On 07/12/2017 04:13 AM, Ladislav Michl wrote: > From: Dragos Bogdan <dragos.bogdan@xxxxxxxxxx> > > LTC2944 is compatible with LTC2943, but used different > voltage and current computing constants. > > Signed-off-by: Dragos Bogdan <dragos.bogdan@xxxxxxxxxx> > [ladis: fix voltage conversion, rebase on LTC2942 patchset] > Signed-off-by: Ladislav Michl <ladis@xxxxxxxxxxxxxx> > --- > Dragos, LTC2944 datasheet states 500K full range temperature, > but the rest of paragraph is the same as in LTC2943 datasheet > (LTC2943 is using 510K full range). As Linear was recently accuired > by Analog, please ask for the truth there, so we can write it > into code comment. Thank you! > http://cds.linear.com/docs/en/datasheet/2943fa.pdf > http://cds.linear.com/docs/en/datasheet/2944f.pdf > both on pdf page 15 The Full-Scale Temperature is 510 K (as it is displayed in the Electrical Characteristics section) for both LTC2943 and LTC2944 parts, so the same computing formula should be used. For LTC2944, the 500 K value used in the Applications Information section is an error that will be fixed in the next version of the datasheet. > Changes: > - v2: fixed voltage and current conversion > - v3: skipped > - v4: skipped > - v5: fixed voltage conversion overflow, rebased on LTC2942 patchset > > .../devicetree/bindings/power/supply/ltc2941.txt | 12 +++++------ > drivers/power/supply/ltc2941-battery-gauge.c | 24 +++++++++++++++++----- > 2 files changed, 25 insertions(+), 11 deletions(-) > > diff --git a/Documentation/devicetree/bindings/power/supply/ltc2941.txt b/Documentation/devicetree/bindings/power/supply/ltc2941.txt > index 8ec10366295d..3b9ba147b041 100644 > --- a/Documentation/devicetree/bindings/power/supply/ltc2941.txt > +++ b/Documentation/devicetree/bindings/power/supply/ltc2941.txt > @@ -1,14 +1,14 @@ > -binding for LTC2941, LTC2942 and LTC2943 battery gauges > +binding for LTC2941, LTC2942, LTC2943 and LTC2944 battery gauges > > 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. > +temperature monitoring, and is runtime detected. LTC2943 and LTC2944 > +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", "lltc,ltc2942" or "lltc,ltc2943" > - which also indicates the type of I2C chip attached. > +- compatible: Should contain "lltc,ltc2941", "lltc,ltc2942", "lltc,ltc2943" > + or "lltc,ltc2944" 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 f67fa8d8009e..b257ec943041 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, LTC2942 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 > * > @@ -154,7 +154,8 @@ static int ltc294x_reset(const struct ltc294x_info *info, int prescaler_exp) > case LTC2942_ID: /* 2942 measures every 2 sec */ > control |= LTC2942_REG_CONTROL_MODE_SCAN; > break; > - case LTC2943_ID: /* 2943 measures every 10 sec */ > + case LTC2943_ID: > + case LTC2944_ID: /* 2943 and 2944 measure every 10 sec */ > control |= LTC2943_REG_CONTROL_MODE_SCAN; > break; > default: > @@ -270,6 +271,10 @@ static int ltc294x_get_voltage(const struct ltc294x_info *info, int *val) > value /= 0xFFFF; > value *= 1000 / 2; > break; > + case LTC2944_ID: > + value *= 70800 / 5*4; > + value /= 0xFFFF; > + value *= 1000 * 5/4; A break is required here. > default: > value *= 6000 * 10; > value /= 0xFFFF; > @@ -290,10 +295,14 @@ static int ltc294x_get_current(const struct ltc294x_info *info, int *val) > 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; > } > > @@ -545,6 +554,7 @@ static const struct i2c_device_id ltc294x_i2c_id[] = { > { "ltc2941", LTC2941_ID, }, > { "ltc2942", LTC2942_ID, }, > { "ltc2943", LTC2943_ID, }, > + { "ltc2944", LTC2944_ID, }, > { }, > }; > MODULE_DEVICE_TABLE(i2c, ltc294x_i2c_id); > @@ -562,6 +572,10 @@ static const struct of_device_id ltc294x_i2c_of_match[] = { > .compatible = "lltc,ltc2943", > .data = (void *)LTC2943_ID, > }, > + { > + .compatible = "lltc,ltc2944", > + .data = (void *)LTC2944_ID, > + }, > { }, > }; > MODULE_DEVICE_TABLE(of, ltc294x_i2c_of_match); > @@ -580,5 +594,5 @@ module_i2c_driver(ltc294x_driver); > > MODULE_AUTHOR("Auryn Verwegen, Topic Embedded Systems"); > MODULE_AUTHOR("Mike Looijmans, Topic Embedded Products"); > -MODULE_DESCRIPTION("LTC2941/LTC2942/LTC2943 Battery Gas Gauge IC driver"); > +MODULE_DESCRIPTION("LTC2941/LTC2942/LTC2943/LTC2944 Battery Gas Gauge IC driver"); > MODULE_LICENSE("GPL"); -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
