root/drivers/usb/musb/jz4740.c
// SPDX-License-Identifier: GPL-2.0+
/*
 * Ingenic JZ4740 "glue layer"
 *
 * Copyright (C) 2013, Apelete Seketeli <apelete@seketeli.net>
 */

#include <linux/clk.h>
#include <linux/dma-mapping.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
#include <linux/usb/role.h>
#include <linux/usb/usb_phy_generic.h>

#include "musb_core.h"

struct jz4740_glue {
        struct platform_device  *pdev;
        struct musb             *musb;
        struct clk              *clk;
        struct usb_role_switch  *role_sw;
};

static irqreturn_t jz4740_musb_interrupt(int irq, void *__hci)
{
        unsigned long   flags;
        irqreturn_t     retval = IRQ_NONE, retval_dma = IRQ_NONE;
        struct musb     *musb = __hci;

        if (IS_ENABLED(CONFIG_USB_INVENTRA_DMA) && musb->dma_controller)
                retval_dma = dma_controller_irq(irq, musb->dma_controller);

        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);

        /*
         * The controller is gadget only, the state of the host mode IRQ bits is
         * undefined. Mask them to make sure that the musb driver core will
         * never see them set
         */
        musb->int_usb &= MUSB_INTR_SUSPEND | MUSB_INTR_RESUME |
                         MUSB_INTR_RESET | MUSB_INTR_SOF;

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

        spin_unlock_irqrestore(&musb->lock, flags);

        if (retval == IRQ_HANDLED || retval_dma == IRQ_HANDLED)
                return IRQ_HANDLED;

        return IRQ_NONE;
}

static const struct musb_fifo_cfg jz4740_musb_fifo_cfg[] = {
        { .hw_ep_num = 1, .style = FIFO_TX, .maxpacket = 512, },
        { .hw_ep_num = 1, .style = FIFO_RX, .maxpacket = 512, },
        { .hw_ep_num = 2, .style = FIFO_TX, .maxpacket = 64, },
};

static const struct musb_hdrc_config jz4740_musb_config = {
        /* Silicon does not implement USB OTG. */
        .multipoint     = 0,
        /* Max EPs scanned, driver will decide which EP can be used. */
        .num_eps        = 4,
        /* RAMbits needed to configure EPs from table */
        .ram_bits       = 9,
        .fifo_cfg       = jz4740_musb_fifo_cfg,
        .fifo_cfg_size  = ARRAY_SIZE(jz4740_musb_fifo_cfg),
};

static int jz4740_musb_role_switch_set(struct usb_role_switch *sw,
                                       enum usb_role role)
{
        struct jz4740_glue *glue = usb_role_switch_get_drvdata(sw);
        struct usb_phy *phy = glue->musb->xceiv;

        if (!phy)
                return 0;

        switch (role) {
        case USB_ROLE_NONE:
                atomic_notifier_call_chain(&phy->notifier, USB_EVENT_NONE, phy);
                break;
        case USB_ROLE_DEVICE:
                atomic_notifier_call_chain(&phy->notifier, USB_EVENT_VBUS, phy);
                break;
        case USB_ROLE_HOST:
                atomic_notifier_call_chain(&phy->notifier, USB_EVENT_ID, phy);
                break;
        }

        return 0;
}

static int jz4740_musb_init(struct musb *musb)
{
        struct device *dev = musb->controller->parent;
        struct jz4740_glue *glue = dev_get_drvdata(dev);
        struct usb_role_switch_desc role_sw_desc = {
                .set = jz4740_musb_role_switch_set,
                .driver_data = glue,
                .fwnode = dev_fwnode(dev),
        };
        int err;

        glue->musb = musb;

        if (IS_ENABLED(CONFIG_GENERIC_PHY)) {
                musb->phy = devm_of_phy_get_by_index(dev, dev->of_node, 0);
                if (IS_ERR(musb->phy)) {
                        err = PTR_ERR(musb->phy);
                        if (err != -ENODEV) {
                                dev_err(dev, "Unable to get PHY\n");
                                return err;
                        }

                        musb->phy = NULL;
                }
        }

        if (musb->phy) {
                err = phy_init(musb->phy);
                if (err) {
                        dev_err(dev, "Failed to init PHY\n");
                        return err;
                }

                err = phy_power_on(musb->phy);
                if (err) {
                        dev_err(dev, "Unable to power on PHY\n");
                        goto err_phy_shutdown;
                }
        } else {
                if (dev->of_node)
                        musb->xceiv = devm_usb_get_phy_by_phandle(dev, "phys", 0);
                else
                        musb->xceiv = devm_usb_get_phy(dev, USB_PHY_TYPE_USB2);
                if (IS_ERR(musb->xceiv)) {
                        dev_err(dev, "No transceiver configured\n");
                        return PTR_ERR(musb->xceiv);
                }
        }

        glue->role_sw = usb_role_switch_register(dev, &role_sw_desc);
        if (IS_ERR(glue->role_sw)) {
                dev_err(dev, "Failed to register USB role switch\n");
                err = PTR_ERR(glue->role_sw);
                goto err_phy_power_down;
        }

        /*
         * Silicon does not implement ConfigData register.
         * Set dyn_fifo to avoid reading EP config from hardware.
         */
        musb->dyn_fifo = true;

        musb->isr = jz4740_musb_interrupt;

        return 0;

err_phy_power_down:
        if (musb->phy)
                phy_power_off(musb->phy);
err_phy_shutdown:
        if (musb->phy)
                phy_exit(musb->phy);
        return err;
}

static int jz4740_musb_exit(struct musb *musb)
{
        struct jz4740_glue *glue = dev_get_drvdata(musb->controller->parent);

        usb_role_switch_unregister(glue->role_sw);
        if (musb->phy) {
                phy_power_off(musb->phy);
                phy_exit(musb->phy);
        }

        return 0;
}

static const struct musb_platform_ops jz4740_musb_ops = {
        .quirks         = MUSB_DMA_INVENTRA | MUSB_INDEXED_EP,
        .fifo_mode      = 2,
        .init           = jz4740_musb_init,
        .exit           = jz4740_musb_exit,
#ifdef CONFIG_USB_INVENTRA_DMA
        .dma_init       = musbhs_dma_controller_create_noirq,
        .dma_exit       = musbhs_dma_controller_destroy,
#endif
};

static const struct musb_hdrc_platform_data jz4740_musb_pdata = {
        .mode           = MUSB_PERIPHERAL,
        .config         = &jz4740_musb_config,
        .platform_ops   = &jz4740_musb_ops,
};

static const struct musb_fifo_cfg jz4770_musb_fifo_cfg[] = {
        { .hw_ep_num = 1, .style = FIFO_TX, .maxpacket = 512, },
        { .hw_ep_num = 1, .style = FIFO_RX, .maxpacket = 512, },
        { .hw_ep_num = 2, .style = FIFO_TX, .maxpacket = 512, },
        { .hw_ep_num = 2, .style = FIFO_RX, .maxpacket = 512, },
        { .hw_ep_num = 3, .style = FIFO_TX, .maxpacket = 512, },
        { .hw_ep_num = 3, .style = FIFO_RX, .maxpacket = 512, },
        { .hw_ep_num = 4, .style = FIFO_TX, .maxpacket = 512, },
        { .hw_ep_num = 4, .style = FIFO_RX, .maxpacket = 512, },
        { .hw_ep_num = 5, .style = FIFO_TX, .maxpacket = 512, },
        { .hw_ep_num = 5, .style = FIFO_RX, .maxpacket = 512, },
};

static struct musb_hdrc_config jz4770_musb_config = {
        .multipoint     = 1,
        .num_eps        = 11,
        .ram_bits       = 11,
        .fifo_cfg       = jz4770_musb_fifo_cfg,
        .fifo_cfg_size  = ARRAY_SIZE(jz4770_musb_fifo_cfg),
};

static const struct musb_hdrc_platform_data jz4770_musb_pdata = {
        .mode           = MUSB_PERIPHERAL, /* TODO: support OTG */
        .config         = &jz4770_musb_config,
        .platform_ops   = &jz4740_musb_ops,
};

static int jz4740_probe(struct platform_device *pdev)
{
        struct device                   *dev = &pdev->dev;
        const struct musb_hdrc_platform_data *pdata;
        struct platform_device          *musb;
        struct jz4740_glue              *glue;
        struct clk                      *clk;
        int                             ret;

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

        pdata = of_device_get_match_data(dev);
        if (!pdata) {
                dev_err(dev, "missing platform data\n");
                return -EINVAL;
        }

        musb = platform_device_alloc("musb-hdrc", PLATFORM_DEVID_AUTO);
        if (!musb) {
                dev_err(dev, "failed to allocate musb device\n");
                return -ENOMEM;
        }

        clk = devm_clk_get(dev, "udc");
        if (IS_ERR(clk)) {
                dev_err(dev, "failed to get clock\n");
                ret = PTR_ERR(clk);
                goto err_platform_device_put;
        }

        ret = clk_prepare_enable(clk);
        if (ret) {
                dev_err(dev, "failed to enable clock\n");
                goto err_platform_device_put;
        }

        musb->dev.parent                = dev;
        musb->dev.dma_mask              = &musb->dev.coherent_dma_mask;
        musb->dev.coherent_dma_mask     = DMA_BIT_MASK(32);
        device_set_of_node_from_dev(&musb->dev, dev);

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

        platform_set_drvdata(pdev, glue);

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

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

        ret = platform_device_add(musb);
        if (ret) {
                dev_err(dev, "failed to register musb device\n");
                goto err_clk_disable;
        }

        return 0;

err_clk_disable:
        clk_disable_unprepare(clk);
err_platform_device_put:
        platform_device_put(musb);
        return ret;
}

static void jz4740_remove(struct platform_device *pdev)
{
        struct jz4740_glue *glue = platform_get_drvdata(pdev);

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

static const struct of_device_id jz4740_musb_of_match[] = {
        { .compatible = "ingenic,jz4740-musb", .data = &jz4740_musb_pdata },
        { .compatible = "ingenic,jz4770-musb", .data = &jz4770_musb_pdata },
        { /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, jz4740_musb_of_match);

static struct platform_driver jz4740_driver = {
        .probe          = jz4740_probe,
        .remove         = jz4740_remove,
        .driver         = {
                .name   = "musb-jz4740",
                .of_match_table = jz4740_musb_of_match,
        },
};

MODULE_DESCRIPTION("JZ4740 MUSB Glue Layer");
MODULE_AUTHOR("Apelete Seketeli <apelete@seketeli.net>");
MODULE_LICENSE("GPL v2");
module_platform_driver(jz4740_driver);