* [PATCH v2] Added LTC2941/LTC2943 Battery Gauge Driver
@ 2014-10-01 13:32 Mike Looijmans
2014-10-08 6:05 ` [PATCH v3] Add " Mike Looijmans
0 siblings, 1 reply; 15+ messages in thread
From: Mike Looijmans @ 2014-10-01 13:32 UTC (permalink / raw)
To: sre, dbaryshkov, dwmw2; +Cc: linux-kernel, linux-pm, Mike Looijmans
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.
To avoid confusion with e.g. the LTC2945, the driver is called
LTC2941 instead of LTC294X.
v2: Fix units of measurement: uV, uA and centidegrees.
Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl>
---
drivers/power/Kconfig | 7 +
drivers/power/Makefile | 1 +
drivers/power/ltc2941-battery-gauge.c | 497 +++++++++++++++++++++++++++++++++
3 files changed, 505 insertions(+)
create mode 100644 drivers/power/ltc2941-battery-gauge.c
diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
index 73cfcdf..3333bf3 100644
--- a/drivers/power/Kconfig
+++ b/drivers/power/Kconfig
@@ -382,6 +382,13 @@ config CHARGER_TPS65090
Say Y here to enable support for battery charging with TPS65090
PMIC chips.
+config BATTERY_GAUGE_LTC2941
+ tristate "LTC2941/LTC2943 Battery Gauge Driver"
+ depends on I2C
+ help
+ Say Y here to include support for LTC2941 and LTC2943 Battery Gauge
+ IC.
+
config AB8500_BM
bool "AB8500 Battery Management Driver"
depends on AB8500_CORE && AB8500_GPADC
diff --git a/drivers/power/Makefile b/drivers/power/Makefile
index dfa8942..4f8e6c0 100644
--- a/drivers/power/Makefile
+++ b/drivers/power/Makefile
@@ -36,6 +36,7 @@ obj-$(CONFIG_BATTERY_MAX17042) += max17042_battery.o
obj-$(CONFIG_BATTERY_Z2) += z2_battery.o
obj-$(CONFIG_BATTERY_S3C_ADC) += s3c_adc_battery.o
obj-$(CONFIG_BATTERY_TWL4030_MADC) += twl4030_madc_battery.o
+obj-$(CONFIG_BATTERY_GAUGE_LTC2941) += ltc2941-battery-gauge.o
obj-$(CONFIG_CHARGER_88PM860X) += 88pm860x_charger.o
obj-$(CONFIG_CHARGER_PCF50633) += pcf50633-charger.o
obj-$(CONFIG_BATTERY_JZ4740) += jz4740-battery.o
diff --git a/drivers/power/ltc2941-battery-gauge.c b/drivers/power/ltc2941-battery-gauge.c
new file mode 100644
index 0000000..b779282
--- /dev/null
+++ b/drivers/power/ltc2941-battery-gauge.c
@@ -0,0 +1,497 @@
+/*
+ * I2C client/driver for the Linear Technology LTC2941 and LTC2943
+ * Battery Gas Gauge IC
+ *
+ * Copyright (C) 2014 Topic Embedded Systems
+ *
+ * Author: Auryn Verwegen
+ * Author: Mike Looijmans
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/swab.h>
+#include <linux/i2c.h>
+#include <linux/delay.h>
+#include <linux/idr.h>
+#include <linux/power_supply.h>
+#include <linux/slab.h>
+
+#define I16_MSB(x) ((x >> 8) & 0xFF)
+#define I16_LSB(x) (x & 0xFF)
+
+#define LTC294X_WORK_DELAY 10 /* Update delay in seconds */
+
+#define LTC294X_MAX_VALUE 0xFFFF
+#define LTC294X_MID_SUPPLY 0x7FFF
+
+#define LTC2941_MAX_PRESCALER_EXP 7
+#define LTC2943_MAX_PRESCALER_EXP 6
+
+enum ltc294x_reg {
+ LTC294X_REG_STATUS = 0x00,
+ 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,
+} ;
+
+#define LTC2943_REG_CONTROL_MODE_MASK (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 delayed_work work; /* Work scheduler */
+ int num_regs; /* Number of registers (chip type) */
+ int id; /* Identifier of ltc294x chip */
+ int charge; /* Last measured charge value (uAh) */
+ int r_sense; /* mOhm */
+ int Qlsb; /* nAh */
+};
+
+static DEFINE_IDR(ltc294x_id);
+static DEFINE_MUTEX(ltc294x_lock);
+
+static inline int convert_bin_to_uAh(
+ const struct ltc294x_info *info, int Q)
+{
+ int uAh;
+ uAh = ((Q * (info->Qlsb / 10))) / 100;
+ return uAh;
+}
+
+static inline int convert_uAh_to_bin(
+ const struct ltc294x_info *info, int uAh)
+{
+ int Q;
+ Q = (uAh * 100) / (info->Qlsb/10);
+ return (Q < LTC294X_MAX_VALUE) ? Q : LTC294X_MAX_VALUE;
+}
+
+static int ltc294x_read_regs(struct i2c_client *client,
+ enum ltc294x_reg reg, u8 *buf, int num_regs)
+{
+ int ret;
+ struct i2c_msg msgs[2] = { };
+ u8 reg_start = reg;
+
+ msgs[0].addr = client->addr;
+ msgs[0].len = 1;
+ msgs[0].buf = ®_start;
+
+ msgs[1].addr = client->addr;
+ msgs[1].len = num_regs;
+ msgs[1].buf = buf;
+ msgs[1].flags = I2C_M_RD;
+
+ ret = i2c_transfer(client->adapter, &msgs[0], 2);
+ if (ret < 0) {
+ dev_err(&client->dev, "ltc2941 read_reg failed!\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static int ltc294x_write_regs(struct i2c_client *client,
+ enum ltc294x_reg reg, const u8* const buf, int num_regs)
+{
+ int ret;
+ u8 reg_start = reg;
+
+ ret = i2c_smbus_write_i2c_block_data(client, reg_start, num_regs, buf);
+ if (ret < 0) {
+ dev_err(&client->dev, "ltc2941 write_reg failed!\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static int ltc294x_reset(const struct ltc294x_info *info, int prescaler_exp)
+{
+ int ret;
+ u8 value;
+ u8 control;
+
+ /* Read status and control registers */
+ ret = ltc294x_read_regs(info->client, LTC294X_REG_CONTROL, &value, 1);
+ if(ret < 0) {
+ dev_err(&info->client->dev, "LTC2941: Could not read registers from device!\n");
+ goto error_exit;
+ }
+
+ 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)
+ control |= LTC2943_REG_CONTROL_MODE_SCAN;
+
+ if (value != control) {
+ ret = ltc294x_write_regs(info->client, LTC294X_REG_CONTROL, &value, 1);
+ if(ret < 0){
+ dev_err(&info->client->dev, "Could not write registers!\n");
+ goto error_exit;
+ }
+ }
+
+ return 0;
+
+error_exit:
+ return ret;
+}
+
+static int ltc294x_get_charge_now(const struct ltc294x_info *info, int *val)
+{
+ int ret;
+ u8 datar[2];
+ u32 value;
+
+ ret = ltc294x_read_regs(info->client, LTC294X_REG_ACC_CHARGE_MSB, &datar[0], 2);
+ value = (datar[0] << 8) + datar[1];
+ *val = convert_bin_to_uAh(info, value);
+ return ret;
+}
+
+static int ltc294x_set_charge_now(const struct ltc294x_info *info, int val)
+{
+ int ret;
+ u8 dataw[2], ctrl_reg;
+ u32 value = convert_uAh_to_bin(info, val);
+
+ /* Read control register */
+ ret = ltc294x_read_regs(info->client, LTC294X_REG_CONTROL, &ctrl_reg, 1);
+ if(ret < 0)
+ goto error_exit;
+ /* Disable analog section */
+ ctrl_reg |= LTC294X_REG_CONTROL_SHUTDOWN_MASK;
+ ret = ltc294x_write_regs(info->client, LTC294X_REG_CONTROL, &ctrl_reg, 1);
+ if(ret < 0)
+ goto error_exit;
+ /* Set new charge value */
+ dataw[0] = I16_MSB(value);
+ dataw[1] = I16_LSB(value);
+ ret = ltc294x_write_regs(info->client, LTC294X_REG_ACC_CHARGE_MSB, &dataw[0], 2);
+ if(ret < 0)
+ goto error_exit;
+ /* Enable analog section */
+ ctrl_reg &= ~LTC294X_REG_CONTROL_SHUTDOWN_MASK;
+ ret = ltc294x_write_regs(info->client, LTC294X_REG_CONTROL, &ctrl_reg, 1);
+ if(ret < 0)
+ goto error_exit;
+
+ return 0;
+
+error_exit:
+ return ret;
+}
+
+static int ltc294x_get_charge_counter(const struct ltc294x_info *info, int *val)
+{
+ int ret;
+ ret = ltc294x_get_charge_now(info, val);
+ *val -= convert_bin_to_uAh(info, LTC294X_MID_SUPPLY);
+ return ret;
+}
+
+static int ltc294x_get_voltage(const struct ltc294x_info *info, int *val)
+{
+ int ret;
+ u8 datar[2];
+ u32 value;
+
+ 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 */
+ return ret;
+}
+
+static int ltc294x_get_current(const struct ltc294x_info *info, int *val)
+{
+ int ret;
+ u8 datar[2];
+ s32 value;
+
+ ret = ltc294x_read_regs(info->client, LTC294X_REG_CURRENT_MSB, &datar[0], 2);
+ value = (datar[0] << 8) | datar[1];
+ value -= 0x7FFF;
+ *val = (60000 * value) / (info->r_sense * 0x7FFF); /* in uA */
+ return ret;
+}
+
+static int ltc294x_get_temperature(const struct ltc294x_info *info, int *val)
+{
+ 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);
+ return ret;
+}
+
+static int ltc294x_get_property(struct power_supply *psy,
+ enum power_supply_property prop,
+ union power_supply_propval *val)
+{
+ struct ltc294x_info *info = container_of(psy, struct ltc294x_info, supply);
+
+ switch (prop) {
+ case POWER_SUPPLY_PROP_CHARGE_NOW:
+ return ltc294x_get_charge_now(info, &val->intval);
+ case POWER_SUPPLY_PROP_CHARGE_COUNTER:
+ return ltc294x_get_charge_counter(info, &val->intval);
+ case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+ return ltc294x_get_voltage(info, &val->intval);
+ case POWER_SUPPLY_PROP_CURRENT_NOW:
+ return ltc294x_get_current(info, &val->intval);
+ case POWER_SUPPLY_PROP_TEMP:
+ return ltc294x_get_temperature(info, &val->intval);
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ltc294x_set_property(struct power_supply *psy,
+ enum power_supply_property psp,
+ const union power_supply_propval *val)
+{
+ struct ltc294x_info *info =
+ container_of(psy, struct ltc294x_info, supply);
+
+ switch (psp) {
+ case POWER_SUPPLY_PROP_CHARGE_NOW:
+ return ltc294x_set_charge_now(info, val->intval);
+ default:
+ return -EPERM;
+ }
+}
+
+static int ltc294x_property_is_writeable(
+ struct power_supply *psy, enum power_supply_property psp)
+{
+ switch (psp)
+ {
+ case POWER_SUPPLY_PROP_CHARGE_NOW:
+ return 1;
+ default:
+ return 0;
+ }
+}
+
+static void ltc294x_update(struct ltc294x_info *info)
+{
+ int charge;
+ charge = info->charge;
+ ltc294x_get_charge_now(info, &info->charge);
+ if(charge != info->charge){
+ power_supply_changed(&info->supply);
+ }
+}
+
+static void ltc294x_work(struct work_struct *work)
+{
+ struct ltc294x_info *info;
+
+ info = container_of(work, struct ltc294x_info, work.work);
+ ltc294x_update(info);
+ schedule_delayed_work(&info->work, LTC294X_WORK_DELAY * HZ);
+}
+
+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,
+};
+
+static int ltc294x_i2c_remove(struct i2c_client *client)
+{
+ struct ltc294x_info *info = i2c_get_clientdata(client);
+
+ cancel_delayed_work(&info->work);
+ power_supply_unregister(&info->supply);
+ kfree(info->supply.name);
+ mutex_lock(<c294x_lock);
+ idr_remove(<c294x_id, info->id);
+ mutex_unlock(<c294x_lock);
+ return 0;
+}
+
+static int ltc294x_i2c_probe(struct i2c_client *client, const struct i2c_device_id *id)
+{
+ struct ltc294x_info *info;
+ int ret;
+ int num;
+ unsigned int prescaler_exp, r_sense;
+ struct device_node *np;
+
+ mutex_lock(<c294x_lock);
+ ret = idr_alloc(<c294x_id, client, 0, 0, GFP_KERNEL);
+ mutex_unlock(<c294x_lock);
+ if(ret < 0)
+ goto fail_id;
+
+ num = ret;
+
+ info = devm_kzalloc(&client->dev, sizeof(*info), GFP_KERNEL);
+ if(info == NULL) {
+ dev_err(&client->dev, "Could not allocate memory for device structure!\n");
+ ret = -ENOMEM;
+ goto fail_info;
+ }
+
+ i2c_set_clientdata(client, info);
+
+ info->num_regs = id->driver_data;
+ info->supply.name = kasprintf(GFP_KERNEL, "%s-%d", client->name, num);
+ if(!info->supply.name) {
+ dev_err(&client->dev, "Could not allocate memory for device name!\n");
+ ret = -ENOMEM;
+ goto fail_name;
+ }
+
+ np = of_node_get(client->dev.of_node);
+
+ ret = of_property_read_u32(np, "resistor-sense", &r_sense);
+ if(ret < 0) {
+ dev_err(&client->dev, "Could not find resistor-sense in devicetree!\n");
+ goto fail_name;
+ }
+ info->r_sense = r_sense;
+
+ ret = of_property_read_u32(np, "prescaler-exponent", &prescaler_exp);
+ if(ret < 0) {
+ dev_err(&client->dev, "PrescalerExponent not in devicetree, assume max.\n");
+ prescaler_exp = LTC2941_MAX_PRESCALER_EXP;
+ }
+
+ if (info->num_regs == LTC2943_NUM_REGS) {
+ if (prescaler_exp > LTC2943_MAX_PRESCALER_EXP)
+ prescaler_exp = LTC2943_MAX_PRESCALER_EXP;
+ info->Qlsb = ((340 * 50000) / r_sense) / (4096 / (1 << (2*prescaler_exp)));
+ } else {
+ if (prescaler_exp > LTC2941_MAX_PRESCALER_EXP)
+ prescaler_exp = LTC2941_MAX_PRESCALER_EXP;
+ info->Qlsb = ((58 * 50000) / r_sense) / (128 / (1 << prescaler_exp));
+ }
+
+ info->client = client;
+ info->id = num;
+ info->supply.type = POWER_SUPPLY_TYPE_BATTERY;
+ info->supply.properties = ltc294x_properties;
+ if (info->num_regs >= LTC294X_REG_TEMPERATURE_LSB)
+ info->supply.num_properties = ARRAY_SIZE(ltc294x_properties);
+ else if (info->num_regs >= LTC294X_REG_CURRENT_LSB)
+ info->supply.num_properties = ARRAY_SIZE(ltc294x_properties) - 1;
+ else if (info->num_regs >= LTC294X_REG_VOLTAGE_LSB)
+ info->supply.num_properties = ARRAY_SIZE(ltc294x_properties) - 2;
+ else
+ info->supply.num_properties = ARRAY_SIZE(ltc294x_properties) - 3;
+ info->supply.get_property = ltc294x_get_property;
+ info->supply.set_property = ltc294x_set_property;
+ info->supply.property_is_writeable = ltc294x_property_is_writeable;
+ info->supply.external_power_changed = NULL;
+
+ INIT_DELAYED_WORK(&info->work, ltc294x_work);
+
+ ret = ltc294x_reset(info, prescaler_exp);
+ if (ret < 0) {
+ dev_err(&client->dev, "Communication with chip failed!\n");
+ goto fail_comm;
+ }
+
+ ret = power_supply_register(&client->dev, &info->supply);
+ if (ret) {
+ dev_err(&client->dev, "failed to register ltc2941\n");
+ goto fail_register;
+ } else {
+ schedule_delayed_work(&info->work, LTC294X_WORK_DELAY * HZ);
+ }
+
+ return 0;
+
+fail_register:
+ kfree(info->supply.name);
+fail_comm:
+fail_name:
+fail_info:
+ mutex_lock(<c294x_lock);
+ idr_remove(<c294x_id, num);
+ mutex_unlock(<c294x_lock);
+fail_id:
+ return ret;
+}
+
+#ifdef CONFIG_PM_SLEEP
+
+static int ltc294x_suspend(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct ltc294x_info *info = i2c_get_clientdata(client);
+
+ cancel_delayed_work(&info->work);
+ return 0;
+}
+
+static int ltc294x_resume(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct ltc294x_info *info = i2c_get_clientdata(client);
+
+ schedule_delayed_work(&info->work, LTC294X_WORK_DELAY * HZ);
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(ltc294x_pm_ops, ltc294x_suspend, ltc294x_resume);
+#define LTC294X_PM_OPS (<c294x_pm_ops)
+
+#else
+#define LTC294X_PM_OPS NULL
+#endif /* CONFIG_PM_SLEEP */
+
+
+static const struct i2c_device_id ltc294x_i2c_id[] = {
+ {"ltc2941", LTC2941_NUM_REGS},
+ {"ltc2943", LTC2943_NUM_REGS},
+ { },
+};
+MODULE_DEVICE_TABLE(i2c, ltc294x_i2c_id);
+
+static struct i2c_driver ltc294x_driver = {
+ .driver = {
+ .name = "LTC2941",
+ .owner = THIS_MODULE,
+ .pm = LTC294X_PM_OPS,
+ },
+ .probe = ltc294x_i2c_probe,
+ .remove = ltc294x_i2c_remove,
+ .id_table = ltc294x_i2c_id,
+};
+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_LICENSE("GPL");
--
1.7.9.5
^ permalink raw reply related [flat|nested] 15+ messages in thread
* [PATCH v3] Add LTC2941/LTC2943 Battery Gauge Driver
2014-10-01 13:32 [PATCH v2] Added LTC2941/LTC2943 Battery Gauge Driver Mike Looijmans
@ 2014-10-08 6:05 ` Mike Looijmans
2014-10-23 12:38 ` [PATCH v4] " Mike Looijmans
0 siblings, 1 reply; 15+ messages in thread
From: Mike Looijmans @ 2014-10-08 6:05 UTC (permalink / raw)
To: sre, dbaryshkov, dwmw2, linux-pm; +Cc: linux-kernel, Mike Looijmans
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.
To avoid confusion with e.g. the LTC2945, the driver is called
LTC2941 instead of LTC294X.
v2: Fix units of measurement: uV, uA and centidegrees.
v3: Correctly set configuration register. Allow negative values
for the sense resistor.
Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl>
---
drivers/power/Kconfig | 7 +
drivers/power/Makefile | 1 +
drivers/power/ltc2941-battery-gauge.c | 524 +++++++++++++++++++++++++++++++++
3 files changed, 532 insertions(+)
create mode 100644 drivers/power/ltc2941-battery-gauge.c
diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
index 73cfcdf..3333bf3 100644
--- a/drivers/power/Kconfig
+++ b/drivers/power/Kconfig
@@ -382,6 +382,13 @@ config CHARGER_TPS65090
Say Y here to enable support for battery charging with TPS65090
PMIC chips.
+config BATTERY_GAUGE_LTC2941
+ tristate "LTC2941/LTC2943 Battery Gauge Driver"
+ depends on I2C
+ help
+ Say Y here to include support for LTC2941 and LTC2943 Battery Gauge
+ IC.
+
config AB8500_BM
bool "AB8500 Battery Management Driver"
depends on AB8500_CORE && AB8500_GPADC
diff --git a/drivers/power/Makefile b/drivers/power/Makefile
index dfa8942..4f8e6c0 100644
--- a/drivers/power/Makefile
+++ b/drivers/power/Makefile
@@ -36,6 +36,7 @@ obj-$(CONFIG_BATTERY_MAX17042) += max17042_battery.o
obj-$(CONFIG_BATTERY_Z2) += z2_battery.o
obj-$(CONFIG_BATTERY_S3C_ADC) += s3c_adc_battery.o
obj-$(CONFIG_BATTERY_TWL4030_MADC) += twl4030_madc_battery.o
+obj-$(CONFIG_BATTERY_GAUGE_LTC2941) += ltc2941-battery-gauge.o
obj-$(CONFIG_CHARGER_88PM860X) += 88pm860x_charger.o
obj-$(CONFIG_CHARGER_PCF50633) += pcf50633-charger.o
obj-$(CONFIG_BATTERY_JZ4740) += jz4740-battery.o
diff --git a/drivers/power/ltc2941-battery-gauge.c b/drivers/power/ltc2941-battery-gauge.c
new file mode 100644
index 0000000..f0c387d
--- /dev/null
+++ b/drivers/power/ltc2941-battery-gauge.c
@@ -0,0 +1,524 @@
+/*
+ * I2C client/driver for the Linear Technology LTC2941 and LTC2943
+ * Battery Gas Gauge IC
+ *
+ * Copyright (C) 2014 Topic Embedded Systems
+ *
+ * Author: Auryn Verwegen
+ * Author: Mike Looijmans
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/swab.h>
+#include <linux/i2c.h>
+#include <linux/delay.h>
+#include <linux/idr.h>
+#include <linux/power_supply.h>
+#include <linux/slab.h>
+
+#define I16_MSB(x) ((x >> 8) & 0xFF)
+#define I16_LSB(x) (x & 0xFF)
+
+#define LTC294X_WORK_DELAY 10 /* Update delay in seconds */
+
+#define LTC294X_MAX_VALUE 0xFFFF
+#define LTC294X_MID_SUPPLY 0x7FFF
+
+#define LTC2941_MAX_PRESCALER_EXP 7
+#define LTC2943_MAX_PRESCALER_EXP 6
+
+enum ltc294x_reg {
+ LTC294X_REG_STATUS = 0x00,
+ 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,
+} ;
+
+#define LTC2943_REG_CONTROL_MODE_MASK (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 delayed_work work; /* Work scheduler */
+ int num_regs; /* Number of registers (chip type) */
+ int id; /* Identifier of ltc294x chip */
+ int charge; /* Last charge register content */
+ int r_sense; /* mOhm */
+ int Qlsb; /* nAh */
+};
+
+static DEFINE_IDR(ltc294x_id);
+static DEFINE_MUTEX(ltc294x_lock);
+
+static inline int convert_bin_to_uAh(
+ const struct ltc294x_info *info, int Q)
+{
+ int uAh;
+ uAh = ((Q * (info->Qlsb / 10))) / 100;
+ return uAh;
+}
+
+static inline int convert_uAh_to_bin(
+ const struct ltc294x_info *info, int uAh)
+{
+ int Q;
+ Q = (uAh * 100) / (info->Qlsb/10);
+ return (Q < LTC294X_MAX_VALUE) ? Q : LTC294X_MAX_VALUE;
+}
+
+static int ltc294x_read_regs(struct i2c_client *client,
+ enum ltc294x_reg reg, u8 *buf, int num_regs)
+{
+ int ret;
+ struct i2c_msg msgs[2] = { };
+ u8 reg_start = reg;
+
+ msgs[0].addr = client->addr;
+ msgs[0].len = 1;
+ msgs[0].buf = ®_start;
+
+ msgs[1].addr = client->addr;
+ msgs[1].len = num_regs;
+ msgs[1].buf = buf;
+ msgs[1].flags = I2C_M_RD;
+
+ ret = i2c_transfer(client->adapter, &msgs[0], 2);
+ if (ret < 0) {
+ dev_err(&client->dev, "ltc2941 read_reg failed!\n");
+ return ret;
+ }
+
+ dev_dbg(&client->dev, "%s (%#x, %d) -> %#x\n",
+ __func__, reg, num_regs, *buf);
+
+ return 0;
+}
+
+static int ltc294x_write_regs(struct i2c_client *client,
+ enum ltc294x_reg reg, const u8* const buf, int num_regs)
+{
+ int ret;
+ u8 reg_start = reg;
+
+ ret = i2c_smbus_write_i2c_block_data(client, reg_start, num_regs, buf);
+ if (ret < 0) {
+ dev_err(&client->dev, "ltc2941 write_reg failed!\n");
+ return ret;
+ }
+
+ dev_dbg(&client->dev, "%s (%#x, %d) -> %#x\n",
+ __func__, reg, num_regs, *buf);
+
+ return 0;
+}
+
+static int ltc294x_reset(const struct ltc294x_info *info, int prescaler_exp)
+{
+ int ret;
+ u8 value;
+ u8 control;
+
+ /* Read status and control registers */
+ ret = ltc294x_read_regs(info->client, LTC294X_REG_CONTROL, &value, 1);
+ if(ret < 0) {
+ dev_err(&info->client->dev, "LTC2941: Could not read registers from device!\n");
+ goto error_exit;
+ }
+
+ 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)
+ control |= LTC2943_REG_CONTROL_MODE_SCAN;
+
+ if (value != control) {
+ ret = ltc294x_write_regs(info->client, LTC294X_REG_CONTROL, &control, 1);
+ if(ret < 0){
+ dev_err(&info->client->dev, "Could not write registers!\n");
+ goto error_exit;
+ }
+ }
+
+ return 0;
+
+error_exit:
+ return ret;
+}
+
+static int ltc294x_read_charge_register(const struct ltc294x_info *info)
+{
+ int ret;
+ u8 datar[2];
+
+ ret = ltc294x_read_regs(info->client, LTC294X_REG_ACC_CHARGE_MSB, &datar[0], 2);
+ if (ret < 0)
+ return ret;
+ return (datar[0] << 8) + datar[1];
+}
+
+static int ltc294x_get_charge_now(const struct ltc294x_info *info, int *val)
+{
+ int value = ltc294x_read_charge_register(info);
+ if (value < 0)
+ return value;
+ /* When r_sense < 0, this counts up when the battery discharges */
+ if (info->Qlsb < 0)
+ value -= 0xFFFF;
+ *val = convert_bin_to_uAh(info, value);
+ return 0;
+}
+
+static int ltc294x_set_charge_now(const struct ltc294x_info *info, int val)
+{
+ int ret;
+ u8 dataw[2];
+ u8 ctrl_reg;
+ s32 value;
+
+ value = convert_uAh_to_bin(info, val);
+ if (info->Qlsb < 0) /* Direction depends on how sense+/- were connected */
+ value += 0xFFFF;
+ if ((value < 0) || (value > 0xFFFF)) /* input validation */
+ return -EINVAL;
+
+ /* Read control register */
+ ret = ltc294x_read_regs(info->client, LTC294X_REG_CONTROL, &ctrl_reg, 1);
+ if(ret < 0)
+ return ret;
+ /* Disable analog section */
+ ctrl_reg |= LTC294X_REG_CONTROL_SHUTDOWN_MASK;
+ ret = ltc294x_write_regs(info->client, LTC294X_REG_CONTROL, &ctrl_reg, 1);
+ if(ret < 0)
+ return ret;
+ /* Set new charge value */
+ dataw[0] = I16_MSB(value);
+ dataw[1] = I16_LSB(value);
+ ret = ltc294x_write_regs(info->client, LTC294X_REG_ACC_CHARGE_MSB, &dataw[0], 2);
+ if(ret < 0)
+ goto error_exit;
+ /* Enable analog section */
+error_exit:
+ ctrl_reg &= ~LTC294X_REG_CONTROL_SHUTDOWN_MASK;
+ ret = ltc294x_write_regs(info->client, LTC294X_REG_CONTROL, &ctrl_reg, 1);
+
+ return ret < 0 ? ret : 0;
+}
+
+static int ltc294x_get_charge_counter(const struct ltc294x_info *info, int *val)
+{
+ int value = ltc294x_read_charge_register(info);
+ if (value < 0)
+ return value;
+ value -= LTC294X_MID_SUPPLY;
+ *val = convert_bin_to_uAh(info, value);
+ return 0;
+}
+
+static int ltc294x_get_voltage(const struct ltc294x_info *info, int *val)
+{
+ int ret;
+ u8 datar[2];
+ u32 value;
+
+ 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 */
+ return ret;
+}
+
+static int ltc294x_get_current(const struct ltc294x_info *info, int *val)
+{
+ int ret;
+ u8 datar[2];
+ s32 value;
+
+ ret = ltc294x_read_regs(info->client, LTC294X_REG_CURRENT_MSB, &datar[0], 2);
+ value = (datar[0] << 8) | datar[1];
+ value -= 0x7FFF;
+ /* 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 */
+ return ret;
+}
+
+static int ltc294x_get_temperature(const struct ltc294x_info *info, int *val)
+{
+ 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);
+ return ret;
+}
+
+static int ltc294x_get_property(struct power_supply *psy,
+ enum power_supply_property prop,
+ union power_supply_propval *val)
+{
+ struct ltc294x_info *info = container_of(psy, struct ltc294x_info, supply);
+
+ switch (prop) {
+ case POWER_SUPPLY_PROP_CHARGE_NOW:
+ return ltc294x_get_charge_now(info, &val->intval);
+ case POWER_SUPPLY_PROP_CHARGE_COUNTER:
+ return ltc294x_get_charge_counter(info, &val->intval);
+ case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+ return ltc294x_get_voltage(info, &val->intval);
+ case POWER_SUPPLY_PROP_CURRENT_NOW:
+ return ltc294x_get_current(info, &val->intval);
+ case POWER_SUPPLY_PROP_TEMP:
+ return ltc294x_get_temperature(info, &val->intval);
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ltc294x_set_property(struct power_supply *psy,
+ enum power_supply_property psp,
+ const union power_supply_propval *val)
+{
+ struct ltc294x_info *info =
+ container_of(psy, struct ltc294x_info, supply);
+
+ switch (psp) {
+ case POWER_SUPPLY_PROP_CHARGE_NOW:
+ return ltc294x_set_charge_now(info, val->intval);
+ default:
+ return -EPERM;
+ }
+}
+
+static int ltc294x_property_is_writeable(
+ struct power_supply *psy, enum power_supply_property psp)
+{
+ switch (psp)
+ {
+ case POWER_SUPPLY_PROP_CHARGE_NOW:
+ return 1;
+ default:
+ return 0;
+ }
+}
+
+static void ltc294x_update(struct ltc294x_info *info)
+{
+ int charge = ltc294x_read_charge_register(info);
+ if (charge != info->charge) {
+ info->charge = charge;
+ power_supply_changed(&info->supply);
+ }
+}
+
+static void ltc294x_work(struct work_struct *work)
+{
+ struct ltc294x_info *info;
+
+ info = container_of(work, struct ltc294x_info, work.work);
+ ltc294x_update(info);
+ schedule_delayed_work(&info->work, LTC294X_WORK_DELAY * HZ);
+}
+
+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,
+};
+
+static int ltc294x_i2c_remove(struct i2c_client *client)
+{
+ struct ltc294x_info *info = i2c_get_clientdata(client);
+
+ cancel_delayed_work(&info->work);
+ power_supply_unregister(&info->supply);
+ kfree(info->supply.name);
+ mutex_lock(<c294x_lock);
+ idr_remove(<c294x_id, info->id);
+ mutex_unlock(<c294x_lock);
+ return 0;
+}
+
+static int ltc294x_i2c_probe(struct i2c_client *client, const struct i2c_device_id *id)
+{
+ struct ltc294x_info *info;
+ int ret;
+ int num;
+ u32 prescaler_exp;
+ s32 r_sense;
+ struct device_node *np;
+
+ mutex_lock(<c294x_lock);
+ ret = idr_alloc(<c294x_id, client, 0, 0, GFP_KERNEL);
+ mutex_unlock(<c294x_lock);
+ if(ret < 0)
+ goto fail_id;
+
+ num = ret;
+
+ info = devm_kzalloc(&client->dev, sizeof(*info), GFP_KERNEL);
+ if(info == NULL) {
+ dev_err(&client->dev, "Could not allocate memory for device structure!\n");
+ ret = -ENOMEM;
+ goto fail_info;
+ }
+
+ i2c_set_clientdata(client, info);
+
+ info->num_regs = id->driver_data;
+ info->supply.name = kasprintf(GFP_KERNEL, "%s-%d", client->name, num);
+ if(!info->supply.name) {
+ dev_err(&client->dev, "Could not allocate memory for device name!\n");
+ ret = -ENOMEM;
+ goto fail_name;
+ }
+
+ np = of_node_get(client->dev.of_node);
+
+ /* r_sense can be negative, when sense+ is connected to the battery
+ * instead of the sense-. This results in reversed measurements. */
+ ret = of_property_read_u32(np, "resistor-sense", &r_sense);
+ if(ret < 0) {
+ dev_err(&client->dev, "Could not find resistor-sense in devicetree!\n");
+ goto fail_name;
+ }
+ info->r_sense = r_sense;
+
+ ret = of_property_read_u32(np, "prescaler-exponent", &prescaler_exp);
+ if(ret < 0) {
+ dev_err(&client->dev, "PrescalerExponent not in devicetree, assume max.\n");
+ prescaler_exp = LTC2941_MAX_PRESCALER_EXP;
+ }
+
+ if (info->num_regs == LTC2943_NUM_REGS) {
+ if (prescaler_exp > LTC2943_MAX_PRESCALER_EXP)
+ prescaler_exp = LTC2943_MAX_PRESCALER_EXP;
+ info->Qlsb = ((340 * 50000) / r_sense) / (4096 / (1 << (2*prescaler_exp)));
+ } else {
+ if (prescaler_exp > LTC2941_MAX_PRESCALER_EXP)
+ prescaler_exp = LTC2941_MAX_PRESCALER_EXP;
+ info->Qlsb = ((58 * 50000) / r_sense) / (128 / (1 << prescaler_exp));
+ }
+
+ info->client = client;
+ info->id = num;
+ info->supply.type = POWER_SUPPLY_TYPE_BATTERY;
+ info->supply.properties = ltc294x_properties;
+ if (info->num_regs >= LTC294X_REG_TEMPERATURE_LSB)
+ info->supply.num_properties = ARRAY_SIZE(ltc294x_properties);
+ else if (info->num_regs >= LTC294X_REG_CURRENT_LSB)
+ info->supply.num_properties = ARRAY_SIZE(ltc294x_properties) - 1;
+ else if (info->num_regs >= LTC294X_REG_VOLTAGE_LSB)
+ info->supply.num_properties = ARRAY_SIZE(ltc294x_properties) - 2;
+ else
+ info->supply.num_properties = ARRAY_SIZE(ltc294x_properties) - 3;
+ info->supply.get_property = ltc294x_get_property;
+ info->supply.set_property = ltc294x_set_property;
+ info->supply.property_is_writeable = ltc294x_property_is_writeable;
+ info->supply.external_power_changed = NULL;
+
+ INIT_DELAYED_WORK(&info->work, ltc294x_work);
+
+ ret = ltc294x_reset(info, prescaler_exp);
+ if (ret < 0) {
+ dev_err(&client->dev, "Communication with chip failed!\n");
+ goto fail_comm;
+ }
+
+ ret = power_supply_register(&client->dev, &info->supply);
+ if (ret) {
+ dev_err(&client->dev, "failed to register ltc2941\n");
+ goto fail_register;
+ } else {
+ schedule_delayed_work(&info->work, LTC294X_WORK_DELAY * HZ);
+ }
+
+ return 0;
+
+fail_register:
+ kfree(info->supply.name);
+fail_comm:
+fail_name:
+fail_info:
+ mutex_lock(<c294x_lock);
+ idr_remove(<c294x_id, num);
+ mutex_unlock(<c294x_lock);
+fail_id:
+ return ret;
+}
+
+#ifdef CONFIG_PM_SLEEP
+
+static int ltc294x_suspend(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct ltc294x_info *info = i2c_get_clientdata(client);
+
+ cancel_delayed_work(&info->work);
+ return 0;
+}
+
+static int ltc294x_resume(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct ltc294x_info *info = i2c_get_clientdata(client);
+
+ schedule_delayed_work(&info->work, LTC294X_WORK_DELAY * HZ);
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(ltc294x_pm_ops, ltc294x_suspend, ltc294x_resume);
+#define LTC294X_PM_OPS (<c294x_pm_ops)
+
+#else
+#define LTC294X_PM_OPS NULL
+#endif /* CONFIG_PM_SLEEP */
+
+
+static const struct i2c_device_id ltc294x_i2c_id[] = {
+ {"ltc2941", LTC2941_NUM_REGS},
+ {"ltc2943", LTC2943_NUM_REGS},
+ { },
+};
+MODULE_DEVICE_TABLE(i2c, ltc294x_i2c_id);
+
+static struct i2c_driver ltc294x_driver = {
+ .driver = {
+ .name = "LTC2941",
+ .owner = THIS_MODULE,
+ .pm = LTC294X_PM_OPS,
+ },
+ .probe = ltc294x_i2c_probe,
+ .remove = ltc294x_i2c_remove,
+ .id_table = ltc294x_i2c_id,
+};
+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_LICENSE("GPL");
--
1.7.9.5
^ permalink raw reply related [flat|nested] 15+ messages in thread
* [PATCH v4] Add LTC2941/LTC2943 Battery Gauge Driver
2014-10-08 6:05 ` [PATCH v3] Add " Mike Looijmans
@ 2014-10-23 12:38 ` Mike Looijmans
2014-10-27 4:14 ` Pavel Machek
2014-10-27 16:38 ` Sebastian Reichel
0 siblings, 2 replies; 15+ messages in thread
From: Mike Looijmans @ 2014-10-23 12:38 UTC (permalink / raw)
To: linux-pm; +Cc: linux-kernel, sre, dbaryshkov, dwmw2, Mike Looijmans
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.
To avoid confusion with e.g. the LTC2945, the driver is called
LTC2941 instead of LTC294X.
v2: Fix units of measurement: uV, uA and centidegrees.
v3: Correctly set configuration register. Allow negative values
for the sense resistor.
v4: Run checkpatch.pl and fix all errors and warnings.
Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl>
---
drivers/power/Kconfig | 8 +
drivers/power/Makefile | 1 +
drivers/power/ltc2941-battery-gauge.c | 547 +++++++++++++++++++++++++++++++++
3 files changed, 556 insertions(+)
create mode 100644 drivers/power/ltc2941-battery-gauge.c
diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
index 73cfcdf..a79921a 100644
--- a/drivers/power/Kconfig
+++ b/drivers/power/Kconfig
@@ -382,6 +382,14 @@ config CHARGER_TPS65090
Say Y here to enable support for battery charging with TPS65090
PMIC chips.
+config BATTERY_GAUGE_LTC2941
+ tristate "LTC2941/LTC2943 Battery Gauge Driver"
+ depends on I2C
+ help
+ Say Y here to include support for LTC2941 and LTC2943 Battery
+ Gauge IC. The driver reports the charge count continuously, and
+ measures the voltage and temperature every 10 seconds.
+
config AB8500_BM
bool "AB8500 Battery Management Driver"
depends on AB8500_CORE && AB8500_GPADC
diff --git a/drivers/power/Makefile b/drivers/power/Makefile
index dfa8942..4f8e6c0 100644
--- a/drivers/power/Makefile
+++ b/drivers/power/Makefile
@@ -36,6 +36,7 @@ obj-$(CONFIG_BATTERY_MAX17042) += max17042_battery.o
obj-$(CONFIG_BATTERY_Z2) += z2_battery.o
obj-$(CONFIG_BATTERY_S3C_ADC) += s3c_adc_battery.o
obj-$(CONFIG_BATTERY_TWL4030_MADC) += twl4030_madc_battery.o
+obj-$(CONFIG_BATTERY_GAUGE_LTC2941) += ltc2941-battery-gauge.o
obj-$(CONFIG_CHARGER_88PM860X) += 88pm860x_charger.o
obj-$(CONFIG_CHARGER_PCF50633) += pcf50633-charger.o
obj-$(CONFIG_BATTERY_JZ4740) += jz4740-battery.o
diff --git a/drivers/power/ltc2941-battery-gauge.c b/drivers/power/ltc2941-battery-gauge.c
new file mode 100644
index 0000000..e4a9c87
--- /dev/null
+++ b/drivers/power/ltc2941-battery-gauge.c
@@ -0,0 +1,547 @@
+/*
+ * I2C client/driver for the Linear Technology LTC2941 and LTC2943
+ * Battery Gas Gauge IC
+ *
+ * Copyright (C) 2014 Topic Embedded Systems
+ *
+ * Author: Auryn Verwegen
+ * Author: Mike Looijmans
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/swab.h>
+#include <linux/i2c.h>
+#include <linux/delay.h>
+#include <linux/idr.h>
+#include <linux/power_supply.h>
+#include <linux/slab.h>
+
+#define I16_MSB(x) ((x >> 8) & 0xFF)
+#define I16_LSB(x) (x & 0xFF)
+
+#define LTC294X_WORK_DELAY 10 /* Update delay in seconds */
+
+#define LTC294X_MAX_VALUE 0xFFFF
+#define LTC294X_MID_SUPPLY 0x7FFF
+
+#define LTC2941_MAX_PRESCALER_EXP 7
+#define LTC2943_MAX_PRESCALER_EXP 6
+
+enum ltc294x_reg {
+ LTC294X_REG_STATUS = 0x00,
+ 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,
+};
+
+#define LTC2943_REG_CONTROL_MODE_MASK (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 delayed_work work; /* Work scheduler */
+ int num_regs; /* Number of registers (chip type) */
+ int id; /* Identifier of ltc294x chip */
+ int charge; /* Last charge register content */
+ int r_sense; /* mOhm */
+ int Qlsb; /* nAh */
+};
+
+static DEFINE_IDR(ltc294x_id);
+static DEFINE_MUTEX(ltc294x_lock);
+
+static inline int convert_bin_to_uAh(
+ const struct ltc294x_info *info, int Q)
+{
+ return ((Q * (info->Qlsb / 10))) / 100;
+}
+
+static inline int convert_uAh_to_bin(
+ const struct ltc294x_info *info, int uAh)
+{
+ int Q;
+
+ Q = (uAh * 100) / (info->Qlsb/10);
+ return (Q < LTC294X_MAX_VALUE) ? Q : LTC294X_MAX_VALUE;
+}
+
+static int ltc294x_read_regs(struct i2c_client *client,
+ enum ltc294x_reg reg, u8 *buf, int num_regs)
+{
+ int ret;
+ struct i2c_msg msgs[2] = { };
+ u8 reg_start = reg;
+
+ msgs[0].addr = client->addr;
+ msgs[0].len = 1;
+ msgs[0].buf = ®_start;
+
+ msgs[1].addr = client->addr;
+ msgs[1].len = num_regs;
+ msgs[1].buf = buf;
+ msgs[1].flags = I2C_M_RD;
+
+ ret = i2c_transfer(client->adapter, &msgs[0], 2);
+ if (ret < 0) {
+ dev_err(&client->dev, "ltc2941 read_reg failed!\n");
+ return ret;
+ }
+
+ dev_dbg(&client->dev, "%s (%#x, %d) -> %#x\n",
+ __func__, reg, num_regs, *buf);
+
+ return 0;
+}
+
+static int ltc294x_write_regs(struct i2c_client *client,
+ enum ltc294x_reg reg, const u8 *buf, int num_regs)
+{
+ int ret;
+ u8 reg_start = reg;
+
+ ret = i2c_smbus_write_i2c_block_data(client, reg_start, num_regs, buf);
+ if (ret < 0) {
+ dev_err(&client->dev, "ltc2941 write_reg failed!\n");
+ return ret;
+ }
+
+ dev_dbg(&client->dev, "%s (%#x, %d) -> %#x\n",
+ __func__, reg, num_regs, *buf);
+
+ return 0;
+}
+
+static int ltc294x_reset(const struct ltc294x_info *info, int prescaler_exp)
+{
+ int ret;
+ u8 value;
+ u8 control;
+
+ /* Read status and control registers */
+ ret = ltc294x_read_regs(info->client, LTC294X_REG_CONTROL, &value, 1);
+ if (ret < 0) {
+ dev_err(&info->client->dev,
+ "Could not read registers from device\n");
+ goto error_exit;
+ }
+
+ 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)
+ control |= LTC2943_REG_CONTROL_MODE_SCAN;
+
+ if (value != control) {
+ ret = ltc294x_write_regs(info->client,
+ LTC294X_REG_CONTROL, &control, 1);
+ if (ret < 0) {
+ dev_err(&info->client->dev,
+ "Could not write register\n");
+ goto error_exit;
+ }
+ }
+
+ return 0;
+
+error_exit:
+ return ret;
+}
+
+static int ltc294x_read_charge_register(const struct ltc294x_info *info)
+{
+ int ret;
+ u8 datar[2];
+
+ ret = ltc294x_read_regs(info->client,
+ LTC294X_REG_ACC_CHARGE_MSB, &datar[0], 2);
+ if (ret < 0)
+ return ret;
+ return (datar[0] << 8) + datar[1];
+}
+
+static int ltc294x_get_charge_now(const struct ltc294x_info *info, int *val)
+{
+ int value = ltc294x_read_charge_register(info);
+
+ if (value < 0)
+ return value;
+ /* When r_sense < 0, this counts up when the battery discharges */
+ if (info->Qlsb < 0)
+ value -= 0xFFFF;
+ *val = convert_bin_to_uAh(info, value);
+ return 0;
+}
+
+static int ltc294x_set_charge_now(const struct ltc294x_info *info, int val)
+{
+ int ret;
+ u8 dataw[2];
+ u8 ctrl_reg;
+ s32 value;
+
+ value = convert_uAh_to_bin(info, val);
+ /* Direction depends on how sense+/- were connected */
+ if (info->Qlsb < 0)
+ value += 0xFFFF;
+ if ((value < 0) || (value > 0xFFFF)) /* input validation */
+ return -EINVAL;
+
+ /* Read control register */
+ ret = ltc294x_read_regs(info->client,
+ LTC294X_REG_CONTROL, &ctrl_reg, 1);
+ if (ret < 0)
+ return ret;
+ /* Disable analog section */
+ ctrl_reg |= LTC294X_REG_CONTROL_SHUTDOWN_MASK;
+ ret = ltc294x_write_regs(info->client,
+ LTC294X_REG_CONTROL, &ctrl_reg, 1);
+ if (ret < 0)
+ return ret;
+ /* Set new charge value */
+ dataw[0] = I16_MSB(value);
+ dataw[1] = I16_LSB(value);
+ ret = ltc294x_write_regs(info->client,
+ LTC294X_REG_ACC_CHARGE_MSB, &dataw[0], 2);
+ if (ret < 0)
+ goto error_exit;
+ /* Enable analog section */
+error_exit:
+ ctrl_reg &= ~LTC294X_REG_CONTROL_SHUTDOWN_MASK;
+ ret = ltc294x_write_regs(info->client,
+ LTC294X_REG_CONTROL, &ctrl_reg, 1);
+
+ return ret < 0 ? ret : 0;
+}
+
+static int ltc294x_get_charge_counter(
+ const struct ltc294x_info *info, int *val)
+{
+ int value = ltc294x_read_charge_register(info);
+
+ if (value < 0)
+ return value;
+ value -= LTC294X_MID_SUPPLY;
+ *val = convert_bin_to_uAh(info, value);
+ return 0;
+}
+
+static int ltc294x_get_voltage(const struct ltc294x_info *info, int *val)
+{
+ int ret;
+ u8 datar[2];
+ u32 value;
+
+ 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 */
+ return ret;
+}
+
+static int ltc294x_get_current(const struct ltc294x_info *info, int *val)
+{
+ int ret;
+ u8 datar[2];
+ s32 value;
+
+ ret = ltc294x_read_regs(info->client,
+ LTC294X_REG_CURRENT_MSB, &datar[0], 2);
+ value = (datar[0] << 8) | datar[1];
+ value -= 0x7FFF;
+ /* 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 */
+ return ret;
+}
+
+static int ltc294x_get_temperature(const struct ltc294x_info *info, int *val)
+{
+ 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);
+ return ret;
+}
+
+static int ltc294x_get_property(struct power_supply *psy,
+ enum power_supply_property prop,
+ union power_supply_propval *val)
+{
+ struct ltc294x_info *info =
+ container_of(psy, struct ltc294x_info, supply);
+
+ switch (prop) {
+ case POWER_SUPPLY_PROP_CHARGE_NOW:
+ return ltc294x_get_charge_now(info, &val->intval);
+ case POWER_SUPPLY_PROP_CHARGE_COUNTER:
+ return ltc294x_get_charge_counter(info, &val->intval);
+ case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+ return ltc294x_get_voltage(info, &val->intval);
+ case POWER_SUPPLY_PROP_CURRENT_NOW:
+ return ltc294x_get_current(info, &val->intval);
+ case POWER_SUPPLY_PROP_TEMP:
+ return ltc294x_get_temperature(info, &val->intval);
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ltc294x_set_property(struct power_supply *psy,
+ enum power_supply_property psp,
+ const union power_supply_propval *val)
+{
+ struct ltc294x_info *info =
+ container_of(psy, struct ltc294x_info, supply);
+
+ switch (psp) {
+ case POWER_SUPPLY_PROP_CHARGE_NOW:
+ return ltc294x_set_charge_now(info, val->intval);
+ default:
+ return -EPERM;
+ }
+}
+
+static int ltc294x_property_is_writeable(
+ struct power_supply *psy, enum power_supply_property psp)
+{
+ switch (psp) {
+ case POWER_SUPPLY_PROP_CHARGE_NOW:
+ return 1;
+ default:
+ return 0;
+ }
+}
+
+static void ltc294x_update(struct ltc294x_info *info)
+{
+ int charge = ltc294x_read_charge_register(info);
+
+ if (charge != info->charge) {
+ info->charge = charge;
+ power_supply_changed(&info->supply);
+ }
+}
+
+static void ltc294x_work(struct work_struct *work)
+{
+ struct ltc294x_info *info;
+
+ info = container_of(work, struct ltc294x_info, work.work);
+ ltc294x_update(info);
+ schedule_delayed_work(&info->work, LTC294X_WORK_DELAY * HZ);
+}
+
+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,
+};
+
+static int ltc294x_i2c_remove(struct i2c_client *client)
+{
+ struct ltc294x_info *info = i2c_get_clientdata(client);
+
+ cancel_delayed_work(&info->work);
+ power_supply_unregister(&info->supply);
+ kfree(info->supply.name);
+ mutex_lock(<c294x_lock);
+ idr_remove(<c294x_id, info->id);
+ mutex_unlock(<c294x_lock);
+ return 0;
+}
+
+static int ltc294x_i2c_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct ltc294x_info *info;
+ int ret;
+ int num;
+ u32 prescaler_exp;
+ s32 r_sense;
+ struct device_node *np;
+
+ mutex_lock(<c294x_lock);
+ ret = idr_alloc(<c294x_id, client, 0, 0, GFP_KERNEL);
+ mutex_unlock(<c294x_lock);
+ if (ret < 0)
+ goto fail_id;
+
+ num = ret;
+
+ info = devm_kzalloc(&client->dev, sizeof(*info), GFP_KERNEL);
+ if (info == NULL) {
+ ret = -ENOMEM;
+ goto fail_info;
+ }
+
+ i2c_set_clientdata(client, info);
+
+ info->num_regs = id->driver_data;
+ info->supply.name = kasprintf(GFP_KERNEL, "%s-%d", client->name, num);
+ if (!info->supply.name) {
+ ret = -ENOMEM;
+ goto fail_name;
+ }
+
+ np = of_node_get(client->dev.of_node);
+
+ /* r_sense can be negative, when sense+ is connected to the battery
+ * instead of the sense-. This results in reversed measurements. */
+ ret = of_property_read_u32(np, "resistor-sense", &r_sense);
+ if (ret < 0) {
+ dev_err(&client->dev,
+ "Could not find resistor-sense in devicetree\n");
+ goto fail_name;
+ }
+ info->r_sense = r_sense;
+
+ ret = of_property_read_u32(np, "prescaler-exponent", &prescaler_exp);
+ if (ret < 0) {
+ dev_err(&client->dev,
+ "PrescalerExponent not in devicetree, assume max\n");
+ prescaler_exp = LTC2941_MAX_PRESCALER_EXP;
+ }
+
+ if (info->num_regs == LTC2943_NUM_REGS) {
+ if (prescaler_exp > LTC2943_MAX_PRESCALER_EXP)
+ prescaler_exp = LTC2943_MAX_PRESCALER_EXP;
+ info->Qlsb = ((340 * 50000) / r_sense) /
+ (4096 / (1 << (2*prescaler_exp)));
+ } else {
+ if (prescaler_exp > LTC2941_MAX_PRESCALER_EXP)
+ prescaler_exp = LTC2941_MAX_PRESCALER_EXP;
+ info->Qlsb = ((58 * 50000) / r_sense) /
+ (128 / (1 << prescaler_exp));
+ }
+
+ info->client = client;
+ info->id = num;
+ info->supply.type = POWER_SUPPLY_TYPE_BATTERY;
+ info->supply.properties = ltc294x_properties;
+ if (info->num_regs >= LTC294X_REG_TEMPERATURE_LSB)
+ info->supply.num_properties =
+ ARRAY_SIZE(ltc294x_properties);
+ else if (info->num_regs >= LTC294X_REG_CURRENT_LSB)
+ info->supply.num_properties =
+ ARRAY_SIZE(ltc294x_properties) - 1;
+ else if (info->num_regs >= LTC294X_REG_VOLTAGE_LSB)
+ info->supply.num_properties =
+ ARRAY_SIZE(ltc294x_properties) - 2;
+ else
+ info->supply.num_properties =
+ ARRAY_SIZE(ltc294x_properties) - 3;
+ info->supply.get_property = ltc294x_get_property;
+ info->supply.set_property = ltc294x_set_property;
+ info->supply.property_is_writeable = ltc294x_property_is_writeable;
+ info->supply.external_power_changed = NULL;
+
+ INIT_DELAYED_WORK(&info->work, ltc294x_work);
+
+ ret = ltc294x_reset(info, prescaler_exp);
+ if (ret < 0) {
+ dev_err(&client->dev, "Communication with chip failed!\n");
+ goto fail_comm;
+ }
+
+ ret = power_supply_register(&client->dev, &info->supply);
+ if (ret) {
+ dev_err(&client->dev, "failed to register ltc2941\n");
+ goto fail_register;
+ } else {
+ schedule_delayed_work(&info->work, LTC294X_WORK_DELAY * HZ);
+ }
+
+ return 0;
+
+fail_register:
+ kfree(info->supply.name);
+fail_comm:
+fail_name:
+fail_info:
+ mutex_lock(<c294x_lock);
+ idr_remove(<c294x_id, num);
+ mutex_unlock(<c294x_lock);
+fail_id:
+ return ret;
+}
+
+#ifdef CONFIG_PM_SLEEP
+
+static int ltc294x_suspend(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct ltc294x_info *info = i2c_get_clientdata(client);
+
+ cancel_delayed_work(&info->work);
+ return 0;
+}
+
+static int ltc294x_resume(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct ltc294x_info *info = i2c_get_clientdata(client);
+
+ schedule_delayed_work(&info->work, LTC294X_WORK_DELAY * HZ);
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(ltc294x_pm_ops, ltc294x_suspend, ltc294x_resume);
+#define LTC294X_PM_OPS (<c294x_pm_ops)
+
+#else
+#define LTC294X_PM_OPS NULL
+#endif /* CONFIG_PM_SLEEP */
+
+
+static const struct i2c_device_id ltc294x_i2c_id[] = {
+ {"ltc2941", LTC2941_NUM_REGS},
+ {"ltc2943", LTC2943_NUM_REGS},
+ { },
+};
+MODULE_DEVICE_TABLE(i2c, ltc294x_i2c_id);
+
+static struct i2c_driver ltc294x_driver = {
+ .driver = {
+ .name = "LTC2941",
+ .owner = THIS_MODULE,
+ .pm = LTC294X_PM_OPS,
+ },
+ .probe = ltc294x_i2c_probe,
+ .remove = ltc294x_i2c_remove,
+ .id_table = ltc294x_i2c_id,
+};
+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_LICENSE("GPL");
--
1.7.9.5
^ permalink raw reply related [flat|nested] 15+ messages in thread
* Re: [PATCH v4] Add LTC2941/LTC2943 Battery Gauge Driver
2014-10-23 12:38 ` [PATCH v4] " Mike Looijmans
@ 2014-10-27 4:14 ` Pavel Machek
2014-10-27 16:38 ` Sebastian Reichel
1 sibling, 0 replies; 15+ messages in thread
From: Pavel Machek @ 2014-10-27 4:14 UTC (permalink / raw)
To: Mike Looijmans; +Cc: linux-pm, linux-kernel, sre, dbaryshkov, dwmw2
Hi!
> +++ b/drivers/power/ltc2941-battery-gauge.c
> @@ -0,0 +1,547 @@
> +/*
> + * I2C client/driver for the Linear Technology LTC2941 and LTC2943
> + * Battery Gas Gauge IC
> + *
> + * Copyright (C) 2014 Topic Embedded Systems
> + *
NOrmally GPL notice would go here.
> + * Author: Auryn Verwegen
> + * Author: Mike Looijmans
> + */
Do you want to add yourself as a maintainers?
> +{
> + int ret;
> + struct i2c_msg msgs[2] = { };
> + u8 reg_start = reg;
> +
> + msgs[0].addr = client->addr;
> + msgs[0].len = 1;
> + msgs[0].buf = ®_start;
> +
> + msgs[1].addr = client->addr;
> + msgs[1].len = num_regs;
> + msgs[1].buf = buf;
> + msgs[1].flags = I2C_M_RD;
> +
> + ret = i2c_transfer(client->adapter, &msgs[0], 2);
Here you send byte from kernel stack to i2c device. I'd add msg[0].flags = 0.
> + ret = ltc294x_write_regs(info->client,
> + LTC294X_REG_CONTROL, &control, 1);
> + if (ret < 0) {
> + dev_err(&info->client->dev,
> + "Could not write register\n");
> + goto error_exit;
return ret; No need to goto when you have nothing to clean up.
> + }
> + }
> +
> + return 0;
> +
> +error_exit:
> + return ret;
> +}
> + if (info->Qlsb < 0)
> + value += 0xFFFF;
q_lsb?
> + dataw[0] = I16_MSB(value);
> + dataw[1] = I16_LSB(value);
> + ret = ltc294x_write_regs(info->client,
> + LTC294X_REG_ACC_CHARGE_MSB, &dataw[0], 2);
> + if (ret < 0)
> + goto error_exit;
> + /* Enable analog section */
> +error_exit:
Interesting use of goto... remove?
> + ret = of_property_read_u32(np, "prescaler-exponent", &prescaler_exp);
> + if (ret < 0) {
> + dev_err(&client->dev,
> + "PrescalerExponent not in devicetree, assume max\n");
assuming?
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [PATCH v4] Add LTC2941/LTC2943 Battery Gauge Driver
2014-10-23 12:38 ` [PATCH v4] " Mike Looijmans
2014-10-27 4:14 ` Pavel Machek
@ 2014-10-27 16:38 ` Sebastian Reichel
2014-10-28 7:03 ` Mike Looijmans
` (2 more replies)
1 sibling, 3 replies; 15+ messages in thread
From: Sebastian Reichel @ 2014-10-27 16:38 UTC (permalink / raw)
To: Mike Looijmans; +Cc: linux-pm, linux-kernel, dbaryshkov, dwmw2
[-- Attachment #1: Type: text/plain, Size: 1608 bytes --]
Hi,
On Thu, Oct 23, 2014 at 02:38:38PM +0200, Mike Looijmans wrote:
> 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.
>
> To avoid confusion with e.g. the LTC2945, the driver is called
> LTC2941 instead of LTC294X.
>
> v2: Fix units of measurement: uV, uA and centidegrees.
> v3: Correctly set configuration register. Allow negative values
> for the sense resistor.
> v4: Run checkpatch.pl and fix all errors and warnings.
>
> Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl>
> ---
> [...]
>
> + np = of_node_get(client->dev.of_node);
> +
> + /* r_sense can be negative, when sense+ is connected to the battery
> + * instead of the sense-. This results in reversed measurements. */
> + ret = of_property_read_u32(np, "resistor-sense", &r_sense);
> + if (ret < 0) {
> + dev_err(&client->dev,
> + "Could not find resistor-sense in devicetree\n");
> + goto fail_name;
> + }
> + info->r_sense = r_sense;
> +
> + ret = of_property_read_u32(np, "prescaler-exponent", &prescaler_exp);
> + if (ret < 0) {
> + dev_err(&client->dev,
> + "PrescalerExponent not in devicetree, assume max\n");
> + prescaler_exp = LTC2941_MAX_PRESCALER_EXP;
> + }
The device tree properties are not documented. Please document them
in a separate patch and Cc devicetree binding maintainers.
Apart from that the properties should be vendor prefixed (e.g.
"lltc,resistor-sense").
-- Sebastian
[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 819 bytes --]
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [PATCH v4] Add LTC2941/LTC2943 Battery Gauge Driver
2014-10-27 16:38 ` Sebastian Reichel
@ 2014-10-28 7:03 ` Mike Looijmans
2014-10-28 7:05 ` [PATCH] " Mike Looijmans
2014-10-28 7:08 ` [PATCH] Add devicetree binding documentation for the LTC2941/LTC2943 driver Mike Looijmans
2 siblings, 0 replies; 15+ messages in thread
From: Mike Looijmans @ 2014-10-28 7:03 UTC (permalink / raw)
To: Sebastian Reichel; +Cc: linux-pm, linux-kernel, dbaryshkov, dwmw2
On 10/27/2014 05:38 PM, Sebastian Reichel wrote:
> Hi,
>
> On Thu, Oct 23, 2014 at 02:38:38PM +0200, Mike Looijmans wrote:
>> 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.
>>
>> To avoid confusion with e.g. the LTC2945, the driver is called
>> LTC2941 instead of LTC294X.
>>
>> v2: Fix units of measurement: uV, uA and centidegrees.
>> v3: Correctly set configuration register. Allow negative values
>> for the sense resistor.
>> v4: Run checkpatch.pl and fix all errors and warnings.
>>
>> Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl>
>> ---
>> [...]
>>
>> + np = of_node_get(client->dev.of_node);
>> +
>> + /* r_sense can be negative, when sense+ is connected to the battery
>> + * instead of the sense-. This results in reversed measurements. */
>> + ret = of_property_read_u32(np, "resistor-sense", &r_sense);
>> + if (ret < 0) {
>> + dev_err(&client->dev,
>> + "Could not find resistor-sense in devicetree\n");
>> + goto fail_name;
>> + }
>> + info->r_sense = r_sense;
>> +
>> + ret = of_property_read_u32(np, "prescaler-exponent", &prescaler_exp);
>> + if (ret < 0) {
>> + dev_err(&client->dev,
>> + "PrescalerExponent not in devicetree, assume max\n");
>> + prescaler_exp = LTC2941_MAX_PRESCALER_EXP;
>> + }
>
> The device tree properties are not documented. Please document them
> in a separate patch and Cc devicetree binding maintainers.
>
> Apart from that the properties should be vendor prefixed (e.g.
> "lltc,resistor-sense").
Thanks for your feedback. I will post the requested changes asap.
Met vriendelijke groet / kind regards,
Mike Looijmans
System Expert
TOPIC Embedded Systems
Eindhovenseweg 32-C, NL-5683 KH Best
Postbus 440, NL-5680 AK Best
Telefoon: (+31) (0) 499 33 69 79
Telefax: (+31) (0) 499 33 69 70
E-mail: mike.looijmans@topic.nl
Website: www.topic.nl
Please consider the environment before printing this e-mail
Topic zoekt gedreven (embedded) software specialisten!
http://topic.nl/vacatures/topic-zoekt-software-engineers/
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [PATCH v4] Add LTC2941/LTC2943 Battery Gauge Driver
@ 2014-10-28 7:03 ` Mike Looijmans
0 siblings, 0 replies; 15+ messages in thread
From: Mike Looijmans @ 2014-10-28 7:03 UTC (permalink / raw)
To: Sebastian Reichel; +Cc: linux-pm, linux-kernel, dbaryshkov, dwmw2
On 10/27/2014 05:38 PM, Sebastian Reichel wrote:
> Hi,
>
> On Thu, Oct 23, 2014 at 02:38:38PM +0200, Mike Looijmans wrote:
>> 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.
>>
>> To avoid confusion with e.g. the LTC2945, the driver is called
>> LTC2941 instead of LTC294X.
>>
>> v2: Fix units of measurement: uV, uA and centidegrees.
>> v3: Correctly set configuration register. Allow negative values
>> for the sense resistor.
>> v4: Run checkpatch.pl and fix all errors and warnings.
>>
>> Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl>
>> ---
>> [...]
>>
>> + np = of_node_get(client->dev.of_node);
>> +
>> + /* r_sense can be negative, when sense+ is connected to the battery
>> + * instead of the sense-. This results in reversed measurements. */
>> + ret = of_property_read_u32(np, "resistor-sense", &r_sense);
>> + if (ret < 0) {
>> + dev_err(&client->dev,
>> + "Could not find resistor-sense in devicetree\n");
>> + goto fail_name;
>> + }
>> + info->r_sense = r_sense;
>> +
>> + ret = of_property_read_u32(np, "prescaler-exponent", &prescaler_exp);
>> + if (ret < 0) {
>> + dev_err(&client->dev,
>> + "PrescalerExponent not in devicetree, assume max\n");
>> + prescaler_exp = LTC2941_MAX_PRESCALER_EXP;
>> + }
>
> The device tree properties are not documented. Please document them
> in a separate patch and Cc devicetree binding maintainers.
>
> Apart from that the properties should be vendor prefixed (e.g.
> "lltc,resistor-sense").
Thanks for your feedback. I will post the requested changes asap.
Met vriendelijke groet / kind regards,
Mike Looijmans
System Expert
TOPIC Embedded Systems
Eindhovenseweg 32-C, NL-5683 KH Best
Postbus 440, NL-5680 AK Best
Telefoon: (+31) (0) 499 33 69 79
Telefax: (+31) (0) 499 33 69 70
E-mail: mike.looijmans@topic.nl
Website: www.topic.nl
Please consider the environment before printing this e-mail
Topic zoekt gedreven (embedded) software specialisten!
http://topic.nl/vacatures/topic-zoekt-software-engineers/
^ permalink raw reply [flat|nested] 15+ messages in thread
* [PATCH] Add LTC2941/LTC2943 Battery Gauge Driver
2014-10-27 16:38 ` Sebastian Reichel
2014-10-28 7:03 ` Mike Looijmans
@ 2014-10-28 7:05 ` Mike Looijmans
2015-01-22 2:24 ` Sebastian Reichel
2014-10-28 7:08 ` [PATCH] Add devicetree binding documentation for the LTC2941/LTC2943 driver Mike Looijmans
2 siblings, 1 reply; 15+ messages in thread
From: Mike Looijmans @ 2014-10-28 7:05 UTC (permalink / raw)
To: sre; +Cc: linux-pm, linux-kernel, dbaryshkov, dwmw2, Mike Looijmans
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.
To avoid confusion with e.g. the LTC2945, the driver is called
LTC2941 instead of LTC294X.
v2: Fix units of measurement: uV, uA and centidegrees.
v3: Correctly set configuration register. Allow negative values
for the sense resistor.
v4: Run checkpatch.pl and fix all errors and warnings.
v5: Prefix "lltc," to devicetree properties.
Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl>
---
drivers/power/Kconfig | 8 +
drivers/power/Makefile | 1 +
drivers/power/ltc2941-battery-gauge.c | 548 +++++++++++++++++++++++++++++++++
3 files changed, 557 insertions(+)
create mode 100644 drivers/power/ltc2941-battery-gauge.c
diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
index 73cfcdf..a79921a 100644
--- a/drivers/power/Kconfig
+++ b/drivers/power/Kconfig
@@ -382,6 +382,14 @@ config CHARGER_TPS65090
Say Y here to enable support for battery charging with TPS65090
PMIC chips.
+config BATTERY_GAUGE_LTC2941
+ tristate "LTC2941/LTC2943 Battery Gauge Driver"
+ depends on I2C
+ help
+ Say Y here to include support for LTC2941 and LTC2943 Battery
+ Gauge IC. The driver reports the charge count continuously, and
+ measures the voltage and temperature every 10 seconds.
+
config AB8500_BM
bool "AB8500 Battery Management Driver"
depends on AB8500_CORE && AB8500_GPADC
diff --git a/drivers/power/Makefile b/drivers/power/Makefile
index dfa8942..4f8e6c0 100644
--- a/drivers/power/Makefile
+++ b/drivers/power/Makefile
@@ -36,6 +36,7 @@ obj-$(CONFIG_BATTERY_MAX17042) += max17042_battery.o
obj-$(CONFIG_BATTERY_Z2) += z2_battery.o
obj-$(CONFIG_BATTERY_S3C_ADC) += s3c_adc_battery.o
obj-$(CONFIG_BATTERY_TWL4030_MADC) += twl4030_madc_battery.o
+obj-$(CONFIG_BATTERY_GAUGE_LTC2941) += ltc2941-battery-gauge.o
obj-$(CONFIG_CHARGER_88PM860X) += 88pm860x_charger.o
obj-$(CONFIG_CHARGER_PCF50633) += pcf50633-charger.o
obj-$(CONFIG_BATTERY_JZ4740) += jz4740-battery.o
diff --git a/drivers/power/ltc2941-battery-gauge.c b/drivers/power/ltc2941-battery-gauge.c
new file mode 100644
index 0000000..7a5a25a
--- /dev/null
+++ b/drivers/power/ltc2941-battery-gauge.c
@@ -0,0 +1,548 @@
+/*
+ * I2C client/driver for the Linear Technology LTC2941 and LTC2943
+ * Battery Gas Gauge IC
+ *
+ * Copyright (C) 2014 Topic Embedded Systems
+ *
+ * Author: Auryn Verwegen
+ * Author: Mike Looijmans
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/swab.h>
+#include <linux/i2c.h>
+#include <linux/delay.h>
+#include <linux/idr.h>
+#include <linux/power_supply.h>
+#include <linux/slab.h>
+
+#define I16_MSB(x) ((x >> 8) & 0xFF)
+#define I16_LSB(x) (x & 0xFF)
+
+#define LTC294X_WORK_DELAY 10 /* Update delay in seconds */
+
+#define LTC294X_MAX_VALUE 0xFFFF
+#define LTC294X_MID_SUPPLY 0x7FFF
+
+#define LTC2941_MAX_PRESCALER_EXP 7
+#define LTC2943_MAX_PRESCALER_EXP 6
+
+enum ltc294x_reg {
+ LTC294X_REG_STATUS = 0x00,
+ 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,
+};
+
+#define LTC2943_REG_CONTROL_MODE_MASK (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 delayed_work work; /* Work scheduler */
+ int num_regs; /* Number of registers (chip type) */
+ int id; /* Identifier of ltc294x chip */
+ int charge; /* Last charge register content */
+ int r_sense; /* mOhm */
+ int Qlsb; /* nAh */
+};
+
+static DEFINE_IDR(ltc294x_id);
+static DEFINE_MUTEX(ltc294x_lock);
+
+static inline int convert_bin_to_uAh(
+ const struct ltc294x_info *info, int Q)
+{
+ return ((Q * (info->Qlsb / 10))) / 100;
+}
+
+static inline int convert_uAh_to_bin(
+ const struct ltc294x_info *info, int uAh)
+{
+ int Q;
+
+ Q = (uAh * 100) / (info->Qlsb/10);
+ return (Q < LTC294X_MAX_VALUE) ? Q : LTC294X_MAX_VALUE;
+}
+
+static int ltc294x_read_regs(struct i2c_client *client,
+ enum ltc294x_reg reg, u8 *buf, int num_regs)
+{
+ int ret;
+ struct i2c_msg msgs[2] = { };
+ u8 reg_start = reg;
+
+ msgs[0].addr = client->addr;
+ msgs[0].len = 1;
+ msgs[0].buf = ®_start;
+
+ msgs[1].addr = client->addr;
+ msgs[1].len = num_regs;
+ msgs[1].buf = buf;
+ msgs[1].flags = I2C_M_RD;
+
+ ret = i2c_transfer(client->adapter, &msgs[0], 2);
+ if (ret < 0) {
+ dev_err(&client->dev, "ltc2941 read_reg failed!\n");
+ return ret;
+ }
+
+ dev_dbg(&client->dev, "%s (%#x, %d) -> %#x\n",
+ __func__, reg, num_regs, *buf);
+
+ return 0;
+}
+
+static int ltc294x_write_regs(struct i2c_client *client,
+ enum ltc294x_reg reg, const u8 *buf, int num_regs)
+{
+ int ret;
+ u8 reg_start = reg;
+
+ ret = i2c_smbus_write_i2c_block_data(client, reg_start, num_regs, buf);
+ if (ret < 0) {
+ dev_err(&client->dev, "ltc2941 write_reg failed!\n");
+ return ret;
+ }
+
+ dev_dbg(&client->dev, "%s (%#x, %d) -> %#x\n",
+ __func__, reg, num_regs, *buf);
+
+ return 0;
+}
+
+static int ltc294x_reset(const struct ltc294x_info *info, int prescaler_exp)
+{
+ int ret;
+ u8 value;
+ u8 control;
+
+ /* Read status and control registers */
+ ret = ltc294x_read_regs(info->client, LTC294X_REG_CONTROL, &value, 1);
+ if (ret < 0) {
+ dev_err(&info->client->dev,
+ "Could not read registers from device\n");
+ goto error_exit;
+ }
+
+ 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)
+ control |= LTC2943_REG_CONTROL_MODE_SCAN;
+
+ if (value != control) {
+ ret = ltc294x_write_regs(info->client,
+ LTC294X_REG_CONTROL, &control, 1);
+ if (ret < 0) {
+ dev_err(&info->client->dev,
+ "Could not write register\n");
+ goto error_exit;
+ }
+ }
+
+ return 0;
+
+error_exit:
+ return ret;
+}
+
+static int ltc294x_read_charge_register(const struct ltc294x_info *info)
+{
+ int ret;
+ u8 datar[2];
+
+ ret = ltc294x_read_regs(info->client,
+ LTC294X_REG_ACC_CHARGE_MSB, &datar[0], 2);
+ if (ret < 0)
+ return ret;
+ return (datar[0] << 8) + datar[1];
+}
+
+static int ltc294x_get_charge_now(const struct ltc294x_info *info, int *val)
+{
+ int value = ltc294x_read_charge_register(info);
+
+ if (value < 0)
+ return value;
+ /* When r_sense < 0, this counts up when the battery discharges */
+ if (info->Qlsb < 0)
+ value -= 0xFFFF;
+ *val = convert_bin_to_uAh(info, value);
+ return 0;
+}
+
+static int ltc294x_set_charge_now(const struct ltc294x_info *info, int val)
+{
+ int ret;
+ u8 dataw[2];
+ u8 ctrl_reg;
+ s32 value;
+
+ value = convert_uAh_to_bin(info, val);
+ /* Direction depends on how sense+/- were connected */
+ if (info->Qlsb < 0)
+ value += 0xFFFF;
+ if ((value < 0) || (value > 0xFFFF)) /* input validation */
+ return -EINVAL;
+
+ /* Read control register */
+ ret = ltc294x_read_regs(info->client,
+ LTC294X_REG_CONTROL, &ctrl_reg, 1);
+ if (ret < 0)
+ return ret;
+ /* Disable analog section */
+ ctrl_reg |= LTC294X_REG_CONTROL_SHUTDOWN_MASK;
+ ret = ltc294x_write_regs(info->client,
+ LTC294X_REG_CONTROL, &ctrl_reg, 1);
+ if (ret < 0)
+ return ret;
+ /* Set new charge value */
+ dataw[0] = I16_MSB(value);
+ dataw[1] = I16_LSB(value);
+ ret = ltc294x_write_regs(info->client,
+ LTC294X_REG_ACC_CHARGE_MSB, &dataw[0], 2);
+ if (ret < 0)
+ goto error_exit;
+ /* Enable analog section */
+error_exit:
+ ctrl_reg &= ~LTC294X_REG_CONTROL_SHUTDOWN_MASK;
+ ret = ltc294x_write_regs(info->client,
+ LTC294X_REG_CONTROL, &ctrl_reg, 1);
+
+ return ret < 0 ? ret : 0;
+}
+
+static int ltc294x_get_charge_counter(
+ const struct ltc294x_info *info, int *val)
+{
+ int value = ltc294x_read_charge_register(info);
+
+ if (value < 0)
+ return value;
+ value -= LTC294X_MID_SUPPLY;
+ *val = convert_bin_to_uAh(info, value);
+ return 0;
+}
+
+static int ltc294x_get_voltage(const struct ltc294x_info *info, int *val)
+{
+ int ret;
+ u8 datar[2];
+ u32 value;
+
+ 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 */
+ return ret;
+}
+
+static int ltc294x_get_current(const struct ltc294x_info *info, int *val)
+{
+ int ret;
+ u8 datar[2];
+ s32 value;
+
+ ret = ltc294x_read_regs(info->client,
+ LTC294X_REG_CURRENT_MSB, &datar[0], 2);
+ value = (datar[0] << 8) | datar[1];
+ value -= 0x7FFF;
+ /* 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 */
+ return ret;
+}
+
+static int ltc294x_get_temperature(const struct ltc294x_info *info, int *val)
+{
+ 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);
+ return ret;
+}
+
+static int ltc294x_get_property(struct power_supply *psy,
+ enum power_supply_property prop,
+ union power_supply_propval *val)
+{
+ struct ltc294x_info *info =
+ container_of(psy, struct ltc294x_info, supply);
+
+ switch (prop) {
+ case POWER_SUPPLY_PROP_CHARGE_NOW:
+ return ltc294x_get_charge_now(info, &val->intval);
+ case POWER_SUPPLY_PROP_CHARGE_COUNTER:
+ return ltc294x_get_charge_counter(info, &val->intval);
+ case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+ return ltc294x_get_voltage(info, &val->intval);
+ case POWER_SUPPLY_PROP_CURRENT_NOW:
+ return ltc294x_get_current(info, &val->intval);
+ case POWER_SUPPLY_PROP_TEMP:
+ return ltc294x_get_temperature(info, &val->intval);
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ltc294x_set_property(struct power_supply *psy,
+ enum power_supply_property psp,
+ const union power_supply_propval *val)
+{
+ struct ltc294x_info *info =
+ container_of(psy, struct ltc294x_info, supply);
+
+ switch (psp) {
+ case POWER_SUPPLY_PROP_CHARGE_NOW:
+ return ltc294x_set_charge_now(info, val->intval);
+ default:
+ return -EPERM;
+ }
+}
+
+static int ltc294x_property_is_writeable(
+ struct power_supply *psy, enum power_supply_property psp)
+{
+ switch (psp) {
+ case POWER_SUPPLY_PROP_CHARGE_NOW:
+ return 1;
+ default:
+ return 0;
+ }
+}
+
+static void ltc294x_update(struct ltc294x_info *info)
+{
+ int charge = ltc294x_read_charge_register(info);
+
+ if (charge != info->charge) {
+ info->charge = charge;
+ power_supply_changed(&info->supply);
+ }
+}
+
+static void ltc294x_work(struct work_struct *work)
+{
+ struct ltc294x_info *info;
+
+ info = container_of(work, struct ltc294x_info, work.work);
+ ltc294x_update(info);
+ schedule_delayed_work(&info->work, LTC294X_WORK_DELAY * HZ);
+}
+
+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,
+};
+
+static int ltc294x_i2c_remove(struct i2c_client *client)
+{
+ struct ltc294x_info *info = i2c_get_clientdata(client);
+
+ cancel_delayed_work(&info->work);
+ power_supply_unregister(&info->supply);
+ kfree(info->supply.name);
+ mutex_lock(<c294x_lock);
+ idr_remove(<c294x_id, info->id);
+ mutex_unlock(<c294x_lock);
+ return 0;
+}
+
+static int ltc294x_i2c_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct ltc294x_info *info;
+ int ret;
+ int num;
+ u32 prescaler_exp;
+ s32 r_sense;
+ struct device_node *np;
+
+ mutex_lock(<c294x_lock);
+ ret = idr_alloc(<c294x_id, client, 0, 0, GFP_KERNEL);
+ mutex_unlock(<c294x_lock);
+ if (ret < 0)
+ goto fail_id;
+
+ num = ret;
+
+ info = devm_kzalloc(&client->dev, sizeof(*info), GFP_KERNEL);
+ if (info == NULL) {
+ ret = -ENOMEM;
+ goto fail_info;
+ }
+
+ i2c_set_clientdata(client, info);
+
+ info->num_regs = id->driver_data;
+ info->supply.name = kasprintf(GFP_KERNEL, "%s-%d", client->name, num);
+ if (!info->supply.name) {
+ ret = -ENOMEM;
+ goto fail_name;
+ }
+
+ np = of_node_get(client->dev.of_node);
+
+ /* r_sense can be negative, when sense+ is connected to the battery
+ * instead of the sense-. This results in reversed measurements. */
+ ret = of_property_read_u32(np, "lltc,resistor-sense", &r_sense);
+ if (ret < 0) {
+ dev_err(&client->dev,
+ "Could not find lltc,resistor-sense in devicetree\n");
+ goto fail_name;
+ }
+ info->r_sense = r_sense;
+
+ ret = of_property_read_u32(np, "lltc,prescaler-exponent",
+ &prescaler_exp);
+ if (ret < 0) {
+ dev_warn(&client->dev,
+ "lltc,prescaler-exponent not in devicetree\n");
+ prescaler_exp = LTC2941_MAX_PRESCALER_EXP;
+ }
+
+ if (info->num_regs == LTC2943_NUM_REGS) {
+ if (prescaler_exp > LTC2943_MAX_PRESCALER_EXP)
+ prescaler_exp = LTC2943_MAX_PRESCALER_EXP;
+ info->Qlsb = ((340 * 50000) / r_sense) /
+ (4096 / (1 << (2*prescaler_exp)));
+ } else {
+ if (prescaler_exp > LTC2941_MAX_PRESCALER_EXP)
+ prescaler_exp = LTC2941_MAX_PRESCALER_EXP;
+ info->Qlsb = ((58 * 50000) / r_sense) /
+ (128 / (1 << prescaler_exp));
+ }
+
+ info->client = client;
+ info->id = num;
+ info->supply.type = POWER_SUPPLY_TYPE_BATTERY;
+ info->supply.properties = ltc294x_properties;
+ if (info->num_regs >= LTC294X_REG_TEMPERATURE_LSB)
+ info->supply.num_properties =
+ ARRAY_SIZE(ltc294x_properties);
+ else if (info->num_regs >= LTC294X_REG_CURRENT_LSB)
+ info->supply.num_properties =
+ ARRAY_SIZE(ltc294x_properties) - 1;
+ else if (info->num_regs >= LTC294X_REG_VOLTAGE_LSB)
+ info->supply.num_properties =
+ ARRAY_SIZE(ltc294x_properties) - 2;
+ else
+ info->supply.num_properties =
+ ARRAY_SIZE(ltc294x_properties) - 3;
+ info->supply.get_property = ltc294x_get_property;
+ info->supply.set_property = ltc294x_set_property;
+ info->supply.property_is_writeable = ltc294x_property_is_writeable;
+ info->supply.external_power_changed = NULL;
+
+ INIT_DELAYED_WORK(&info->work, ltc294x_work);
+
+ ret = ltc294x_reset(info, prescaler_exp);
+ if (ret < 0) {
+ dev_err(&client->dev, "Communication with chip failed\n");
+ goto fail_comm;
+ }
+
+ ret = power_supply_register(&client->dev, &info->supply);
+ if (ret) {
+ dev_err(&client->dev, "failed to register ltc2941\n");
+ goto fail_register;
+ } else {
+ schedule_delayed_work(&info->work, LTC294X_WORK_DELAY * HZ);
+ }
+
+ return 0;
+
+fail_register:
+ kfree(info->supply.name);
+fail_comm:
+fail_name:
+fail_info:
+ mutex_lock(<c294x_lock);
+ idr_remove(<c294x_id, num);
+ mutex_unlock(<c294x_lock);
+fail_id:
+ return ret;
+}
+
+#ifdef CONFIG_PM_SLEEP
+
+static int ltc294x_suspend(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct ltc294x_info *info = i2c_get_clientdata(client);
+
+ cancel_delayed_work(&info->work);
+ return 0;
+}
+
+static int ltc294x_resume(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct ltc294x_info *info = i2c_get_clientdata(client);
+
+ schedule_delayed_work(&info->work, LTC294X_WORK_DELAY * HZ);
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(ltc294x_pm_ops, ltc294x_suspend, ltc294x_resume);
+#define LTC294X_PM_OPS (<c294x_pm_ops)
+
+#else
+#define LTC294X_PM_OPS NULL
+#endif /* CONFIG_PM_SLEEP */
+
+
+static const struct i2c_device_id ltc294x_i2c_id[] = {
+ {"ltc2941", LTC2941_NUM_REGS},
+ {"ltc2943", LTC2943_NUM_REGS},
+ { },
+};
+MODULE_DEVICE_TABLE(i2c, ltc294x_i2c_id);
+
+static struct i2c_driver ltc294x_driver = {
+ .driver = {
+ .name = "LTC2941",
+ .owner = THIS_MODULE,
+ .pm = LTC294X_PM_OPS,
+ },
+ .probe = ltc294x_i2c_probe,
+ .remove = ltc294x_i2c_remove,
+ .id_table = ltc294x_i2c_id,
+};
+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_LICENSE("GPL");
--
1.7.9.5
^ permalink raw reply related [flat|nested] 15+ messages in thread
* [PATCH] Add devicetree binding documentation for the LTC2941/LTC2943 driver
2014-10-27 16:38 ` Sebastian Reichel
2014-10-28 7:03 ` Mike Looijmans
2014-10-28 7:05 ` [PATCH] " Mike Looijmans
@ 2014-10-28 7:08 ` Mike Looijmans
2015-01-22 2:24 ` Sebastian Reichel
2 siblings, 1 reply; 15+ messages in thread
From: Mike Looijmans @ 2014-10-28 7:08 UTC (permalink / raw)
To: sre; +Cc: linux-pm, linux-kernel, dbaryshkov, dwmw2, devicetree, Mike Looijmans
This adds the devicetree binding documentation for the LTC2941 and LTC2943
driver. These are I2C connected battery gas gauge ICs.
Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl>
---
.../devicetree/bindings/power/ltc2941.txt | 27 ++++++++++++++++++++
1 file changed, 27 insertions(+)
create mode 100644 Documentation/devicetree/bindings/power/ltc2941.txt
diff --git a/Documentation/devicetree/bindings/power/ltc2941.txt b/Documentation/devicetree/bindings/power/ltc2941.txt
new file mode 100644
index 0000000..ea42ae1
--- /dev/null
+++ b/Documentation/devicetree/bindings/power/ltc2941.txt
@@ -0,0 +1,27 @@
+binding for LTC2941 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.
+
+Required properties:
+- compatible: Should contain "ltc2941" or "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
+ resistor.
+- lltc,prescaler-exponent: The prescaler exponent as explained in the datasheet.
+ This determines the range and accuracy of the gauge. The value is programmed
+ into the chip only if it differs from the current setting. The setting is
+ lost when the battery is disconnected.
+
+Example from the Topic Miami Florida board:
+
+ fuelgauge: ltc2943@64 {
+ compatible = "ltc2943";
+ reg = <0x64>;
+ lltc,resistor-sense = <15>;
+ lltc,prescaler-exponent = <5>; /* 2^(2*5) = 1024 */
+ };
--
1.7.9.5
^ permalink raw reply related [flat|nested] 15+ messages in thread
* Re: [PATCH] Add LTC2941/LTC2943 Battery Gauge Driver
2014-10-28 7:05 ` [PATCH] " Mike Looijmans
@ 2015-01-22 2:24 ` Sebastian Reichel
2015-02-11 11:21 ` Mike Looijmans
0 siblings, 1 reply; 15+ messages in thread
From: Sebastian Reichel @ 2015-01-22 2:24 UTC (permalink / raw)
To: Mike Looijmans; +Cc: linux-pm, linux-kernel, dbaryshkov, dwmw2
[-- Attachment #1: Type: text/plain, Size: 455 bytes --]
Hi,
On Tue, Oct 28, 2014 at 08:05:12AM +0100, Mike Looijmans wrote:
> 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.
>
> To avoid confusion with e.g. the LTC2945, the driver is called
> LTC2941 instead of LTC294X.
Applied with .owner field removed.
-- Sebastian
[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 819 bytes --]
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [PATCH] Add devicetree binding documentation for the LTC2941/LTC2943 driver
@ 2015-01-22 2:24 ` Sebastian Reichel
0 siblings, 0 replies; 15+ messages in thread
From: Sebastian Reichel @ 2015-01-22 2:24 UTC (permalink / raw)
To: Mike Looijmans; +Cc: linux-pm, linux-kernel, dbaryshkov, dwmw2, devicetree
[-- Attachment #1: Type: text/plain, Size: 235 bytes --]
Hi,
On Tue, Oct 28, 2014 at 08:08:04AM +0100, Mike Looijmans wrote:
> This adds the devicetree binding documentation for the LTC2941 and LTC2943
> driver. These are I2C connected battery gas gauge ICs.
Thanks, applied.
-- Sebastian
[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 819 bytes --]
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [PATCH] Add devicetree binding documentation for the LTC2941/LTC2943 driver
@ 2015-01-22 2:24 ` Sebastian Reichel
0 siblings, 0 replies; 15+ messages in thread
From: Sebastian Reichel @ 2015-01-22 2:24 UTC (permalink / raw)
To: Mike Looijmans
Cc: linux-pm-u79uwXL29TY76Z2rM5mHXA,
linux-kernel-u79uwXL29TY76Z2rM5mHXA,
dbaryshkov-Re5JQEeQqe8AvxtiuMwx3w, dwmw2-wEGCiKHe2LqWVfeAwA7xHQ,
devicetree-u79uwXL29TY76Z2rM5mHXA
[-- Attachment #1: Type: text/plain, Size: 235 bytes --]
Hi,
On Tue, Oct 28, 2014 at 08:08:04AM +0100, Mike Looijmans wrote:
> This adds the devicetree binding documentation for the LTC2941 and LTC2943
> driver. These are I2C connected battery gas gauge ICs.
Thanks, applied.
-- Sebastian
[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 819 bytes --]
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [PATCH] Add LTC2941/LTC2943 Battery Gauge Driver
2015-01-22 2:24 ` Sebastian Reichel
@ 2015-02-11 11:21 ` Mike Looijmans
0 siblings, 0 replies; 15+ messages in thread
From: Mike Looijmans @ 2015-02-11 11:21 UTC (permalink / raw)
To: Sebastian Reichel; +Cc: linux-pm, linux-kernel, dbaryshkov, dwmw2
On 22-01-15 03:24, Sebastian Reichel wrote:
> Hi,
>
> On Tue, Oct 28, 2014 at 08:05:12AM +0100, Mike Looijmans wrote:
>> 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.
>>
>> To avoid confusion with e.g. the LTC2945, the driver is called
>> LTC2941 instead of LTC294X.
>
> Applied with .owner field removed.
>
> -- Sebastian
>
Hello,
We found a bug in the LTC2941 driver (typo, it says "58" in the formula which
should be "85") just yesterday. I couldn't find it in mainline yet, I'll post
a patch to fix it.
Met vriendelijke groet / kind regards,
Mike Looijmans
System Expert
TOPIC Embedded Systems
Eindhovenseweg 32-C, NL-5683 KH Best
Postbus 440, NL-5680 AK Best
Telefoon: (+31) (0) 499 33 69 79
Telefax: (+31) (0) 499 33 69 70
E-mail: mike.looijmans@topic.nl
Website: www.topic.nl
Please consider the environment before printing this e-mail
Visit us at Embedded World 2015 Nuernberg, 24.02.2015 till 26.02.2015, Hall 1, stand number 136.
https://www.embedded-world.de/de/ausstellerprodukte/?focus=edb3exhibitor&focus2=14017667&focus3=embwld15&highlight=topic
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [PATCH] Add LTC2941/LTC2943 Battery Gauge Driver
@ 2015-02-11 11:21 ` Mike Looijmans
0 siblings, 0 replies; 15+ messages in thread
From: Mike Looijmans @ 2015-02-11 11:21 UTC (permalink / raw)
To: Sebastian Reichel; +Cc: linux-pm, linux-kernel, dbaryshkov, dwmw2
On 22-01-15 03:24, Sebastian Reichel wrote:
> Hi,
>
> On Tue, Oct 28, 2014 at 08:05:12AM +0100, Mike Looijmans wrote:
>> 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.
>>
>> To avoid confusion with e.g. the LTC2945, the driver is called
>> LTC2941 instead of LTC294X.
>
> Applied with .owner field removed.
>
> -- Sebastian
>
Hello,
We found a bug in the LTC2941 driver (typo, it says "58" in the formula which
should be "85") just yesterday. I couldn't find it in mainline yet, I'll post
a patch to fix it.
Met vriendelijke groet / kind regards,
Mike Looijmans
System Expert
TOPIC Embedded Systems
Eindhovenseweg 32-C, NL-5683 KH Best
Postbus 440, NL-5680 AK Best
Telefoon: (+31) (0) 499 33 69 79
Telefax: (+31) (0) 499 33 69 70
E-mail: mike.looijmans@topic.nl
Website: www.topic.nl
Please consider the environment before printing this e-mail
Visit us at Embedded World 2015 Nuernberg, 24.02.2015 till 26.02.2015, Hall 1, stand number 136.
https://www.embedded-world.de/de/ausstellerprodukte/?focus=edb3exhibitor&focus2=14017667&focus3=embwld15&highlight=topic
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [PATCH] Add LTC2941/LTC2943 Battery Gauge Driver
2015-02-11 11:21 ` Mike Looijmans
(?)
@ 2015-02-11 17:01 ` Sebastian Reichel
-1 siblings, 0 replies; 15+ messages in thread
From: Sebastian Reichel @ 2015-02-11 17:01 UTC (permalink / raw)
To: Mike Looijmans; +Cc: linux-pm, linux-kernel, dbaryshkov, dwmw2
[-- Attachment #1: Type: text/plain, Size: 956 bytes --]
On Wed, Feb 11, 2015 at 12:21:52PM +0100, Mike Looijmans wrote:
> On 22-01-15 03:24, Sebastian Reichel wrote:
> >Hi,
> >
> >On Tue, Oct 28, 2014 at 08:05:12AM +0100, Mike Looijmans wrote:
> >>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.
> >>
> >>To avoid confusion with e.g. the LTC2945, the driver is called
> >>LTC2941 instead of LTC294X.
> >
> >Applied with .owner field removed.
> >
> >-- Sebastian
> >
>
> Hello,
>
> We found a bug in the LTC2941 driver (typo, it says "58" in the formula
> which should be "85") just yesterday. I couldn't find it in mainline yet,
> I'll post a patch to fix it.
pull request has already been sent:
https://lkml.org/lkml/2015/2/9/373
I will send your patch as fix during -rc cycle.
-- Sebastian
[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 819 bytes --]
^ permalink raw reply [flat|nested] 15+ messages in thread
end of thread, other threads:[~2015-02-11 17:01 UTC | newest]
Thread overview: 15+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2014-10-01 13:32 [PATCH v2] Added LTC2941/LTC2943 Battery Gauge Driver Mike Looijmans
2014-10-08 6:05 ` [PATCH v3] Add " Mike Looijmans
2014-10-23 12:38 ` [PATCH v4] " Mike Looijmans
2014-10-27 4:14 ` Pavel Machek
2014-10-27 16:38 ` Sebastian Reichel
2014-10-28 7:03 ` Mike Looijmans
2014-10-28 7:03 ` Mike Looijmans
2014-10-28 7:05 ` [PATCH] " Mike Looijmans
2015-01-22 2:24 ` Sebastian Reichel
2015-02-11 11:21 ` Mike Looijmans
2015-02-11 11:21 ` Mike Looijmans
2015-02-11 17:01 ` Sebastian Reichel
2014-10-28 7:08 ` [PATCH] Add devicetree binding documentation for the LTC2941/LTC2943 driver Mike Looijmans
2015-01-22 2:24 ` Sebastian Reichel
2015-01-22 2:24 ` Sebastian Reichel
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