/**
 * dwc3-omap.c - OMAP Specific Glue layer
 *
 * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com
 *
 * Authors: Felipe Balbi <balbi@ti.com>,
 *	    Sebastian Andrzej Siewior <bigeasy@linutronix.de>
 *
 * Taken from Linux Kernel v3.19-rc1 (drivers/usb/dwc3/dwc3-omap.c) and ported
 * to uboot.
 *
 * commit 7ee2566ff5 : usb: dwc3: dwc3-omap: get rid of ->prepare()/->complete()
 *
 * SPDX-License-Identifier:     GPL-2.0
 */

#include <common.h>
#include <malloc.h>
#include <asm/io.h>
#include <dwc3-omap-uboot.h>
#include <linux/usb/dwc3-omap.h>
#include <linux/ioport.h>

#include <linux/usb/otg.h>
#include <linux/compat.h>

#include "linux-compat.h"

/*
 * All these registers belong to OMAP's Wrapper around the
 * DesignWare USB3 Core.
 */

#define USBOTGSS_REVISION			0x0000
#define USBOTGSS_SYSCONFIG			0x0010
#define USBOTGSS_IRQ_EOI			0x0020
#define USBOTGSS_EOI_OFFSET			0x0008
#define USBOTGSS_IRQSTATUS_RAW_0		0x0024
#define USBOTGSS_IRQSTATUS_0			0x0028
#define USBOTGSS_IRQENABLE_SET_0		0x002c
#define USBOTGSS_IRQENABLE_CLR_0		0x0030
#define USBOTGSS_IRQ0_OFFSET			0x0004
#define USBOTGSS_IRQSTATUS_RAW_1		0x0030
#define USBOTGSS_IRQSTATUS_1			0x0034
#define USBOTGSS_IRQENABLE_SET_1		0x0038
#define USBOTGSS_IRQENABLE_CLR_1		0x003c
#define USBOTGSS_IRQSTATUS_RAW_2		0x0040
#define USBOTGSS_IRQSTATUS_2			0x0044
#define USBOTGSS_IRQENABLE_SET_2		0x0048
#define USBOTGSS_IRQENABLE_CLR_2		0x004c
#define USBOTGSS_IRQSTATUS_RAW_3		0x0050
#define USBOTGSS_IRQSTATUS_3			0x0054
#define USBOTGSS_IRQENABLE_SET_3		0x0058
#define USBOTGSS_IRQENABLE_CLR_3		0x005c
#define USBOTGSS_IRQSTATUS_EOI_MISC		0x0030
#define USBOTGSS_IRQSTATUS_RAW_MISC		0x0034
#define USBOTGSS_IRQSTATUS_MISC			0x0038
#define USBOTGSS_IRQENABLE_SET_MISC		0x003c
#define USBOTGSS_IRQENABLE_CLR_MISC		0x0040
#define USBOTGSS_IRQMISC_OFFSET			0x03fc
#define USBOTGSS_UTMI_OTG_CTRL			0x0080
#define USBOTGSS_UTMI_OTG_STATUS		0x0084
#define USBOTGSS_UTMI_OTG_OFFSET		0x0480
#define USBOTGSS_TXFIFO_DEPTH			0x0508
#define USBOTGSS_RXFIFO_DEPTH			0x050c
#define USBOTGSS_MMRAM_OFFSET			0x0100
#define USBOTGSS_FLADJ				0x0104
#define USBOTGSS_DEBUG_CFG			0x0108
#define USBOTGSS_DEBUG_DATA			0x010c
#define USBOTGSS_DEV_EBC_EN			0x0110
#define USBOTGSS_DEBUG_OFFSET			0x0600

/* SYSCONFIG REGISTER */
#define USBOTGSS_SYSCONFIG_DMADISABLE		(1 << 16)

/* IRQ_EOI REGISTER */
#define USBOTGSS_IRQ_EOI_LINE_NUMBER		(1 << 0)

/* IRQS0 BITS */
#define USBOTGSS_IRQO_COREIRQ_ST		(1 << 0)

/* IRQMISC BITS */
#define USBOTGSS_IRQMISC_DMADISABLECLR		(1 << 17)
#define USBOTGSS_IRQMISC_OEVT			(1 << 16)
#define USBOTGSS_IRQMISC_DRVVBUS_RISE		(1 << 13)
#define USBOTGSS_IRQMISC_CHRGVBUS_RISE		(1 << 12)
#define USBOTGSS_IRQMISC_DISCHRGVBUS_RISE	(1 << 11)
#define USBOTGSS_IRQMISC_IDPULLUP_RISE		(1 << 8)
#define USBOTGSS_IRQMISC_DRVVBUS_FALL		(1 << 5)
#define USBOTGSS_IRQMISC_CHRGVBUS_FALL		(1 << 4)
#define USBOTGSS_IRQMISC_DISCHRGVBUS_FALL		(1 << 3)
#define USBOTGSS_IRQMISC_IDPULLUP_FALL		(1 << 0)

#define USBOTGSS_INTERRUPTS (USBOTGSS_IRQMISC_OEVT | \
			     USBOTGSS_IRQMISC_DRVVBUS_RISE | \
			     USBOTGSS_IRQMISC_CHRGVBUS_RISE | \
			     USBOTGSS_IRQMISC_DISCHRGVBUS_RISE | \
			     USBOTGSS_IRQMISC_IDPULLUP_RISE | \
			     USBOTGSS_IRQMISC_DRVVBUS_FALL | \
			     USBOTGSS_IRQMISC_CHRGVBUS_FALL | \
			     USBOTGSS_IRQMISC_DISCHRGVBUS_FALL | \
			     USBOTGSS_IRQMISC_IDPULLUP_FALL)

/* UTMI_OTG_CTRL REGISTER */
#define USBOTGSS_UTMI_OTG_CTRL_DRVVBUS		(1 << 5)
#define USBOTGSS_UTMI_OTG_CTRL_CHRGVBUS		(1 << 4)
#define USBOTGSS_UTMI_OTG_CTRL_DISCHRGVBUS	(1 << 3)
#define USBOTGSS_UTMI_OTG_CTRL_IDPULLUP		(1 << 0)

/* UTMI_OTG_STATUS REGISTER */
#define USBOTGSS_UTMI_OTG_STATUS_SW_MODE	(1 << 31)
#define USBOTGSS_UTMI_OTG_STATUS_POWERPRESENT	(1 << 9)
#define USBOTGSS_UTMI_OTG_STATUS_TXBITSTUFFENABLE (1 << 8)
#define USBOTGSS_UTMI_OTG_STATUS_IDDIG		(1 << 4)
#define USBOTGSS_UTMI_OTG_STATUS_SESSEND	(1 << 3)
#define USBOTGSS_UTMI_OTG_STATUS_SESSVALID	(1 << 2)
#define USBOTGSS_UTMI_OTG_STATUS_VBUSVALID	(1 << 1)

struct dwc3_omap {
	struct device		*dev;

	void __iomem		*base;

	u32			utmi_otg_status;
	u32			utmi_otg_offset;
	u32			irqmisc_offset;
	u32			irq_eoi_offset;
	u32			debug_offset;
	u32			irq0_offset;

	u32			dma_status:1;
	struct list_head	list;
	u32			index;
};

static LIST_HEAD(dwc3_omap_list);

static inline u32 dwc3_omap_readl(void __iomem *base, u32 offset)
{
	return readl(base + offset);
}

static inline void dwc3_omap_writel(void __iomem *base, u32 offset, u32 value)
{
	writel(value, base + offset);
}

static u32 dwc3_omap_read_utmi_status(struct dwc3_omap *omap)
{
	return dwc3_omap_readl(omap->base, USBOTGSS_UTMI_OTG_STATUS +
							omap->utmi_otg_offset);
}

static void dwc3_omap_write_utmi_status(struct dwc3_omap *omap, u32 value)
{
	dwc3_omap_writel(omap->base, USBOTGSS_UTMI_OTG_STATUS +
					omap->utmi_otg_offset, value);

}

static u32 dwc3_omap_read_irq0_status(struct dwc3_omap *omap)
{
	return dwc3_omap_readl(omap->base, USBOTGSS_IRQSTATUS_0 -
						omap->irq0_offset);
}

static void dwc3_omap_write_irq0_status(struct dwc3_omap *omap, u32 value)
{
	dwc3_omap_writel(omap->base, USBOTGSS_IRQSTATUS_0 -
						omap->irq0_offset, value);

}

static u32 dwc3_omap_read_irqmisc_status(struct dwc3_omap *omap)
{
	return dwc3_omap_readl(omap->base, USBOTGSS_IRQSTATUS_MISC +
						omap->irqmisc_offset);
}

static void dwc3_omap_write_irqmisc_status(struct dwc3_omap *omap, u32 value)
{
	dwc3_omap_writel(omap->base, USBOTGSS_IRQSTATUS_MISC +
					omap->irqmisc_offset, value);

}

static void dwc3_omap_write_irqmisc_set(struct dwc3_omap *omap, u32 value)
{
	dwc3_omap_writel(omap->base, USBOTGSS_IRQENABLE_SET_MISC +
						omap->irqmisc_offset, value);

}

static void dwc3_omap_write_irq0_set(struct dwc3_omap *omap, u32 value)
{
	dwc3_omap_writel(omap->base, USBOTGSS_IRQENABLE_SET_0 -
						omap->irq0_offset, value);
}

static void dwc3_omap_write_irqmisc_clr(struct dwc3_omap *omap, u32 value)
{
	dwc3_omap_writel(omap->base, USBOTGSS_IRQENABLE_CLR_MISC +
						omap->irqmisc_offset, value);
}

static void dwc3_omap_write_irq0_clr(struct dwc3_omap *omap, u32 value)
{
	dwc3_omap_writel(omap->base, USBOTGSS_IRQENABLE_CLR_0 -
						omap->irq0_offset, value);
}

static void dwc3_omap_set_mailbox(struct dwc3_omap *omap,
	enum omap_dwc3_vbus_id_status status)
{
	u32	val;

	switch (status) {
	case OMAP_DWC3_ID_GROUND:
		dev_dbg(omap->dev, "ID GND\n");

		val = dwc3_omap_read_utmi_status(omap);
		val &= ~(USBOTGSS_UTMI_OTG_STATUS_IDDIG
				| USBOTGSS_UTMI_OTG_STATUS_VBUSVALID
				| USBOTGSS_UTMI_OTG_STATUS_SESSEND);
		val |= USBOTGSS_UTMI_OTG_STATUS_SESSVALID
				| USBOTGSS_UTMI_OTG_STATUS_POWERPRESENT;
		dwc3_omap_write_utmi_status(omap, val);
		break;

	case OMAP_DWC3_VBUS_VALID:
		dev_dbg(omap->dev, "VBUS Connect\n");

		val = dwc3_omap_read_utmi_status(omap);
		val &= ~USBOTGSS_UTMI_OTG_STATUS_SESSEND;
		val |= USBOTGSS_UTMI_OTG_STATUS_IDDIG
				| USBOTGSS_UTMI_OTG_STATUS_VBUSVALID
				| USBOTGSS_UTMI_OTG_STATUS_SESSVALID
				| USBOTGSS_UTMI_OTG_STATUS_POWERPRESENT;
		dwc3_omap_write_utmi_status(omap, val);
		break;

	case OMAP_DWC3_ID_FLOAT:
	case OMAP_DWC3_VBUS_OFF:
		dev_dbg(omap->dev, "VBUS Disconnect\n");

		val = dwc3_omap_read_utmi_status(omap);
		val &= ~(USBOTGSS_UTMI_OTG_STATUS_SESSVALID
				| USBOTGSS_UTMI_OTG_STATUS_VBUSVALID
				| USBOTGSS_UTMI_OTG_STATUS_POWERPRESENT);
		val |= USBOTGSS_UTMI_OTG_STATUS_SESSEND
				| USBOTGSS_UTMI_OTG_STATUS_IDDIG;
		dwc3_omap_write_utmi_status(omap, val);
		break;

	default:
		dev_dbg(omap->dev, "invalid state\n");
	}
}

static irqreturn_t dwc3_omap_interrupt(int irq, void *_omap)
{
	struct dwc3_omap	*omap = _omap;
	u32			reg;

	reg = dwc3_omap_read_irqmisc_status(omap);

	if (reg & USBOTGSS_IRQMISC_DMADISABLECLR) {
		dev_dbg(omap->dev, "DMA Disable was Cleared\n");
		omap->dma_status = false;
	}

	if (reg & USBOTGSS_IRQMISC_OEVT)
		dev_dbg(omap->dev, "OTG Event\n");

	if (reg & USBOTGSS_IRQMISC_DRVVBUS_RISE)
		dev_dbg(omap->dev, "DRVVBUS Rise\n");

	if (reg & USBOTGSS_IRQMISC_CHRGVBUS_RISE)
		dev_dbg(omap->dev, "CHRGVBUS Rise\n");

	if (reg & USBOTGSS_IRQMISC_DISCHRGVBUS_RISE)
		dev_dbg(omap->dev, "DISCHRGVBUS Rise\n");

	if (reg & USBOTGSS_IRQMISC_IDPULLUP_RISE)
		dev_dbg(omap->dev, "IDPULLUP Rise\n");

	if (reg & USBOTGSS_IRQMISC_DRVVBUS_FALL)
		dev_dbg(omap->dev, "DRVVBUS Fall\n");

	if (reg & USBOTGSS_IRQMISC_CHRGVBUS_FALL)
		dev_dbg(omap->dev, "CHRGVBUS Fall\n");

	if (reg & USBOTGSS_IRQMISC_DISCHRGVBUS_FALL)
		dev_dbg(omap->dev, "DISCHRGVBUS Fall\n");

	if (reg & USBOTGSS_IRQMISC_IDPULLUP_FALL)
		dev_dbg(omap->dev, "IDPULLUP Fall\n");

	dwc3_omap_write_irqmisc_status(omap, reg);

	reg = dwc3_omap_read_irq0_status(omap);

	dwc3_omap_write_irq0_status(omap, reg);

	return IRQ_HANDLED;
}

static void dwc3_omap_enable_irqs(struct dwc3_omap *omap)
{
	/* enable all IRQs */
	dwc3_omap_write_irq0_set(omap, USBOTGSS_IRQO_COREIRQ_ST);

	dwc3_omap_write_irqmisc_set(omap, USBOTGSS_INTERRUPTS);
}

static void dwc3_omap_disable_irqs(struct dwc3_omap *omap)
{
	/* disable all IRQs */
	dwc3_omap_write_irq0_clr(omap, USBOTGSS_IRQO_COREIRQ_ST);

	dwc3_omap_write_irqmisc_clr(omap, USBOTGSS_INTERRUPTS);
}

static void dwc3_omap_map_offset(struct dwc3_omap *omap)
{
	/*
	 * Differentiate between OMAP5 and AM437x.
	 *
	 * For OMAP5(ES2.0) and AM437x wrapper revision is same, even
	 * though there are changes in wrapper register offsets.
	 *
	 * Using dt compatible to differentiate AM437x.
	 */
#ifdef CONFIG_AM43XX
	omap->irq_eoi_offset = USBOTGSS_EOI_OFFSET;
	omap->irq0_offset = USBOTGSS_IRQ0_OFFSET;
	omap->irqmisc_offset = USBOTGSS_IRQMISC_OFFSET;
	omap->utmi_otg_offset = USBOTGSS_UTMI_OTG_OFFSET;
	omap->debug_offset = USBOTGSS_DEBUG_OFFSET;
#endif
}

static void dwc3_omap_set_utmi_mode(struct dwc3_omap *omap, int utmi_mode)
{
	u32			reg;

	reg = dwc3_omap_read_utmi_status(omap);

	switch (utmi_mode) {
	case DWC3_OMAP_UTMI_MODE_SW:
		reg |= USBOTGSS_UTMI_OTG_STATUS_SW_MODE;
		break;
	case DWC3_OMAP_UTMI_MODE_HW:
		reg &= ~USBOTGSS_UTMI_OTG_STATUS_SW_MODE;
		break;
	default:
		dev_dbg(omap->dev, "UNKNOWN utmi mode %d\n", utmi_mode);
	}

	dwc3_omap_write_utmi_status(omap, reg);
}

/**
 * dwc3_omap_uboot_init - dwc3 omap uboot initialization code
 * @dev: struct dwc3_omap_device containing initialization data
 *
 * Entry point for dwc3 omap driver (equivalent to dwc3_omap_probe in linux
 * kernel driver). Pointer to dwc3_omap_device should be passed containing
 * base address and other initialization data. Returns '0' on success and
 * a negative value on failure.
 *
 * Generally called from board_usb_init() implemented in board file.
 */
int dwc3_omap_uboot_init(struct dwc3_omap_device *omap_dev)
{
	u32			reg;
	struct device		*dev = NULL;
	struct dwc3_omap	*omap;

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

	omap->base	= omap_dev->base;
	omap->index	= omap_dev->index;

	dwc3_omap_map_offset(omap);
	dwc3_omap_set_utmi_mode(omap, omap_dev->utmi_mode);

	/* check the DMA Status */
	reg = dwc3_omap_readl(omap->base, USBOTGSS_SYSCONFIG);
	omap->dma_status = !!(reg & USBOTGSS_SYSCONFIG_DMADISABLE);

	dwc3_omap_set_mailbox(omap, omap_dev->vbus_id_status);

	dwc3_omap_enable_irqs(omap);
	list_add_tail(&omap->list, &dwc3_omap_list);

	return 0;
}

/**
 * dwc3_omap_uboot_exit - dwc3 omap uboot cleanup code
 * @index: index of this controller
 *
 * Performs cleanup of memory allocated in dwc3_omap_uboot_init
 * (equivalent to dwc3_omap_remove in linux). index of _this_ controller
 * should be passed and should match with the index passed in
 * dwc3_omap_device during init.
 *
 * Generally called from board file.
 */
void dwc3_omap_uboot_exit(int index)
{
	struct dwc3_omap *omap = NULL;

	list_for_each_entry(omap, &dwc3_omap_list, list) {
		if (omap->index != index)
			continue;

		dwc3_omap_disable_irqs(omap);
		list_del(&omap->list);
		kfree(omap);
		break;
	}
}

/**
 * dwc3_omap_uboot_interrupt_status - check the status of interrupt
 * @index: index of this controller
 *
 * Checks the status of interrupts and returns true if an interrupt
 * is detected or false otherwise.
 *
 * Generally called from board file.
 */
int dwc3_omap_uboot_interrupt_status(int index)
{
	struct dwc3_omap *omap = NULL;

	list_for_each_entry(omap, &dwc3_omap_list, list)
		if (omap->index == index)
			return dwc3_omap_interrupt(-1, omap);

	return 0;
}

MODULE_ALIAS("platform:omap-dwc3");
MODULE_AUTHOR("Felipe Balbi <balbi@ti.com>");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("DesignWare USB3 OMAP Glue Layer");