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path: root/drivers/power/supply/ltc2941-battery-gauge.c
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Diffstat (limited to 'drivers/power/supply/ltc2941-battery-gauge.c')
-rw-r--r--drivers/power/supply/ltc2941-battery-gauge.c156
1 files changed, 113 insertions, 43 deletions
diff --git a/drivers/power/supply/ltc2941-battery-gauge.c b/drivers/power/supply/ltc2941-battery-gauge.c
index 7efb908f4451..08e4fd9ee607 100644
--- a/drivers/power/supply/ltc2941-battery-gauge.c
+++ b/drivers/power/supply/ltc2941-battery-gauge.c
@@ -1,6 +1,6 @@
/*
- * I2C client/driver for the Linear Technology LTC2941 and LTC2943
- * Battery Gas Gauge IC
+ * I2C client/driver for the Linear Technology LTC2941, LTC2942, LTC2943
+ * and LTC2944 Battery Gas Gauge IC
*
* Copyright (C) 2014 Topic Embedded Systems
*
@@ -34,35 +34,39 @@ enum ltc294x_reg {
LTC294X_REG_CONTROL = 0x01,
LTC294X_REG_ACC_CHARGE_MSB = 0x02,
LTC294X_REG_ACC_CHARGE_LSB = 0x03,
- LTC294X_REG_THRESH_HIGH_MSB = 0x04,
- LTC294X_REG_THRESH_HIGH_LSB = 0x05,
- LTC294X_REG_THRESH_LOW_MSB = 0x06,
- LTC294X_REG_THRESH_LOW_LSB = 0x07,
- LTC294X_REG_VOLTAGE_MSB = 0x08,
- LTC294X_REG_VOLTAGE_LSB = 0x09,
- LTC294X_REG_CURRENT_MSB = 0x0E,
- LTC294X_REG_CURRENT_LSB = 0x0F,
- LTC294X_REG_TEMPERATURE_MSB = 0x14,
- LTC294X_REG_TEMPERATURE_LSB = 0x15,
+ LTC294X_REG_VOLTAGE_MSB = 0x08,
+ LTC294X_REG_VOLTAGE_LSB = 0x09,
+ LTC2942_REG_TEMPERATURE_MSB = 0x0C,
+ LTC2942_REG_TEMPERATURE_LSB = 0x0D,
+ LTC2943_REG_CURRENT_MSB = 0x0E,
+ LTC2943_REG_CURRENT_LSB = 0x0F,
+ LTC2943_REG_TEMPERATURE_MSB = 0x14,
+ LTC2943_REG_TEMPERATURE_LSB = 0x15,
};
-#define LTC2943_REG_CONTROL_MODE_MASK (BIT(7) | BIT(6))
-#define LTC2943_REG_CONTROL_MODE_SCAN BIT(7)
+enum ltc294x_id {
+ LTC2941_ID,
+ LTC2942_ID,
+ LTC2943_ID,
+ LTC2944_ID,
+};
+
+#define LTC2941_REG_STATUS_CHIP_ID BIT(7)
+
+#define LTC2942_REG_CONTROL_MODE_SCAN (BIT(7) | BIT(6))
+#define LTC2943_REG_CONTROL_MODE_SCAN BIT(7)
#define LTC294X_REG_CONTROL_PRESCALER_MASK (BIT(5) | BIT(4) | BIT(3))
#define LTC294X_REG_CONTROL_SHUTDOWN_MASK (BIT(0))
#define LTC294X_REG_CONTROL_PRESCALER_SET(x) \
((x << 3) & LTC294X_REG_CONTROL_PRESCALER_MASK)
#define LTC294X_REG_CONTROL_ALCC_CONFIG_DISABLED 0
-#define LTC2941_NUM_REGS 0x08
-#define LTC2943_NUM_REGS 0x18
-
struct ltc294x_info {
struct i2c_client *client; /* I2C Client pointer */
struct power_supply *supply; /* Supply pointer */
struct power_supply_desc supply_desc; /* Supply description */
struct delayed_work work; /* Work scheduler */
- unsigned long num_regs; /* Number of registers (chip type) */
+ enum ltc294x_id id; /* Chip type */
int charge; /* Last charge register content */
int r_sense; /* mOhm */
int Qlsb; /* nAh */
@@ -145,9 +149,18 @@ static int ltc294x_reset(const struct ltc294x_info *info, int prescaler_exp)
control = LTC294X_REG_CONTROL_PRESCALER_SET(prescaler_exp) |
LTC294X_REG_CONTROL_ALCC_CONFIG_DISABLED;
- /* Put the 2943 into "monitor" mode, so it measures every 10 sec */
- if (info->num_regs == LTC2943_NUM_REGS)
+ /* Put device into "monitor" mode */
+ switch (info->id) {
+ case LTC2942_ID: /* 2942 measures every 2 sec */
+ control |= LTC2942_REG_CONTROL_MODE_SCAN;
+ break;
+ case LTC2943_ID:
+ case LTC2944_ID: /* 2943 and 2944 measure every 10 sec */
control |= LTC2943_REG_CONTROL_MODE_SCAN;
+ break;
+ default:
+ break;
+ }
if (value != control) {
ret = ltc294x_write_regs(info->client,
@@ -252,7 +265,24 @@ static int ltc294x_get_voltage(const struct ltc294x_info *info, int *val)
ret = ltc294x_read_regs(info->client,
LTC294X_REG_VOLTAGE_MSB, &datar[0], 2);
value = (datar[0] << 8) | datar[1];
- *val = ((value * 23600) / 0xFFFF) * 1000; /* in uV */
+ switch (info->id) {
+ case LTC2943_ID:
+ value *= 23600 * 2;
+ value /= 0xFFFF;
+ value *= 1000 / 2;
+ break;
+ case LTC2944_ID:
+ value *= 70800 / 5*4;
+ value /= 0xFFFF;
+ value *= 1000 * 5/4;
+ break;
+ default:
+ value *= 6000 * 10;
+ value /= 0xFFFF;
+ value *= 1000 / 10;
+ break;
+ }
+ *val = value;
return ret;
}
@@ -263,27 +293,38 @@ static int ltc294x_get_current(const struct ltc294x_info *info, int *val)
s32 value;
ret = ltc294x_read_regs(info->client,
- LTC294X_REG_CURRENT_MSB, &datar[0], 2);
+ LTC2943_REG_CURRENT_MSB, &datar[0], 2);
value = (datar[0] << 8) | datar[1];
value -= 0x7FFF;
+ if (info->id == LTC2944_ID)
+ value *= 64000;
+ else
+ value *= 60000;
/* Value is in range -32k..+32k, r_sense is usually 10..50 mOhm,
* the formula below keeps everything in s32 range while preserving
* enough digits */
- *val = 1000 * ((60000 * value) / (info->r_sense * 0x7FFF)); /* in uA */
+ *val = 1000 * (value / (info->r_sense * 0x7FFF)); /* in uA */
return ret;
}
static int ltc294x_get_temperature(const struct ltc294x_info *info, int *val)
{
+ enum ltc294x_reg reg;
int ret;
u8 datar[2];
u32 value;
- ret = ltc294x_read_regs(info->client,
- LTC294X_REG_TEMPERATURE_MSB, &datar[0], 2);
- value = (datar[0] << 8) | datar[1];
- /* Full-scale is 510 Kelvin, convert to centidegrees */
- *val = (((51000 * value) / 0xFFFF) - 27215);
+ if (info->id == LTC2942_ID) {
+ reg = LTC2942_REG_TEMPERATURE_MSB;
+ value = 60000; /* Full-scale is 600 Kelvin */
+ } else {
+ reg = LTC2943_REG_TEMPERATURE_MSB;
+ value = 51000; /* Full-scale is 510 Kelvin */
+ }
+ ret = ltc294x_read_regs(info->client, reg, &datar[0], 2);
+ value *= (datar[0] << 8) | datar[1];
+ /* Convert to centidegrees */
+ *val = value / 0xFFFF - 27215;
return ret;
}
@@ -357,8 +398,8 @@ static enum power_supply_property ltc294x_properties[] = {
POWER_SUPPLY_PROP_CHARGE_COUNTER,
POWER_SUPPLY_PROP_CHARGE_NOW,
POWER_SUPPLY_PROP_VOLTAGE_NOW,
- POWER_SUPPLY_PROP_CURRENT_NOW,
POWER_SUPPLY_PROP_TEMP,
+ POWER_SUPPLY_PROP_CURRENT_NOW,
};
static int ltc294x_i2c_remove(struct i2c_client *client)
@@ -375,10 +416,11 @@ static int ltc294x_i2c_probe(struct i2c_client *client,
{
struct power_supply_config psy_cfg = {};
struct ltc294x_info *info;
+ struct device_node *np;
int ret;
u32 prescaler_exp;
s32 r_sense;
- struct device_node *np;
+ u8 status;
info = devm_kzalloc(&client->dev, sizeof(*info), GFP_KERNEL);
if (info == NULL)
@@ -388,7 +430,7 @@ static int ltc294x_i2c_probe(struct i2c_client *client,
np = of_node_get(client->dev.of_node);
- info->num_regs = (unsigned long)of_device_get_match_data(&client->dev);
+ info->id = (enum ltc294x_id)of_device_get_match_data(&client->dev);
info->supply_desc.name = np->name;
/* r_sense can be negative, when sense+ is connected to the battery
@@ -409,7 +451,7 @@ static int ltc294x_i2c_probe(struct i2c_client *client,
prescaler_exp = LTC2941_MAX_PRESCALER_EXP;
}
- if (info->num_regs == LTC2943_NUM_REGS) {
+ if (info->id == LTC2943_ID) {
if (prescaler_exp > LTC2943_MAX_PRESCALER_EXP)
prescaler_exp = LTC2943_MAX_PRESCALER_EXP;
info->Qlsb = ((340 * 50000) / r_sense) /
@@ -421,21 +463,39 @@ static int ltc294x_i2c_probe(struct i2c_client *client,
(128 / (1 << prescaler_exp));
}
+ /* Read status register to check for LTC2942 */
+ if (info->id == LTC2941_ID || info->id == LTC2942_ID) {
+ ret = ltc294x_read_regs(client, LTC294X_REG_STATUS, &status, 1);
+ if (ret < 0) {
+ dev_err(&client->dev,
+ "Could not read status register\n");
+ return ret;
+ }
+ if (status & LTC2941_REG_STATUS_CHIP_ID)
+ info->id = LTC2941_ID;
+ else
+ info->id = LTC2942_ID;
+ }
+
info->client = client;
info->supply_desc.type = POWER_SUPPLY_TYPE_BATTERY;
info->supply_desc.properties = ltc294x_properties;
- if (info->num_regs >= LTC294X_REG_TEMPERATURE_LSB)
+ switch (info->id) {
+ case LTC2944_ID:
+ case LTC2943_ID:
info->supply_desc.num_properties =
ARRAY_SIZE(ltc294x_properties);
- else if (info->num_regs >= LTC294X_REG_CURRENT_LSB)
+ break;
+ case LTC2942_ID:
info->supply_desc.num_properties =
ARRAY_SIZE(ltc294x_properties) - 1;
- else if (info->num_regs >= LTC294X_REG_VOLTAGE_LSB)
- info->supply_desc.num_properties =
- ARRAY_SIZE(ltc294x_properties) - 2;
- else
+ break;
+ case LTC2941_ID:
+ default:
info->supply_desc.num_properties =
ARRAY_SIZE(ltc294x_properties) - 3;
+ break;
+ }
info->supply_desc.get_property = ltc294x_get_property;
info->supply_desc.set_property = ltc294x_set_property;
info->supply_desc.property_is_writeable = ltc294x_property_is_writeable;
@@ -492,8 +552,10 @@ static SIMPLE_DEV_PM_OPS(ltc294x_pm_ops, ltc294x_suspend, ltc294x_resume);
static const struct i2c_device_id ltc294x_i2c_id[] = {
- {"ltc2941", LTC2941_NUM_REGS},
- {"ltc2943", LTC2943_NUM_REGS},
+ { "ltc2941", LTC2941_ID, },
+ { "ltc2942", LTC2942_ID, },
+ { "ltc2943", LTC2943_ID, },
+ { "ltc2944", LTC2944_ID, },
{ },
};
MODULE_DEVICE_TABLE(i2c, ltc294x_i2c_id);
@@ -501,11 +563,19 @@ MODULE_DEVICE_TABLE(i2c, ltc294x_i2c_id);
static const struct of_device_id ltc294x_i2c_of_match[] = {
{
.compatible = "lltc,ltc2941",
- .data = (void *)LTC2941_NUM_REGS
+ .data = (void *)LTC2941_ID,
+ },
+ {
+ .compatible = "lltc,ltc2942",
+ .data = (void *)LTC2942_ID,
},
{
.compatible = "lltc,ltc2943",
- .data = (void *)LTC2943_NUM_REGS
+ .data = (void *)LTC2943_ID,
+ },
+ {
+ .compatible = "lltc,ltc2944",
+ .data = (void *)LTC2944_ID,
},
{ },
};
@@ -525,5 +595,5 @@ module_i2c_driver(ltc294x_driver);
MODULE_AUTHOR("Auryn Verwegen, Topic Embedded Systems");
MODULE_AUTHOR("Mike Looijmans, Topic Embedded Products");
-MODULE_DESCRIPTION("LTC2941/LTC2943 Battery Gas Gauge IC driver");
+MODULE_DESCRIPTION("LTC2941/LTC2942/LTC2943/LTC2944 Battery Gas Gauge IC driver");
MODULE_LICENSE("GPL");