usb: dwc3: Add Meson G12A USB Glue

Adds support for Amlogic G12A USB Control Glue HW.

The Amlogic G12A SoC Family embeds 2 USB Controllers :
- a DWC3 IP configured as Host for USB2 and USB3
- a DWC2 IP configured as Peripheral USB2 Only

A glue connects these both controllers to 2 USB2 PHYs, and optionnally
to an USB3+PCIE Combo PHY shared with the PCIE controller.

The Glue configures the UTMI 8bit interfaces for the USB2 PHYs, including
routing of the OTG PHY between the DWC3 and DWC2 controllers, and
setups the on-chip OTG mode selection for this PHY.

This driver sets the OTG capable port as Host mode by default,
the switch to Device mode is to be done in a separate patch.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Marek Vasut <marex@denx.de>

3 files changed, 465 insertions, 0 deletions

diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
index bbd8105c06..25e1a38aee 100644
--- a/drivers/usb/dwc3/Kconfig
+++ b/drivers/usb/dwc3/Kconfig
@@ -44,6 +44,14 @@ config USB_DWC3_GENERIC
 	  Select this for Xilinx ZynqMP and similar Platforms.
 	  This wrapper supports Host and Peripheral operation modes.
 
+config USB_DWC3_MESON_G12A
+	bool "Amlogic Meson G12A USB wrapper"
+	depends on DM_USB && USB_DWC3 && ARCH_MESON
+	imply PHY
+	help
+	  Select this for Amlogic Meson G12A Platforms.
+	  This wrapper supports Host and Peripheral operation modes.
+
 config USB_DWC3_UNIPHIER
 	bool "DesignWare USB3 Host Support on UniPhier Platforms"
 	depends on ARCH_UNIPHIER && USB_XHCI_DWC3
diff --git a/drivers/usb/dwc3/Makefile b/drivers/usb/dwc3/Makefile
index 60b5515a67..0b652a6f36 100644
--- a/drivers/usb/dwc3/Makefile
+++ b/drivers/usb/dwc3/Makefile
@@ -7,6 +7,7 @@ dwc3-y					:= core.o
 obj-$(CONFIG_USB_DWC3_GADGET)		+= gadget.o ep0.o
 
 obj-$(CONFIG_USB_DWC3_OMAP)		+= dwc3-omap.o
+obj-$(CONFIG_USB_DWC3_MESON_G12A)	+= dwc3-meson-g12a.o
 obj-$(CONFIG_USB_DWC3_GENERIC)		+= dwc3-generic.o
 obj-$(CONFIG_USB_DWC3_UNIPHIER)		+= dwc3-uniphier.o
 obj-$(CONFIG_USB_DWC3_PHY_OMAP)		+= ti_usb_phy.o
diff --git a/drivers/usb/dwc3/dwc3-meson-g12a.c b/drivers/usb/dwc3/dwc3-meson-g12a.c
new file mode 100644
index 0000000000..832bcd70ff
--- /dev/null
+++ b/drivers/usb/dwc3/dwc3-meson-g12a.c
@@ -0,0 +1,456 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Amlogic G12A DWC3 Glue layer
+ *
+ * Copyright (C) 2019 BayLibre, SAS
+ * Author: Neil Armstrong <narmstrong@baylibre.com>
+ */
+
+#include <common.h>
+#include <asm-generic/io.h>
+#include <dm.h>
+#include <dm/device-internal.h>
+#include <dm/lists.h>
+#include <dwc3-uboot.h>
+#include <generic-phy.h>
+#include <linux/usb/ch9.h>
+#include <linux/usb/gadget.h>
+#include <malloc.h>
+#include <regmap.h>
+#include <usb.h>
+#include "core.h"
+#include "gadget.h"
+#include <reset.h>
+#include <clk.h>
+#include <power/regulator.h>
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/compat.h>
+
+/* USB2 Ports Control Registers */
+
+#define U2P_REG_SIZE						0x20
+
+#define U2P_R0							0x0
+	#define U2P_R0_HOST_DEVICE				BIT(0)
+	#define U2P_R0_POWER_OK					BIT(1)
+	#define U2P_R0_HAST_MODE				BIT(2)
+	#define U2P_R0_POWER_ON_RESET				BIT(3)
+	#define U2P_R0_ID_PULLUP				BIT(4)
+	#define U2P_R0_DRV_VBUS					BIT(5)
+
+#define U2P_R1							0x4
+	#define U2P_R1_PHY_READY				BIT(0)
+	#define U2P_R1_ID_DIG					BIT(1)
+	#define U2P_R1_OTG_SESSION_VALID			BIT(2)
+	#define U2P_R1_VBUS_VALID				BIT(3)
+
+/* USB Glue Control Registers */
+
+#define USB_R0							0x80
+	#define USB_R0_P30_LANE0_TX2RX_LOOPBACK			BIT(17)
+	#define USB_R0_P30_LANE0_EXT_PCLK_REQ			BIT(18)
+	#define USB_R0_P30_PCS_RX_LOS_MASK_VAL_MASK		GENMASK(28, 19)
+	#define USB_R0_U2D_SS_SCALEDOWN_MODE_MASK		GENMASK(30, 29)
+	#define USB_R0_U2D_ACT					BIT(31)
+
+#define USB_R1							0x84
+	#define USB_R1_U3H_BIGENDIAN_GS				BIT(0)
+	#define USB_R1_U3H_PME_ENABLE				BIT(1)
+	#define USB_R1_U3H_HUB_PORT_OVERCURRENT_MASK		GENMASK(4, 2)
+	#define USB_R1_U3H_HUB_PORT_PERM_ATTACH_MASK		GENMASK(9, 7)
+	#define USB_R1_U3H_HOST_U2_PORT_DISABLE_MASK		GENMASK(13, 12)
+	#define USB_R1_U3H_HOST_U3_PORT_DISABLE			BIT(16)
+	#define USB_R1_U3H_HOST_PORT_POWER_CONTROL_PRESENT	BIT(17)
+	#define USB_R1_U3H_HOST_MSI_ENABLE			BIT(18)
+	#define USB_R1_U3H_FLADJ_30MHZ_REG_MASK			GENMASK(24, 19)
+	#define USB_R1_P30_PCS_TX_SWING_FULL_MASK		GENMASK(31, 25)
+
+#define USB_R2							0x88
+	#define USB_R2_P30_PCS_TX_DEEMPH_3P5DB_MASK		GENMASK(25, 20)
+	#define USB_R2_P30_PCS_TX_DEEMPH_6DB_MASK		GENMASK(31, 26)
+
+#define USB_R3							0x8c
+	#define USB_R3_P30_SSC_ENABLE				BIT(0)
+	#define USB_R3_P30_SSC_RANGE_MASK			GENMASK(3, 1)
+	#define USB_R3_P30_SSC_REF_CLK_SEL_MASK			GENMASK(12, 4)
+	#define USB_R3_P30_REF_SSP_EN				BIT(13)
+
+#define USB_R4							0x90
+	#define USB_R4_P21_PORT_RESET_0				BIT(0)
+	#define USB_R4_P21_SLEEP_M0				BIT(1)
+	#define USB_R4_MEM_PD_MASK				GENMASK(3, 2)
+	#define USB_R4_P21_ONLY					BIT(4)
+
+#define USB_R5							0x94
+	#define USB_R5_ID_DIG_SYNC				BIT(0)
+	#define USB_R5_ID_DIG_REG				BIT(1)
+	#define USB_R5_ID_DIG_CFG_MASK				GENMASK(3, 2)
+	#define USB_R5_ID_DIG_EN_0				BIT(4)
+	#define USB_R5_ID_DIG_EN_1				BIT(5)
+	#define USB_R5_ID_DIG_CURR				BIT(6)
+	#define USB_R5_ID_DIG_IRQ				BIT(7)
+	#define USB_R5_ID_DIG_TH_MASK				GENMASK(15, 8)
+	#define USB_R5_ID_DIG_CNT_MASK				GENMASK(23, 16)
+
+enum {
+	USB2_HOST_PHY = 0,
+	USB2_OTG_PHY,
+	USB3_HOST_PHY,
+	PHY_COUNT,
+};
+
+static const char *phy_names[PHY_COUNT] = {
+	"usb2-phy0", "usb2-phy1", "usb3-phy0",
+};
+
+struct dwc3_meson_g12a {
+	struct udevice		*dev;
+	struct regmap           *regmap;
+	struct clk		clk;
+	struct reset_ctl	reset;
+	struct phy		phys[PHY_COUNT];
+	enum usb_dr_mode	otg_mode;
+	enum usb_dr_mode	otg_phy_mode;
+	unsigned int		usb2_ports;
+	unsigned int		usb3_ports;
+#if CONFIG_IS_ENABLED(DM_REGULATOR)
+	struct udevice		*vbus_supply;
+#endif
+};
+
+#define U2P_REG_SIZE						0x20
+#define USB_REG_OFFSET						0x80
+
+static void dwc3_meson_g12a_usb2_set_mode(struct dwc3_meson_g12a *priv,
+					  int i, enum usb_dr_mode mode)
+{
+	switch (mode) {
+	case USB_DR_MODE_HOST:
+	case USB_DR_MODE_OTG:
+	case USB_DR_MODE_UNKNOWN:
+		regmap_update_bits(priv->regmap, U2P_R0 + (U2P_REG_SIZE * i),
+				U2P_R0_HOST_DEVICE,
+				U2P_R0_HOST_DEVICE);
+		break;
+
+	case USB_DR_MODE_PERIPHERAL:
+		regmap_update_bits(priv->regmap, U2P_R0 + (U2P_REG_SIZE * i),
+				U2P_R0_HOST_DEVICE, 0);
+		break;
+	}
+}
+
+static int dwc3_meson_g12a_usb2_init(struct dwc3_meson_g12a *priv)
+{
+	int i;
+
+	if (priv->otg_mode == USB_DR_MODE_PERIPHERAL)
+		priv->otg_phy_mode = USB_DR_MODE_PERIPHERAL;
+	else
+		priv->otg_phy_mode = USB_DR_MODE_HOST;
+
+	for (i = 0 ; i < USB3_HOST_PHY ; ++i) {
+		if (!priv->phys[i].dev)
+			continue;
+
+		regmap_update_bits(priv->regmap, U2P_R0 + (U2P_REG_SIZE * i),
+				   U2P_R0_POWER_ON_RESET,
+				   U2P_R0_POWER_ON_RESET);
+
+		if (i == USB2_OTG_PHY) {
+			regmap_update_bits(priv->regmap,
+					   U2P_R0 + (U2P_REG_SIZE * i),
+					   U2P_R0_ID_PULLUP | U2P_R0_DRV_VBUS,
+					   U2P_R0_ID_PULLUP | U2P_R0_DRV_VBUS);
+
+			dwc3_meson_g12a_usb2_set_mode(priv, i,
+						      priv->otg_phy_mode);
+		} else
+			dwc3_meson_g12a_usb2_set_mode(priv, i,
+						      USB_DR_MODE_HOST);
+
+		regmap_update_bits(priv->regmap, U2P_R0 + (U2P_REG_SIZE * i),
+				   U2P_R0_POWER_ON_RESET, 0);
+	}
+
+	return 0;
+}
+
+static void dwc3_meson_g12a_usb3_init(struct dwc3_meson_g12a *priv)
+{
+	regmap_update_bits(priv->regmap, USB_R3,
+			USB_R3_P30_SSC_RANGE_MASK |
+			USB_R3_P30_REF_SSP_EN,
+			USB_R3_P30_SSC_ENABLE |
+			FIELD_PREP(USB_R3_P30_SSC_RANGE_MASK, 2) |
+			USB_R3_P30_REF_SSP_EN);
+	udelay(2);
+
+	regmap_update_bits(priv->regmap, USB_R2,
+			USB_R2_P30_PCS_TX_DEEMPH_3P5DB_MASK,
+			FIELD_PREP(USB_R2_P30_PCS_TX_DEEMPH_3P5DB_MASK, 0x15));
+
+	regmap_update_bits(priv->regmap, USB_R2,
+			USB_R2_P30_PCS_TX_DEEMPH_6DB_MASK,
+			FIELD_PREP(USB_R2_P30_PCS_TX_DEEMPH_6DB_MASK, 0x20));
+
+	udelay(2);
+
+	regmap_update_bits(priv->regmap, USB_R1,
+			USB_R1_U3H_HOST_PORT_POWER_CONTROL_PRESENT,
+			USB_R1_U3H_HOST_PORT_POWER_CONTROL_PRESENT);
+
+	regmap_update_bits(priv->regmap, USB_R1,
+			USB_R1_P30_PCS_TX_SWING_FULL_MASK,
+			FIELD_PREP(USB_R1_P30_PCS_TX_SWING_FULL_MASK, 127));
+}
+
+static void dwc3_meson_g12a_usb_init_mode(struct dwc3_meson_g12a *priv)
+{
+	if (priv->otg_phy_mode == USB_DR_MODE_PERIPHERAL) {
+		regmap_update_bits(priv->regmap, USB_R0,
+				USB_R0_U2D_ACT, USB_R0_U2D_ACT);
+		regmap_update_bits(priv->regmap, USB_R0,
+				USB_R0_U2D_SS_SCALEDOWN_MODE_MASK, 0);
+		regmap_update_bits(priv->regmap, USB_R4,
+				USB_R4_P21_SLEEP_M0, USB_R4_P21_SLEEP_M0);
+	} else {
+		regmap_update_bits(priv->regmap, USB_R0,
+				USB_R0_U2D_ACT, 0);
+		regmap_update_bits(priv->regmap, USB_R4,
+				USB_R4_P21_SLEEP_M0, 0);
+	}
+}
+
+static int dwc3_meson_g12a_usb_init(struct dwc3_meson_g12a *priv)
+{
+	int ret;
+
+	ret = dwc3_meson_g12a_usb2_init(priv);
+	if (ret)
+		return ret;
+
+	regmap_update_bits(priv->regmap, USB_R1,
+			USB_R1_U3H_FLADJ_30MHZ_REG_MASK,
+			FIELD_PREP(USB_R1_U3H_FLADJ_30MHZ_REG_MASK, 0x20));
+
+	regmap_update_bits(priv->regmap, USB_R5,
+			USB_R5_ID_DIG_EN_0,
+			USB_R5_ID_DIG_EN_0);
+	regmap_update_bits(priv->regmap, USB_R5,
+			USB_R5_ID_DIG_EN_1,
+			USB_R5_ID_DIG_EN_1);
+	regmap_update_bits(priv->regmap, USB_R5,
+			USB_R5_ID_DIG_TH_MASK,
+			FIELD_PREP(USB_R5_ID_DIG_TH_MASK, 0xff));
+
+	/* If we have an actual SuperSpeed port, initialize it */
+	if (priv->usb3_ports)
+		dwc3_meson_g12a_usb3_init(priv);
+
+	dwc3_meson_g12a_usb_init_mode(priv);
+
+	return 0;
+}
+
+int dwc3_meson_g12a_force_mode(struct udevice *dev, enum usb_dr_mode mode)
+{
+	struct dwc3_meson_g12a *priv = dev_get_platdata(dev);
+
+	if (!priv)
+		return -EINVAL;
+
+	if (mode != USB_DR_MODE_HOST && mode != USB_DR_MODE_PERIPHERAL)
+		return -EINVAL;
+
+	if (!priv->phys[USB2_OTG_PHY].dev)
+		return -EINVAL;
+
+	if (mode == priv->otg_mode)
+		return 0;
+
+	if (mode == USB_DR_MODE_HOST)
+		debug("%s: switching to Host Mode\n", __func__);
+	else
+		debug("%s: switching to Device Mode\n", __func__);
+
+#if CONFIG_IS_ENABLED(DM_REGULATOR)
+	if (priv->vbus_supply) {
+		int ret = regulator_set_enable(priv->vbus_supply,
+					(mode == USB_DR_MODE_PERIPHERAL));
+		if (ret)
+			return ret;
+	}
+#endif
+	priv->otg_phy_mode = mode;
+
+	dwc3_meson_g12a_usb2_set_mode(priv, USB2_OTG_PHY, mode);
+
+	dwc3_meson_g12a_usb_init_mode(priv);
+
+	return 0;
+}
+
+static int dwc3_meson_g12a_get_phys(struct dwc3_meson_g12a *priv)
+{
+	int i, ret;
+
+	for (i = 0 ; i < PHY_COUNT ; ++i) {
+		ret = generic_phy_get_by_name(priv->dev, phy_names[i],
+					      &priv->phys[i]);
+		if (ret == -ENOENT)
+			continue;
+
+		if (ret)
+			return ret;
+
+		if (i == USB3_HOST_PHY)
+			priv->usb3_ports++;
+		else
+			priv->usb2_ports++;
+	}
+
+	debug("%s: usb2 ports: %d\n", __func__, priv->usb2_ports);
+	debug("%s: usb3 ports: %d\n", __func__, priv->usb3_ports);
+
+	return 0;
+}
+
+static int dwc3_meson_g12a_reset_init(struct dwc3_meson_g12a *priv)
+{
+	int ret;
+
+	ret = reset_get_by_index(priv->dev, 0, &priv->reset);
+	if (ret)
+		return ret;
+
+	ret = reset_assert(&priv->reset);
+	udelay(1);
+	ret |= reset_deassert(&priv->reset);
+	if (ret) {
+		reset_free(&priv->reset);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int dwc3_meson_g12a_clk_init(struct dwc3_meson_g12a *priv)
+{
+	int ret;
+
+	ret = clk_get_by_index(priv->dev, 0, &priv->clk);
+	if (ret)
+		return ret;
+
+#if CONFIG_IS_ENABLED(CLK)
+	ret = clk_enable(&priv->clk);
+	if (ret) {
+		clk_free(&priv->clk);
+		return ret;
+	}
+#endif
+
+	return 0;
+}
+
+static int dwc3_meson_g12a_probe(struct udevice *dev)
+{
+	struct dwc3_meson_g12a *priv = dev_get_platdata(dev);
+	int ret, i;
+
+	priv->dev = dev;
+
+	ret = regmap_init_mem(dev_ofnode(dev), &priv->regmap);
+	if (ret)
+		return ret;
+
+	ret = dwc3_meson_g12a_clk_init(priv);
+	if (ret)
+		return ret;
+
+	ret = dwc3_meson_g12a_reset_init(priv);
+	if (ret)
+		return ret;
+
+	ret = dwc3_meson_g12a_get_phys(priv);
+	if (ret)
+		return ret;
+
+#if CONFIG_IS_ENABLED(DM_REGULATOR)
+	ret = device_get_supply_regulator(dev, "vbus-supply",
+					  &priv->vbus_supply);
+	if (ret && ret != -ENOENT) {
+		pr_err("Failed to get PHY regulator\n");
+		return ret;
+	}
+
+	if (priv->vbus_supply) {
+		ret = regulator_set_enable(priv->vbus_supply, true);
+		if (ret)
+			return ret;
+	}
+#endif
+
+	priv->otg_mode = usb_get_dr_mode(dev_of_offset(dev));
+
+	ret = dwc3_meson_g12a_usb_init(priv);
+	if (ret)
+		return ret;
+
+	for (i = 0 ; i < PHY_COUNT ; ++i) {
+		if (!priv->phys[i].dev)
+			continue;
+
+		ret = generic_phy_init(&priv->phys[i]);
+		if (ret)
+			goto err_phy_init;
+	}
+
+	return 0;
+
+err_phy_init:
+	for (i = 0 ; i < PHY_COUNT ; ++i) {
+		if (!priv->phys[i].dev)
+			continue;
+
+		 generic_phy_exit(&priv->phys[i]);
+	}
+
+	return ret;
+}
+
+static int dwc3_meson_g12a_remove(struct udevice *dev)
+{
+	struct dwc3_meson_g12a *priv = dev_get_platdata(dev);
+	int i;
+
+	reset_release_all(&priv->reset, 1);
+
+	clk_release_all(&priv->clk, 1);
+
+	for (i = 0 ; i < PHY_COUNT ; ++i) {
+		if (!priv->phys[i].dev)
+			continue;
+
+		 generic_phy_exit(&priv->phys[i]);
+	}
+
+	return dm_scan_fdt_dev(dev);
+}
+
+static const struct udevice_id dwc3_meson_g12a_ids[] = {
+	{ .compatible = "amlogic,meson-g12a-usb-ctrl" },
+	{ }
+};
+
+U_BOOT_DRIVER(dwc3_generic_wrapper) = {
+	.name	= "dwc3-meson-g12a",
+	.id	= UCLASS_SIMPLE_BUS,
+	.of_match = dwc3_meson_g12a_ids,
+	.probe = dwc3_meson_g12a_probe,
+	.remove = dwc3_meson_g12a_remove,
+	.platdata_auto_alloc_size = sizeof(struct dwc3_meson_g12a),
+
+};