[PATCH v2] power: supply: ltc2941-battery-gauge: Add LTC2944 support
From: Dragos Bogdan
Date: Tue Jul 11 2017 - 12:08:20 EST
The only difference between the already supported LTC2943 and LTC2944 is the operating range (3.6V - 20V compared to 3.6V - 60V).
Signed-off-by: Dragos Bogdan <dragos.bogdan@xxxxxxxxxx>
---
Changes in v2:
- Fix the voltage and current conversion.
.../devicetree/bindings/power/supply/ltc2941.txt | 10 ++---
drivers/power/supply/ltc2941-battery-gauge.c | 46 +++++++++++++++++-----
2 files changed, 41 insertions(+), 15 deletions(-)
diff --git a/Documentation/devicetree/bindings/power/supply/ltc2941.txt b/Documentation/devicetree/bindings/power/supply/ltc2941.txt
index a9d7aa60558b..ed0f02846d10 100644
--- a/Documentation/devicetree/bindings/power/supply/ltc2941.txt
+++ b/Documentation/devicetree/bindings/power/supply/ltc2941.txt
@@ -1,9 +1,9 @@
-binding for LTC2941 and LTC2943 battery gauges
+binding for LTC2941, LTC2943 and LTC2944 battery gauges
-Both the LTC2941 and LTC2943 measure battery capacity.
-The LTC2943 is compatible with the LTC2941, it adds voltage and
-temperature monitoring, and uses a slightly different conversion
-formula for the charge counter.
+All the LTC2941, LTC2943 and LTC2944 measure battery capacity.
+The LTC2943 and LTC2944 are compatible with the LTC2941, they add voltage and
+temperature monitoring, and use a slightly different conversion formula for the
+charge counter.
Required properties:
- compatible: Should contain "lltc,ltc2941" or "lltc,ltc2943" which also
diff --git a/drivers/power/supply/ltc2941-battery-gauge.c b/drivers/power/supply/ltc2941-battery-gauge.c
index 7efb908f4451..4c979b1a022b 100644
--- a/drivers/power/supply/ltc2941-battery-gauge.c
+++ b/drivers/power/supply/ltc2941-battery-gauge.c
@@ -1,5 +1,5 @@
/*
- * I2C client/driver for the Linear Technology LTC2941 and LTC2943
+ * I2C client/driver for the Linear Technology LTC2941, LTC2943 and LTC2944
* Battery Gas Gauge IC
*
* Copyright (C) 2014 Topic Embedded Systems
@@ -57,6 +57,12 @@ enum ltc294x_reg {
#define LTC2941_NUM_REGS 0x08
#define LTC2943_NUM_REGS 0x18
+enum ltc294x_id {
+ LTC2941_ID,
+ LTC2943_ID,
+ LTC2944_ID,
+};
+
struct ltc294x_info {
struct i2c_client *client; /* I2C Client pointer */
struct power_supply *supply; /* Supply pointer */
@@ -66,6 +72,7 @@ struct ltc294x_info {
int charge; /* Last charge register content */
int r_sense; /* mOhm */
int Qlsb; /* nAh */
+ enum ltc294x_id id;
};
static inline int convert_bin_to_uAh(
@@ -145,7 +152,7 @@ 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 */
+ /* Put the 2943/4 into "monitor" mode, so it measures every 10 sec */
if (info->num_regs == LTC2943_NUM_REGS)
control |= LTC2943_REG_CONTROL_MODE_SCAN;
@@ -248,11 +255,16 @@ static int ltc294x_get_voltage(const struct ltc294x_info *info, int *val)
int ret;
u8 datar[2];
u32 value;
+ u32 full_scale;
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 */
+ if (info->id == LTC2944_ID)
+ full_scale = 70800;
+ else
+ full_scale = 23600;
+ *val = ((value * full_scale) / 0xFFFF) * 1000; /* in uV */
return ret;
}
@@ -261,15 +273,20 @@ static int ltc294x_get_current(const struct ltc294x_info *info, int *val)
int ret;
u8 datar[2];
s32 value;
+ u32 full_scale;
ret = ltc294x_read_regs(info->client,
LTC294X_REG_CURRENT_MSB, &datar[0], 2);
value = (datar[0] << 8) | datar[1];
value -= 0x7FFF;
+ if (info->id == LTC2944_ID)
+ full_scale = 64000;
+ else
+ full_scale = 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 * ((full_scale * value) / (info->r_sense * 0x7FFF)); /* in uA */
return ret;
}
@@ -388,7 +405,11 @@ 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);
+ if (info->id == LTC2941_ID)
+ info->num_regs = LTC2941_NUM_REGS;
+ else
+ info->num_regs = LTC2943_NUM_REGS;
info->supply_desc.name = np->name;
/* r_sense can be negative, when sense+ is connected to the battery
@@ -492,8 +513,9 @@ 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},
+ {"ltc2943", LTC2943_ID},
+ {"ltc2944", LTC2944_ID},
{ },
};
MODULE_DEVICE_TABLE(i2c, ltc294x_i2c_id);
@@ -501,11 +523,15 @@ 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,ltc2943",
- .data = (void *)LTC2943_NUM_REGS
+ .data = (void *)LTC2943_ID
+ },
+ {
+ .compatible = "lltc,ltc2944",
+ .data = (void *)LTC2944_ID
},
{ },
};
@@ -525,5 +551,5 @@ 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/LTC2943/LTC2944 Battery Gas Gauge IC driver");
MODULE_LICENSE("GPL");
--
2.11.0