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authorLadislav Michl <ladis@linux-mips.org>2017-07-16 11:34:00 +0200
committerSebastian Reichel <sre@kernel.org>2017-07-25 12:10:52 +0200
commita65df832f96588debbbdd93d392a4ff77d5d237c (patch)
tree7d0d646d71008c39abfd19f55d8fbd68852ac1d8 /drivers/power
parent63e67c5769c23e0af729ecc2d28e4326f3a67a08 (diff)
downloadlinux-a65df832f96588debbbdd93d392a4ff77d5d237c.tar.bz2
power: supply: ltc2941-battery-gauge: Add LTC2942 support
LTC2942 is pin compatible with LTC2941 providing additional informations about battery voltage and temperature. It can be runtime detected using bit A7 in the Status register. Signed-off-by: Ladislav Michl <ladis@linux-mips.org> Acked-by: Rob Herring <robh@kernel.org> Acked-by: Dragos Bogdan <dragos.bogdan@analog.com> Tested-by: Dragos Bogdan <dragos.bogdan@analog.com> Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Diffstat (limited to 'drivers/power')
-rw-r--r--drivers/power/supply/ltc2941-battery-gauge.c80
1 files changed, 67 insertions, 13 deletions
diff --git a/drivers/power/supply/ltc2941-battery-gauge.c b/drivers/power/supply/ltc2941-battery-gauge.c
index b0de448a226b..42ff4e3daf35 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, LTC2942 and LTC2943
* Battery Gas Gauge IC
*
* Copyright (C) 2014 Topic Embedded Systems
@@ -46,11 +46,14 @@ enum ltc294x_reg {
enum ltc294x_id {
LTC2941_ID,
+ LTC2942_ID,
LTC2943_ID,
};
-#define LTC2943_REG_CONTROL_MODE_MASK (BIT(7) | BIT(6))
-#define LTC2943_REG_CONTROL_MODE_SCAN BIT(7)
+#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) \
@@ -145,9 +148,17 @@ 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->id == LTC2941_ID)
+ /* 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: /* 2943 measures every 10 sec */
control |= LTC2943_REG_CONTROL_MODE_SCAN;
+ break;
+ default:
+ break;
+ }
if (value != control) {
ret = ltc294x_write_regs(info->client,
@@ -252,7 +263,19 @@ 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;
+ default:
+ value *= 6000 * 10;
+ value /= 0xFFFF;
+ value *= 1000 / 10;
+ break;
+ }
+ *val = value;
return ret;
}
@@ -275,15 +298,22 @@ static int ltc294x_get_current(const struct ltc294x_info *info, int *val)
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,
- LTC2943_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;
}
@@ -375,10 +405,11 @@ 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)
@@ -421,6 +452,20 @@ 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;
@@ -429,6 +474,10 @@ static int ltc294x_i2c_probe(struct i2c_client *client,
info->supply_desc.num_properties =
ARRAY_SIZE(ltc294x_properties);
break;
+ case LTC2942_ID:
+ info->supply_desc.num_properties =
+ ARRAY_SIZE(ltc294x_properties) - 1;
+ break;
case LTC2941_ID:
default:
info->supply_desc.num_properties =
@@ -492,6 +541,7 @@ static SIMPLE_DEV_PM_OPS(ltc294x_pm_ops, ltc294x_suspend, ltc294x_resume);
static const struct i2c_device_id ltc294x_i2c_id[] = {
{ "ltc2941", LTC2941_ID, },
+ { "ltc2942", LTC2942_ID, },
{ "ltc2943", LTC2943_ID, },
{ },
};
@@ -503,6 +553,10 @@ static const struct of_device_id ltc294x_i2c_of_match[] = {
.data = (void *)LTC2941_ID,
},
{
+ .compatible = "lltc,ltc2942",
+ .data = (void *)LTC2942_ID,
+ },
+ {
.compatible = "lltc,ltc2943",
.data = (void *)LTC2943_ID,
},
@@ -524,5 +578,5 @@ 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 Battery Gas Gauge IC driver");
MODULE_LICENSE("GPL");