Re: [PATCH v3 2/2] power: supply: ltc3350-charger: Add driver
From: Sebastian Reichel
Date: Wed Apr 10 2024 - 03:56:37 EST
Hi,
On Tue, Apr 09, 2024 at 03:54:41PM +0200, 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 <mike.looijmans@xxxxxxxx>
>
> ---
please share output of
./tools/testing/selftests/power_supply/test_power_supply_properties.sh
below the fold with your next submission. It's useful for verifying,
that you got the unit scaling correct for the standard properties :)
> (no changes since v2)
>
> Changes in v2:
> Duplicate "vin_ov" and "vin_uv" attributes
>
> drivers/power/supply/Kconfig | 10 +
> drivers/power/supply/Makefile | 1 +
> drivers/power/supply/ltc3350-charger.c | 718 +++++++++++++++++++++++++
> 3 files changed, 729 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..84c7a3ca914e
> --- /dev/null
> +++ b/drivers/power/supply/ltc3350-charger.c
> @@ -0,0 +1,718 @@
> +// 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>
replace of_device.h with mod_devicetable.h (which defines of_device_id).
> +#include <linux/pm_runtime.h>
> +#include <linux/power_supply.h>
add
#include <linux/property.h>
since you are using device_property_*
> +#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 */
please keep custom uAPI consistent with the general uAPI and use µV.
> + 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 */
obviously also applied to writing.
> +
> + 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);
I suppose it would be sensible to expose this as a second
power_supply device of type battery with ltc3350_config.supplied_to
set to this second power_supply device.
Then you can map
LTC3350_REG_MEAS_VCAP -> VOLTAGE_NOW
LTC3350_REG_VCAP_UV_LVL -> VOLTAGE_MIN
LTC3350_REG_VCAP_OV_LVL -> VOLTAGE_MAX
LTC3350_REG_VSHUNT -> CURRENT_NOW
TECHNOLOGY = POWER_SUPPLY_TECHNOLOGY_CAPACITOR (new)
Also the single capacitor voltages are similar to per-cell voltage
information, so I think we should create generic properties for
that:
LTC3350_REG_NUM_CAPS -> NUMBER_OF_CELLS (new)
LTC3350_REG_MEAS_VCAP1 -> CELL1_VOLTAGE_NOW (new)
LTC3350_REG_MEAS_VCAP2 -> CELL2_VOLTAGE_NOW (new)
LTC3350_REG_MEAS_VCAP3 -> CELL3_VOLTAGE_NOW (new)
LTC3350_REG_MEAS_VCAP4 -> CELL4_VOLTAGE_NOW (new)
LTC3350_REG_CAP_UV_LVL -> CELL_VOLTAGE_MIN (new)
LTC3350_REG_CAP_OV_LVL -> CELL_VOLTAGE_MAX (new)
> +/* 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.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_vout.attr,
> + &dev_attr_vout_uv.attr,
> + &dev_attr_vout_ov.attr,
> + &dev_attr_num_caps.attr,
> + &dev_attr_charge_status.attr,
> + NULL,
> +};
Exposing these to sysfs makes them ABI and ABI needs to be
documented in Documentation/ABI, see for example
Documentation/ABI/testing/sysfs-class-power-rt9467
> +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;
> + }
return dev_err_probe(dev, -ENODEV, "No support for SMBUS_WORD_DATA\n");
But I think this can just be dropped. devm_regmap_init_i2c() should
generate an error, if the i2c adapter requirements are not met.
> + 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);
> + }
dev_err_probe()
> +
> + 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;
> + }
dev_err_probe()
> + 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;
> + }
dev_err_probe()
> + 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;
> + }
dev_err_probe()
> + 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;
replace with
ltc3350_config.fwnode = dev_fwnode(dev);
> + 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);
> + }
dev_err_probe()
> +
> + /* 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),
Please check what of_match_ptr() does and then drop it :)
> + },
> +};
> +module_i2c_driver(ltc3350_driver);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_AUTHOR("Mike Looijmans <mike.looijmans@xxxxxxxx>");
> +MODULE_DESCRIPTION("LTC3350 charger driver");
Thanks for your patch,
-- Sebastian
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