root/drivers/usb/musb/ux500.c
// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2010 ST-Ericsson AB
 * Mian Yousaf Kaukab <mian.yousaf.kaukab@stericsson.com>
 *
 * Based on omap2430.c
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/usb/musb-ux500.h>

#include "musb_core.h"

static const struct musb_hdrc_config ux500_musb_hdrc_config = {
        .multipoint     = true,
        .dyn_fifo       = true,
        .num_eps        = 16,
        .ram_bits       = 16,
};

struct ux500_glue {
        struct device           *dev;
        struct platform_device  *musb;
        struct clk              *clk;
};
#define glue_to_musb(g) platform_get_drvdata(g->musb)

static void ux500_musb_set_vbus(struct musb *musb, int is_on)
{
        u8            devctl;
        unsigned long timeout = jiffies + msecs_to_jiffies(1000);
        /* HDRC controls CPEN, but beware current surges during device
         * connect.  They can trigger transient overcurrent conditions
         * that must be ignored.
         */

        devctl = musb_readb(musb->mregs, MUSB_DEVCTL);

        if (is_on) {
                if (musb->xceiv->otg->state == OTG_STATE_A_IDLE) {
                        /* start the session */
                        devctl |= MUSB_DEVCTL_SESSION;
                        musb_writeb(musb->mregs, MUSB_DEVCTL, devctl);
                        /*
                         * Wait for the musb to set as A device to enable the
                         * VBUS
                         */
                        while (musb_readb(musb->mregs, MUSB_DEVCTL) & 0x80) {

                                if (time_after(jiffies, timeout)) {
                                        dev_err(musb->controller,
                                        "configured as A device timeout");
                                        break;
                                }
                        }

                } else {
                        musb->is_active = 1;
                        musb->xceiv->otg->state = OTG_STATE_A_WAIT_VRISE;
                        devctl |= MUSB_DEVCTL_SESSION;
                        MUSB_HST_MODE(musb);
                }
        } else {
                musb->is_active = 0;

                /* NOTE: we're skipping A_WAIT_VFALL -> A_IDLE and jumping
                 * right to B_IDLE...
                 */
                devctl &= ~MUSB_DEVCTL_SESSION;
                MUSB_DEV_MODE(musb);
        }
        musb_writeb(musb->mregs, MUSB_DEVCTL, devctl);

        /*
         * Devctl values will be updated after vbus goes below
         * session_valid. The time taken depends on the capacitance
         * on VBUS line. The max discharge time can be upto 1 sec
         * as per the spec. Typically on our platform, it is 200ms
         */
        if (!is_on)
                mdelay(200);

        dev_dbg(musb->controller, "VBUS %s, devctl %02x\n",
                usb_otg_state_string(musb->xceiv->otg->state),
                musb_readb(musb->mregs, MUSB_DEVCTL));
}

static int musb_otg_notifications(struct notifier_block *nb,
                unsigned long event, void *unused)
{
        struct musb *musb = container_of(nb, struct musb, nb);

        dev_dbg(musb->controller, "musb_otg_notifications %ld %s\n",
                        event, usb_otg_state_string(musb->xceiv->otg->state));

        switch (event) {
        case UX500_MUSB_ID:
                dev_dbg(musb->controller, "ID GND\n");
                ux500_musb_set_vbus(musb, 1);
                break;
        case UX500_MUSB_VBUS:
                dev_dbg(musb->controller, "VBUS Connect\n");
                break;
        case UX500_MUSB_NONE:
                dev_dbg(musb->controller, "VBUS Disconnect\n");
                if (is_host_active(musb))
                        ux500_musb_set_vbus(musb, 0);
                else
                        musb->xceiv->otg->state = OTG_STATE_B_IDLE;
                break;
        default:
                dev_dbg(musb->controller, "ID float\n");
                return NOTIFY_DONE;
        }
        return NOTIFY_OK;
}

static irqreturn_t ux500_musb_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_readb(musb->mregs, MUSB_INTRUSB);
        musb->int_tx = musb_readw(musb->mregs, MUSB_INTRTX);
        musb->int_rx = musb_readw(musb->mregs, MUSB_INTRRX);

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

        spin_unlock_irqrestore(&musb->lock, flags);

        return retval;
}

static int ux500_musb_init(struct musb *musb)
{
        int status;

        musb->xceiv = usb_get_phy(USB_PHY_TYPE_USB2);
        if (IS_ERR_OR_NULL(musb->xceiv)) {
                pr_err("HS USB OTG: no transceiver configured\n");
                return -EPROBE_DEFER;
        }

        musb->nb.notifier_call = musb_otg_notifications;
        status = usb_register_notifier(musb->xceiv, &musb->nb);
        if (status < 0) {
                dev_dbg(musb->controller, "notification register failed\n");
                return status;
        }

        musb->isr = ux500_musb_interrupt;

        return 0;
}

static int ux500_musb_exit(struct musb *musb)
{
        usb_unregister_notifier(musb->xceiv, &musb->nb);

        usb_put_phy(musb->xceiv);

        return 0;
}

static const struct musb_platform_ops ux500_ops = {
        .quirks         = MUSB_DMA_UX500 | MUSB_INDEXED_EP,
#ifdef CONFIG_USB_UX500_DMA
        .dma_init       = ux500_dma_controller_create,
        .dma_exit       = ux500_dma_controller_destroy,
#endif
        .init           = ux500_musb_init,
        .exit           = ux500_musb_exit,
        .fifo_mode      = 5,

        .set_vbus       = ux500_musb_set_vbus,
};

static struct musb_hdrc_platform_data *
ux500_of_probe(struct platform_device *pdev, struct device_node *np)
{
        struct musb_hdrc_platform_data *pdata;
        const char *mode;
        int strlen;

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

        mode = of_get_property(np, "dr_mode", &strlen);
        if (!mode) {
                dev_err(&pdev->dev, "No 'dr_mode' property found\n");
                return NULL;
        }

        if (strlen > 0) {
                if (!strcmp(mode, "host"))
                        pdata->mode = MUSB_HOST;
                if (!strcmp(mode, "otg"))
                        pdata->mode = MUSB_OTG;
                if (!strcmp(mode, "peripheral"))
                        pdata->mode = MUSB_PERIPHERAL;
        }

        return pdata;
}

static int ux500_probe(struct platform_device *pdev)
{
        struct musb_hdrc_platform_data  *pdata = dev_get_platdata(&pdev->dev);
        struct device_node              *np = pdev->dev.of_node;
        struct platform_device          *musb;
        struct ux500_glue               *glue;
        struct clk                      *clk;
        int                             ret = -ENOMEM;

        if (!pdata) {
                if (np) {
                        pdata = ux500_of_probe(pdev, np);
                        if (!pdata)
                                goto err0;

                        pdev->dev.platform_data = pdata;
                } else {
                        dev_err(&pdev->dev, "no pdata or device tree found\n");
                        goto err0;
                }
        }

        glue = devm_kzalloc(&pdev->dev, sizeof(*glue), GFP_KERNEL);
        if (!glue)
                goto err0;

        musb = platform_device_alloc("musb-hdrc", PLATFORM_DEVID_AUTO);
        if (!musb) {
                dev_err(&pdev->dev, "failed to allocate musb device\n");
                goto err0;
        }

        clk = devm_clk_get(&pdev->dev, NULL);
        if (IS_ERR(clk)) {
                dev_err(&pdev->dev, "failed to get clock\n");
                ret = PTR_ERR(clk);
                goto err1;
        }

        ret = clk_prepare_enable(clk);
        if (ret) {
                dev_err(&pdev->dev, "failed to enable clock\n");
                goto err1;
        }

        musb->dev.parent                = &pdev->dev;
        musb->dev.dma_mask              = &pdev->dev.coherent_dma_mask;
        musb->dev.coherent_dma_mask     = pdev->dev.coherent_dma_mask;
        device_set_of_node_from_dev(&musb->dev, &pdev->dev);

        glue->dev                       = &pdev->dev;
        glue->musb                      = musb;
        glue->clk                       = clk;

        pdata->platform_ops             = &ux500_ops;
        pdata->config                   = &ux500_musb_hdrc_config;

        platform_set_drvdata(pdev, glue);

        ret = platform_device_add_resources(musb, pdev->resource, pdev->num_resources);
        if (ret) {
                dev_err(&pdev->dev, "failed to add resources\n");
                goto err2;
        }

        ret = platform_device_add_data(musb, pdata, sizeof(*pdata));
        if (ret) {
                dev_err(&pdev->dev, "failed to add platform_data\n");
                goto err2;
        }

        ret = platform_device_add(musb);
        if (ret) {
                dev_err(&pdev->dev, "failed to register musb device\n");
                goto err2;
        }

        return 0;

err2:
        clk_disable_unprepare(clk);

err1:
        platform_device_put(musb);

err0:
        return ret;
}

static void ux500_remove(struct platform_device *pdev)
{
        struct ux500_glue       *glue = platform_get_drvdata(pdev);

        platform_device_unregister(glue->musb);
        clk_disable_unprepare(glue->clk);
}

#ifdef CONFIG_PM_SLEEP
static int ux500_suspend(struct device *dev)
{
        struct ux500_glue       *glue = dev_get_drvdata(dev);
        struct musb             *musb = glue_to_musb(glue);

        if (musb)
                usb_phy_set_suspend(musb->xceiv, 1);

        clk_disable_unprepare(glue->clk);

        return 0;
}

static int ux500_resume(struct device *dev)
{
        struct ux500_glue       *glue = dev_get_drvdata(dev);
        struct musb             *musb = glue_to_musb(glue);
        int                     ret;

        ret = clk_prepare_enable(glue->clk);
        if (ret) {
                dev_err(dev, "failed to enable clock\n");
                return ret;
        }

        if (musb)
                usb_phy_set_suspend(musb->xceiv, 0);

        return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(ux500_pm_ops, ux500_suspend, ux500_resume);

static const struct of_device_id ux500_match[] = {
        { .compatible = "stericsson,db8500-musb", },
        {}
};

MODULE_DEVICE_TABLE(of, ux500_match);

static struct platform_driver ux500_driver = {
        .probe          = ux500_probe,
        .remove         = ux500_remove,
        .driver         = {
                .name   = "musb-ux500",
                .pm     = &ux500_pm_ops,
                .of_match_table = ux500_match,
        },
};

MODULE_DESCRIPTION("UX500 MUSB Glue Layer");
MODULE_AUTHOR("Mian Yousaf Kaukab <mian.yousaf.kaukab@stericsson.com>");
MODULE_LICENSE("GPL v2");
module_platform_driver(ux500_driver);