power_supply: Add driver for TI BQ20Z75 gas gauge IC
authorRhyland Klein <rklein@nvidia.com>
Sun, 5 Sep 2010 22:31:23 +0000 (15:31 -0700)
committerAnton Vorontsov <cbouatmailru@gmail.com>
Mon, 6 Sep 2010 07:35:39 +0000 (11:35 +0400)
This driver depends on I2C and uses SMBUS for communication with
the host.

Signed-off-by: Rhyland Klein <rklein@nvidia.com>
Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>
drivers/power/Kconfig
drivers/power/Makefile
drivers/power/bq20z75.c [new file with mode: 0644]

index c2a1b8b713f67aa9fe096f1541eb8fbdcb74846a..4d9a637539b6cbc5c7f8cc0aee1bda620f72b013 100644 (file)
@@ -109,6 +109,13 @@ config BATTERY_WM97XX
        help
          Say Y to enable support for battery measured by WM97xx aux port.
 
+config BATTERY_BQ20Z75
+        tristate "TI BQ20z75 gas gauge"
+        depends on I2C
+        help
+         Say Y to include support for TI BQ20z75 SBS-compliant
+         gas gauge and protection IC.
+
 config BATTERY_BQ27x00
        tristate "BQ27x00 battery driver"
        depends on I2C
index c73d381037a0b63716529c8a609983b11d5db83d..2799a8418186b8f262e21960ac3d122a2535c45e 100644 (file)
@@ -29,6 +29,7 @@ obj-$(CONFIG_BATTERY_OLPC)    += olpc_battery.o
 obj-$(CONFIG_BATTERY_TOSA)     += tosa_battery.o
 obj-$(CONFIG_BATTERY_COLLIE)   += collie_battery.o
 obj-$(CONFIG_BATTERY_WM97XX)   += wm97xx_battery.o
+obj-$(CONFIG_BATTERY_BQ20Z75)  += bq20z75.o
 obj-$(CONFIG_BATTERY_BQ27x00)  += bq27x00_battery.o
 obj-$(CONFIG_BATTERY_DA9030)   += da9030_battery.o
 obj-$(CONFIG_BATTERY_MAX17040) += max17040_battery.o
diff --git a/drivers/power/bq20z75.c b/drivers/power/bq20z75.c
new file mode 100644 (file)
index 0000000..a1c7ae2
--- /dev/null
@@ -0,0 +1,385 @@
+/*
+ * Gas Gauge driver for TI's BQ20Z75
+ *
+ * Copyright (c) 2010, NVIDIA Corporation.
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/err.h>
+#include <linux/power_supply.h>
+#include <linux/i2c.h>
+#include <linux/slab.h>
+
+enum {
+       REG_MANUFACTURER_DATA,
+       REG_TEMPERATURE,
+       REG_VOLTAGE,
+       REG_CURRENT,
+       REG_CAPACITY,
+       REG_TIME_TO_EMPTY,
+       REG_TIME_TO_FULL,
+       REG_STATUS,
+       REG_CYCLE_COUNT,
+       REG_SERIAL_NUMBER
+};
+
+/* manufacturer access defines */
+#define MANUFACTURER_ACCESS_STATUS     0x0006
+#define MANUFACTURER_ACCESS_SLEEP      0x0011
+
+/* battery status value bits */
+#define BATTERY_CHARGING               0x40
+#define BATTERY_FULL_CHARGED           0x20
+#define BATTERY_FULL_DISCHARGED                0x10
+
+#define BQ20Z75_DATA(_psp, _addr, _min_value, _max_value) { \
+       .psp = _psp, \
+       .addr = _addr, \
+       .min_value = _min_value, \
+       .max_value = _max_value, \
+}
+
+static const struct bq20z75_device_data {
+       enum power_supply_property psp;
+       u8 addr;
+       int min_value;
+       int max_value;
+} bq20z75_data[] = {
+       [REG_MANUFACTURER_DATA] =
+               BQ20Z75_DATA(POWER_SUPPLY_PROP_PRESENT, 0x00, 0, 65535),
+       [REG_TEMPERATURE] =
+               BQ20Z75_DATA(POWER_SUPPLY_PROP_TEMP, 0x08, 0, 65535),
+       [REG_VOLTAGE] =
+               BQ20Z75_DATA(POWER_SUPPLY_PROP_VOLTAGE_NOW, 0x09, 0, 20000),
+       [REG_CURRENT] =
+               BQ20Z75_DATA(POWER_SUPPLY_PROP_CURRENT_NOW, 0x0A, -32768,
+                       32767),
+       [REG_CAPACITY] =
+               BQ20Z75_DATA(POWER_SUPPLY_PROP_CAPACITY, 0x0E, 0, 100),
+       [REG_TIME_TO_EMPTY] =
+               BQ20Z75_DATA(POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG, 0x12, 0,
+                       65535),
+       [REG_TIME_TO_FULL] =
+               BQ20Z75_DATA(POWER_SUPPLY_PROP_TIME_TO_FULL_AVG, 0x13, 0,
+                       65535),
+       [REG_STATUS] =
+               BQ20Z75_DATA(POWER_SUPPLY_PROP_STATUS, 0x16, 0, 65535),
+       [REG_CYCLE_COUNT] =
+               BQ20Z75_DATA(POWER_SUPPLY_PROP_CYCLE_COUNT, 0x17, 0, 65535),
+       [REG_SERIAL_NUMBER] =
+               BQ20Z75_DATA(POWER_SUPPLY_PROP_SERIAL_NUMBER, 0x1C, 0, 65535),
+};
+
+static enum power_supply_property bq20z75_properties[] = {
+       POWER_SUPPLY_PROP_STATUS,
+       POWER_SUPPLY_PROP_HEALTH,
+       POWER_SUPPLY_PROP_PRESENT,
+       POWER_SUPPLY_PROP_TECHNOLOGY,
+       POWER_SUPPLY_PROP_CYCLE_COUNT,
+       POWER_SUPPLY_PROP_VOLTAGE_NOW,
+       POWER_SUPPLY_PROP_CURRENT_NOW,
+       POWER_SUPPLY_PROP_CAPACITY,
+       POWER_SUPPLY_PROP_TEMP,
+       POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG,
+       POWER_SUPPLY_PROP_TIME_TO_FULL_AVG,
+       POWER_SUPPLY_PROP_SERIAL_NUMBER,
+};
+
+struct bq20z75_info {
+       struct i2c_client       *client;
+       struct power_supply     power_supply;
+};
+
+static int bq20z75_get_battery_presence_and_health(
+       struct i2c_client *client, enum power_supply_property psp,
+       union power_supply_propval *val)
+{
+       s32 ret;
+
+       /* Write to ManufacturerAccess with
+        * ManufacturerAccess command and then
+        * read the status */
+       ret = i2c_smbus_write_word_data(client,
+               bq20z75_data[REG_MANUFACTURER_DATA].addr,
+               MANUFACTURER_ACCESS_STATUS);
+       if (ret < 0) {
+               dev_err(&client->dev,
+                       "%s: i2c write for battery presence failed\n",
+                       __func__);
+               return -ENODEV;
+       }
+
+       ret = i2c_smbus_read_word_data(client,
+               bq20z75_data[REG_MANUFACTURER_DATA].addr);
+       if (ret < 0) {
+               dev_err(&client->dev,
+                       "%s: i2c read for battery presence failed\n",
+                       __func__);
+               return -EIO;
+       }
+
+       if (ret < bq20z75_data[REG_MANUFACTURER_DATA].min_value ||
+           ret > bq20z75_data[REG_MANUFACTURER_DATA].max_value) {
+               val->intval = 0;
+               return 0;
+       }
+
+       /* Mask the upper nibble of 2nd byte and
+        * lower byte of response then
+        * shift the result by 8 to get status*/
+       ret &= 0x0F00;
+       ret >>= 8;
+       if (psp == POWER_SUPPLY_PROP_PRESENT) {
+               if (ret == 0x0F)
+                       /* battery removed */
+                       val->intval = 0;
+               else
+                       val->intval = 1;
+       } else if (psp == POWER_SUPPLY_PROP_HEALTH) {
+               if (ret == 0x09)
+                       val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
+               else if (ret == 0x0B)
+                       val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
+               else if (ret == 0x0C)
+                       val->intval = POWER_SUPPLY_HEALTH_DEAD;
+               else
+                       val->intval = POWER_SUPPLY_HEALTH_GOOD;
+       }
+
+       return 0;
+}
+
+static int bq20z75_get_battery_property(struct i2c_client *client,
+       int reg_offset, enum power_supply_property psp,
+       union power_supply_propval *val)
+{
+       s32 ret;
+
+       ret = i2c_smbus_read_word_data(client,
+               bq20z75_data[reg_offset].addr);
+       if (ret < 0) {
+               dev_err(&client->dev,
+                       "%s: i2c read for %d failed\n", __func__, reg_offset);
+               return -EIO;
+       }
+
+       if (ret >= bq20z75_data[reg_offset].min_value &&
+           ret <= bq20z75_data[reg_offset].max_value) {
+               val->intval = ret;
+               if (psp == POWER_SUPPLY_PROP_STATUS) {
+                       if (ret & BATTERY_CHARGING)
+                               val->intval = POWER_SUPPLY_STATUS_CHARGING;
+                       else if (ret & BATTERY_FULL_CHARGED)
+                               val->intval = POWER_SUPPLY_STATUS_FULL;
+                       else if (ret & BATTERY_FULL_DISCHARGED)
+                               val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
+                       else
+                               val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
+               }
+               /* bq20z75 provides battery tempreture in 0.1°K
+                * so convert it to °C */
+               else if (psp == POWER_SUPPLY_PROP_TEMP)
+                       val->intval = ret - 2731;
+       } else {
+               if (psp == POWER_SUPPLY_PROP_STATUS)
+                       val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
+               else
+                       val->intval = 0;
+       }
+
+       return 0;
+}
+
+static int bq20z75_get_battery_capacity(struct i2c_client *client,
+       union power_supply_propval *val)
+{
+       s32 ret;
+
+       ret = i2c_smbus_read_byte_data(client, bq20z75_data[REG_CAPACITY].addr);
+       if (ret < 0) {
+               dev_err(&client->dev,
+                       "%s: i2c read for %d failed\n", __func__, REG_CAPACITY);
+               return -EIO;
+       }
+
+       /* bq20z75 spec says that this can be >100 %
+        * even if max value is 100 % */
+       val->intval = min(ret, 100);
+
+       return 0;
+}
+
+static int bq20z75_get_property(struct power_supply *psy,
+       enum power_supply_property psp,
+       union power_supply_propval *val)
+{
+       int count;
+       int ret;
+       struct bq20z75_info *bq20z75_device = container_of(psy,
+                               struct bq20z75_info, power_supply);
+       struct i2c_client *client = bq20z75_device->client;
+
+       switch (psp) {
+       case POWER_SUPPLY_PROP_PRESENT:
+       case POWER_SUPPLY_PROP_HEALTH:
+               ret = bq20z75_get_battery_presence_and_health(client, psp, val);
+               if (ret)
+                       return ret;
+               break;
+
+       case POWER_SUPPLY_PROP_TECHNOLOGY:
+               val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
+               break;
+
+       case POWER_SUPPLY_PROP_CAPACITY:
+               ret = bq20z75_get_battery_capacity(client, val);
+               if (ret)
+                       return ret;
+               break;
+
+       case POWER_SUPPLY_PROP_STATUS:
+       case POWER_SUPPLY_PROP_CYCLE_COUNT:
+       case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+       case POWER_SUPPLY_PROP_CURRENT_NOW:
+       case POWER_SUPPLY_PROP_TEMP:
+       case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
+       case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG:
+       case POWER_SUPPLY_PROP_SERIAL_NUMBER:
+               for (count = 0; count < ARRAY_SIZE(bq20z75_data); count++) {
+                       if (psp == bq20z75_data[count].psp)
+                               break;
+               }
+
+               ret = bq20z75_get_battery_property(client, count, psp, val);
+               if (ret)
+                       return ret;
+               break;
+
+       default:
+               dev_err(&client->dev,
+                       "%s: INVALID property\n", __func__);
+               return -EINVAL;
+       }
+
+       dev_dbg(&client->dev,
+               "%s: property = %d, value = %d\n", __func__, psp, val->intval);
+
+       return 0;
+}
+
+static int bq20z75_probe(struct i2c_client *client,
+       const struct i2c_device_id *id)
+{
+       struct bq20z75_info *bq20z75_device;
+       int rc;
+
+       bq20z75_device = kzalloc(sizeof(struct bq20z75_info), GFP_KERNEL);
+       if (!bq20z75_device)
+               return -ENOMEM;
+
+       bq20z75_device->client = client;
+       bq20z75_device->power_supply.name = "battery";
+       bq20z75_device->power_supply.type = POWER_SUPPLY_TYPE_BATTERY;
+       bq20z75_device->power_supply.properties = bq20z75_properties;
+       bq20z75_device->power_supply.num_properties =
+               ARRAY_SIZE(bq20z75_properties);
+       bq20z75_device->power_supply.get_property = bq20z75_get_property;
+
+       i2c_set_clientdata(client, bq20z75_device);
+
+       rc = power_supply_register(&client->dev, &bq20z75_device->power_supply);
+       if (rc) {
+               dev_err(&client->dev,
+                       "%s: Failed to register power supply\n", __func__);
+               kfree(bq20z75_device);
+               return rc;
+       }
+
+       dev_info(&client->dev,
+               "%s: battery gas gauge device registered\n", client->name);
+
+       return 0;
+}
+
+static int bq20z75_remove(struct i2c_client *client)
+{
+       struct bq20z75_info *bq20z75_device = i2c_get_clientdata(client);
+
+       power_supply_unregister(&bq20z75_device->power_supply);
+       kfree(bq20z75_device);
+       bq20z75_device = NULL;
+
+       return 0;
+}
+
+#if defined CONFIG_PM
+static int bq20z75_suspend(struct i2c_client *client,
+       pm_message_t state)
+{
+       s32 ret;
+
+       /* write to manufacturer access with sleep command */
+       ret = i2c_smbus_write_word_data(client,
+               bq20z75_data[REG_MANUFACTURER_DATA].addr,
+               MANUFACTURER_ACCESS_SLEEP);
+       if (ret < 0) {
+               dev_err(&client->dev,
+                       "%s: i2c write for %d failed\n",
+                       __func__, MANUFACTURER_ACCESS_SLEEP);
+               return -EIO;
+       }
+
+       return 0;
+}
+#else
+#define bq20z75_suspend                NULL
+#endif
+/* any smbus transaction will wake up bq20z75 */
+#define bq20z75_resume         NULL
+
+static const struct i2c_device_id bq20z75_id[] = {
+       { "bq20z75", 0 },
+       {}
+};
+
+static struct i2c_driver bq20z75_battery_driver = {
+       .probe          = bq20z75_probe,
+       .remove         = bq20z75_remove,
+       .suspend        = bq20z75_suspend,
+       .resume         = bq20z75_resume,
+       .id_table       = bq20z75_id,
+       .driver = {
+               .name   = "bq20z75-battery",
+       },
+};
+
+static int __init bq20z75_battery_init(void)
+{
+       return i2c_add_driver(&bq20z75_battery_driver);
+}
+module_init(bq20z75_battery_init);
+
+static void __exit bq20z75_battery_exit(void)
+{
+       i2c_del_driver(&bq20z75_battery_driver);
+}
+module_exit(bq20z75_battery_exit);
+
+MODULE_DESCRIPTION("BQ20z75 battery monitor driver");
+MODULE_LICENSE("GPL");