MLK-10085-1 power: imx6: add imx6 USB charger detection

Add imx6 USB charger detection, the vbus supplier will create and
remove struct usb_charger, and notify vbus connect and disconnect
event. The detail USB charger detection flow is at: "i.MX6 RM,
Chapter Universal Serial Bus 2.0 Integrated PHY (USB-PHY),
Charger detection, Charger detection software flow".

Since imx6 only has charger detection function, and no charging
current function is existed. It the user wants the detection abilities
from SoC, it can use this detection method
(add imx6-usb-charger-detection at dts). If the charger IC
already has USB charger detection function, and the user wants
to use the detection method from charger IC, please do not add
imx6-usb-charger-detection property at dts.

Signed-off-by: Peter Chen <peter.chen@freescale.com>

3 files changed, 294 insertions, 0 deletions

diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
index 63a199b83d0e..aa7c85c423ca 100644
--- a/drivers/power/Kconfig
+++ b/drivers/power/Kconfig
@@ -397,6 +397,12 @@ config BATTERY_GOLDFISH
 	  Say Y to enable support for the battery and AC power in the
 	  Goldfish emulator.
 
+config IMX6_USB_CHARGER
+	bool "Freescale imx6 USB Charger"
+	depends on SOC_IMX6Q || SOC_IMX6SL || SOC_IMX6SX
+	help
+	  Say Y to enable Freescale imx6 USB Charger Detect.
+
 source "drivers/power/reset/Kconfig"
 
 endif # POWER_SUPPLY
diff --git a/drivers/power/Makefile b/drivers/power/Makefile
index f98b37350fa9..4c828bc23e1b 100644
--- a/drivers/power/Makefile
+++ b/drivers/power/Makefile
@@ -59,3 +59,4 @@ obj-$(CONFIG_POWER_AVS)		+= avs/
 obj-$(CONFIG_CHARGER_SMB347)	+= smb347-charger.o
 obj-$(CONFIG_CHARGER_TPS65090)	+= tps65090-charger.o
 obj-$(CONFIG_POWER_RESET)	+= reset/
+obj-$(CONFIG_IMX6_USB_CHARGER)	+= imx6_usb_charger.o
diff --git a/drivers/power/imx6_usb_charger.c b/drivers/power/imx6_usb_charger.c
new file mode 100644
index 000000000000..7ec8ace6dcfc
--- /dev/null
+++ b/drivers/power/imx6_usb_charger.c
@@ -0,0 +1,287 @@
+/*
+ * Copyright (C) 2013-2015 Freescale Semiconductor, Inc. All Rights Reserved.
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/power/imx6_usb_charger.h>
+#include <linux/regmap.h>
+
+#define HW_ANADIG_USB1_CHRG_DETECT_SET	(0x000001b4)
+#define HW_ANADIG_USB1_CHRG_DETECT_CLR	(0x000001b8)
+
+#define BM_ANADIG_USB1_CHRG_DETECT_EN_B 0x00100000
+#define BM_ANADIG_USB1_CHRG_DETECT_CHK_CHRG_B 0x00080000
+#define BM_ANADIG_USB1_CHRG_DETECT_CHK_CONTACT 0x00040000
+
+#define HW_ANADIG_USB1_VBUS_DET_STAT	(0x000001c0)
+
+#define BM_ANADIG_USB1_VBUS_DET_STAT_VBUS_VALID 0x00000008
+
+#define HW_ANADIG_USB1_CHRG_DET_STAT	(0x000001d0)
+
+#define BM_ANADIG_USB1_CHRG_DET_STAT_DM_STATE 0x00000004
+#define BM_ANADIG_USB1_CHRG_DET_STAT_CHRG_DETECTED 0x00000002
+#define BM_ANADIG_USB1_CHRG_DET_STAT_PLUG_CONTACT 0x00000001
+
+static char *imx6_usb_charger_supplied_to[] = {
+	"imx6_usb_charger",
+};
+
+static enum power_supply_property imx6_usb_charger_power_props[] = {
+	POWER_SUPPLY_PROP_PRESENT,	/* Charger detected */
+	POWER_SUPPLY_PROP_ONLINE,	/* VBUS online */
+	POWER_SUPPLY_PROP_CURRENT_MAX,	/* Maximum current in mA */
+};
+
+static int imx6_usb_charger_get_property(struct power_supply *psy,
+				enum power_supply_property psp,
+				union power_supply_propval *val)
+{
+	struct usb_charger *charger =
+		container_of(psy, struct usb_charger, psy);
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_PRESENT:
+		val->intval = charger->present;
+		break;
+	case POWER_SUPPLY_PROP_ONLINE:
+		val->intval = charger->online;
+		break;
+	case POWER_SUPPLY_PROP_CURRENT_MAX:
+		val->intval = charger->max_current;
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static void disable_charger_detector(struct regmap *regmap)
+{
+	regmap_write(regmap, HW_ANADIG_USB1_CHRG_DETECT_SET,
+		BM_ANADIG_USB1_CHRG_DETECT_EN_B |
+		BM_ANADIG_USB1_CHRG_DETECT_CHK_CHRG_B);
+}
+
+/* Return value if the charger is present */
+static int imx6_usb_charger_detect(struct usb_charger *charger)
+{
+	struct regmap *regmap = charger->anatop;
+	u32 val;
+	int i, data_pin_contact_count = 0;
+
+	/* check if vbus is valid */
+	regmap_read(regmap, HW_ANADIG_USB1_VBUS_DET_STAT, &val);
+	if (!(val & BM_ANADIG_USB1_VBUS_DET_STAT_VBUS_VALID)) {
+		dev_err(charger->dev, "vbus is error\n");
+		return -EINVAL;
+	}
+
+	/* Enable charger detector */
+	regmap_write(regmap, HW_ANADIG_USB1_CHRG_DETECT_CLR,
+			BM_ANADIG_USB1_CHRG_DETECT_EN_B);
+	/*
+	 * - Do not check whether a charger is connected to the USB port
+	 * - Check whether the USB plug has been in contact with each other
+	 */
+	regmap_write(regmap, HW_ANADIG_USB1_CHRG_DETECT_SET,
+			BM_ANADIG_USB1_CHRG_DETECT_CHK_CONTACT |
+			BM_ANADIG_USB1_CHRG_DETECT_CHK_CHRG_B);
+
+	/* Check if plug is connected */
+	for (i = 0; i < 100; i = i + 1) {
+		regmap_read(regmap, HW_ANADIG_USB1_CHRG_DET_STAT, &val);
+		if (val & BM_ANADIG_USB1_CHRG_DET_STAT_PLUG_CONTACT) {
+			if (data_pin_contact_count++ > 5)
+			/* Data pin makes contact */
+				break;
+			else
+				usleep_range(5000, 10000);
+		} else {
+			data_pin_contact_count = 0;
+			msleep(20);
+		}
+	}
+
+	if (i == 100) {
+		dev_err(charger->dev,
+			"VBUS is coming from a dedicated power supply.\n");
+		disable_charger_detector(regmap);
+		return -ENXIO;
+	}
+
+	/*
+	 * - Do check whether a charger is connected to the USB port
+	 * - Do not Check whether the USB plug has been in contact with
+	 * each other
+	 */
+	regmap_write(regmap, HW_ANADIG_USB1_CHRG_DETECT_CLR,
+			BM_ANADIG_USB1_CHRG_DETECT_CHK_CONTACT |
+			BM_ANADIG_USB1_CHRG_DETECT_CHK_CHRG_B);
+	msleep(100);
+
+	/* Check if it is a charger */
+	regmap_read(regmap, HW_ANADIG_USB1_CHRG_DET_STAT, &val);
+	if (!(val & BM_ANADIG_USB1_CHRG_DET_STAT_CHRG_DETECTED)) {
+		dev_dbg(charger->dev, "It is a stardard downstream port\n");
+		charger->psy.type = POWER_SUPPLY_TYPE_USB;
+		charger->max_current = 500;
+		disable_charger_detector(regmap);
+	} else {
+		/* It is a charger */
+		disable_charger_detector(regmap);
+		msleep(45);
+	}
+
+	return 0;
+}
+
+static void usb_charger_is_present(struct usb_charger *charger, bool present)
+{
+	if (present)
+		charger->present = 1;
+	else
+		charger->present = 0;
+
+	power_supply_changed(&charger->psy);
+	sysfs_notify(&charger->psy.dev->kobj, NULL, "present");
+}
+
+/*
+ * imx6_usb_vbus_connect - inform about VBUS connection
+ * @charger: the usb charger
+ *
+ * Inform the charger VBUS is connected, vbus detect supplier should call it.
+ * Besides, the USB device controller is expected to keep the dataline
+ * pullups disabled.
+ */
+int imx6_usb_vbus_connect(struct usb_charger *charger)
+{
+	int ret;
+
+	charger->online = 1;
+
+	mutex_lock(&charger->lock);
+
+	/* Start the 1st period charger detection. */
+	ret = imx6_usb_charger_detect(charger);
+	if (ret) {
+		dev_err(charger->dev,
+				"Error occurs during detection: %d\n",
+				ret);
+	} else {
+		if (charger->psy.type == POWER_SUPPLY_TYPE_USB)
+			usb_charger_is_present(charger, true);
+	}
+
+	mutex_unlock(&charger->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL(imx6_usb_vbus_connect);
+
+/*
+ * It must be called after dp is pulled up (from USB controller driver),
+ * That is used to differentiate DCP and CDP
+ */
+int imx6_usb_charger_detect_post(struct usb_charger *charger)
+{
+	struct regmap *regmap = charger->anatop;
+	int val;
+
+	mutex_lock(&charger->lock);
+
+	msleep(40);
+
+	regmap_read(regmap, HW_ANADIG_USB1_CHRG_DET_STAT, &val);
+	if (val & BM_ANADIG_USB1_CHRG_DET_STAT_DM_STATE) {
+		dev_dbg(charger->dev, "It is a dedicate charging port\n");
+		charger->psy.type = POWER_SUPPLY_TYPE_USB_DCP;
+		charger->max_current = 1500;
+	} else {
+		dev_dbg(charger->dev, "It is a charging downstream port\n");
+		charger->psy.type = POWER_SUPPLY_TYPE_USB_CDP;
+		charger->max_current = 900;
+	}
+
+	usb_charger_is_present(charger, true);
+	mutex_unlock(&charger->lock);
+
+	return 0;
+}
+EXPORT_SYMBOL(imx6_usb_charger_detect_post);
+
+/*
+ * imx6_usb_vbus_disconnect - inform about VBUS disconnection
+ * @charger: the usb charger
+ *
+ * Inform the charger that VBUS is disconnected. The charging will be
+ * stopped and the charger properties cleared.
+ */
+int imx6_usb_vbus_disconnect(struct usb_charger *charger)
+{
+	charger->online = 0;
+	charger->max_current = 0;
+	charger->psy.type = POWER_SUPPLY_TYPE_MAINS;
+
+	usb_charger_is_present(charger, false);
+
+	return 0;
+}
+EXPORT_SYMBOL(imx6_usb_vbus_disconnect);
+
+/*
+ * imx6_usb_create_charger - create a USB charger
+ * @charger: the charger to be initialized
+ * @name: name for the power supply
+
+ * Registers a power supply for the charger. The USB Controller
+ * driver will call this after filling struct usb_charger.
+ */
+int imx6_usb_create_charger(struct usb_charger *charger,
+		const char *name)
+{
+	struct power_supply	*psy = &charger->psy;
+
+	if (!charger->dev)
+		return -EINVAL;
+
+	if (name)
+		psy->name = name;
+	else
+		psy->name = "imx6_usb_charger";
+
+	charger->bc = BATTERY_CHARGING_SPEC_1_2;
+	mutex_init(&charger->lock);
+
+	psy->type		= POWER_SUPPLY_TYPE_MAINS;
+	psy->properties		= imx6_usb_charger_power_props;
+	psy->num_properties	= ARRAY_SIZE(imx6_usb_charger_power_props);
+	psy->get_property	= imx6_usb_charger_get_property;
+	psy->supplied_to	= imx6_usb_charger_supplied_to;
+	psy->num_supplicants	= sizeof(imx6_usb_charger_supplied_to)
+		/ sizeof(char *);
+
+	return power_supply_register(charger->dev, psy);
+}
+EXPORT_SYMBOL(imx6_usb_create_charger);
+
+/*
+ * imx6_usb_remove_charger - remove a USB charger
+ * @charger: the charger to be removed
+ *
+ * Unregister the chargers power supply.
+ */
+void imx6_usb_remove_charger(struct usb_charger *charger)
+{
+	power_supply_unregister(&charger->psy);
+}
+EXPORT_SYMBOL(imx6_usb_remove_charger);