/*
 * Driver for the NXP ISP1760 chip
 *
 * Copyright 2014 Laurent Pinchart
 * Copyright 2007 Sebastian Siewior
 *
 * Contacts:
 *      Sebastian Siewior <bigeasy@linutronix.de>
 *      Laurent Pinchart <laurent.pinchart@ideasonboard.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 */

#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/usb.h>

#include "isp1760-core.h"
#include "isp1760-hcd.h"
#include "isp1760-regs.h"
#include "isp1760-udc.h"

static void isp1760_init_core(struct isp1760_device *isp)
{
        u32 otgctrl;
        u32 hwmode;

        /* Low-level chip reset */
        if (isp->rst_gpio) {
                gpiod_set_value_cansleep(isp->rst_gpio, 1);
                mdelay(50);
                gpiod_set_value_cansleep(isp->rst_gpio, 0);
        }

        /*
         * Reset the host controller, including the CPU interface
         * configuration.
         */
        isp1760_write32(isp->regs, HC_RESET_REG, SW_RESET_RESET_ALL);
        msleep(100);

        /* Setup HW Mode Control: This assumes a level active-low interrupt */
        hwmode = HW_DATA_BUS_32BIT;

        if (isp->devflags & ISP1760_FLAG_BUS_WIDTH_16)
                hwmode &= ~HW_DATA_BUS_32BIT;
        if (isp->devflags & ISP1760_FLAG_ANALOG_OC)
                hwmode |= HW_ANA_DIGI_OC;
        if (isp->devflags & ISP1760_FLAG_DACK_POL_HIGH)
                hwmode |= HW_DACK_POL_HIGH;
        if (isp->devflags & ISP1760_FLAG_DREQ_POL_HIGH)
                hwmode |= HW_DREQ_POL_HIGH;
        if (isp->devflags & ISP1760_FLAG_INTR_POL_HIGH)
                hwmode |= HW_INTR_HIGH_ACT;
        if (isp->devflags & ISP1760_FLAG_INTR_EDGE_TRIG)
                hwmode |= HW_INTR_EDGE_TRIG;

        /*
         * The ISP1761 has a dedicated DC IRQ line but supports sharing the HC
         * IRQ line for both the host and device controllers. Hardcode IRQ
         * sharing for now and disable the DC interrupts globally to avoid
         * spurious interrupts during HCD registration.
         */
        if (isp->devflags & ISP1760_FLAG_ISP1761) {
                isp1760_write32(isp->regs, DC_MODE, 0);
                hwmode |= HW_COMN_IRQ;
        }

        /*
         * We have to set this first in case we're in 16-bit mode.
         * Write it twice to ensure correct upper bits if switching
         * to 16-bit mode.
         */
        isp1760_write32(isp->regs, HC_HW_MODE_CTRL, hwmode);
        isp1760_write32(isp->regs, HC_HW_MODE_CTRL, hwmode);

        /*
         * PORT 1 Control register of the ISP1760 is the OTG control register
         * on ISP1761.
         *
         * TODO: Really support OTG. For now we configure port 1 in device mode
         * when OTG is requested.
         */
        if ((isp->devflags & ISP1760_FLAG_ISP1761) &&
            (isp->devflags & ISP1760_FLAG_OTG_EN))
                otgctrl = ((HW_DM_PULLDOWN | HW_DP_PULLDOWN) << 16)
                        | HW_OTG_DISABLE;
        else
                otgctrl = (HW_SW_SEL_HC_DC << 16)
                        | (HW_VBUS_DRV | HW_SEL_CP_EXT);

        isp1760_write32(isp->regs, HC_PORT1_CTRL, otgctrl);

        dev_info(isp->dev, "bus width: %u, oc: %s\n",
                 isp->devflags & ISP1760_FLAG_BUS_WIDTH_16 ? 16 : 32,
                 isp->devflags & ISP1760_FLAG_ANALOG_OC ? "analog" : "digital");
}

void isp1760_set_pullup(struct isp1760_device *isp, bool enable)
{
        isp1760_write32(isp->regs, HW_OTG_CTRL_SET,
                        enable ? HW_DP_PULLUP : HW_DP_PULLUP << 16);
}

int isp1760_register(struct resource *mem, int irq, unsigned long irqflags,
                     struct device *dev, unsigned int devflags)
{
        struct isp1760_device *isp;
        bool udc_disabled = !(devflags & ISP1760_FLAG_ISP1761);
        int ret;

        /*
         * If neither the HCD not the UDC is enabled return an error, as no
         * device would be registered.
         */
        if ((!IS_ENABLED(CONFIG_USB_ISP1760_HCD) || usb_disabled()) &&
            (!IS_ENABLED(CONFIG_USB_ISP1761_UDC) || udc_disabled))
                return -ENODEV;

        /* prevent usb-core allocating DMA pages */
        dev->dma_mask = NULL;

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

        isp->dev = dev;
        isp->devflags = devflags;

        isp->rst_gpio = devm_gpiod_get_optional(dev, NULL, GPIOD_OUT_HIGH);
        if (IS_ERR(isp->rst_gpio))
                return PTR_ERR(isp->rst_gpio);

        isp->regs = devm_ioremap_resource(dev, mem);
        if (IS_ERR(isp->regs))
                return PTR_ERR(isp->regs);

        isp1760_init_core(isp);

        if (IS_ENABLED(CONFIG_USB_ISP1760_HCD) && !usb_disabled()) {
                ret = isp1760_hcd_register(&isp->hcd, isp->regs, mem, irq,
                                           irqflags | IRQF_SHARED, dev);
                if (ret < 0)
                        return ret;
        }

        if (IS_ENABLED(CONFIG_USB_ISP1761_UDC) && !udc_disabled) {
                ret = isp1760_udc_register(isp, irq, irqflags);
                if (ret < 0) {
                        isp1760_hcd_unregister(&isp->hcd);
                        return ret;
                }
        }

        dev_set_drvdata(dev, isp);

        return 0;
}

void isp1760_unregister(struct device *dev)
{
        struct isp1760_device *isp = dev_get_drvdata(dev);

        isp1760_udc_unregister(isp);
        isp1760_hcd_unregister(&isp->hcd);
}

MODULE_DESCRIPTION("Driver for the ISP1760 USB-controller from NXP");
MODULE_AUTHOR("Sebastian Siewior <bigeasy@linuxtronix.de>");
MODULE_LICENSE("GPL v2");