usb: dwc3: Add dwc3 glue driver support for STi

This patch adds the ST glue logic to manage the DWC3 HC
on STiH407 SoC family. It configures the internal glue
logic and syscfg registers.

Part of this code been extracted from kernel.org driver
(drivers/usb/dwc3/dwc3-st.c)

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

3 files changed, 267 insertions, 0 deletions

diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
index eb035a476b..f797a2568c 100644
--- a/drivers/usb/host/Kconfig
+++ b/drivers/usb/host/Kconfig
@@ -47,6 +47,15 @@ config USB_XHCI_ROCKCHIP
 	help
 	  Enables support for the on-chip xHCI controller on Rockchip SoCs.
 
+config USB_XHCI_STI
+	bool "Support for STMicroelectronics STiH407 family on-chip xHCI USB controller"
+	depends on ARCH_STI
+	default y
+	help
+	  Enables support for the on-chip xHCI controller on STMicroelectronics
+	  STiH407 family SoCs. This is a driver for the dwc3 to provide the glue logic
+	  to configure the controller.
+
 config USB_XHCI_ZYNQMP
 	bool "Support for Xilinx ZynqMP on-chip xHCI USB controller"
 	depends on ARCH_ZYNQMP
diff --git a/drivers/usb/host/Makefile b/drivers/usb/host/Makefile
index ab5a99faa8..29afb7cf1d 100644
--- a/drivers/usb/host/Makefile
+++ b/drivers/usb/host/Makefile
@@ -60,6 +60,7 @@ obj-$(CONFIG_USB_XHCI_FSL) += xhci-fsl.o
 obj-$(CONFIG_USB_XHCI_MVEBU) += xhci-mvebu.o
 obj-$(CONFIG_USB_XHCI_OMAP) += xhci-omap.o
 obj-$(CONFIG_USB_XHCI_PCI) += xhci-pci.o
+obj-$(CONFIG_USB_XHCI_STI) += dwc3-sti-glue.o
 
 # designware
 obj-$(CONFIG_USB_DWC2) += dwc2.o
diff --git a/drivers/usb/host/dwc3-sti-glue.c b/drivers/usb/host/dwc3-sti-glue.c
new file mode 100644
index 0000000000..02ad3115df
--- /dev/null
+++ b/drivers/usb/host/dwc3-sti-glue.c
@@ -0,0 +1,257 @@
+/*
+ * STiH407 family DWC3 specific Glue layer
+ *
+ * Copyright (c) 2017
+ * Patrice Chotard <patrice.chotard@st.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <dm.h>
+#include <errno.h>
+#include <fdtdec.h>
+#include <libfdt.h>
+#include <dm/lists.h>
+#include <regmap.h>
+#include <reset-uclass.h>
+#include <syscon.h>
+#include <usb.h>
+
+#include <linux/usb/dwc3.h>
+#include <linux/usb/otg.h>
+#include <dwc3-sti-glue.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/*
+ * struct sti_dwc3_glue_platdata - dwc3 STi glue driver private structure
+ * @syscfg_base:	addr for the glue syscfg
+ * @glue_base:		addr for the glue registers
+ * @syscfg_offset:	usb syscfg control offset
+ * @powerdown_ctl:	rest controller for powerdown signal
+ * @softreset_ctl:	reset controller for softreset signal
+ * @mode:		drd static host/device config
+ */
+struct sti_dwc3_glue_platdata {
+	phys_addr_t syscfg_base;
+	phys_addr_t glue_base;
+	phys_addr_t syscfg_offset;
+	struct reset_ctl powerdown_ctl;
+	struct reset_ctl softreset_ctl;
+	enum usb_dr_mode mode;
+};
+
+static int sti_dwc3_glue_drd_init(struct sti_dwc3_glue_platdata *plat)
+{
+	unsigned long val;
+
+	val = readl(plat->syscfg_base + plat->syscfg_offset);
+
+	val &= USB3_CONTROL_MASK;
+
+	switch (plat->mode) {
+	case USB_DR_MODE_PERIPHERAL:
+		val &= ~(USB3_DELAY_VBUSVALID
+			| USB3_SEL_FORCE_OPMODE | USB3_FORCE_OPMODE(0x3)
+			| USB3_SEL_FORCE_DPPULLDOWN2 | USB3_FORCE_DPPULLDOWN2
+			| USB3_SEL_FORCE_DMPULLDOWN2 | USB3_FORCE_DMPULLDOWN2);
+
+		val |= USB3_DEVICE_NOT_HOST | USB3_FORCE_VBUSVALID;
+		break;
+
+	case USB_DR_MODE_HOST:
+		val &= ~(USB3_DEVICE_NOT_HOST | USB3_FORCE_VBUSVALID
+			| USB3_SEL_FORCE_OPMODE	| USB3_FORCE_OPMODE(0x3)
+			| USB3_SEL_FORCE_DPPULLDOWN2 | USB3_FORCE_DPPULLDOWN2
+			| USB3_SEL_FORCE_DMPULLDOWN2 | USB3_FORCE_DMPULLDOWN2);
+
+		val |= USB3_DELAY_VBUSVALID;
+		break;
+
+	default:
+		error("Unsupported mode of operation %d\n", plat->mode);
+		return -EINVAL;
+	}
+	writel(val, plat->syscfg_base + plat->syscfg_offset);
+
+	return 0;
+}
+
+static void sti_dwc3_glue_init(struct sti_dwc3_glue_platdata *plat)
+{
+	unsigned long reg;
+
+	reg = readl(plat->glue_base + CLKRST_CTRL);
+
+	reg |= AUX_CLK_EN | EXT_CFG_RESET_N | XHCI_REVISION;
+	reg &= ~SW_PIPEW_RESET_N;
+
+	writel(reg, plat->glue_base + CLKRST_CTRL);
+
+	/* configure mux for vbus, powerpresent and bvalid signals */
+	reg = readl(plat->glue_base + USB2_VBUS_MNGMNT_SEL1);
+
+	reg |= SEL_OVERRIDE_VBUSVALID(USB2_VBUS_UTMIOTG) |
+	       SEL_OVERRIDE_POWERPRESENT(USB2_VBUS_UTMIOTG) |
+	       SEL_OVERRIDE_BVALID(USB2_VBUS_UTMIOTG);
+
+	writel(reg, plat->glue_base + USB2_VBUS_MNGMNT_SEL1);
+
+	setbits_le32(plat->glue_base + CLKRST_CTRL, SW_PIPEW_RESET_N);
+}
+
+static int sti_dwc3_glue_ofdata_to_platdata(struct udevice *dev)
+{
+	struct sti_dwc3_glue_platdata *plat = dev_get_platdata(dev);
+	struct udevice *syscon;
+	struct regmap *regmap;
+	int ret;
+	u32 reg[4];
+
+	ret = fdtdec_get_int_array(gd->fdt_blob, dev_of_offset(dev),
+				   "reg", reg, ARRAY_SIZE(reg));
+	if (ret) {
+		error("unable to find st,stih407-dwc3 reg property(%d)\n", ret);
+		return ret;
+	}
+
+	plat->glue_base = reg[0];
+	plat->syscfg_offset = reg[2];
+
+	/* get corresponding syscon phandle */
+	ret = uclass_get_device_by_phandle(UCLASS_SYSCON, dev, "st,syscfg",
+					   &syscon);
+	if (ret) {
+		error("unable to find syscon device (%d)\n", ret);
+		return ret;
+	}
+
+	/* get syscfg-reg base address */
+	regmap = syscon_get_regmap(syscon);
+	if (!regmap) {
+		error("unable to find regmap\n");
+		return -ENODEV;
+	}
+	plat->syscfg_base = regmap->base;
+
+	/* get powerdown reset */
+	ret = reset_get_by_name(dev, "powerdown", &plat->powerdown_ctl);
+	if (ret) {
+		error("can't get powerdown reset for %s (%d)", dev->name, ret);
+		return ret;
+	}
+
+	/* get softreset reset */
+	ret = reset_get_by_name(dev, "softreset", &plat->softreset_ctl);
+	if (ret)
+		error("can't get soft reset for %s (%d)", dev->name, ret);
+
+	return ret;
+};
+
+static int sti_dwc3_glue_bind(struct udevice *dev)
+{
+	struct sti_dwc3_glue_platdata *plat = dev_get_platdata(dev);
+	int dwc3_node;
+
+	/* check if one subnode is present */
+	dwc3_node = fdt_first_subnode(gd->fdt_blob, dev_of_offset(dev));
+	if (dwc3_node <= 0) {
+		error("Can't find subnode for %s\n", dev->name);
+		return -ENODEV;
+	}
+
+	/* check if the subnode compatible string is the dwc3 one*/
+	if (fdt_node_check_compatible(gd->fdt_blob, dwc3_node,
+				      "snps,dwc3") != 0) {
+		error("Can't find dwc3 subnode for %s\n", dev->name);
+		return -ENODEV;
+	}
+
+	/* retrieve the DWC3 dual role mode */
+	plat->mode = usb_get_dr_mode(dwc3_node);
+	if (plat->mode == USB_DR_MODE_UNKNOWN)
+		/* by default set dual role mode to HOST */
+		plat->mode = USB_DR_MODE_HOST;
+
+	return dm_scan_fdt_dev(dev);
+}
+
+static int sti_dwc3_glue_probe(struct udevice *dev)
+{
+	struct sti_dwc3_glue_platdata *plat = dev_get_platdata(dev);
+	int ret;
+
+	/* deassert both powerdown and softreset */
+	ret = reset_deassert(&plat->powerdown_ctl);
+	if (ret < 0) {
+		error("DWC3 powerdown reset deassert failed: %d", ret);
+		return ret;
+	}
+
+	ret = reset_deassert(&plat->softreset_ctl);
+	if (ret < 0) {
+		error("DWC3 soft reset deassert failed: %d", ret);
+		goto softreset_err;
+	}
+
+	ret = sti_dwc3_glue_drd_init(plat);
+	if (ret)
+		goto init_err;
+
+	sti_dwc3_glue_init(plat);
+
+	return 0;
+
+init_err:
+	ret = reset_assert(&plat->softreset_ctl);
+	if (ret < 0) {
+		error("DWC3 soft reset deassert failed: %d", ret);
+		return ret;
+	}
+
+softreset_err:
+	ret = reset_assert(&plat->powerdown_ctl);
+	if (ret < 0)
+		error("DWC3 powerdown reset deassert failed: %d", ret);
+
+	return ret;
+}
+
+static int sti_dwc3_glue_remove(struct udevice *dev)
+{
+	struct sti_dwc3_glue_platdata *plat = dev_get_platdata(dev);
+	int ret;
+
+	/* assert both powerdown and softreset */
+	ret = reset_assert(&plat->powerdown_ctl);
+	if (ret < 0) {
+		error("DWC3 powerdown reset deassert failed: %d", ret);
+		return ret;
+	}
+
+	ret = reset_assert(&plat->softreset_ctl);
+	if (ret < 0)
+		error("DWC3 soft reset deassert failed: %d", ret);
+
+	return ret;
+}
+
+static const struct udevice_id sti_dwc3_glue_ids[] = {
+	{ .compatible = "st,stih407-dwc3" },
+	{ }
+};
+
+U_BOOT_DRIVER(dwc3_sti_glue) = {
+	.name = "dwc3_sti_glue",
+	.id = UCLASS_MISC,
+	.of_match = sti_dwc3_glue_ids,
+	.ofdata_to_platdata = sti_dwc3_glue_ofdata_to_platdata,
+	.probe = sti_dwc3_glue_probe,
+	.remove = sti_dwc3_glue_remove,
+	.bind = sti_dwc3_glue_bind,
+	.platdata_auto_alloc_size = sizeof(struct sti_dwc3_glue_platdata),
+	.flags = DM_FLAG_ALLOC_PRIV_DMA,
+};