[PATCH V3 6/8] phy: tegra: xusb: Add support for charger detect

[Nagarjuna Kristam <nkristam-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>]

Perform charger-detect operation if corresponding dt property is enabled.
Update usb-phy with the detected charger state and max current values.
Register charger-detect API's of usb-phy to provide needed functionalities.

Signed-off-by: Nagarjuna Kristam <nkristam-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
---
V3:
 - Allighed functions and its arguments.
 - replaced spaced by tabs for MACRO definition allignments.
 - Unified primary and secondary charger detect API's.
 - Used readl_poll_timeout instead of while loop condition check for register.
 - Fixed other comments as per inputs from Thierry.
---
V2:
 - Patch re-based.
---
 drivers/phy/tegra/Makefile |   2 +-
 drivers/phy/tegra/cd.c     | 283 +++++++++++++++++++++++++++++++++++++++++++++
 drivers/phy/tegra/xusb.c   |  80 +++++++++++++
 drivers/phy/tegra/xusb.h   |   7 ++
 4 files changed, 371 insertions(+), 1 deletion(-)
 create mode 100644 drivers/phy/tegra/cd.c

diff --git a/drivers/phy/tegra/Makefile b/drivers/phy/tegra/Makefile
index 89b8406..befdfc4 100644
--- a/drivers/phy/tegra/Makefile
+++ b/drivers/phy/tegra/Makefile
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0-only
 obj-$(CONFIG_PHY_TEGRA_XUSB) += phy-tegra-xusb.o
 
-phy-tegra-xusb-y += xusb.o
+phy-tegra-xusb-y += xusb.o cd.o
 phy-tegra-xusb-$(CONFIG_ARCH_TEGRA_124_SOC) += xusb-tegra124.o
 phy-tegra-xusb-$(CONFIG_ARCH_TEGRA_132_SOC) += xusb-tegra124.o
 phy-tegra-xusb-$(CONFIG_ARCH_TEGRA_210_SOC) += xusb-tegra210.o
diff --git a/drivers/phy/tegra/cd.c b/drivers/phy/tegra/cd.c
new file mode 100644
index 0000000..fddbe4c
--- /dev/null
+++ b/drivers/phy/tegra/cd.c
@@ -0,0 +1,283 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2020, NVIDIA CORPORATION.  All rights reserved.
+ */
+
+#include <linux/delay.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/phy/phy.h>
+
+#include "xusb.h"
+
+/* Data contact detection timeout */
+#define TDCD_TIMEOUT_MS				400
+
+#define USB2_BATTERY_CHRG_OTGPADX_CTL0(x)	(0x80 + (x) * 0x40)
+#define  PD_CHG					(1 << 0)
+#define  VDCD_DET_FILTER_EN			(1 << 4)
+#define  VDAT_DET				(1 << 5)
+#define  VDAT_DET_FILTER_EN			(1 << 8)
+#define  OP_SINK_EN				(1 << 9)
+#define  OP_SRC_EN				(1 << 10)
+#define  ON_SINK_EN				(1 << 11)
+#define  ON_SRC_EN				(1 << 12)
+#define  OP_I_SRC_EN				(1 << 13)
+#define  ZIP_FILTER_EN				(1 << 21)
+#define  ZIN_FILTER_EN				(1 << 25)
+#define  DCD_DETECTED				(1 << 26)
+
+#define USB2_BATTERY_CHRG_OTGPADX_CTL1(x)	(0x84 + (x) * 0x40)
+#define  PD_VREG				(1 << 6)
+#define  VREG_LEV(x)				(((x) & 0x3) << 7)
+#define  VREG_DIR(x)				(((x) & 0x3) << 11)
+#define  VREG_DIR_IN				VREG_DIR(1)
+#define  VREG_DIR_OUT				VREG_DIR(2)
+#define  USBOP_RPD_OVRD				(1 << 16)
+#define  USBOP_RPD_OVRD_VAL			(1 << 17)
+#define  USBOP_RPU_OVRD				(1 << 18)
+#define  USBOP_RPU_OVRD_VAL			(1 << 19)
+#define  USBON_RPD_OVRD				(1 << 20)
+#define  USBON_RPD_OVRD_VAL			(1 << 21)
+#define  USBON_RPU_OVRD				(1 << 22)
+#define  USBON_RPU_OVRD_VAL			(1 << 23)
+
+#define XUSB_PADCTL_USB2_OTG_PADX_CTL0(x)	(0x88 + (x) * 0x40)
+#define  USB2_OTG_PD2				(1 << 27)
+#define  USB2_OTG_PD2_OVRD_EN			(1 << 28)
+#define  USB2_OTG_PD_ZI				(1 << 29)
+
+#define XUSB_PADCTL_USB2_BATTERY_CHRG_TDCD_DBNC_TIMER_0 (0x280)
+#define   TDCD_DBNC(x)				(((x) & 0x7ff) << 0)
+
+static void
+tegra_xusb_padctl_set_debounce_time(struct tegra_xusb_padctl *padctl,
+				    u32 debounce)
+{
+	u32 value;
+
+	value = padctl_readl(padctl,
+		XUSB_PADCTL_USB2_BATTERY_CHRG_TDCD_DBNC_TIMER_0);
+	value &= ~(TDCD_DBNC(0));
+	value |= TDCD_DBNC(debounce);
+	padctl_writel(padctl, value,
+		XUSB_PADCTL_USB2_BATTERY_CHRG_TDCD_DBNC_TIMER_0);
+}
+
+static void
+tegra_xusb_padctl_charger_detect_on(struct tegra_xusb_padctl *padctl, u32 index)
+{
+	u32 value;
+
+	value = padctl_readl(padctl, XUSB_PADCTL_USB2_OTG_PADX_CTL0(index));
+	value &= ~USB2_OTG_PD_ZI;
+	padctl_writel(padctl, value, XUSB_PADCTL_USB2_OTG_PADX_CTL0(index));
+
+	value = padctl_readl(padctl, XUSB_PADCTL_USB2_OTG_PADX_CTL0(index));
+	value |= (USB2_OTG_PD2 | USB2_OTG_PD2_OVRD_EN);
+	padctl_writel(padctl, value, XUSB_PADCTL_USB2_OTG_PADX_CTL0(index));
+
+	value = padctl_readl(padctl, USB2_BATTERY_CHRG_OTGPADX_CTL0(index));
+	value &= ~PD_CHG;
+	padctl_writel(padctl, value, USB2_BATTERY_CHRG_OTGPADX_CTL0(index));
+
+	/* Set DP/DN Pull up/down to zero by default */
+	value = padctl_readl(padctl, USB2_BATTERY_CHRG_OTGPADX_CTL1(index));
+	value &= ~(USBOP_RPD_OVRD_VAL | USBOP_RPU_OVRD_VAL |
+		USBON_RPD_OVRD_VAL | USBON_RPU_OVRD_VAL);
+	value |= (USBOP_RPD_OVRD | USBOP_RPU_OVRD |
+		USBON_RPD_OVRD | USBON_RPU_OVRD);
+	padctl_writel(padctl, value, USB2_BATTERY_CHRG_OTGPADX_CTL1(index));
+
+	/* Disable DP/DN as src/sink */
+	value = padctl_readl(padctl, USB2_BATTERY_CHRG_OTGPADX_CTL0(index));
+	value &= ~(OP_SRC_EN | ON_SINK_EN |
+	ON_SRC_EN | OP_SINK_EN);
+	padctl_writel(padctl, value, USB2_BATTERY_CHRG_OTGPADX_CTL0(index));
+}
+
+static void
+tegra_xusb_padctl_charger_detect_off(struct tegra_xusb_padctl *padctl,
+				     u32 index)
+{
+	u32 value;
+
+	value = padctl_readl(padctl, USB2_BATTERY_CHRG_OTGPADX_CTL1(index));
+	value &= ~(USBOP_RPD_OVRD | USBOP_RPU_OVRD |
+		 USBON_RPD_OVRD | USBON_RPU_OVRD);
+	padctl_writel(padctl, value, USB2_BATTERY_CHRG_OTGPADX_CTL1(index));
+
+	/* power down necessary stuff */
+	value = padctl_readl(padctl, USB2_BATTERY_CHRG_OTGPADX_CTL0(index));
+	value |= PD_CHG;
+	padctl_writel(padctl, value, USB2_BATTERY_CHRG_OTGPADX_CTL0(index));
+
+	value = padctl_readl(padctl, XUSB_PADCTL_USB2_OTG_PADX_CTL0(index));
+	value &= ~(USB2_OTG_PD2 | USB2_OTG_PD2_OVRD_EN);
+	padctl_writel(padctl, value, XUSB_PADCTL_USB2_OTG_PADX_CTL0(index));
+}
+
+
+static void tegra_xusb_padctl_detect_filters(struct tegra_xusb_padctl *padctl,
+					     u32 index, bool on)
+{
+	u32 value;
+
+	if (on) {
+		value = padctl_readl(padctl,
+				     USB2_BATTERY_CHRG_OTGPADX_CTL0(index));
+		value |= (VDCD_DET_FILTER_EN | VDAT_DET_FILTER_EN |
+			  ZIP_FILTER_EN | ZIN_FILTER_EN);
+		padctl_writel(padctl, value,
+			      USB2_BATTERY_CHRG_OTGPADX_CTL0(index));
+	} else {
+		value = padctl_readl(padctl,
+				     USB2_BATTERY_CHRG_OTGPADX_CTL0(index));
+		value &= ~(VDCD_DET_FILTER_EN | VDAT_DET_FILTER_EN |
+			   ZIP_FILTER_EN | ZIN_FILTER_EN);
+		padctl_writel(padctl, value,
+			      USB2_BATTERY_CHRG_OTGPADX_CTL0(index));
+	}
+}
+
+static void tegra_xusb_padctl_dcd(struct tegra_xusb_padctl *padctl, u32 index)
+{
+	u32 value;
+	unsigned int offset;
+	bool ret = false;
+
+	/* Turn on IDP_SRC */
+	value = padctl_readl(padctl, USB2_BATTERY_CHRG_OTGPADX_CTL0(index));
+	value |= OP_I_SRC_EN;
+	padctl_writel(padctl, value, USB2_BATTERY_CHRG_OTGPADX_CTL0(index));
+
+	/* Turn on D- pull-down resistor */
+	value = padctl_readl(padctl, USB2_BATTERY_CHRG_OTGPADX_CTL1(index));
+	value |= USBON_RPD_OVRD_VAL;
+	padctl_writel(padctl, value, USB2_BATTERY_CHRG_OTGPADX_CTL1(index));
+
+	/* Wait for TDCD_DBNC (DCD debounce), refer to BC1.2 spec Table 5 */
+	usleep_range(10000, 20000);
+
+	offset = USB2_BATTERY_CHRG_OTGPADX_CTL0(index);
+	ret = readl_poll_timeout(padctl->regs + offset, value,
+				 value & DCD_DETECTED, 20000,
+				 TDCD_TIMEOUT_MS * 1000);
+	if (!ret)
+		dev_warn(padctl->dev, "%s: DCD timeout.", __func__);
+
+	/* Turn off IP_SRC, clear DCD DETECTED*/
+	value = padctl_readl(padctl, USB2_BATTERY_CHRG_OTGPADX_CTL0(index));
+	value &= ~OP_I_SRC_EN;
+	value |= DCD_DETECTED;
+	padctl_writel(padctl, value, USB2_BATTERY_CHRG_OTGPADX_CTL0(index));
+
+	/* Turn off D- pull-down resistor */
+	value = padctl_readl(padctl, USB2_BATTERY_CHRG_OTGPADX_CTL1(index));
+	value &= ~USBON_RPD_OVRD_VAL;
+	padctl_writel(padctl, value, USB2_BATTERY_CHRG_OTGPADX_CTL1(index));
+
+	dev_dbg(padctl->dev, "DCD detected: %d\n", !ret);
+}
+
+static bool
+tegra_xusb_padctl_primary_secondary(struct tegra_xusb_padctl *padctl, u32 index,
+				    bool is_primary)
+{
+	u32 value;
+	u32 config = is_primary ? (OP_SRC_EN | ON_SINK_EN) :
+				  (ON_SRC_EN | OP_SINK_EN);
+	bool ret = false;
+
+	if (is_primary)
+		/* data contact detection */
+		tegra_xusb_padctl_dcd(padctl, index);
+
+	/* Source D- to D+ */
+	value = padctl_readl(padctl, USB2_BATTERY_CHRG_OTGPADX_CTL0(index));
+	value |= config;
+	padctl_writel(padctl, value, USB2_BATTERY_CHRG_OTGPADX_CTL0(index));
+
+	/*
+	 * Wait for TVDPSRC_ON/TVDMSRC_ON(D+/- voltage source on time),
+	 * refer to BC1.2 spec Table 5
+	 */
+	msleep(40);
+
+	value = padctl_readl(padctl, USB2_BATTERY_CHRG_OTGPADX_CTL0(index));
+	if (is_primary)
+		ret = !!(value & VDAT_DET);
+	else
+		ret = !(value & VDAT_DET);
+
+	/* Turn off ON_SRC, OP_SINK, clear VDAT, ZIP status change */
+	value = padctl_readl(padctl, USB2_BATTERY_CHRG_OTGPADX_CTL0(index));
+	value &= ~config;
+	padctl_writel(padctl, value, USB2_BATTERY_CHRG_OTGPADX_CTL0(index));
+
+	return ret;
+}
+
+static const char *const chrg_types[] = {
+	[UNKNOWN_TYPE] = "Unknown Type",
+	[SDP_TYPE] = "SDP Type",
+	[DCP_TYPE] = "DCP Type",
+	[CDP_TYPE] = "CDP Type",
+	[ACA_TYPE] = "ACA Type",
+};
+
+enum usb_charger_type
+tegra_xusb_padctl_charger_detect(struct tegra_xusb_port *port)
+{
+	struct tegra_xusb_padctl *padctl = port->padctl;
+	struct phy *phy = port->lane->pad->lanes[port->index];
+	struct tegra_xusb_usb2_lane *usb2 = to_usb2_lane(port->lane);
+	u32 index = port->index;
+	enum usb_charger_type chrg_type;
+	bool pad_power_off = false;
+
+	mutex_lock(&padctl->lock);
+
+	if (!usb2->powered_on) {
+		padctl->soc->ops->utmi_pad_power_on(phy);
+		pad_power_off = true;
+	}
+
+	tegra_xusb_padctl_charger_detect_on(padctl, index);
+	tegra_xusb_padctl_set_debounce_time(padctl, 10);
+	tegra_xusb_padctl_detect_filters(padctl, index, true);
+
+	if (tegra_xusb_padctl_primary_secondary(padctl, index, true)) {
+		/*
+		 * wait 20ms (max of TVDMSRC_DIS) for D- to be disabled
+		 * from host side, before we perform secondary detection.
+		 * Some hosts may not respond well if we do secondary
+		 * detection right after primary detection.
+		 */
+		msleep(20);
+
+		if (tegra_xusb_padctl_primary_secondary(padctl, index, false))
+			chrg_type = CDP_TYPE;
+		else
+			chrg_type = DCP_TYPE;
+	} else {
+		chrg_type = SDP_TYPE;
+	}
+
+	dev_dbg(&port->dev, "charger detected of type %s",
+		chrg_types[chrg_type]);
+
+	tegra_xusb_padctl_detect_filters(padctl, index, false);
+	tegra_xusb_padctl_charger_detect_off(padctl, index);
+
+	if (pad_power_off)
+		padctl->soc->ops->utmi_pad_power_down(phy);
+
+	mutex_unlock(&padctl->lock);
+	return chrg_type;
+}
+
+MODULE_AUTHOR("Nagarjuna Kristam <nkristam-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>");
+MODULE_DESCRIPTION("NVIDIA Tegra186 XUSB charger detect driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/phy/tegra/xusb.c b/drivers/phy/tegra/xusb.c
index de4a46f..7252982 100644
--- a/drivers/phy/tegra/xusb.c
+++ b/drivers/phy/tegra/xusb.c
@@ -591,6 +591,50 @@ static enum usb_phy_events to_usb_phy_event(enum usb_role role)
 	}
 }
 
+#define VON_DIV2P0_DET BIT(0)
+#define VON_DIV2P7_DET BIT(1)
+#define VOP_DIV2P0_DET BIT(2)
+#define VOP_DIV2P7_DET BIT(3)
+
+#define VREG_CUR_LEVEL_0        500
+#define VREG_CUR_LEVEL_1        900
+#define VREG_CUR_LEVEL_2        1500
+#define VREG_CUR_LEVEL_3        2000
+
+#define IS_CUR_IN_RANGE(ma, low, high)  \
+	((ma >= VREG_CUR_LEVEL_##low) && (ma <= (VREG_CUR_LEVEL_##high - 1)))
+#define VREG_LVL(ma, level)     IS_CUR_IN_RANGE(ma, level, level + 1)
+
+static void tegra_xusb_padctl_vbus_pad_portection(struct tegra_xusb_port *port)
+{
+	struct tegra_xusb_padctl *padctl = port->padctl;
+	int level = 0;
+	enum tegra_vbus_dir dir = TEGRA_VBUS_SINK;
+	int max_ua, min_ua;
+
+	if (!padctl->soc->ops->utmi_pad_set_protection)
+		return;
+
+	usb_phy_get_charger_current(&port->usb_phy, &min_ua, &max_ua);
+
+	if (max_ua == 0) {
+		level = -1;
+		dir = TEGRA_VBUS_DEFAULT;
+	} else if (VREG_LVL(max_ua, 0)) {
+		level = 0;
+	} else if (VREG_LVL(max_ua, 1)) {
+		level = 1;
+	} else if (VREG_LVL(max_ua, 2)) {
+		level = 2;
+	} else if (max_ua >= VREG_CUR_LEVEL_3) {
+		level = 3;
+	} else {
+		return;
+	}
+
+	padctl->soc->ops->utmi_pad_set_protection(port, level, dir);
+}
+
 static void tegra_xusb_usb_phy_work(struct work_struct *work)
 {
 	struct tegra_xusb_port *port = container_of(work,
@@ -598,6 +642,10 @@ static void tegra_xusb_usb_phy_work(struct work_struct *work)
 						    usb_phy_work);
 	enum usb_role role = usb_role_switch_get_role(port->usb_role_sw);
 
+	/* Set role to none, if charger is DCP type */
+	if (port->chrg_type == DCP_TYPE)
+		role = USB_ROLE_NONE;
+
 	usb_phy_set_event(&port->usb_phy, to_usb_phy_event(role));
 
 	dev_dbg(&port->dev, "%s(): calling notifier for role %s\n", __func__,
@@ -610,9 +658,26 @@ static int tegra_xusb_role_sw_set(struct usb_role_switch *sw,
 				  enum usb_role role)
 {
 	struct tegra_xusb_port *port = usb_role_switch_get_drvdata(sw);
+	enum usb_charger_state charger_state;
 
 	dev_dbg(&port->dev, "%s(): role %s\n", __func__, usb_roles[role]);
 
+	/* Do charger detect if role is Device and charger detect is enabled */
+	if (port->charger_detect) {
+		if (role == USB_ROLE_DEVICE)
+			port->chrg_type =
+					 tegra_xusb_padctl_charger_detect(port);
+		else
+			port->chrg_type = UNKNOWN_TYPE;
+
+		charger_state = (port->chrg_type == UNKNOWN_TYPE) ?
+				 USB_CHARGER_ABSENT : USB_CHARGER_PRESENT;
+
+		usb_phy_set_charger_state(&port->usb_phy, charger_state);
+
+		tegra_xusb_padctl_vbus_pad_portection(port);
+	}
+
 	schedule_work(&port->usb_phy_work);
 
 	return 0;
@@ -643,6 +708,14 @@ static int tegra_xusb_set_host(struct usb_otg *otg, struct usb_bus *host)
 	return 0;
 }
 
+static enum usb_charger_type tegra_xusb_charger_detect(struct usb_phy *usb_phy)
+{
+	struct tegra_xusb_port *port = container_of(usb_phy,
+						    struct tegra_xusb_port,
+						    usb_phy);
+
+	return port->chrg_type;
+}
 
 static int tegra_xusb_setup_usb_role_switch(struct tegra_xusb_port *port)
 {
@@ -693,6 +766,9 @@ static int tegra_xusb_setup_usb_role_switch(struct tegra_xusb_port *port)
 	port->usb_phy.otg->set_peripheral = tegra_xusb_set_peripheral;
 	port->usb_phy.otg->set_host = tegra_xusb_set_host;
 
+	if (port->charger_detect)
+		port->usb_phy.charger_detect = tegra_xusb_charger_detect;
+
 	err = usb_add_phy_dev(&port->usb_phy);
 	if (err < 0) {
 		dev_err(&port->dev, "Failed to add USB PHY: %d\n", err);
@@ -727,6 +803,10 @@ static int tegra_xusb_usb2_port_parse_dt(struct tegra_xusb_usb2_port *usb2)
 		usb2->mode = USB_DR_MODE_HOST;
 	}
 
+	if (port->padctl->soc->supports_charger_detect &&
+	    of_property_read_bool(np, "nvidia,charger-detect"))
+		port->charger_detect = true;
+
 	/* usb-role-switch property is mandatory for OTG/Peripheral modes */
 	if (usb2->mode == USB_DR_MODE_PERIPHERAL ||
 	    usb2->mode == USB_DR_MODE_OTG) {
diff --git a/drivers/phy/tegra/xusb.h b/drivers/phy/tegra/xusb.h
index 475bcc6..7b9a798 100644
--- a/drivers/phy/tegra/xusb.h
+++ b/drivers/phy/tegra/xusb.h
@@ -282,6 +282,9 @@ struct tegra_xusb_port {
 	struct work_struct usb_phy_work;
 	struct usb_phy usb_phy;
 
+	bool charger_detect;
+	enum usb_charger_type chrg_type;
+
 	const struct tegra_xusb_port_ops *ops;
 };
 
@@ -306,6 +309,9 @@ struct tegra_xusb_port *
 tegra_xusb_find_port(struct tegra_xusb_padctl *padctl, const char *type,
 		     unsigned int index);
 
+enum usb_charger_type tegra_xusb_padctl_charger_detect(
+					  struct tegra_xusb_port *port);
+
 struct tegra_xusb_usb2_port {
 	struct tegra_xusb_port base;
 
@@ -430,6 +436,7 @@ struct tegra_xusb_padctl_soc {
 	unsigned int num_supplies;
 	bool supports_gen2;
 	bool need_fake_usb3_port;
+	bool supports_charger_detect;
 };
 
 struct tegra_xusb_padctl {
-- 
2.7.4