USB: XHCI: Add xHCI host controller support for Exynos5

This adds driver layer for xHCI controller in Samsung's
exynos5 soc. This interacts with xHCI host controller stack.

Signed-off-by: Vikas C Sajjan <vikas.sajjan@samsung.com>
Signed-off-by: Vivek Gautam <gautam.vivek@samsung.com>
Cc: Julius Werner <jwerner@chromium.org>
Cc: Simon Glass <sjg@chromium.org>
Cc: Minkyu Kang <mk7.kang@samsung.com>
Cc: Dan Murphy <dmurphy@ti.com>
Cc: Marek Vasut <marex@denx.de>
diff --git a/drivers/usb/host/xhci-exynos5.c b/drivers/usb/host/xhci-exynos5.c
new file mode 100644
index 0000000..eb0ef6c
--- /dev/null
+++ b/drivers/usb/host/xhci-exynos5.c
@@ -0,0 +1,316 @@
+/*
+ * SAMSUNG EXYNOS5 USB HOST XHCI Controller
+ *
+ * Copyright (C) 2012 Samsung Electronics Co.Ltd
+ *	Vivek Gautam <gautam.vivek@samsung.com>
+ *	Vikas Sajjan <vikas.sajjan@samsung.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+/*
+ * This file is a conglomeration for DWC3-init sequence and further
+ * exynos5 specific PHY-init sequence.
+ */
+
+#include <common.h>
+#include <fdtdec.h>
+#include <libfdt.h>
+#include <malloc.h>
+#include <usb.h>
+#include <watchdog.h>
+#include <asm/arch/cpu.h>
+#include <asm/arch/power.h>
+#include <asm/arch/xhci-exynos.h>
+#include <asm-generic/errno.h>
+#include <linux/compat.h>
+#include <linux/usb/dwc3.h>
+
+#include "xhci.h"
+
+/* Declare global data pointer */
+DECLARE_GLOBAL_DATA_PTR;
+
+/**
+ * Contains pointers to register base addresses
+ * for the usb controller.
+ */
+struct exynos_xhci {
+	struct exynos_usb3_phy *usb3_phy;
+	struct xhci_hccr *hcd;
+	struct dwc3 *dwc3_reg;
+};
+
+static struct exynos_xhci exynos;
+
+#ifdef CONFIG_OF_CONTROL
+static int exynos_usb3_parse_dt(const void *blob, struct exynos_xhci *exynos)
+{
+	fdt_addr_t addr;
+	unsigned int node;
+	int depth;
+
+	node = fdtdec_next_compatible(blob, 0, COMPAT_SAMSUNG_EXYNOS5_XHCI);
+	if (node <= 0) {
+		debug("XHCI: Can't get device node for xhci\n");
+		return -ENODEV;
+	}
+
+	/*
+	 * Get the base address for XHCI controller from the device node
+	 */
+	addr = fdtdec_get_addr(blob, node, "reg");
+	if (addr == FDT_ADDR_T_NONE) {
+		debug("Can't get the XHCI register base address\n");
+		return -ENXIO;
+	}
+	exynos->hcd = (struct xhci_hccr *)addr;
+
+	depth = 0;
+	node = fdtdec_next_compatible_subnode(blob, node,
+				COMPAT_SAMSUNG_EXYNOS5_USB3_PHY, &depth);
+	if (node <= 0) {
+		debug("XHCI: Can't get device node for usb3-phy controller\n");
+		return -ENODEV;
+	}
+
+	/*
+	 * Get the base address for usbphy from the device node
+	 */
+	exynos->usb3_phy = (struct exynos_usb3_phy *)fdtdec_get_addr(blob, node,
+								"reg");
+	if (exynos->usb3_phy == NULL) {
+		debug("Can't get the usbphy register address\n");
+		return -ENXIO;
+	}
+
+	return 0;
+}
+#endif
+
+static void exynos5_usb3_phy_init(struct exynos_usb3_phy *phy)
+{
+	u32 reg;
+
+	/* enabling usb_drd phy */
+	set_usbdrd_phy_ctrl(POWER_USB_DRD_PHY_CTRL_EN);
+
+	/* Reset USB 3.0 PHY */
+	writel(0x0, &phy->phy_reg0);
+
+	clrbits_le32(&phy->phy_param0,
+			/* Select PHY CLK source */
+			PHYPARAM0_REF_USE_PAD |
+			/* Set Loss-of-Signal Detector sensitivity */
+			PHYPARAM0_REF_LOSLEVEL_MASK);
+	setbits_le32(&phy->phy_param0, PHYPARAM0_REF_LOSLEVEL);
+
+	writel(0x0, &phy->phy_resume);
+
+	/*
+	 * Setting the Frame length Adj value[6:1] to default 0x20
+	 * See xHCI 1.0 spec, 5.2.4
+	 */
+	setbits_le32(&phy->link_system,
+			LINKSYSTEM_XHCI_VERSION_CONTROL |
+			LINKSYSTEM_FLADJ(0x20));
+
+	/* Set Tx De-Emphasis level */
+	clrbits_le32(&phy->phy_param1, PHYPARAM1_PCS_TXDEEMPH_MASK);
+	setbits_le32(&phy->phy_param1, PHYPARAM1_PCS_TXDEEMPH);
+
+	setbits_le32(&phy->phy_batchg, PHYBATCHG_UTMI_CLKSEL);
+
+	/* PHYTEST POWERDOWN Control */
+	clrbits_le32(&phy->phy_test,
+			PHYTEST_POWERDOWN_SSP |
+			PHYTEST_POWERDOWN_HSP);
+
+	/* UTMI Power Control */
+	writel(PHYUTMI_OTGDISABLE, &phy->phy_utmi);
+
+		/* Use core clock from main PLL */
+	reg = PHYCLKRST_REFCLKSEL_EXT_REFCLK |
+		/* Default 24Mhz crystal clock */
+		PHYCLKRST_FSEL(FSEL_CLKSEL_24M) |
+		PHYCLKRST_MPLL_MULTIPLIER_24MHZ_REF |
+		PHYCLKRST_SSC_REFCLKSEL(0x88) |
+		/* Force PortReset of PHY */
+		PHYCLKRST_PORTRESET |
+		/* Digital power supply in normal operating mode */
+		PHYCLKRST_RETENABLEN |
+		/* Enable ref clock for SS function */
+		PHYCLKRST_REF_SSP_EN |
+		/* Enable spread spectrum */
+		PHYCLKRST_SSC_EN |
+		/* Power down HS Bias and PLL blocks in suspend mode */
+		PHYCLKRST_COMMONONN;
+
+	writel(reg, &phy->phy_clk_rst);
+
+	/* giving time to Phy clock to settle before resetting */
+	udelay(10);
+
+	reg &= ~PHYCLKRST_PORTRESET;
+	writel(reg, &phy->phy_clk_rst);
+}
+
+static void exynos5_usb3_phy_exit(struct exynos_usb3_phy *phy)
+{
+	setbits_le32(&phy->phy_utmi,
+			PHYUTMI_OTGDISABLE |
+			PHYUTMI_FORCESUSPEND |
+			PHYUTMI_FORCESLEEP);
+
+	clrbits_le32(&phy->phy_clk_rst,
+			PHYCLKRST_REF_SSP_EN |
+			PHYCLKRST_SSC_EN |
+			PHYCLKRST_COMMONONN);
+
+	/* PHYTEST POWERDOWN Control to remove leakage current */
+	setbits_le32(&phy->phy_test,
+			PHYTEST_POWERDOWN_SSP |
+			PHYTEST_POWERDOWN_HSP);
+
+	/* disabling usb_drd phy */
+	set_usbdrd_phy_ctrl(POWER_USB_DRD_PHY_CTRL_DISABLE);
+}
+
+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);
+
+	/* Assert USB3 PHY reset */
+	setbits_le32(&dwc3_reg->g_usb3pipectl[0],
+			DWC3_GUSB3PIPECTL_PHYSOFTRST);
+
+	/* Assert USB2 PHY reset */
+	setbits_le32(&dwc3_reg->g_usb2phycfg,
+			DWC3_GUSB2PHYCFG_PHYSOFTRST);
+
+	mdelay(100);
+
+	/* Clear USB3 PHY reset */
+	clrbits_le32(&dwc3_reg->g_usb3pipectl[0],
+			DWC3_GUSB3PIPECTL_PHYSOFTRST);
+
+	/* Clear USB2 PHY reset */
+	clrbits_le32(&dwc3_reg->g_usb2phycfg,
+			DWC3_GUSB2PHYCFG_PHYSOFTRST);
+
+	/* 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 -EINVAL;
+	}
+
+	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 exynos_xhci_core_init(struct exynos_xhci *exynos)
+{
+	int ret;
+
+	exynos5_usb3_phy_init(exynos->usb3_phy);
+
+	ret = dwc3_core_init(exynos->dwc3_reg);
+	if (ret) {
+		debug("failed to initialize core\n");
+		return -EINVAL;
+	}
+
+	/* We are hard-coding DWC3 core to Host Mode */
+	dwc3_set_mode(exynos->dwc3_reg, DWC3_GCTL_PRTCAP_HOST);
+
+	return 0;
+}
+
+static void exynos_xhci_core_exit(struct exynos_xhci *exynos)
+{
+	exynos5_usb3_phy_exit(exynos->usb3_phy);
+}
+
+int xhci_hcd_init(int index, struct xhci_hccr **hccr, struct xhci_hcor **hcor)
+{
+	struct exynos_xhci *ctx = &exynos;
+	int ret;
+
+#ifdef CONFIG_OF_CONTROL
+	exynos_usb3_parse_dt(gd->fdt_blob, ctx);
+#else
+	ctx->usb3_phy = (struct exynos_usb3_phy *)samsung_get_base_usb3_phy();
+	ctx->hcd = (struct xhci_hccr *)samsung_get_base_usb_xhci();
+#endif
+
+	ctx->dwc3_reg = (struct dwc3 *)((char *)(ctx->hcd) + DWC3_REG_OFFSET);
+
+	ret = exynos_xhci_core_init(ctx);
+	if (ret) {
+		puts("XHCI: failed to initialize controller\n");
+		return -EINVAL;
+	}
+
+	*hccr = (ctx->hcd);
+	*hcor = (struct xhci_hcor *)((uint32_t) *hccr
+				+ HC_LENGTH(xhci_readl(&(*hccr)->cr_capbase)));
+
+	debug("Exynos5-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 0;
+}
+
+void xhci_hcd_stop(int index)
+{
+	struct exynos_xhci *ctx = &exynos;
+
+	exynos_xhci_core_exit(ctx);
+}