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>

1 files changed, 491 insertions, 0 deletions

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");