
                upper_32_bits(evt->dma));
        dwc3_writel(dwc->regs, DWC3_GEVNTSIZ(n),
                evt->length & 0xffff);
        dwc3_writel(dwc->regs, DWC3_GEVNTCOUNT(n), 0);
    }

    return 0;
}

static void dwc3_event_buffers_cleanup(struct dwc3 *dwc)
{
    struct dwc3_event_buffer    *evt;
    int             n;

    for (n = 0; n < dwc->num_event_buffers; n++) {
        evt = dwc->ev_buffs[n];

        evt->lpos = 0;

        dwc3_writel(dwc->regs, DWC3_GEVNTADRLO(n), 0);
        dwc3_writel(dwc->regs, DWC3_GEVNTADRHI(n), 0);
        dwc3_writel(dwc->regs, DWC3_GEVNTSIZ(n), 0);
        dwc3_writel(dwc->regs, DWC3_GEVNTCOUNT(n), 0);
    }
}

static void __devinit dwc3_cache_hwparams(struct dwc3 *dwc)
{
    struct dwc3_hwparams    *parms = &dwc->hwparams;

    parms->hwparams0 = dwc3_readl(dwc->regs, DWC3_GHWPARAMS0);
    parms->hwparams1 = dwc3_readl(dwc->regs, DWC3_GHWPARAMS1);
    parms->hwparams2 = dwc3_readl(dwc->regs, DWC3_GHWPARAMS2);
    parms->hwparams3 = dwc3_readl(dwc->regs, DWC3_GHWPARAMS3);
    parms->hwparams4 = dwc3_readl(dwc->regs, DWC3_GHWPARAMS4);
    parms->hwparams5 = dwc3_readl(dwc->regs, DWC3_GHWPARAMS5);
    parms->hwparams6 = dwc3_readl(dwc->regs, DWC3_GHWPARAMS6);
    parms->hwparams7 = dwc3_readl(dwc->regs, DWC3_GHWPARAMS7);
    parms->hwparams8 = dwc3_readl(dwc->regs, DWC3_GHWPARAMS8);
}

static int __devinit dwc3_core_init(struct dwc3 *dwc)
{
    unsigned long       timeout;
    u32         reg;
    int         ret;

    reg = dwc3_readl(dwc->regs, DWC3_GSNPSID);
    /* This should read as U3 followed by revision number */
    if ((reg & DWC3_GSNPSID_MASK) != 0x55330000) {
        dev_err(dwc->dev, "this is not a DesignWare USB3 DRD Core\n");
        ret = -ENODEV;
        goto err0;
    }
    dwc->revision = reg;

    /* issue device SoftReset too */
    timeout = jiffies + msecs_to_jiffies(500);
    dwc3_writel(dwc->regs, DWC3_DCTL, DWC3_DCTL_CSFTRST);
    do {
        reg = dwc3_readl(dwc->regs, DWC3_DCTL);
        if (!(reg & DWC3_DCTL_CSFTRST))
            break;

        if (time_after(jiffies, timeout)) {
            dev_err(dwc->dev, "Reset Timed Out\n");
            ret = -ETIMEDOUT;
            goto err0;
        }

        cpu_relax();
    } while (true);

    dwc3_core_soft_reset(dwc);

    dwc3_cache_hwparams(dwc);

    reg = dwc3_readl(dwc->regs, DWC3_GCTL);
    reg &= ~DWC3_GCTL_SCALEDOWN_MASK;
    reg &= ~DWC3_GCTL_DISSCRAMBLE;

    switch (DWC3_GHWPARAMS1_EN_PWROPT(dwc->hwparams.hwparams1)) {
    case DWC3_GHWPARAMS1_EN_PWROPT_CLK:
        reg &= ~DWC3_GCTL_DSBLCLKGTNG;
        break;
    default:
        dev_dbg(dwc->dev, "No power optimization available\n");
    }

    /*
     * WORKAROUND: DWC3 revisions <1.90a have a bug
     * where the device can fail to connect at SuperSpeed
     * and falls back to high-speed mode which causes
     * the device to enter a Connect/Disconnect loop
     */
    if (dwc->revision < DWC3_REVISION_190A)
        reg |= DWC3_GCTL_U2RSTECN;

    dwc3_writel(dwc->regs, DWC3_GCTL, reg);

    ret = dwc3_alloc_event_buffers(dwc, DWC3_EVENT_BUFFERS_SIZE);
    if (ret) {
        dev_err(dwc->dev, "failed to allocate event buffers\n");
        ret = -ENOMEM;
        goto err1;
    }

    ret = dwc3_event_buffers_setup(dwc);
    if (ret) {
        dev_err(dwc->dev, "failed to setup event buffers\n");
        goto err1;
    }

    return 0;

err1:
    dwc3_free_event_buffers(dwc);

err0:
    return ret;
}

static void dwc3_core_exit(struct dwc3 *dwc)
{
    dwc3_event_buffers_cleanup(dwc);
    dwc3_free_event_buffers(dwc);

    usb_phy_shutdown(dwc->usb2_phy);
    usb_phy_shutdown(dwc->usb3_phy);

}

#define DWC3_ALIGN_MASK     (16 - 1)

static int __devinit dwc3_probe(struct platform_device *pdev)
{
    struct device_node  *node = pdev->dev.of_node;
    struct resource     *res;
    struct dwc3     *dwc;
    struct device       *dev = &pdev->dev;

    int         ret = -ENOMEM;

    void __iomem        *regs;
    void            *mem;

    u8          mode;

    mem = devm_kzalloc(dev, sizeof(*dwc) + DWC3_ALIGN_MASK, GFP_KERNEL);
    if (!mem) {
        dev_err(dev, "not enough memory\n");
        return -ENOMEM;
    }
    dwc = PTR_ALIGN(mem, DWC3_ALIGN_MASK + 1);
    dwc->mem = mem;

    res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
    if (!res) {
        dev_err(dev, "missing IRQ\n");
        return -ENODEV;
    }
    dwc->xhci_resources[1].start = res->start;
    dwc->xhci_resources[1].end = res->end;
    dwc->xhci_resources[1].flags = res->flags;
    dwc->xhci_resources[1].name = res->name;

    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    if (!res) {
        dev_err(dev, "missing memory resource\n");
        return -ENODEV;
    }
    dwc->xhci_resources[0].start = res->start;
    dwc->xhci_resources[0].end = dwc->xhci_resources[0].start +
                    DWC3_XHCI_REGS_END;
    dwc->xhci_resources[0].flags = res->flags;
    dwc->xhci_resources[0].name = res->name;

     /*
      * Request memory region but exclude xHCI regs,
      * since it will be requested by the xhci-plat driver.
      */
    res = devm_request_mem_region(dev, res->start + DWC3_GLOBALS_REGS_START,
            resource_size(res) - DWC3_GLOBALS_REGS_START,
            dev_name(dev));
    if (!res) {
        dev_err(dev, "can't request mem region\n");
        return -ENOMEM;
    }

    regs = devm_ioremap_nocache(dev, res->start, resource_size(res));
    if (!regs) {
        dev_err(dev, "ioremap failed\n");
        return -ENOMEM;
    }

    dwc->usb2_phy = devm_usb_get_phy(dev, USB_PHY_TYPE_USB2);
    if (IS_ERR_OR_NULL(dwc->usb2_phy)) {
        dev_err(dev, "no usb2 phy configured\n");
        return -EPROBE_DEFER;
    }

    dwc->usb3_phy = devm_usb_get_phy(dev, USB_PHY_TYPE_USB3);
    if (IS_ERR_OR_NULL(dwc->usb3_phy)) {
        dev_err(dev, "no usb3 phy configured\n");
        return -EPROBE_DEFER;
    }

    spin_lock_init(&dwc->lock);
    platform_set_drvdata(pdev, dwc);

    dwc->regs   = regs;
    dwc->regs_size  = resource_size(res);
    dwc->dev    = dev;

    if (!strncmp("super", maximum_speed, 5))
        dwc->maximum_speed = DWC3_DCFG_SUPERSPEED;
    else if (!strncmp("high", maximum_speed, 4))
        dwc->maximum_speed = DWC3_DCFG_HIGHSPEED;
    else if (!strncmp("full", maximum_speed, 4))
        dwc->maximum_speed = DWC3_DCFG_FULLSPEED1;
    else if (!strncmp("low", maximum_speed, 3))
        dwc->maximum_speed = DWC3_DCFG_LOWSPEED;
    else
        dwc->maximum_speed = DWC3_DCFG_SUPERSPEED;

    if (of_get_property(node, "tx-fifo-resize", NULL))
        dwc->needs_fifo_resize = true;

    pm_runtime_enable(dev);
    pm_runtime_get_sync(dev);
    pm_runtime_forbid(dev);

    ret = dwc3_core_init(dwc);
    if (ret) {
        dev_err(dev, "failed to initialize core\n");
        return ret;
    }

    mode = DWC3_MODE(dwc->hwparams.hwparams0);

    switch (mode) {
    case DWC3_MODE_DEVICE:
        dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_DEVICE);
        ret = dwc3_gadget_init(dwc);
        if (ret) {
            dev_err(dev, "failed to initialize gadget\n");
            goto err1;
        }
        break;
    case DWC3_MODE_HOST:
        dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_HOST);
        ret = dwc3_host_init(dwc);
        if (ret) {
            dev_err(dev, "failed to initialize host\n");
            goto err1;
        }
        break;
    case DWC3_MODE_DRD:
        dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_OTG);
        ret = dwc3_host_init(dwc);
        if (ret) {
            dev_err(dev, "failed to initialize host\n");
            goto err1;
        }

        ret = dwc3_gadget_init(dwc);
        if (ret) {
            dev_err(dev, "failed to initialize gadget\n");
            goto err1;
        }
        break;
    default:
        dev_err(dev, "Unsupported mode of operation %d\n", mode);
        goto err1;
    }
    dwc->mode = mode;

    ret = dwc3_debugfs_init(dwc);
    if (ret) {
        dev_err(dev, "failed to initialize debugfs\n");
        goto err2;
    }

    pm_runtime_allow(dev);

    return 0;

err2:
    switch (mode) {
    case DWC3_MODE_DEVICE:
        dwc3_gadget_exit(dwc);
        break;
    case DWC3_MODE_HOST:
        dwc3_host_exit(dwc);
        break;
    case DWC3_MODE_DRD:
        dwc3_host_exit(dwc);
        dwc3_gadget_exit(dwc);
        break;
    default:
        /* do nothing */
        break;
    }

err1:
    dwc3_core_exit(dwc);

    return ret;
}

static int __devexit dwc3_remove(struct platform_device *pdev)
{
    struct dwc3 *dwc = platform_get_drvdata(pdev);
    struct resource *res;

    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

    pm_runtime_put(&pdev->dev);
    pm_runtime_disable(&pdev->dev);

    dwc3_debugfs_exit(dwc);

    switch (dwc->mode) {
    case DWC3_MODE_DEVICE:
        dwc3_gadget_exit(dwc);
        break;
    case DWC3_MODE_HOST:
        dwc3_host_exit(dwc);
        break;
    case DWC3_MODE_DRD:
        dwc3_host_exit(dwc);
        dwc3_gadget_exit(dwc);
        break;
    default:
        /* do nothing */
        break;
    }

    dwc3_core_exit(dwc);

    return 0;
}

static struct platform_driver dwc3_driver = {
    .probe      = dwc3_probe,
    .remove     = __devexit_p(dwc3_remove),
    .driver     = {
        .name   = "dwc3",
    },
};

module_platform_driver(dwc3_driver);

MODULE_ALIAS("platform:dwc3");
MODULE_AUTHOR("Felipe Balbi <[email protected]>");
MODULE_LICENSE("Dual BSD/GPL");
MODULE_DESCRIPTION("DesignWare USB3 DRD Controller Driver");