The LTC3350 is a backup power controller that can charge and monitor
a series stack of one to four supercapacitors.
Signed-off-by: Mike Looijmans <[email protected]>
---
.../bindings/power/supply/ltc3350.yaml | 55 +++++++++++++++++++
1 file changed, 55 insertions(+)
create mode 100644 Documentation/devicetree/bindings/power/supply/ltc3350.yaml
diff --git a/Documentation/devicetree/bindings/power/supply/ltc3350.yaml b/Documentation/devicetree/bindings/power/supply/ltc3350.yaml
new file mode 100644
index 000000000000..607a62fd25ba
--- /dev/null
+++ b/Documentation/devicetree/bindings/power/supply/ltc3350.yaml
@@ -0,0 +1,55 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+# Copyright (C) 2024 Topic Embedded Products
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/power/supply/ltc3350.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Linear Technology (Analog Devices) LTC3350 Supercap Charger
+
+maintainers:
+ - Mike Looijmans <[email protected]>
+
+description: |
+ The LTC3350 is a High Current Supercapacitor Backup Controller and System
+ Monitor.
+ Specifications about the charger can be found at:
+ https://www.analog.com/en/products/ltc3350.html
+
+properties:
+ compatible:
+ enum:
+ - lltc,ltc3350
+
+ reg:
+ maxItems: 1
+ description: I2C address of the charger.
+
+ lltc,rsnsc-micro-ohms:
+ description: Capacitor charger sense resistor in microohm.
+ minimum: 1000
+
+ lltc,rsnsi-micro-ohms:
+ description: Input current sense resistor in microohm.
+ minimum: 1000
+
+required:
+ - compatible
+ - reg
+ - lltc,rsnsc-micro-ohms
+ - lltc,rsnsi-micro-ohms
+
+additionalProperties: false
+
+examples:
+ - |
+ i2c {
+ #address-cells = <1>;
+ #size-cells = <0>;
+ charger: battery-charger@9 {
+ compatible = "lltc,ltc3350";
+ reg = <0x9>;
+ lltc,rsnsc-micro-ohms = <10000>;
+ lltc,rsnsi-micro-ohms = <10000>;
+ };
+ };
--
2.34.1
Met vriendelijke groet / kind regards,
Mike Looijmans
System Expert
TOPIC Embedded Products B.V.
Materiaalweg 4, 5681 RJ Best
The Netherlands
T: +31 (0) 499 33 69 69
E: [email protected]
W: http://www.topic.nl
Please consider the environment before printing this e-mail
The LTC3350 is a backup power controller that can charge and monitor
a series stack of one to four supercapacitors.
Signed-off-by: Mike Looijmans <[email protected]>
---
drivers/power/supply/Kconfig | 10 +
drivers/power/supply/Makefile | 1 +
drivers/power/supply/ltc3350-charger.c | 720 +++++++++++++++++++++++++
3 files changed, 731 insertions(+)
create mode 100644 drivers/power/supply/ltc3350-charger.c
diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
index 3e31375491d5..7cb1a66e522d 100644
--- a/drivers/power/supply/Kconfig
+++ b/drivers/power/supply/Kconfig
@@ -514,6 +514,16 @@ config CHARGER_LT3651
Say Y to include support for the Analog Devices (Linear Technology)
LT3651 battery charger which reports its status via GPIO lines.
+config CHARGER_LTC3350
+ tristate "LTC3350 Supercapacitor Backup Controller and System Monitor"
+ depends on I2C
+ select REGMAP_I2C
+ select I2C_SMBUS
+ help
+ Say Y to include support for the Analog Devices (Linear Technology)
+ LTC3350 Supercapacitor Backup Controller and System Monitor connected
+ to I2C.
+
config CHARGER_LTC4162L
tristate "LTC4162-L charger"
depends on I2C
diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile
index 58b567278034..a8d618e4ac91 100644
--- a/drivers/power/supply/Makefile
+++ b/drivers/power/supply/Makefile
@@ -72,6 +72,7 @@ obj-$(CONFIG_CHARGER_LP8788) += lp8788-charger.o
obj-$(CONFIG_CHARGER_GPIO) += gpio-charger.o
obj-$(CONFIG_CHARGER_MANAGER) += charger-manager.o
obj-$(CONFIG_CHARGER_LT3651) += lt3651-charger.o
+obj-$(CONFIG_CHARGER_LTC3350) += ltc3350-charger.o
obj-$(CONFIG_CHARGER_LTC4162L) += ltc4162-l-charger.o
obj-$(CONFIG_CHARGER_MAX14577) += max14577_charger.o
obj-$(CONFIG_CHARGER_DETECTOR_MAX14656) += max14656_charger_detector.o
diff --git a/drivers/power/supply/ltc3350-charger.c b/drivers/power/supply/ltc3350-charger.c
new file mode 100644
index 000000000000..b3a23447ebf4
--- /dev/null
+++ b/drivers/power/supply/ltc3350-charger.c
@@ -0,0 +1,720 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Driver for Analog Devices (Linear Technology) LTC3350
+ * High Current Supercapacitor Backup Controller and System Monitor
+ * Copyright (C) 2024, Topic Embedded Products
+ */
+
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/of_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/power_supply.h>
+#include <linux/i2c.h>
+#include <linux/regmap.h>
+
+/* Registers (names based on what datasheet uses) */
+#define LTC3350_REG_CLR_ALARMS 0x00
+#define LTC3350_REG_MSK_ALARMS 0x01
+#define LTC3350_REG_MSK_MON_STATUS 0x02
+#define LTC3350_REG_CAP_ESR_PER 0x04
+#define LTC3350_REG_VCAPFB_DAC 0x05
+#define LTC3350_REG_VSHUNT 0x06
+#define LTC3350_REG_CAP_UV_LVL 0x07
+#define LTC3350_REG_CAP_OV_LVL 0x08
+#define LTC3350_REG_GPI_UV_LVL 0x09
+#define LTC3350_REG_GPI_OV_LVL 0x0A
+#define LTC3350_REG_VIN_UV_LVL 0x0B
+#define LTC3350_REG_VIN_OV_LVL 0x0C
+#define LTC3350_REG_VCAP_UV_LVL 0x0D
+#define LTC3350_REG_VCAP_OV_LVL 0x0E
+#define LTC3350_REG_VOUT_UV_LVL 0x0F
+#define LTC3350_REG_VOUT_OV_LVL 0x10
+#define LTC3350_REG_IIN_OC_LVL 0x11
+#define LTC3350_REG_ICHG_UC_LVL 0x12
+#define LTC3350_REG_DTEMP_COLD_LVL 0x13
+#define LTC3350_REG_DTEMP_HOT_LVL 0x14
+#define LTC3350_REG_ESR_HI_LVL 0x15
+#define LTC3350_REG_CAP_LO_LVL 0x16
+#define LTC3350_REG_CTL_REG 0x17
+#define LTC3350_REG_NUM_CAPS 0x1A
+#define LTC3350_REG_CHRG_STATUS 0x1B
+#define LTC3350_REG_MON_STATUS 0x1C
+#define LTC3350_REG_ALARM_REG 0x1D
+#define LTC3350_REG_MEAS_CAP 0x1E
+#define LTC3350_REG_MEAS_ESR 0x1F
+#define LTC3350_REG_MEAS_VCAP1 0x20
+#define LTC3350_REG_MEAS_VCAP2 0x21
+#define LTC3350_REG_MEAS_VCAP3 0x22
+#define LTC3350_REG_MEAS_VCAP4 0x23
+#define LTC3350_REG_MEAS_GPI 0x24
+#define LTC3350_REG_MEAS_VIN 0x25
+#define LTC3350_REG_MEAS_VCAP 0x26
+#define LTC3350_REG_MEAS_VOUT 0x27
+#define LTC3350_REG_MEAS_IIN 0x28
+#define LTC3350_REG_MEAS_ICHG 0x29
+#define LTC3350_REG_MEAS_DTEMP 0x2A
+
+/* LTC3350_REG_CLR_ALARMS, LTC3350_REG_MASK_ALARMS, LTC3350_REG_ALARM_REG */
+#define LTC3350_MSK_CAP_UV BIT(0) /* capacitor undervoltage alarm */
+#define LTC3350_MSK_CAP_OV BIT(1) /* capacitor overvoltage alarm */
+#define LTC3350_MSK_GPI_UV BIT(2) /* GPI undervoltage alarm */
+#define LTC3350_MSK_GPI_OV BIT(3) /* GPI overvoltage alarm */
+#define LTC3350_MSK_VIN_UV BIT(4) /* VIN undervoltage alarm */
+#define LTC3350_MSK_VIN_OV BIT(5) /* VIN overvoltage alarm */
+#define LTC3350_MSK_VCAP_UV BIT(6) /* VCAP undervoltage alarm */
+#define LTC3350_MSK_VCAP_OV BIT(7) /* VCAP overvoltage alarm */
+#define LTC3350_MSK_VOUT_UV BIT(8) /* VOUT undervoltage alarm */
+#define LTC3350_MSK_VOUT_OV BIT(9) /* VOUT overvoltage alarm */
+#define LTC3350_MSK_IIN_OC BIT(10) /* input overcurrent alarm */
+#define LTC3350_MSK_ICHG_UC BIT(11) /* charge undercurrent alarm */
+#define LTC3350_MSK_DTEMP_COLD BIT(12) /* die temperature cold alarm */
+#define LTC3350_MSK_DTEMP_HOT BIT(13) /* die temperature hot alarm */
+#define LTC3350_MSK_ESR_HI BIT(14) /* ESR high alarm */
+#define LTC3350_MSK_CAP_LO BIT(15) /* capacitance low alarm */
+
+/* LTC3350_REG_MSK_MON_STATUS masks */
+#define LTC3350_MSK_MON_CAPESR_ACTIVE BIT(0)
+#define LTC3350_MSK_MON_CAPESR_SCHEDULED BIT(1)
+#define LTC3350_MSK_MON_CAPESR_PENDING BIT(2)
+#define LTC3350_MSK_MON_CAP_DONE BIT(3)
+#define LTC3350_MSK_MON_ESR_DONE BIT(4)
+#define LTC3350_MSK_MON_CAP_FAILED BIT(5)
+#define LTC3350_MSK_MON_ESR_FAILED BIT(6)
+#define LTC3350_MSK_MON_POWER_FAILED BIT(8)
+#define LTC3350_MSK_MON_POWER_RETURNED BIT(9)
+
+/* LTC3350_REG_CTL_REG */
+/* Begin a capacitance and ESR measurement when possible */
+#define LTC3350_CTL_STRT_CAPESR BIT(0)
+/* A one in this bit location enables the input buffer on the GPI pin */
+#define LTC3350_CTL_GPI_BUFFER_EN BIT(1)
+/* Stops an active capacitance/ESR measurement */
+#define LTC3350_CTL_STOP_CAPESR BIT(2)
+/* Increases capacitor measurement resolution by 100x for smaller capacitors */
+#define LTC3350_CTL_CAP_SCALE BIT(3)
+
+/* LTC3350_REG_CHRG_STATUS */
+#define LTC3350_CHRG_STEPDOWN BIT(0) /* Synchronous controller in step-down mode (charging) */
+#define LTC3350_CHRG_STEPUP BIT(1) /* Synchronous controller in step-up mode (backup) */
+#define LTC3350_CHRG_CV BIT(2) /* The charger is in constant voltage mode */
+#define LTC3350_CHRG_UVLO BIT(3) /* The charger is in undervoltage lockout */
+#define LTC3350_CHRG_INPUT_ILIM BIT(4) /* The charger is in input current limit */
+#define LTC3350_CHRG_CAPPG BIT(5) /* The capacitor voltage is above power good threshold */
+#define LTC3350_CHRG_SHNT BIT(6) /* The capacitor manager is shunting */
+#define LTC3350_CHRG_BAL BIT(7) /* The capacitor manager is balancing */
+#define LTC3350_CHRG_DIS BIT(8) /* Charger disabled for capacitance measurement */
+#define LTC3350_CHRG_CI BIT(9) /* The charger is in constant current mode */
+#define LTC3350_CHRG_PFO BIT(11) /* Input voltage is below PFI threshold */
+
+/* LTC3350_REG_MON_STATUS */
+#define LTC3350_MON_CAPESR_ACTIVE BIT(0) /* Capacitance/ESR measurement in progress */
+#define LTC3350_MON_CAPESR_SCHEDULED BIT(1) /* Waiting programmed time */
+#define LTC3350_MON_CAPESR_PENDING BIT(2) /* Waiting for satisfactory conditions */
+#define LTC3350_MON_CAP_DONE BIT(3) /* Capacitance measurement has completed */
+#define LTC3350_MON_ESR_DONE BIT(4) /* ESR Measurement has completed */
+#define LTC3350_MON_CAP_FAILED BIT(5) /* Last capacitance measurement failed */
+#define LTC3350_MON_ESR_FAILED BIT(6) /* Last ESR measurement failed */
+#define LTC3350_MON_POWER_FAILED BIT(8) /* Unable to charge */
+#define LTC3350_MON_POWER_RETURNED BIT(9) /* Able to charge */
+
+
+struct ltc3350_info {
+ struct i2c_client *client;
+ struct regmap *regmap;
+ struct power_supply *charger;
+ u32 rsnsc; /* Series resistor that sets charge current, microOhm */
+ u32 rsnsi; /* Series resistor to measure input current, microOhm */
+};
+
+/*
+ * About LTC3350 "alarm" functions: Setting a bit in the LTC3350_REG_MSK_ALARMS
+ * register enables the alarm. The alarm will trigger an SMBALERT only once.
+ * To reset the alarm, write a "1" bit to LTC3350_REG_CLR_ALARMS. Then the alarm
+ * will trigger another SMBALERT when conditions are met (may be immediately).
+ * After writing to one of the corresponding level registers, enable the alarm,
+ * so that a UEVENT triggers when the alarm goes off.
+ */
+static void ltc3350_enable_alarm(struct ltc3350_info *info, unsigned int reg)
+{
+ unsigned int mask;
+
+ /* Register locations correspond to alarm mask bits */
+ mask = BIT(reg - LTC3350_REG_CAP_UV_LVL);
+ /* Clear the alarm bit so it may trigger again */
+ regmap_write(info->regmap, LTC3350_REG_CLR_ALARMS, mask);
+ /* Enable the alarm */
+ regmap_update_bits(info->regmap, LTC3350_REG_MSK_ALARMS, mask, mask);
+}
+
+/* Convert enum value to POWER_SUPPLY_STATUS value */
+static int ltc3350_state_decode(unsigned int value)
+{
+ if (value & LTC3350_CHRG_STEPUP)
+ return POWER_SUPPLY_STATUS_DISCHARGING; /* running on backup */
+
+ if (value & LTC3350_CHRG_PFO)
+ return POWER_SUPPLY_STATUS_NOT_CHARGING;
+
+ if (value & LTC3350_CHRG_STEPDOWN) {
+ /* The chip remains in CV mode indefinitely, hence "full" */
+ if (value & LTC3350_CHRG_CV)
+ return POWER_SUPPLY_STATUS_FULL;
+
+ return POWER_SUPPLY_STATUS_CHARGING;
+ }
+
+ /* Not in step down? Must be full then (never seen this) */
+ return POWER_SUPPLY_STATUS_FULL;
+};
+
+static int ltc3350_get_status(struct ltc3350_info *info, union power_supply_propval *val)
+{
+ unsigned int regval;
+ int ret;
+
+ ret = regmap_read(info->regmap, LTC3350_REG_CHRG_STATUS, ®val);
+ if (ret)
+ return ret;
+
+ val->intval = ltc3350_state_decode(regval);
+
+ return 0;
+}
+
+static int ltc3350_charge_status_decode(unsigned int value)
+{
+ if (!(value & LTC3350_CHRG_STEPDOWN))
+ return POWER_SUPPLY_CHARGE_TYPE_NONE;
+
+ /* constant voltage is "topping off" */
+ if (value & LTC3350_CHRG_CV)
+ return POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
+
+ /* input limiter */
+ if (value & LTC3350_CHRG_INPUT_ILIM)
+ return POWER_SUPPLY_CHARGE_TYPE_ADAPTIVE;
+
+ /* constant current is "fast" */
+ if (value & LTC3350_CHRG_CI)
+ return POWER_SUPPLY_CHARGE_TYPE_FAST;
+
+ return POWER_SUPPLY_CHARGE_TYPE_UNKNOWN;
+}
+
+static int ltc3350_get_charge_type(struct ltc3350_info *info, union power_supply_propval *val)
+{
+ unsigned int regval;
+ int ret;
+
+ ret = regmap_read(info->regmap, LTC3350_REG_CHRG_STATUS, ®val);
+ if (ret)
+ return ret;
+
+ val->intval = ltc3350_charge_status_decode(regval);
+
+ return 0;
+}
+
+static int ltc3350_get_online(struct ltc3350_info *info, union power_supply_propval *val)
+{
+ unsigned int regval;
+ int ret;
+
+ ret = regmap_read(info->regmap, LTC3350_REG_MON_STATUS, ®val);
+ if (ret)
+ return ret;
+
+ /* indicates if input voltage is sufficient to charge */
+ val->intval = !!(regval & LTC3350_MON_POWER_RETURNED);
+
+ return 0;
+}
+
+static int ltc3350_get_input_voltage(struct ltc3350_info *info, union power_supply_propval *val)
+{
+ unsigned int regval;
+ int ret;
+
+ ret = regmap_read(info->regmap, LTC3350_REG_MEAS_VIN, ®val);
+ if (ret)
+ return ret;
+
+ /* 2.21mV/LSB */
+ val->intval = regval * 2210;
+
+ return 0;
+}
+
+static int ltc3350_get_input_current(struct ltc3350_info *info, union power_supply_propval *val)
+{
+ unsigned int regval;
+ int ret;
+
+ ret = regmap_read(info->regmap, LTC3350_REG_MEAS_IIN, ®val);
+ if (ret)
+ return ret;
+
+ /* 1.983µV/RSNSI amperes per LSB */
+ ret = regval * 19830;
+ ret /= info->rsnsi;
+ ret *= 100;
+
+ val->intval = ret;
+
+ return 0;
+}
+
+static int ltc3350_get_icharge(struct ltc3350_info *info, union power_supply_propval *val)
+{
+ unsigned int regval;
+ int ret;
+
+ ret = regmap_read(info->regmap, LTC3350_REG_MEAS_ICHG, ®val);
+ if (ret)
+ return ret;
+
+ /* 1.983µV/RSNSC amperes per LSB */
+ ret = regval * 19830;
+ ret /= info->rsnsc;
+ ret *= 100;
+
+ val->intval = ret;
+
+ return 0;
+}
+
+static int ltc3350_get_icharge_max(struct ltc3350_info *info, union power_supply_propval *val)
+{
+ /* I_CHG(MAX) = 32mV / RSNSC (Ampere) */
+ val->intval = 3200000000U / (info->rsnsc / 10);
+
+ return 0;
+}
+
+static int ltc3350_get_iin_max(struct ltc3350_info *info, union power_supply_propval *val)
+{
+ /* I_IN(MAX) = 32mV / RSNSI (Ampere) */
+ val->intval = 3200000000U / (info->rsnsi / 10);
+
+ return 0;
+}
+
+
+static int ltc3350_get_die_temp(struct ltc3350_info *info, unsigned int reg,
+ union power_supply_propval *val)
+{
+ unsigned int regval;
+ int ret;
+
+ ret = regmap_read(info->regmap, reg, ®val);
+ if (ret)
+ return ret;
+
+ /* 0.028°C per LSB – 251.4°C */
+ ret = 280 * regval;
+ ret /= 100; /* Centidegrees scale */
+ ret -= 25140;
+ val->intval = ret;
+
+ return 0;
+}
+
+static int ltc3350_set_die_temp(struct ltc3350_info *info, unsigned int reg, int val)
+{
+ unsigned int regval;
+ int ret;
+
+ /* 0.028°C per LSB – 251.4°C */
+ regval = val + 25140;
+ regval *= 100;
+ regval /= 280;
+
+ ret = regmap_write(info->regmap, reg, regval);
+ if (ret)
+ return ret;
+
+ ltc3350_enable_alarm(info, reg);
+ return 0;
+}
+
+/* Custom properties */
+
+static ssize_t ltc3350_attr_show(struct device *dev,
+ struct device_attribute *attr, char *buf,
+ unsigned int reg, unsigned int scale)
+{
+ struct power_supply *psy = to_power_supply(dev);
+ struct ltc3350_info *info = power_supply_get_drvdata(psy);
+ unsigned int regval;
+ int ret;
+
+ ret = regmap_read(info->regmap, reg, ®val);
+ if (ret)
+ return ret;
+
+ regval *= scale; /* Scale is in 10 μV units */
+ regval /= 10;
+
+ return sprintf(buf, "%u\n", regval);
+}
+
+static ssize_t ltc3350_attr_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count,
+ unsigned int reg, unsigned int scale)
+{
+ struct power_supply *psy = to_power_supply(dev);
+ struct ltc3350_info *info = power_supply_get_drvdata(psy);
+ unsigned long val;
+ int ret;
+
+ ret = kstrtoul(buf, 10, &val);
+ if (ret)
+ return ret;
+
+ val *= 10;
+ val = DIV_ROUND_CLOSEST(val, scale); /* Scale is in 10 μV units */
+
+ ret = regmap_write(info->regmap, reg, val);
+ if (ret)
+ return ret;
+
+ /* When writing to one of the LVL registers, update the alarm mask */
+ if (reg >= LTC3350_REG_CAP_UV_LVL && reg <= LTC3350_REG_CAP_LO_LVL)
+ ltc3350_enable_alarm(info, reg);
+
+ return count;
+}
+
+#define LTC3350_DEVICE_ATTR_RO(_name, _reg, _scale) \
+static ssize_t _name##_show(struct device *dev, struct device_attribute *attr, \
+ char *buf) \
+{ \
+ return ltc3350_attr_show(dev, attr, buf, _reg, _scale); \
+} \
+static DEVICE_ATTR_RO(_name)
+
+#define LTC3350_DEVICE_ATTR_RW(_name, _reg, _scale) \
+static ssize_t _name##_show(struct device *dev, struct device_attribute *attr, \
+ char *buf) \
+{ \
+ return ltc3350_attr_show(dev, attr, buf, _reg, _scale); \
+} \
+static ssize_t _name##_store(struct device *dev, struct device_attribute *attr, \
+ const char *buf, size_t count) \
+{ \
+ return ltc3350_attr_store(dev, attr, buf, count, _reg, _scale); \
+} \
+static DEVICE_ATTR_RW(_name)
+
+/* Shunt voltage, 183.5μV per LSB */
+LTC3350_DEVICE_ATTR_RW(vshunt, LTC3350_REG_VSHUNT, 1835);
+
+/* Single capacitor voltages, 183.5μV per LSB */
+LTC3350_DEVICE_ATTR_RO(vcap1, LTC3350_REG_MEAS_VCAP1, 1835);
+LTC3350_DEVICE_ATTR_RO(vcap2, LTC3350_REG_MEAS_VCAP2, 1835);
+LTC3350_DEVICE_ATTR_RO(vcap3, LTC3350_REG_MEAS_VCAP3, 1835);
+LTC3350_DEVICE_ATTR_RO(vcap4, LTC3350_REG_MEAS_VCAP4, 1835);
+LTC3350_DEVICE_ATTR_RW(cap_uv, LTC3350_REG_CAP_UV_LVL, 1835);
+LTC3350_DEVICE_ATTR_RW(cap_ov, LTC3350_REG_CAP_OV_LVL, 1835);
+
+/* General purpose input, 183.5μV per LSB */
+LTC3350_DEVICE_ATTR_RO(gpi, LTC3350_REG_MEAS_GPI, 1835);
+LTC3350_DEVICE_ATTR_RW(gpi_uv, LTC3350_REG_GPI_UV_LVL, 1835);
+LTC3350_DEVICE_ATTR_RW(gpi_ov, LTC3350_REG_GPI_OV_LVL, 1835);
+
+/* Input voltage, 2.21mV per LSB */
+LTC3350_DEVICE_ATTR_RO(vin, LTC3350_REG_MEAS_VIN, 22100);
+LTC3350_DEVICE_ATTR_RW(vin_uv, LTC3350_REG_VIN_UV_LVL, 22100);
+LTC3350_DEVICE_ATTR_RW(vin_ov, LTC3350_REG_VIN_OV_LVL, 22100);
+
+/* Capacitor stack voltage, 1.476 mV per LSB */
+LTC3350_DEVICE_ATTR_RO(vcap, LTC3350_REG_MEAS_VCAP, 14760);
+LTC3350_DEVICE_ATTR_RW(vcap_uv, LTC3350_REG_VCAP_UV_LVL, 14760);
+LTC3350_DEVICE_ATTR_RW(vcap_ov, LTC3350_REG_VCAP_OV_LVL, 14760);
+
+/* Output, 2.21mV per LSB */
+LTC3350_DEVICE_ATTR_RO(vout, LTC3350_REG_MEAS_VOUT, 22100);
+LTC3350_DEVICE_ATTR_RW(vout_uv, LTC3350_REG_VOUT_UV_LVL, 22100);
+LTC3350_DEVICE_ATTR_RW(vout_ov, LTC3350_REG_VOUT_OV_LVL, 22100);
+
+static ssize_t num_caps_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct power_supply *psy = to_power_supply(dev);
+ struct ltc3350_info *info = power_supply_get_drvdata(psy);
+ unsigned int regval;
+ int ret;
+
+ ret = regmap_read(info->regmap, LTC3350_REG_NUM_CAPS, ®val);
+ if (ret)
+ return ret;
+
+ return sprintf(buf, "%u\n", regval + 1);
+}
+static DEVICE_ATTR_RO(num_caps);
+
+static ssize_t charge_status_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct power_supply *psy = to_power_supply(dev);
+ struct ltc3350_info *info = power_supply_get_drvdata(psy);
+ unsigned int regval;
+ int ret;
+
+ ret = regmap_read(info->regmap, LTC3350_REG_CHRG_STATUS, ®val);
+ if (ret)
+ return ret;
+
+ return sprintf(buf, "0x%x\n", regval);
+}
+static DEVICE_ATTR_RO(charge_status);
+
+static struct attribute *ltc3350_sysfs_entries[] = {
+ &dev_attr_vshunt.attr,
+ &dev_attr_vcap1.attr,
+ &dev_attr_vcap2.attr,
+ &dev_attr_vcap3.attr,
+ &dev_attr_vcap4.attr,
+ &dev_attr_cap_uv.attr,
+ &dev_attr_cap_ov.attr,
+ &dev_attr_gpi.attr,
+ &dev_attr_gpi_uv.attr,
+ &dev_attr_gpi_ov.attr,
+ &dev_attr_vin_uv.attr,
+ &dev_attr_vin_ov.attr,
+ &dev_attr_vcap.attr,
+ &dev_attr_vcap_uv.attr,
+ &dev_attr_vcap_ov.attr,
+ &dev_attr_vin.attr,
+ &dev_attr_vin_uv.attr,
+ &dev_attr_vin_ov.attr,
+ &dev_attr_vout.attr,
+ &dev_attr_vout_uv.attr,
+ &dev_attr_vout_ov.attr,
+ &dev_attr_num_caps.attr,
+ &dev_attr_charge_status.attr,
+ NULL,
+};
+
+static const struct attribute_group ltc3350_attr_group = {
+ .name = NULL, /* put in device directory */
+ .attrs = ltc3350_sysfs_entries,
+};
+
+static const struct attribute_group *ltc3350_attr_groups[] = {
+ <c3350_attr_group,
+ NULL,
+};
+
+static int ltc3350_get_property(struct power_supply *psy, enum power_supply_property psp,
+ union power_supply_propval *val)
+{
+ struct ltc3350_info *info = power_supply_get_drvdata(psy);
+
+ switch (psp) {
+ case POWER_SUPPLY_PROP_STATUS:
+ return ltc3350_get_status(info, val);
+ case POWER_SUPPLY_PROP_CHARGE_TYPE:
+ return ltc3350_get_charge_type(info, val);
+ case POWER_SUPPLY_PROP_ONLINE:
+ return ltc3350_get_online(info, val);
+ case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+ return ltc3350_get_input_voltage(info, val);
+ case POWER_SUPPLY_PROP_CURRENT_NOW:
+ return ltc3350_get_input_current(info, val);
+ case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
+ return ltc3350_get_icharge(info, val);
+ case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
+ return ltc3350_get_icharge_max(info, val);
+ case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
+ return ltc3350_get_iin_max(info, val);
+ case POWER_SUPPLY_PROP_TEMP:
+ return ltc3350_get_die_temp(info, LTC3350_REG_MEAS_DTEMP, val);
+ case POWER_SUPPLY_PROP_TEMP_ALERT_MIN:
+ return ltc3350_get_die_temp(info, LTC3350_REG_DTEMP_COLD_LVL, val);
+ case POWER_SUPPLY_PROP_TEMP_ALERT_MAX:
+ return ltc3350_get_die_temp(info, LTC3350_REG_DTEMP_HOT_LVL, val);
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ltc3350_set_property(struct power_supply *psy, enum power_supply_property psp,
+ const union power_supply_propval *val)
+{
+ struct ltc3350_info *info = power_supply_get_drvdata(psy);
+
+ switch (psp) {
+ case POWER_SUPPLY_PROP_TEMP_ALERT_MIN:
+ return ltc3350_set_die_temp(info, LTC3350_REG_DTEMP_COLD_LVL, val->intval);
+ case POWER_SUPPLY_PROP_TEMP_ALERT_MAX:
+ return ltc3350_set_die_temp(info, LTC3350_REG_DTEMP_HOT_LVL, val->intval);
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ltc3350_property_is_writeable(struct power_supply *psy, enum power_supply_property psp)
+{
+ switch (psp) {
+ case POWER_SUPPLY_PROP_TEMP_ALERT_MIN:
+ case POWER_SUPPLY_PROP_TEMP_ALERT_MAX:
+ return 1;
+ default:
+ return 0;
+ }
+}
+
+/* Charger power supply property routines */
+static enum power_supply_property ltc3350_properties[] = {
+ POWER_SUPPLY_PROP_STATUS,
+ POWER_SUPPLY_PROP_CHARGE_TYPE,
+ POWER_SUPPLY_PROP_ONLINE,
+ POWER_SUPPLY_PROP_VOLTAGE_NOW,
+ POWER_SUPPLY_PROP_CURRENT_NOW,
+ POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT,
+ POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX,
+ POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT,
+ POWER_SUPPLY_PROP_TEMP,
+ POWER_SUPPLY_PROP_TEMP_ALERT_MIN,
+ POWER_SUPPLY_PROP_TEMP_ALERT_MAX,
+};
+
+static const struct power_supply_desc ltc3350_desc = {
+ .name = "ltc3350",
+ .type = POWER_SUPPLY_TYPE_MAINS,
+ .properties = ltc3350_properties,
+ .num_properties = ARRAY_SIZE(ltc3350_properties),
+ .get_property = ltc3350_get_property,
+ .set_property = ltc3350_set_property,
+ .property_is_writeable = ltc3350_property_is_writeable,
+};
+
+static bool ltc3350_is_writeable_reg(struct device *dev, unsigned int reg)
+{
+ /* all registers up to this one are writeable */
+ return reg < LTC3350_REG_NUM_CAPS;
+}
+
+static bool ltc3350_is_volatile_reg(struct device *dev, unsigned int reg)
+{
+ /* read-only status registers and self-clearing register */
+ return reg > LTC3350_REG_NUM_CAPS || reg == LTC3350_REG_CLR_ALARMS;
+}
+
+static const struct regmap_config ltc3350_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 16,
+ .val_format_endian = REGMAP_ENDIAN_LITTLE,
+ .writeable_reg = ltc3350_is_writeable_reg,
+ .volatile_reg = ltc3350_is_volatile_reg,
+ .max_register = LTC3350_REG_MEAS_DTEMP,
+ .cache_type = REGCACHE_MAPLE,
+};
+
+static int ltc3350_probe(struct i2c_client *client)
+{
+ struct i2c_adapter *adapter = client->adapter;
+ struct device *dev = &client->dev;
+ struct ltc3350_info *info;
+ struct power_supply_config ltc3350_config = {};
+ int ret;
+
+ if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA)) {
+ dev_err(dev, "No support for SMBUS_WORD_DATA\n");
+ return -ENODEV;
+ }
+ info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
+ if (!info)
+ return -ENOMEM;
+
+ info->client = client;
+ i2c_set_clientdata(client, info);
+
+ info->regmap = devm_regmap_init_i2c(client, <c3350_regmap_config);
+ if (IS_ERR(info->regmap)) {
+ dev_err(dev, "Failed to initialize register map\n");
+ return PTR_ERR(info->regmap);
+ }
+
+ ret = device_property_read_u32(dev, "lltc,rsnsc-micro-ohms",
+ &info->rsnsc);
+ if (ret) {
+ dev_err(dev, "Missing lltc,rsnsc-micro-ohms property\n");
+ return ret;
+ }
+ if (!info->rsnsc)
+ return -EINVAL;
+
+ ret = device_property_read_u32(dev, "lltc,rsnsi-micro-ohms",
+ &info->rsnsi);
+ if (ret) {
+ dev_err(dev, "Missing lltc,rsnsi-micro-ohms property\n");
+ return ret;
+ }
+ if (!info->rsnsi)
+ return -EINVAL;
+
+ /* Clear and disable all interrupt sources*/
+ ret = regmap_write(info->regmap, LTC3350_REG_CLR_ALARMS, 0xFFFF);
+ if (ret) {
+ dev_err(dev, "Failed to write configuration\n");
+ return ret;
+ }
+ regmap_write(info->regmap, LTC3350_REG_MSK_ALARMS, 0);
+ regmap_write(info->regmap, LTC3350_REG_MSK_MON_STATUS, 0);
+
+ ltc3350_config.of_node = dev->of_node;
+ ltc3350_config.drv_data = info;
+ ltc3350_config.attr_grp = ltc3350_attr_groups;
+
+ info->charger = devm_power_supply_register(dev, <c3350_desc,
+ <c3350_config);
+ if (IS_ERR(info->charger)) {
+ dev_err(dev, "Failed to register charger\n");
+ return PTR_ERR(info->charger);
+ }
+
+ /* Enable interrupts on status changes */
+ regmap_write(info->regmap, LTC3350_REG_MSK_MON_STATUS,
+ LTC3350_MON_POWER_FAILED | LTC3350_MON_POWER_RETURNED);
+
+ return 0;
+}
+
+static void ltc3350_alert(struct i2c_client *client, enum i2c_alert_protocol type,
+ unsigned int flag)
+{
+ struct ltc3350_info *info = i2c_get_clientdata(client);
+
+ if (type != I2C_PROTOCOL_SMBUS_ALERT)
+ return;
+
+ power_supply_changed(info->charger);
+}
+
+static const struct i2c_device_id ltc3350_i2c_id_table[] = {
+ { "ltc3350", 0 },
+ { },
+};
+MODULE_DEVICE_TABLE(i2c, ltc3350_i2c_id_table);
+
+static const struct of_device_id ltc3350_of_match[] = {
+ { .compatible = "lltc,ltc3350", },
+ { },
+};
+MODULE_DEVICE_TABLE(of, ltc3350_of_match);
+
+static struct i2c_driver ltc3350_driver = {
+ .probe = ltc3350_probe,
+ .alert = ltc3350_alert,
+ .id_table = ltc3350_i2c_id_table,
+ .driver = {
+ .name = "ltc3350-charger",
+ .of_match_table = of_match_ptr(ltc3350_of_match),
+ },
+};
+module_i2c_driver(ltc3350_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Mike Looijmans <[email protected]>");
+MODULE_DESCRIPTION("LTC3350 charger driver");
--
2.34.1
Met vriendelijke groet / kind regards,
Mike Looijmans
System Expert
TOPIC Embedded Products B.V.
Materiaalweg 4, 5681 RJ Best
The Netherlands
T: +31 (0) 499 33 69 69
E: [email protected]
W: http://www.topic.nl
Please consider the environment before printing this e-mail
On 08/04/2024 08:49, Mike Looijmans wrote:
> The LTC3350 is a backup power controller that can charge and monitor
> a series stack of one to four supercapacitors.
>
> Signed-off-by: Mike Looijmans <[email protected]>
> ---
>
> .../bindings/power/supply/ltc3350.yaml | 55 +++++++++++++++++++
Missing vendor prefix, use compatible as filename.
> 1 file changed, 55 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/power/supply/ltc3350.yaml
>
> diff --git a/Documentation/devicetree/bindings/power/supply/ltc3350.yaml b/Documentation/devicetree/bindings/power/supply/ltc3350.yaml
> new file mode 100644
> index 000000000000..607a62fd25ba
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/power/supply/ltc3350.yaml
> @@ -0,0 +1,55 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +# Copyright (C) 2024 Topic Embedded Products
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/power/supply/ltc3350.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Linear Technology (Analog Devices) LTC3350 Supercap Charger
> +
> +maintainers:
> + - Mike Looijmans <[email protected]>
> +
> +description: |
> + The LTC3350 is a High Current Supercapacitor Backup Controller and System
Just one space after 'a'.
> + Monitor.
> + Specifications about the charger can be found at:
> + https://www.analog.com/en/products/ltc3350.html
> +
> +properties:
> + compatible:
> + enum:
> + - lltc,ltc3350
> +
> + reg:
> + maxItems: 1
> + description: I2C address of the charger.
Drop description, it is obvious.
> +
> + lltc,rsnsc-micro-ohms:
> + description: Capacitor charger sense resistor in microohm.
> + minimum: 1000
> +
> + lltc,rsnsi-micro-ohms:
> + description: Input current sense resistor in microohm.
> + minimum: 1000
Looks like it is shunt-resistor-micro-ohms. Unless it is something
different?
> +
> +required:
> + - compatible
> + - reg
> + - lltc,rsnsc-micro-ohms
> + - lltc,rsnsi-micro-ohms
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + i2c {
> + #address-cells = <1>;
> + #size-cells = <0>;
> + charger: battery-charger@9 {
> + compatible = "lltc,ltc3350";
Messed indentation. Keep it consistent.
Best regards,
Krzysztof
Thanks for your feedback. Will fix them all, except see below.
I'll send a v2
On 09-04-2024 10:27, Krzysztof Kozlowski wrote:
..
>> +
>> + lltc,rsnsc-micro-ohms:
>> + description: Capacitor charger sense resistor in microohm.
>> + minimum: 1000
>> +
>> + lltc,rsnsi-micro-ohms:
>> + description: Input current sense resistor in microohm.
>> + minimum: 1000
> Looks like it is shunt-resistor-micro-ohms. Unless it is something
> different?
It's a shunt, but different and there's two of them (akin to the
ltc4162-l which has the same property with the same meaning). One to
measure input, one to measure charge current.
When the datasheet talks about "shunt" it means the resistor that can be
used to balance or discharge the caps. So I'd rather avoid the word
completely so users aren't tempted to put the wrong resistor value there.
The datasheet uses "rsnsi" and "rsnsc" whenever referring to these
resistors.
..
--
Mike Looijmans
System Expert
TOPIC Embedded Products B.V.
Materiaalweg 4, 5681 RJ Best
The Netherlands
T: +31 (0) 499 33 69 69
E: [email protected]
W: http://www.topic.nl