On Tue, Sep 26, 2023 at 05:05:30PM +0300, Antoniu Miclaus wrote: > Add support for LTC2991 Octal I2C Voltage, Current, and Temperature > Monitor. > > The LTC2991 is used to monitor system temperatures, voltages and > currents. Through the I 2C serial interface, theeight monitors can > individually measure supply voltages and can be paired for > differential measurements of current sense resistors or temperature > sensing transistors. Additional measurements include internal > temperature and internal VCC. > > Signed-off-by: Antoniu Miclaus <antoniu.miclaus@xxxxxxxxxx> > --- > Documentation/hwmon/index.rst | 1 + > Documentation/hwmon/ltc2991.rst | 43 +++ > MAINTAINERS | 8 + > drivers/hwmon/Kconfig | 11 + > drivers/hwmon/Makefile | 1 + > drivers/hwmon/ltc2991.c | 490 ++++++++++++++++++++++++++++++++ > 6 files changed, 554 insertions(+) > create mode 100644 Documentation/hwmon/ltc2991.rst > create mode 100644 drivers/hwmon/ltc2991.c > > diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst > index 88dadea85cfc..0ec96abe3f7d 100644 > --- a/Documentation/hwmon/index.rst > +++ b/Documentation/hwmon/index.rst > @@ -121,6 +121,7 @@ Hardware Monitoring Kernel Drivers > ltc2947 > ltc2978 > ltc2990 > + ltc2991 > ltc3815 > ltc4151 > ltc4215 > diff --git a/Documentation/hwmon/ltc2991.rst b/Documentation/hwmon/ltc2991.rst > new file mode 100644 > index 000000000000..9ab29dd85012 > --- /dev/null > +++ b/Documentation/hwmon/ltc2991.rst > @@ -0,0 +1,43 @@ > +.. SPDX-License-Identifier: GPL-2.0 > + > +Kernel driver ltc2991 > +===================== > + > +Supported chips: > + > + * Analog Devices LTC2991 > + > + Prefix: 'ltc2991' > + > + Addresses scanned: I2C 0x48 - 0x4f > + > + Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/2991ff.pdf > + > +Authors: > + > + - Antoniu Miclaus <antoniu.miclaus@xxxxxxxxxx> > + > + > +Description > +----------- > + > +This driver supports hardware monitoring for Analog Devices LTC2991 Octal I2C > +Voltage, Current and Temperature Monitor. > + > +The LTC2991 is used to monitor system temperatures, voltages and currents. > +Through the I2C serial interface, the eight monitors can individually measure > +supply voltages and can be paired for differential measurements of current sense > +resistors or temperature sensing transistors. Additional measurements include > +internal temperatureand internal VCC. > + > + > +sysfs-Interface > +------------- > + > +The following attributes are supported. Limits are read-only. > + > +=============== ================= > +inX_input: voltage input > +currX_input: current input > +tempX_input: temperature input > +=============== ================= > diff --git a/MAINTAINERS b/MAINTAINERS > index b19995690904..98dd8a8e1f84 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -12451,6 +12451,14 @@ F: drivers/hwmon/ltc2947-i2c.c > F: drivers/hwmon/ltc2947-spi.c > F: drivers/hwmon/ltc2947.h > > +LTC2991 HARDWARE MONITOR DRIVER > +M: Antoniu Miclaus <antoniu.miclaus@xxxxxxxxxx> > +L: linux-hwmon@xxxxxxxxxxxxxxx > +S: Supported > +W: https://ez.analog.com/linux-software-drivers > +F: Documentation/devicetree/bindings/hwmon/adi,ltc2991.yaml > +F: drivers/hwmon/ltc2991.c > + > LTC2983 IIO TEMPERATURE DRIVER > M: Nuno Sá <nuno.sa@xxxxxxxxxx> > L: linux-iio@xxxxxxxxxxxxxxx > diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig > index ec38c8892158..818a67328fcd 100644 > --- a/drivers/hwmon/Kconfig > +++ b/drivers/hwmon/Kconfig > @@ -932,6 +932,17 @@ config SENSORS_LTC2990 > This driver can also be built as a module. If so, the module will > be called ltc2990. > > +config SENSORS_LTC2991 > + tristate "Analog Devices LTC2991" > + depends on I2C > + help > + If you say yes here you get support for Analog Devices LTC2991 > + Octal I2C Voltage, Current, and Temperature Monitor. The LTC2991 > + supports a combination of voltage, current and temperature monitoring. > + > + This driver can also be built as a module. If so, the module will > + be called ltc2991. > + > config SENSORS_LTC2992 > tristate "Linear Technology LTC2992" > depends on I2C > diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile > index 4ac9452b5430..f324d057535a 100644 > --- a/drivers/hwmon/Makefile > +++ b/drivers/hwmon/Makefile > @@ -127,6 +127,7 @@ obj-$(CONFIG_SENSORS_LTC2947) += ltc2947-core.o > obj-$(CONFIG_SENSORS_LTC2947_I2C) += ltc2947-i2c.o > obj-$(CONFIG_SENSORS_LTC2947_SPI) += ltc2947-spi.o > obj-$(CONFIG_SENSORS_LTC2990) += ltc2990.o > +obj-$(CONFIG_SENSORS_LTC2991) += ltc2991.o > obj-$(CONFIG_SENSORS_LTC2992) += ltc2992.o > obj-$(CONFIG_SENSORS_LTC4151) += ltc4151.o > obj-$(CONFIG_SENSORS_LTC4215) += ltc4215.o > diff --git a/drivers/hwmon/ltc2991.c b/drivers/hwmon/ltc2991.c > new file mode 100644 > index 000000000000..51a60ca8c24e > --- /dev/null > +++ b/drivers/hwmon/ltc2991.c > @@ -0,0 +1,490 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (C) 2023 Analog Devices, Inc. > + * Author: Antoniu Miclaus <antoniu.miclaus@xxxxxxxxxx> > + */ > + > +#include <linux/bitops.h> > +#include <linux/err.h> > +#include <linux/hwmon.h> > +#include <linux/hwmon-sysfs.h> > +#include <linux/i2c.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/property.h> > +#include <linux/regmap.h> > +#include <linux/regulator/consumer.h> > + > +#define LTC2991_STATUS_LOW 0x00 > +#define LTC2991_CH_EN_TRIGGER 0x01 > +#define LTC2991_V1_V4_CTRL 0x06 > +#define LTC2991_V5_V8_CTRL 0x07 > +#define LTC2991_PWM_TH_LSB_T_INT 0x08 > +#define LTC2991_PWM_TH_MSB 0x09 > +#define LTC2991_CHANNEL_V_MSB(x) (0x0A + ((x) * 2)) > +#define LTC2991_CHANNEL_T_MSB(x) (0x0A + ((x) * 4)) > +#define LTC2991_CHANNEL_C_MSB(x) (0x0C + ((x) * 4)) > +#define LTC2991_T_INT_MSB 0x1A > +#define LTC2991_VCC_MSB 0x1C > + > +#define LTC2991_V7_V8_EN BIT(7) > +#define LTC2991_V5_V6_EN BIT(6) > +#define LTC2991_V3_V4_EN BIT(5) > +#define LTC2991_V1_V2_EN BIT(4) > +#define LTC2991_T_INT_VCC_EN BIT(3) > + > +#define LTC2991_V3_V4_FILT_EN BIT(7) > +#define LTC2991_V3_V4_TEMP_EN BIT(5) > +#define LTC2991_V3_V4_DIFF_EN BIT(4) > +#define LTC2991_V1_V2_FILT_EN BIT(3) > +#define LTC2991_V1_V2_TEMP_EN BIT(1) > +#define LTC2991_V1_V2_DIFF_EN BIT(0) > + > +#define LTC2991_V7_V8_FILT_EN BIT(7) > +#define LTC2991_V7_V8_TEMP_EN BIT(5) > +#define LTC2991_V7_V8_DIFF_EN BIT(4) > +#define LTC2991_V5_V6_FILT_EN BIT(7) > +#define LTC2991_V5_V6_TEMP_EN BIT(5) > +#define LTC2991_V5_V6_DIFF_EN BIT(4) > + > +#define LTC2991_REPEAT_ACQ_EN BIT(4) > +#define LTC2991_T_INT_FILT_EN BIT(3) > + > +#define LTC2991_MAX_CHANNEL 4 > +#define LTC2991_T_INT_CH_NR 4 > +#define LTC2991_VCC_CH_NR 0 > + > +static const char *const label_voltages[] = { > + "vcc", > + "voltage1", > + "voltage2", > + "voltage3", > + "voltage4", > + "voltage5", > + "voltage6", > + "voltage7", > + "voltage8" > +}; > + > +static const char *const label_temp[] = { > + "t1", > + "t2", > + "t3", > + "t4", > + "t_int" > +}; > + > +static const char *const label_curr[] = { > + "v1-v2", > + "v3-v4", > + "v5-v6", > + "v7-v8" Those labels are all but pointless. Please drop. > +}; > + > +struct ltc2991_state { > + struct i2c_client *client; > + struct regmap *regmap; > + u32 r_sense_mohm[LTC2991_MAX_CHANNEL]; > + bool temp_en[LTC2991_MAX_CHANNEL]; > +}; > + > +static int ltc2991_read_reg(struct ltc2991_state *st, u8 addr, u8 reg_len, > + int *val) > +{ > + u8 regvals[2]; > + int ret; > + int i; > + > + ret = regmap_bulk_read(st->regmap, addr, regvals, reg_len); > + if (ret) > + return ret; > + > + *val = 0; > + for (i = 0; i < reg_len; i++) > + *val |= regvals[reg_len - i - 1] << (i * 8); > + > + return 0; > +} > + > +static int ltc2991_get_voltage(struct ltc2991_state *st, u32 reg, long *val) > +{ > + int reg_val, ret, offset = 0; > + > + ret = ltc2991_read_reg(st, reg, 2, ®_val); > + if (ret) > + return ret; > + > + if (reg == LTC2991_VCC_MSB) > + /* Vcc 2.5V offset */ > + offset = 2500; > + > + /* Vx, 305.18uV/LSB */ > + *val = DIV_ROUND_CLOSEST(sign_extend32(reg_val, 14) * 30518, > + 1000 * 100) + offset; > + > + return 0; > +} > + > +static int ltc2991_read_in(struct device *dev, u32 attr, int channel, long *val) > +{ > + struct ltc2991_state *st = dev_get_drvdata(dev); > + u32 reg; > + > + switch (attr) { > + case hwmon_in_input: > + if (channel == LTC2991_VCC_CH_NR) > + reg = LTC2991_VCC_MSB; > + else > + reg = LTC2991_CHANNEL_V_MSB(channel - 1); > + break; > + default: > + return -EOPNOTSUPP; > + } > + > + return ltc2991_get_voltage(st, reg, val); I see no value having this code here. WHy not in the case statement above ? > +} > + > +static int ltc2991_get_curr(struct ltc2991_state *st, u32 reg, int channel, > + long *val) > +{ > + int reg_val, ret; > + > + ret = ltc2991_read_reg(st, reg, 2, ®_val); > + if (ret) > + return ret; > + > + /* Vx-Vy, 19.075uV/LSB */ > + *val = DIV_ROUND_CLOSEST(sign_extend32(reg_val, 14) * 19075, 1000) > + / st->r_sense_mohm[channel]; > + > + return 0; > +} > + > +static int ltc2991_read_curr(struct device *dev, u32 attr, int channel, > + long *val) > +{ > + struct ltc2991_state *st = dev_get_drvdata(dev); > + u32 reg; > + > + switch (attr) { > + case hwmon_curr_input: > + reg = LTC2991_CHANNEL_C_MSB(channel); > + break; > + default: > + return -EOPNOTSUPP; > + } > + > + return ltc2991_get_curr(st, reg, channel, val); Even less value than above. That would only make sense if there were more attributes to read. > +} > + > +static int ltc2991_get_temp(struct ltc2991_state *st, u32 reg, int channel, > + long *val) > +{ > + int reg_val, ret; > + > + ret = ltc2991_read_reg(st, reg, 2, ®_val); > + if (ret) > + return ret; > + > + /* Temp LSB = 0.0625 Degrees */ > + *val = DIV_ROUND_CLOSEST(sign_extend32(reg_val, 12) * 1000, 16); > + > + return 0; > +} > + > +static int ltc2991_read_temp(struct device *dev, u32 attr, int channel, > + long *val) > +{ > + struct ltc2991_state *st = dev_get_drvdata(dev); > + u32 reg; > + > + switch (attr) { > + case hwmon_temp_input: > + if (channel == LTC2991_T_INT_CH_NR) > + reg = LTC2991_T_INT_MSB; > + else > + reg = LTC2991_CHANNEL_T_MSB(channel); > + break; > + default: > + return -EOPNOTSUPP; > + } > + > + return ltc2991_get_temp(st, reg, channel, val); And again. > +} > + > +static int ltc2991_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel, > + long *val) > +{ > + switch (type) { > + case hwmon_in: > + return ltc2991_read_in(dev, attr, channel, val); > + case hwmon_curr: > + return ltc2991_read_curr(dev, attr, channel, val); > + case hwmon_temp: > + return ltc2991_read_temp(dev, attr, channel, val); > + default: > + return -EOPNOTSUPP; > + } > +} > + > +static umode_t ltc2991_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr, > + int channel) > +{ > + const struct ltc2991_state *st = data; > + > + switch (type) { > + case hwmon_in: > + switch (attr) { > + case hwmon_in_input: > + case hwmon_in_label: > + return 0444; > + } > + break; > + case hwmon_curr: > + switch (attr) { > + case hwmon_curr_input: > + case hwmon_curr_label: > + if (st->r_sense_mohm[channel]) > + return 0444; > + break; > + } > + break; > + case hwmon_temp: > + switch (attr) { > + case hwmon_temp_input: > + case hwmon_temp_label: > + if (st->temp_en[channel] || channel == LTC2991_T_INT_CH_NR) > + return 0444; > + break; > + } > + break; > + default: > + break; > + } > + > + return 0; > +} > + > +static int ltc2991_read_string(struct device *dev, enum hwmon_sensor_types type, u32 attr, > + int channel, const char **str) > +{ > + switch (type) { > + case hwmon_temp: > + *str = label_temp[channel]; > + break; > + case hwmon_curr: > + *str = label_curr[channel]; > + break; > + case hwmon_in: > + *str = label_voltages[channel]; > + break; > + default: > + return -EOPNOTSUPP; > + } > + > + return 0; > +} > + > +static const struct hwmon_ops ltc2991_hwmon_ops = { > + .is_visible = ltc2991_is_visible, > + .read = ltc2991_read, > + .read_string = ltc2991_read_string, > +}; > + > +static const struct hwmon_channel_info *ltc2991_info[] = { > + HWMON_CHANNEL_INFO(temp, > + HWMON_T_INPUT | HWMON_T_LABEL, > + HWMON_T_INPUT | HWMON_T_LABEL, > + HWMON_T_INPUT | HWMON_T_LABEL, > + HWMON_T_INPUT | HWMON_T_LABEL, > + HWMON_T_INPUT | HWMON_T_LABEL > + ), > + HWMON_CHANNEL_INFO(curr, > + HWMON_C_INPUT | HWMON_C_LABEL, > + HWMON_C_INPUT | HWMON_C_LABEL, > + HWMON_C_INPUT | HWMON_C_LABEL, > + HWMON_C_INPUT | HWMON_C_LABEL > + ), > + HWMON_CHANNEL_INFO(in, > + HWMON_I_INPUT | HWMON_I_LABEL, > + HWMON_I_INPUT | HWMON_I_LABEL, > + HWMON_I_INPUT | HWMON_I_LABEL, > + HWMON_I_INPUT | HWMON_I_LABEL, > + HWMON_I_INPUT | HWMON_I_LABEL, > + HWMON_I_INPUT | HWMON_I_LABEL, > + HWMON_I_INPUT | HWMON_I_LABEL, > + HWMON_I_INPUT | HWMON_I_LABEL, > + HWMON_I_INPUT | HWMON_I_LABEL > + ), > + NULL > +}; > + > +static const struct hwmon_chip_info ltc2991_chip_info = { > + .ops = <c2991_hwmon_ops, > + .info = ltc2991_info, > +}; > + > +static const struct regmap_config ltc2991_regmap_config = { > + .reg_bits = 8, > + .val_bits = 8, > + .max_register = 0x1D, > +}; > + > +static int ltc2991_init(struct ltc2991_state *st) > +{ > + struct fwnode_handle *fwnode; > + struct fwnode_handle *child; > + int ret; > + u32 val, addr; > + u8 v5_v8_reg_data = 0, v1_v4_reg_data = 0; > + > + ret = devm_regulator_get_enable(&st->client->dev, "vcc"); The only use of st->client is in this function, which is called from probe. Please just pass client as parameter (or even &client->dev since that is what is really used). > + if (ret) > + return dev_err_probe(&st->client->dev, ret, > + "failed to enable regulator\n"); > + > + fwnode = dev_fwnode(&st->client->dev); > + > + fwnode_for_each_available_child_node(fwnode, child) { > + ret = fwnode_property_read_u32(child, "reg", &addr); > + if (ret < 0) { > + fwnode_handle_put(child); > + return ret; > + } > + > + if (addr > 3) { > + fwnode_handle_put(child); > + return -EINVAL; > + } > + > + ret = fwnode_property_read_u32(child, "shunt-resistor-mili-ohms", &val); > + if (!ret) { > + st->r_sense_mohm[addr] = val; shunt resistors may be in fraction of milli-ohms. > + switch (addr) { > + case 0: > + v1_v4_reg_data |= LTC2991_V1_V2_DIFF_EN; > + break; > + case 1: > + v1_v4_reg_data |= LTC2991_V3_V4_DIFF_EN; > + break; > + case 2: > + v5_v8_reg_data |= LTC2991_V5_V6_DIFF_EN; > + break; > + case 3: > + v5_v8_reg_data |= LTC2991_V7_V8_DIFF_EN; > + break; > + default: > + break; > + } While the above accepts sense resistor values of 0, it does not distinguish that from "value not provided". At the very least that needs an explanation. > + } > + > + ret = fwnode_property_read_bool(child, "temperature-enable"); > + if (ret) { > + st->temp_en[addr] = ret; > + switch (addr) { > + case 0: > + v1_v4_reg_data |= LTC2991_V1_V2_TEMP_EN; > + break; > + case 1: > + v1_v4_reg_data |= LTC2991_V3_V4_TEMP_EN; > + break; > + case 2: > + v5_v8_reg_data |= LTC2991_V5_V6_TEMP_EN; > + break; > + case 3: > + v5_v8_reg_data |= LTC2991_V7_V8_TEMP_EN; > + break; > + default: > + break; > + } > + } > + } I am not happy that there are no defaults, meaning the chip can not be used without devicetree or firmware (acpi) data. This is very undesirable and not common for hwmon sensors. I would very much prefer the use of defaults (i.e., existing register values and a default for the shunt resistor). > + > + /* Setup V5-V8 Control register */ > + ret = regmap_write(st->regmap, LTC2991_V5_V8_CTRL, v5_v8_reg_data); > + if (ret) > + return dev_err_probe(&st->client->dev, ret, > + "Error: Failed to set V5-V8 CTRL reg.\n"); > + > + /* Setup V1-V4 Control register */ > + ret = regmap_write(st->regmap, LTC2991_V1_V4_CTRL, v1_v4_reg_data); > + if (ret) > + return dev_err_probe(&st->client->dev, ret, > + "Error: Failed to set V1-V4 CTRL reg.\n"); > + > + /* Setup continuous mode */ > + ret = regmap_write(st->regmap, LTC2991_PWM_TH_LSB_T_INT, > + LTC2991_REPEAT_ACQ_EN); > + if (ret) > + return dev_err_probe(&st->client->dev, ret, > + "Error: Failed to set contiuous mode.\n"); > + > + /* Enable all channels and trigger conversions */ > + ret = regmap_write(st->regmap, LTC2991_CH_EN_TRIGGER, > + LTC2991_V7_V8_EN | LTC2991_V5_V6_EN | > + LTC2991_V3_V4_EN | LTC2991_V1_V2_EN | > + LTC2991_T_INT_VCC_EN); > + if (ret) > + return dev_err_probe(&st->client->dev, ret, > + "Error: Failed to enable conversions.\n"); > + > + return 0; > +} > + > +static int ltc2991_i2c_probe(struct i2c_client *client) > +{ > + int ret; > + struct device *hwmon_dev; > + struct ltc2991_state *st; > + > + if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA)) > + return -EOPNOTSUPP; > + > + st = devm_kzalloc(&client->dev, sizeof(*st), GFP_KERNEL); > + if (!st) > + return -ENOMEM; > + > + st->client = client; > + st->regmap = devm_regmap_init_i2c(client, <c2991_regmap_config); > + if (IS_ERR(st->regmap)) > + return PTR_ERR(st->regmap); > + > + ret = ltc2991_init(st); > + if (ret) > + return ret; > + > + hwmon_dev = devm_hwmon_device_register_with_info(&client->dev, > + client->name, st, > + <c2991_chip_info, > + NULL); > + > + return PTR_ERR_OR_ZERO(hwmon_dev); > +} > + > +static const struct of_device_id ltc2991_of_match[] = { > + { .compatible = "adi,ltc2991" }, > + { } > +}; > +MODULE_DEVICE_TABLE(of, ltc2991_of_match); > + > +static const struct i2c_device_id ltc2991_i2c_id[] = { > + { "ltc2991", 0 }, > + {} > +}; > +MODULE_DEVICE_TABLE(i2c, ltc2991_i2c_id); > + > +static struct i2c_driver ltc2991_i2c_driver = { > + .class = I2C_CLASS_HWMON, > + .driver = { > + .name = "ltc2991", > + .of_match_table = ltc2991_of_match, > + }, > + .probe = ltc2991_i2c_probe, > + .id_table = ltc2991_i2c_id, > +}; > + > +module_i2c_driver(ltc2991_i2c_driver); > + > +MODULE_AUTHOR("Antoniu Miclaus <antoniu.miclaus@xxxxxxxxxx>"); > +MODULE_DESCRIPTION("Analog Devices LTC2991 HWMON Driver"); > +MODULE_LICENSE("GPL"); > -- > 2.42.0 >
