power_supply: Add support for bq24735 charger

Adds support for the bq24735 charger chipset. The bq24735 is a
high-efficiency, synchronous battery charger.

It allows control of the charging current, input current, and the charger
voltage DAC's through SMBus.

Signed-off-by: Darbha Sriharsha <dsriharsha@nvidia.com>
Signed-off-by: Rhyland Klein <rklein@nvidia.com>
Thanks-to: Stephen Warren <swarren@wwwdotorg.org>
Thanks-to: Thierry Reding <thierry.reding@gmail.com>
Thanks-to: Manish Badarkhe <badarkhe.manish@gmail.com>
Signed-off-by: Anton Vorontsov <anton@enomsg.org>

3 files changed, 426 insertions, 0 deletions

diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
index e6f92b450913..5e2054afe840 100644
--- a/drivers/power/Kconfig
+++ b/drivers/power/Kconfig
@@ -346,6 +346,12 @@ config CHARGER_BQ24190
         help
           Say Y to enable support for the TI BQ24190 battery charger.
 
+config CHARGER_BQ24735
+        tristate "TI BQ24735 battery charger support"
+        depends on I2C && GPIOLIB
+        help
+          Say Y to enable support for the TI BQ24735 battery charger.
+
 config CHARGER_SMB347
         tristate "Summit Microelectronics SMB347 Battery Charger"
         depends on I2C
diff --git a/drivers/power/Makefile b/drivers/power/Makefile
index a4b74177706f..372b4e8ab598 100644
--- a/drivers/power/Makefile
+++ b/drivers/power/Makefile
@@ -52,6 +52,7 @@ obj-$(CONFIG_CHARGER_MAX8997)	+= max8997_charger.o
 obj-$(CONFIG_CHARGER_MAX8998)   += max8998_charger.o
 obj-$(CONFIG_CHARGER_BQ2415X)   += bq2415x_charger.o
 obj-$(CONFIG_CHARGER_BQ24190)   += bq24190_charger.o
+obj-$(CONFIG_CHARGER_BQ24735)   += bq24735-charger.o
 obj-$(CONFIG_POWER_AVS)         += avs/
 obj-$(CONFIG_CHARGER_SMB347)    += smb347-charger.o
 obj-$(CONFIG_CHARGER_TPS65090)  += tps65090-charger.o
diff --git a/drivers/power/bq24735-charger.c b/drivers/power/bq24735-charger.c
new file mode 100644
index 000000000000..d022b823305b
--- /dev/null
+++ b/drivers/power/bq24735-charger.c
@@ -0,0 +1,419 @@
+/*
+ * Battery charger driver for TI BQ24735
+ *
+ * Copyright (c) 2013, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation;
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+#include <linux/err.h>
+#include <linux/gpio.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/power_supply.h>
+#include <linux/slab.h>
+
+#include <linux/power/bq24735-charger.h>
+
+#define BQ24735_CHG_OPT                 0x12
+#define BQ24735_CHG_OPT_CHARGE_DISABLE  (1 << 0)
+#define BQ24735_CHG_OPT_AC_PRESENT      (1 << 4)
+#define BQ24735_CHARGE_CURRENT          0x14
+#define BQ24735_CHARGE_CURRENT_MASK     0x1fc0
+#define BQ24735_CHARGE_VOLTAGE          0x15
+#define BQ24735_CHARGE_VOLTAGE_MASK     0x7ff0
+#define BQ24735_INPUT_CURRENT           0x3f
+#define BQ24735_INPUT_CURRENT_MASK      0x1f80
+#define BQ24735_MANUFACTURER_ID         0xfe
+#define BQ24735_DEVICE_ID               0xff
+
+struct bq24735 {
+        struct power_supply     charger;
+        struct i2c_client       *client;
+        struct bq24735_platform *pdata;
+};
+
+static inline struct bq24735 *to_bq24735(struct power_supply *psy)
+{
+        return container_of(psy, struct bq24735, charger);
+}
+
+static enum power_supply_property bq24735_charger_properties[] = {
+        POWER_SUPPLY_PROP_ONLINE,
+};
+
+static inline int bq24735_write_word(struct i2c_client *client, u8 reg,
+                                     u16 value)
+{
+        return i2c_smbus_write_word_data(client, reg, le16_to_cpu(value));
+}
+
+static inline int bq24735_read_word(struct i2c_client *client, u8 reg)
+{
+        s32 ret = i2c_smbus_read_word_data(client, reg);
+
+        return ret < 0 ? ret : le16_to_cpu(ret);
+}
+
+static int bq24735_update_word(struct i2c_client *client, u8 reg,
+                               u16 mask, u16 value)
+{
+        unsigned int tmp;
+        int ret;
+
+        ret = bq24735_read_word(client, reg);
+        if (ret < 0)
+                return ret;
+
+        tmp = ret & ~mask;
+        tmp |= value & mask;
+
+        return bq24735_write_word(client, reg, tmp);
+}
+
+static inline int bq24735_enable_charging(struct bq24735 *charger)
+{
+        return bq24735_update_word(charger->client, BQ24735_CHG_OPT,
+                                   BQ24735_CHG_OPT_CHARGE_DISABLE,
+                                   ~BQ24735_CHG_OPT_CHARGE_DISABLE);
+}
+
+static inline int bq24735_disable_charging(struct bq24735 *charger)
+{
+        return bq24735_update_word(charger->client, BQ24735_CHG_OPT,
+                                   BQ24735_CHG_OPT_CHARGE_DISABLE,
+                                   BQ24735_CHG_OPT_CHARGE_DISABLE);
+}
+
+static int bq24735_config_charger(struct bq24735 *charger)
+{
+        struct bq24735_platform *pdata = charger->pdata;
+        int ret;
+        u16 value;
+
+        if (pdata->charge_current) {
+                value = pdata->charge_current & BQ24735_CHARGE_CURRENT_MASK;
+
+                ret = bq24735_write_word(charger->client,
+                                         BQ24735_CHARGE_CURRENT, value);
+                if (ret < 0) {
+                        dev_err(&charger->client->dev,
+                                "Failed to write charger current : %d\n",
+                                ret);
+                        return ret;
+                }
+        }
+
+        if (pdata->charge_voltage) {
+                value = pdata->charge_voltage & BQ24735_CHARGE_VOLTAGE_MASK;
+
+                ret = bq24735_write_word(charger->client,
+                                         BQ24735_CHARGE_VOLTAGE, value);
+                if (ret < 0) {
+                        dev_err(&charger->client->dev,
+                                "Failed to write charger voltage : %d\n",
+                                ret);
+                        return ret;
+                }
+        }
+
+        if (pdata->input_current) {
+                value = pdata->input_current & BQ24735_INPUT_CURRENT_MASK;
+
+                ret = bq24735_write_word(charger->client,
+                                         BQ24735_INPUT_CURRENT, value);
+                if (ret < 0) {
+                        dev_err(&charger->client->dev,
+                                "Failed to write input current : %d\n",
+                                ret);
+                        return ret;
+                }
+        }
+
+        return 0;
+}
+
+static bool bq24735_charger_is_present(struct bq24735 *charger)
+{
+        struct bq24735_platform *pdata = charger->pdata;
+        int ret;
+
+        if (pdata->status_gpio_valid) {
+                ret = gpio_get_value_cansleep(pdata->status_gpio);
+                return ret ^= pdata->status_gpio_active_low == 0;
+        } else {
+                int ac = 0;
+
+                ac = bq24735_read_word(charger->client, BQ24735_CHG_OPT);
+                if (ac < 0) {
+                        dev_err(&charger->client->dev,
+                                "Failed to read charger options : %d\n",
+                                ac);
+                        return false;
+                }
+                return (ac & BQ24735_CHG_OPT_AC_PRESENT) ? true : false;
+        }
+
+        return false;
+}
+
+static irqreturn_t bq24735_charger_isr(int irq, void *devid)
+{
+        struct power_supply *psy = devid;
+        struct bq24735 *charger = to_bq24735(psy);
+
+        if (bq24735_charger_is_present(charger))
+                bq24735_enable_charging(charger);
+        else
+                bq24735_disable_charging(charger);
+
+        power_supply_changed(psy);
+
+        return IRQ_HANDLED;
+}
+
+static int bq24735_charger_get_property(struct power_supply *psy,
+                                        enum power_supply_property psp,
+                                        union power_supply_propval *val)
+{
+        struct bq24735 *charger;
+
+        charger = container_of(psy, struct bq24735, charger);
+
+        switch (psp) {
+        case POWER_SUPPLY_PROP_ONLINE:
+                val->intval = bq24735_charger_is_present(charger) ? 1 : 0;
+                break;
+        default:
+                return -EINVAL;
+        }
+
+        return 0;
+}
+
+static struct bq24735_platform *bq24735_parse_dt_data(struct i2c_client *client)
+{
+        struct bq24735_platform *pdata;
+        struct device_node *np = client->dev.of_node;
+        u32 val;
+        int ret;
+        enum of_gpio_flags flags;
+
+        pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL);
+        if (!pdata) {
+                dev_err(&client->dev,
+                        "Memory alloc for bq24735 pdata failed\n");
+                return NULL;
+        }
+
+        pdata->status_gpio = of_get_named_gpio_flags(np, "ti,ac-detect-gpios",
+                                                     0, &flags);
+
+        if (flags & OF_GPIO_ACTIVE_LOW)
+                pdata->status_gpio_active_low = 1;
+
+        ret = of_property_read_u32(np, "ti,charge-current", &val);
+        if (!ret)
+                pdata->charge_current = val;
+
+        ret = of_property_read_u32(np, "ti,charge-voltage", &val);
+        if (!ret)
+                pdata->charge_voltage = val;
+
+        ret = of_property_read_u32(np, "ti,input-current", &val);
+        if (!ret)
+                pdata->input_current = val;
+
+        return pdata;
+}
+
+static int bq24735_charger_probe(struct i2c_client *client,
+                                 const struct i2c_device_id *id)
+{
+        int ret;
+        struct bq24735 *charger;
+        struct power_supply *supply;
+        char *name;
+
+        charger = devm_kzalloc(&client->dev, sizeof(*charger), GFP_KERNEL);
+        if (!charger)
+                return -ENOMEM;
+
+        charger->pdata = client->dev.platform_data;
+
+        if (IS_ENABLED(CONFIG_OF) && !charger->pdata && client->dev.of_node)
+                charger->pdata = bq24735_parse_dt_data(client);
+
+        if (!charger->pdata) {
+                dev_err(&client->dev, "no platform data provided\n");
+                return -EINVAL;
+        }
+
+        name = (char *)charger->pdata->name;
+        if (!name) {
+                name = kasprintf(GFP_KERNEL, "bq24735@%s",
+                                 dev_name(&client->dev));
+                if (!name) {
+                        dev_err(&client->dev, "Failed to alloc device name\n");
+                        return -ENOMEM;
+                }
+        }
+
+        charger->client = client;
+
+        supply = &charger->charger;
+
+        supply->name = name;
+        supply->type = POWER_SUPPLY_TYPE_MAINS;
+        supply->properties = bq24735_charger_properties;
+        supply->num_properties = ARRAY_SIZE(bq24735_charger_properties);
+        supply->get_property = bq24735_charger_get_property;
+        supply->supplied_to = charger->pdata->supplied_to;
+        supply->num_supplicants = charger->pdata->num_supplicants;
+        supply->of_node = client->dev.of_node;
+
+        i2c_set_clientdata(client, charger);
+
+        ret = bq24735_read_word(client, BQ24735_MANUFACTURER_ID);
+        if (ret < 0) {
+                dev_err(&client->dev, "Failed to read manufacturer id : %d\n",
+                        ret);
+                goto err_free_name;
+        } else if (ret != 0x0040) {
+                dev_err(&client->dev,
+                        "manufacturer id mismatch. 0x0040 != 0x%04x\n", ret);
+                ret = -ENODEV;
+                goto err_free_name;
+        }
+
+        ret = bq24735_read_word(client, BQ24735_DEVICE_ID);
+        if (ret < 0) {
+                dev_err(&client->dev, "Failed to read device id : %d\n", ret);
+                goto err_free_name;
+        } else if (ret != 0x000B) {
+                dev_err(&client->dev,
+                        "device id mismatch. 0x000b != 0x%04x\n", ret);
+                ret = -ENODEV;
+                goto err_free_name;
+        }
+
+        if (gpio_is_valid(charger->pdata->status_gpio)) {
+                ret = devm_gpio_request(&client->dev,
+                                        charger->pdata->status_gpio,
+                                        name);
+                if (ret) {
+                        dev_err(&client->dev,
+                                "Failed GPIO request for GPIO %d: %d\n",
+                                charger->pdata->status_gpio, ret);
+                }
+
+                charger->pdata->status_gpio_valid = !ret;
+        }
+
+        ret = bq24735_config_charger(charger);
+        if (ret < 0) {
+                dev_err(&client->dev, "failed in configuring charger");
+                goto err_free_name;
+        }
+
+        /* check for AC adapter presence */
+        if (bq24735_charger_is_present(charger)) {
+                ret = bq24735_enable_charging(charger);
+                if (ret < 0) {
+                        dev_err(&client->dev, "Failed to enable charging\n");
+                        goto err_free_name;
+                }
+        }
+
+        ret = power_supply_register(&client->dev, supply);
+        if (ret < 0) {
+                dev_err(&client->dev, "Failed to register power supply: %d\n",
+                        ret);
+                goto err_free_name;
+        }
+
+        if (client->irq) {
+                ret = devm_request_threaded_irq(&client->dev, client->irq,
+                                                NULL, bq24735_charger_isr,
+                                                IRQF_TRIGGER_RISING |
+                                                IRQF_TRIGGER_FALLING |
+                                                IRQF_ONESHOT,
+                                                supply->name, supply);
+                if (ret) {
+                        dev_err(&client->dev,
+                                "Unable to register IRQ %d err %d\n",
+                                client->irq, ret);
+                        goto err_unregister_supply;
+                }
+        }
+
+        return 0;
+err_unregister_supply:
+        power_supply_unregister(supply);
+err_free_name:
+        if (name != charger->pdata->name)
+                kfree(name);
+
+        return ret;
+}
+
+static int bq24735_charger_remove(struct i2c_client *client)
+{
+        struct bq24735 *charger = i2c_get_clientdata(client);
+
+        if (charger->client->irq)
+                devm_free_irq(&charger->client->dev, charger->client->irq,
+                              &charger->charger);
+
+        power_supply_unregister(&charger->charger);
+
+        if (charger->charger.name != charger->pdata->name)
+                kfree(charger->charger.name);
+
+        return 0;
+}
+
+static const struct i2c_device_id bq24735_charger_id[] = {
+        { "bq24735-charger", 0 },
+        {}
+};
+MODULE_DEVICE_TABLE(i2c, bq24735_charger_id);
+
+static const struct of_device_id bq24735_match_ids[] = {
+        { .compatible = "ti,bq24735", },
+        { /* end */ }
+};
+MODULE_DEVICE_TABLE(of, bq24735_match_ids);
+
+static struct i2c_driver bq24735_charger_driver = {
+        .driver = {
+                .name = "bq24735-charger",
+                .owner = THIS_MODULE,
+                .of_match_table = bq24735_match_ids,
+        },
+        .probe = bq24735_charger_probe,
+        .remove = bq24735_charger_remove,
+        .id_table = bq24735_charger_id,
+};
+
+module_i2c_driver(bq24735_charger_driver);
+
+MODULE_DESCRIPTION("bq24735 battery charging driver");
+MODULE_AUTHOR("Darbha Sriharsha <dsriharsha@nvidia.com>");
+MODULE_LICENSE("GPL v2");