drivers/usb/host/xhci-omap.c

/*
 * OMAP USB HOST xHCI Controller
 *
 * (C) Copyright 2013
 * Texas Instruments, <www.ti.com>
 *
 * Author: Dan Murphy <dmurphy@ti.com>
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

#include <common.h>
#include <usb.h>
#include <asm-generic/errno.h>
#include <asm/omap_common.h>
#include <asm/arch/cpu.h>
#include <asm/arch/sys_proto.h>

#include <linux/compat.h>
#include <linux/usb/dwc3.h>
#include <linux/usb/xhci-omap.h>

#include "xhci.h"

/* Declare global data pointer */
DECLARE_GLOBAL_DATA_PTR;

static struct omap_xhci omap;

inline int __board_usb_init(int index, enum usb_init_type init)
{
	return 0;
}
int board_usb_init(int index, enum usb_init_type init)
	__attribute__((weak, alias("__board_usb_init")));

static void dwc3_set_mode(struct dwc3 *dwc3_reg, u32 mode)
{
	clrsetbits_le32(&dwc3_reg->g_ctl,
			DWC3_GCTL_PRTCAPDIR(DWC3_GCTL_PRTCAP_OTG),
			DWC3_GCTL_PRTCAPDIR(mode));
}

static void dwc3_core_soft_reset(struct dwc3 *dwc3_reg)
{
	/* Before Resetting PHY, put Core in Reset */
	setbits_le32(&dwc3_reg->g_ctl, DWC3_GCTL_CORESOFTRESET);

	omap_reset_usb_phy(dwc3_reg);

	/* After PHYs are stable we can take Core out of reset state */
	clrbits_le32(&dwc3_reg->g_ctl, DWC3_GCTL_CORESOFTRESET);
}

static int dwc3_core_init(struct dwc3 *dwc3_reg)
{
	u32 reg;
	u32 revision;
	unsigned int dwc3_hwparams1;

	revision = readl(&dwc3_reg->g_snpsid);
	/* This should read as U3 followed by revision number */
	if ((revision & DWC3_GSNPSID_MASK) != 0x55330000) {
		puts("this is not a DesignWare USB3 DRD Core\n");
		return -1;
	}

	dwc3_core_soft_reset(dwc3_reg);

	dwc3_hwparams1 = readl(&dwc3_reg->g_hwparams1);

	reg = readl(&dwc3_reg->g_ctl);
	reg &= ~DWC3_GCTL_SCALEDOWN_MASK;
	reg &= ~DWC3_GCTL_DISSCRAMBLE;
	switch (DWC3_GHWPARAMS1_EN_PWROPT(dwc3_hwparams1)) {
	case DWC3_GHWPARAMS1_EN_PWROPT_CLK:
		reg &= ~DWC3_GCTL_DSBLCLKGTNG;
		break;
	default:
		debug("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 ((revision & DWC3_REVISION_MASK) < 0x190a)
		reg |= DWC3_GCTL_U2RSTECN;

	writel(reg, &dwc3_reg->g_ctl);

	return 0;
}

static int omap_xhci_core_init(struct omap_xhci *omap)
{
	int ret = 0;

	omap_enable_phy(omap);

	ret = dwc3_core_init(omap->dwc3_reg);
	if (ret) {
		debug("%s:failed to initialize core\n", __func__);
		return ret;
	}

	/* We are hard-coding DWC3 core to Host Mode */
	dwc3_set_mode(omap->dwc3_reg, DWC3_GCTL_PRTCAP_HOST);

	return ret;
}

static void omap_xhci_core_exit(struct omap_xhci *omap)
{
	usb_phy_power(0);
}

int xhci_hcd_init(int index, struct xhci_hccr **hccr, struct xhci_hcor **hcor)
{
	struct omap_xhci *ctx = &omap;
	int ret = 0;

	ctx->hcd = (struct xhci_hccr *)OMAP_XHCI_BASE;
	ctx->dwc3_reg = (struct dwc3 *)((char *)(ctx->hcd) + DWC3_REG_OFFSET);
	ctx->usb3_phy = (struct omap_usb3_phy *)OMAP_OCP1_SCP_BASE;
	ctx->otg_wrapper = (struct omap_dwc_wrapper *)OMAP_OTG_WRAPPER_BASE;

	ret = board_usb_init(index, USB_INIT_HOST);
	if (ret != 0) {
		puts("Failed to initialize board for USB\n");
		return ret;
	}

	ret = omap_xhci_core_init(ctx);
	if (ret < 0) {
		puts("Failed to initialize xhci\n");
		return ret;
	}

	*hccr = (struct xhci_hccr *)(OMAP_XHCI_BASE);
	*hcor = (struct xhci_hcor *)((uint32_t) *hccr
				+ HC_LENGTH(xhci_readl(&(*hccr)->cr_capbase)));

	debug("omap-xhci: init hccr %x and hcor %x hc_length %d\n",
	      (uint32_t)*hccr, (uint32_t)*hcor,
	      (uint32_t)HC_LENGTH(xhci_readl(&(*hccr)->cr_capbase)));

	return ret;
}

void xhci_hcd_stop(int index)
{
	struct omap_xhci *ctx = &omap;

	omap_xhci_core_exit(ctx);
}