power_supply: Add LP8727 charger driver

National Semiconductor LP8727 is the battery charger with Micro/Mini
USB interface. This IC includes below functions:

- I2C interface for accessing user registers
- Single input Li-Ion battery charger
- Charger input ID detection from Micro/Mini USB
- Multiplexing switches on USB, UART

Signed-off-by: Woogyom Kim <milo.kim@ti.com>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>

3 files changed, 498 insertions, 0 deletions

diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
index 363f4d1ae067..ac807c4fda57 100644
--- a/drivers/power/Kconfig
+++ b/drivers/power/Kconfig
@@ -225,6 +225,12 @@ config CHARGER_TWL4030
 	help
 	  Say Y here to enable support for TWL4030 Battery Charge Interface.
 
+config CHARGER_LP8727
+	tristate "National Semiconductor LP8727 charger driver"
+	depends on I2C
+	help
+	  Say Y here to enable support for LP8727 Charger Driver.
+
 config CHARGER_GPIO
 	tristate "GPIO charger"
 	depends on GPIOLIB
diff --git a/drivers/power/Makefile b/drivers/power/Makefile
index d3b24e99acbe..9a78b1dd570b 100644
--- a/drivers/power/Makefile
+++ b/drivers/power/Makefile
@@ -35,6 +35,7 @@ obj-$(CONFIG_BATTERY_INTEL_MID)	+= intel_mid_battery.o
 obj-$(CONFIG_CHARGER_ISP1704)	+= isp1704_charger.o
 obj-$(CONFIG_CHARGER_MAX8903)	+= max8903_charger.o
 obj-$(CONFIG_CHARGER_TWL4030)	+= twl4030_charger.o
+obj-$(CONFIG_CHARGER_LP8727)	+= lp8727_charger.o
 obj-$(CONFIG_CHARGER_GPIO)	+= gpio-charger.o
 obj-$(CONFIG_CHARGER_MANAGER)	+= charger-manager.o
 obj-$(CONFIG_CHARGER_MAX8997)	+= max8997_charger.o
diff --git a/drivers/power/lp8727_charger.c b/drivers/power/lp8727_charger.c
new file mode 100644
index 000000000000..2a649e07ddde
--- /dev/null
+++ b/drivers/power/lp8727_charger.c
@@ -0,0 +1,491 @@
+/*
+ * Driver for LP8727 Micro/Mini USB IC with intergrated charger
+ *
+ *			Copyright (C) 2011 National Semiconductor
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/i2c.h>
+#include <linux/power_supply.h>
+#include <linux/lp8727.h>
+
+#define DEBOUNCE_MSEC	270
+
+/* Registers */
+#define CTRL1		0x1
+#define CTRL2		0x2
+#define	SWCTRL		0x3
+#define INT1		0x4
+#define INT2		0x5
+#define STATUS1		0x6
+#define STATUS2 	0x7
+#define CHGCTRL2	0x9
+
+/* CTRL1 register */
+#define CP_EN		(1 << 0)
+#define ADC_EN		(1 << 1)
+#define ID200_EN	(1 << 4)
+
+/* CTRL2 register */
+#define CHGDET_EN	(1 << 1)
+#define INT_EN		(1 << 6)
+
+/* SWCTRL register */
+#define SW_DM1_DM	(0x0 << 0)
+#define SW_DM1_U1	(0x1 << 0)
+#define SW_DM1_HiZ	(0x7 << 0)
+#define SW_DP2_DP	(0x0 << 3)
+#define SW_DP2_U2	(0x1 << 3)
+#define SW_DP2_HiZ	(0x7 << 3)
+
+/* INT1 register */
+#define IDNO		(0xF << 0)
+#define VBUS		(1 << 4)
+
+/* STATUS1 register */
+#define CHGSTAT		(3 << 4)
+#define CHPORT		(1 << 6)
+#define DCPORT		(1 << 7)
+
+/* STATUS2 register */
+#define TEMP_STAT	(3 << 5)
+
+enum lp8727_dev_id {
+	ID_NONE,
+	ID_TA,
+	ID_DEDICATED_CHG,
+	ID_USB_CHG,
+	ID_USB_DS,
+	ID_MAX,
+};
+
+enum lp8727_chg_stat {
+	PRECHG,
+	CC,
+	CV,
+	EOC,
+};
+
+struct lp8727_psy {
+	struct power_supply ac;
+	struct power_supply usb;
+	struct power_supply batt;
+};
+
+struct lp8727_chg {
+	struct device *dev;
+	struct i2c_client *client;
+	struct mutex xfer_lock;
+	struct delayed_work work;
+	struct workqueue_struct *irqthread;
+	struct lp8727_platform_data *pdata;
+	struct lp8727_psy *psy;
+	struct lp8727_chg_param *chg_parm;
+	enum lp8727_dev_id devid;
+};
+
+static int lp8727_i2c_read(struct lp8727_chg *pchg, u8 reg, u8 * data, u8 len)
+{
+	s32 ret;
+
+	mutex_lock(&pchg->xfer_lock);
+	ret = i2c_smbus_read_i2c_block_data(pchg->client, reg, len, data);
+	mutex_unlock(&pchg->xfer_lock);
+
+	return (ret != len) ? -EIO : 0;
+}
+
+static int lp8727_i2c_write(struct lp8727_chg *pchg, u8 reg, u8 * data, u8 len)
+{
+	s32 ret;
+
+	mutex_lock(&pchg->xfer_lock);
+	ret = i2c_smbus_write_i2c_block_data(pchg->client, reg, len, data);
+	mutex_unlock(&pchg->xfer_lock);
+
+	return ret;
+}
+
+static inline int lp8727_i2c_read_byte(struct lp8727_chg *pchg, u8 reg,
+				       u8 * data)
+{
+	return lp8727_i2c_read(pchg, reg, data, 1);
+}
+
+static inline int lp8727_i2c_write_byte(struct lp8727_chg *pchg, u8 reg,
+					u8 * data)
+{
+	return lp8727_i2c_write(pchg, reg, data, 1);
+}
+
+static int lp8727_is_charger_attached(const char *name, int id)
+{
+	if (name) {
+		if (!strcmp(name, "ac"))
+			return (id == ID_TA || id == ID_DEDICATED_CHG) ? 1 : 0;
+		else if (!strcmp(name, "usb"))
+			return (id == ID_USB_CHG) ? 1 : 0;
+	}
+
+	return (id >= ID_TA && id <= ID_USB_CHG) ? 1 : 0;
+}
+
+static void lp8727_init_device(struct lp8727_chg *pchg)
+{
+	u8 val;
+
+	val = ID200_EN | ADC_EN | CP_EN;
+	if (lp8727_i2c_write_byte(pchg, CTRL1, &val))
+		dev_err(pchg->dev, "i2c write err : addr=0x%.2x\n", CTRL1);
+
+	val = INT_EN | CHGDET_EN;
+	if (lp8727_i2c_write_byte(pchg, CTRL2, &val))
+		dev_err(pchg->dev, "i2c write err : addr=0x%.2x\n", CTRL2);
+}
+
+static int lp8727_is_dedicated_charger(struct lp8727_chg *pchg)
+{
+	u8 val;
+	(void)lp8727_i2c_read_byte(pchg, STATUS1, &val);
+	return (val & DCPORT);
+}
+
+static int lp8727_is_usb_charger(struct lp8727_chg *pchg)
+{
+	u8 val;
+	(void)lp8727_i2c_read_byte(pchg, STATUS1, &val);
+	return (val & CHPORT);
+}
+
+static void lp8727_ctrl_switch(struct lp8727_chg *pchg, u8 sw)
+{
+	u8 val = sw;
+	(void)lp8727_i2c_write_byte(pchg, SWCTRL, &val);
+}
+
+static void lp8727_id_detection(struct lp8727_chg *pchg, u8 id, int vbusin)
+{
+	u8 devid = ID_NONE;
+	u8 swctrl = SW_DM1_HiZ | SW_DP2_HiZ;
+
+	switch (id) {
+	case 0x5:
+		devid = ID_TA;
+		pchg->chg_parm = &pchg->pdata->ac;
+		break;
+	case 0xB:
+		if (lp8727_is_dedicated_charger(pchg)) {
+			pchg->chg_parm = &pchg->pdata->ac;
+			devid = ID_DEDICATED_CHG;
+		} else if (lp8727_is_usb_charger(pchg)) {
+			pchg->chg_parm = &pchg->pdata->usb;
+			devid = ID_USB_CHG;
+			swctrl = SW_DM1_DM | SW_DP2_DP;
+		} else if (vbusin) {
+			devid = ID_USB_DS;
+			swctrl = SW_DM1_DM | SW_DP2_DP;
+		}
+		break;
+	default:
+		devid = ID_NONE;
+		pchg->chg_parm = NULL;
+		break;
+	}
+
+	pchg->devid = devid;
+	lp8727_ctrl_switch(pchg, swctrl);
+}
+
+static void lp8727_enable_chgdet(struct lp8727_chg *pchg)
+{
+	u8 val;
+
+	(void)lp8727_i2c_read_byte(pchg, CTRL2, &val);
+	val |= CHGDET_EN;
+	(void)lp8727_i2c_write_byte(pchg, CTRL2, &val);
+}
+
+static void lp8727_delayed_func(struct work_struct *_work)
+{
+	u8 intstat[2], idno, vbus;
+	struct lp8727_chg *pchg =
+	    container_of(_work, struct lp8727_chg, work.work);
+
+	if (lp8727_i2c_read(pchg, INT1, intstat, 2)) {
+		dev_err(pchg->dev, "can not read INT registers\n");
+		return;
+	}
+
+	idno = intstat[0] & IDNO;
+	vbus = intstat[0] & VBUS;
+
+	lp8727_id_detection(pchg, idno, vbus);
+	lp8727_enable_chgdet(pchg);
+
+	power_supply_changed(&pchg->psy->ac);
+	power_supply_changed(&pchg->psy->usb);
+	power_supply_changed(&pchg->psy->batt);
+}
+
+static irqreturn_t lp8727_isr_func(int irq, void *ptr)
+{
+	struct lp8727_chg *pchg = ptr;
+	unsigned long delay = msecs_to_jiffies(DEBOUNCE_MSEC);
+
+	queue_delayed_work(pchg->irqthread, &pchg->work, delay);
+
+	return IRQ_HANDLED;
+}
+
+static void lp8727_intr_config(struct lp8727_chg *pchg)
+{
+	INIT_DELAYED_WORK(&pchg->work, lp8727_delayed_func);
+
+	pchg->irqthread = create_singlethread_workqueue("lp8727-irqthd");
+	if (!pchg->irqthread)
+		dev_err(pchg->dev, "can not create thread for lp8727\n");
+
+	if (request_threaded_irq(pchg->client->irq,
+				 NULL,
+				 lp8727_isr_func,
+				 IRQF_TRIGGER_FALLING, "lp8727_irq", pchg)) {
+		dev_err(pchg->dev, "lp8727 irq can not be registered\n");
+	}
+}
+
+static enum power_supply_property lp8727_charger_prop[] = {
+	POWER_SUPPLY_PROP_ONLINE,
+};
+
+static enum power_supply_property lp8727_battery_prop[] = {
+	POWER_SUPPLY_PROP_STATUS,
+	POWER_SUPPLY_PROP_HEALTH,
+	POWER_SUPPLY_PROP_PRESENT,
+	POWER_SUPPLY_PROP_VOLTAGE_NOW,
+	POWER_SUPPLY_PROP_CAPACITY,
+	POWER_SUPPLY_PROP_TEMP,
+};
+
+static char *battery_supplied_to[] = {
+	"main_batt",
+};
+
+static int lp8727_charger_get_property(struct power_supply *psy,
+				       enum power_supply_property psp,
+				       union power_supply_propval *val)
+{
+	struct lp8727_chg *pchg = dev_get_drvdata(psy->dev->parent);
+
+	if (psp == POWER_SUPPLY_PROP_ONLINE) {
+		val->intval = lp8727_is_charger_attached(psy->name,
+							 pchg->devid);
+	}
+
+	return 0;
+}
+
+static int lp8727_battery_get_property(struct power_supply *psy,
+				       enum power_supply_property psp,
+				       union power_supply_propval *val)
+{
+	struct lp8727_chg *pchg = dev_get_drvdata(psy->dev->parent);
+	u8 read;
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_STATUS:
+		if (lp8727_is_charger_attached(psy->name, pchg->devid)) {
+			(void)lp8727_i2c_read_byte(pchg, STATUS1, &read);
+			if (((read & CHGSTAT) >> 4) == EOC)
+				val->intval = POWER_SUPPLY_STATUS_FULL;
+			else
+				val->intval = POWER_SUPPLY_STATUS_CHARGING;
+		} else {
+			val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
+		}
+		break;
+	case POWER_SUPPLY_PROP_HEALTH:
+		(void)lp8727_i2c_read_byte(pchg, STATUS2, &read);
+		read = (read & TEMP_STAT) >> 5;
+		if (read >= 0x1 && read <= 0x3)
+			val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
+		else
+			val->intval = POWER_SUPPLY_HEALTH_GOOD;
+		break;
+	case POWER_SUPPLY_PROP_PRESENT:
+		if (pchg->pdata->get_batt_present)
+			val->intval = pchg->pdata->get_batt_present();
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+		if (pchg->pdata->get_batt_level)
+			val->intval = pchg->pdata->get_batt_level();
+		break;
+	case POWER_SUPPLY_PROP_CAPACITY:
+		if (pchg->pdata->get_batt_capacity)
+			val->intval = pchg->pdata->get_batt_capacity();
+		break;
+	case POWER_SUPPLY_PROP_TEMP:
+		if (pchg->pdata->get_batt_temp)
+			val->intval = pchg->pdata->get_batt_temp();
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+static void lp8727_charger_changed(struct power_supply *psy)
+{
+	struct lp8727_chg *pchg = dev_get_drvdata(psy->dev->parent);
+	u8 val;
+	u8 eoc_level, ichg;
+
+	if (lp8727_is_charger_attached(psy->name, pchg->devid)) {
+		if (pchg->chg_parm) {
+			eoc_level = pchg->chg_parm->eoc_level;
+			ichg = pchg->chg_parm->ichg;
+			val = (ichg << 4) | eoc_level;
+			(void)lp8727_i2c_write_byte(pchg, CHGCTRL2, &val);
+		}
+	}
+}
+
+static int lp8727_register_psy(struct lp8727_chg *pchg)
+{
+	struct lp8727_psy *psy;
+
+	psy = kzalloc(sizeof(*psy), GFP_KERNEL);
+	if (!psy)
+		goto err_mem;
+
+	pchg->psy = psy;
+
+	psy->ac.name = "ac";
+	psy->ac.type = POWER_SUPPLY_TYPE_MAINS;
+	psy->ac.properties = lp8727_charger_prop;
+	psy->ac.num_properties = ARRAY_SIZE(lp8727_charger_prop);
+	psy->ac.get_property = lp8727_charger_get_property;
+	psy->ac.supplied_to = battery_supplied_to;
+	psy->ac.num_supplicants = ARRAY_SIZE(battery_supplied_to);
+
+	if (power_supply_register(pchg->dev, &psy->ac))
+		goto err_psy;
+
+	psy->usb.name = "usb";
+	psy->usb.type = POWER_SUPPLY_TYPE_USB;
+	psy->usb.properties = lp8727_charger_prop;
+	psy->usb.num_properties = ARRAY_SIZE(lp8727_charger_prop);
+	psy->usb.get_property = lp8727_charger_get_property;
+	psy->usb.supplied_to = battery_supplied_to;
+	psy->usb.num_supplicants = ARRAY_SIZE(battery_supplied_to);
+
+	if (power_supply_register(pchg->dev, &psy->usb))
+		goto err_psy;
+
+	psy->batt.name = "main_batt";
+	psy->batt.type = POWER_SUPPLY_TYPE_BATTERY;
+	psy->batt.properties = lp8727_battery_prop;
+	psy->batt.num_properties = ARRAY_SIZE(lp8727_battery_prop);
+	psy->batt.get_property = lp8727_battery_get_property;
+	psy->batt.external_power_changed = lp8727_charger_changed;
+
+	if (power_supply_register(pchg->dev, &psy->batt))
+		goto err_psy;
+
+	return 0;
+
+err_mem:
+	return -ENOMEM;
+err_psy:
+	kfree(psy);
+	return -EPERM;
+}
+
+static void lp8727_unregister_psy(struct lp8727_chg *pchg)
+{
+	struct lp8727_psy *psy = pchg->psy;
+
+	if (psy) {
+		power_supply_unregister(&psy->ac);
+		power_supply_unregister(&psy->usb);
+		power_supply_unregister(&psy->batt);
+		kfree(psy);
+	}
+}
+
+static int lp8727_probe(struct i2c_client *cl, const struct i2c_device_id *id)
+{
+	struct lp8727_chg *pchg;
+	int ret;
+
+	pchg = kzalloc(sizeof(*pchg), GFP_KERNEL);
+	if (!pchg)
+		return -ENOMEM;
+
+	pchg->client = cl;
+	pchg->dev = &cl->dev;
+	pchg->pdata = cl->dev.platform_data;
+	i2c_set_clientdata(cl, pchg);
+
+	mutex_init(&pchg->xfer_lock);
+
+	lp8727_init_device(pchg);
+	lp8727_intr_config(pchg);
+
+	ret = lp8727_register_psy(pchg);
+	if (ret) {
+		dev_err(pchg->dev,
+			"can not register power supplies. err=%d", ret);
+	}
+
+	return 0;
+}
+
+static int __devexit lp8727_remove(struct i2c_client *cl)
+{
+	struct lp8727_chg *pchg = i2c_get_clientdata(cl);
+
+	lp8727_unregister_psy(pchg);
+	free_irq(pchg->client->irq, pchg);
+	flush_workqueue(pchg->irqthread);
+	destroy_workqueue(pchg->irqthread);
+	kfree(pchg);
+	return 0;
+}
+
+static const struct i2c_device_id lp8727_ids[] = {
+	{"lp8727", 0},
+};
+
+static struct i2c_driver lp8727_driver = {
+	.driver = {
+		   .name = "lp8727",
+		   },
+	.probe = lp8727_probe,
+	.remove = __devexit_p(lp8727_remove),
+	.id_table = lp8727_ids,
+};
+
+static int __init lp8727_init(void)
+{
+	return i2c_add_driver(&lp8727_driver);
+}
+
+static void __exit lp8727_chg_exit(void)
+{
+	i2c_del_driver(&lp8727_driver);
+}
+
+module_init(lp8727_init);
+module_exit(lp8727_chg_exit);
+
+MODULE_DESCRIPTION("National Semiconductor LP8727 charger driver");
+MODULE_AUTHOR("Woogyom Kim <milo.kim@nsc.com>");
+MODULE_LICENSE("GPL");