diff options
| -rw-r--r-- | Documentation/devicetree/bindings/power/supply/ltc2941.txt | 15 | ||||
| -rw-r--r-- | drivers/power/supply/ltc2941-battery-gauge.c | 80 |
2 files changed, 75 insertions, 20 deletions
diff --git a/Documentation/devicetree/bindings/power/supply/ltc2941.txt b/Documentation/devicetree/bindings/power/supply/ltc2941.txt index a9d7aa60558b..8ec10366295d 100644 --- a/Documentation/devicetree/bindings/power/supply/ltc2941.txt +++ b/Documentation/devicetree/bindings/power/supply/ltc2941.txt @@ -1,13 +1,14 @@ -binding for LTC2941 and LTC2943 battery gauges +binding for LTC2941, LTC2942 and LTC2943 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 chips measure battery capacity. +The LTC2942 is pin compatible with the LTC2941, it adds voltage and +temperature monitoring, and is runtime detected. LTC2943 is software +compatible, uses a slightly different conversion formula for the +charge counter and adds voltage, current and temperature monitoring. Required properties: -- compatible: Should contain "lltc,ltc2941" or "lltc,ltc2943" which also - indicates the type of I2C chip attached. +- compatible: Should contain "lltc,ltc2941", "lltc,ltc2942" or "lltc,ltc2943" + which also indicates the type of I2C chip attached. - reg: The 7-bit I2C address. - lltc,resistor-sense: The sense resistor value in milli-ohms. Can be a 32-bit negative value when the battery has been connected to the wrong end of the 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"); |