| Message ID | 20230811083222.15978-1-lothar.felten@gmail.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | [v1,1/2] hwmon: (ltc4271) new driver for LTC4271 PoE PSE controller | expand |
On 8/11/23 01:32, Lothar Felten wrote: > Driver for Analog Devices LTC4271 PoE PSE controller with I2C interface. > The device monitors voltage, current (via shunt resistor) and controls > power for each port. > > Signed-off-by: Lothar Felten <lothar.felten@gmail.com> > --- > Documentation/hwmon/index.rst | 1 + > Documentation/hwmon/ltc4271.rst | 65 +++++ > MAINTAINERS | 7 + > drivers/hwmon/Kconfig | 11 + > drivers/hwmon/Makefile | 1 + > drivers/hwmon/ltc4271.c | 449 ++++++++++++++++++++++++++++++++ > 6 files changed, 534 insertions(+) > create mode 100644 Documentation/hwmon/ltc4271.rst > create mode 100644 drivers/hwmon/ltc4271.c > > diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst > index f1fe75f59..0724b04fc 100644 > --- a/Documentation/hwmon/index.rst > +++ b/Documentation/hwmon/index.rst > @@ -124,6 +124,7 @@ Hardware Monitoring Kernel Drivers > ltc4245 > ltc4260 > ltc4261 > + ltc4271 > max127 > max15301 > max16064 > diff --git a/Documentation/hwmon/ltc4271.rst b/Documentation/hwmon/ltc4271.rst > new file mode 100644 > index 000000000..e65bc325b > --- /dev/null > +++ b/Documentation/hwmon/ltc4271.rst > @@ -0,0 +1,65 @@ > +.. SPDX-License-Identifier: GPL-2.0-or-later > + > +Kernel driver ltc4271 > +====================== > + > +Supported chips: > + * Analog Devices LTC4271 > + > + Prefix: 'ltc4271' > + > + Datasheet: https://www.analog.com/en/products/ltc4271.html > + > +Author: Lothar Felten <lothar.felten@gmail.com> > + > +Description > +----------- > + > +This driver supports hardware monitoring for Analog Devices LTC4271 PoE PSE. > + > +LTC4271 is a quad port IEEE802.3at PSE controller with optional I2C control > +and monitoring capabilities. > + > +This driver provides monitoring as well as enabling/disabling the four ports. > + > +Usage Notes > +----------- > + > +This driver does not probe for I2C devices. You will have to instantiate > +devices explicitly, either by adding nodes to the device tree or by loading > +the driver manually (see below). > + > +Example: the following commands will load the driver for the LTC4271 at address > +0x20 on I2C bus #3: > + > + # modprobe ltc4271 > + # echo ltc4271 0x20 > /sys/bus/i2c/devices/i2c-3/new_device > + > +The lm-sensors tool can be use to display the current status > + > +Example: > + # sensors > + ltc4271-i2c-3-20 > + Adapter: SMBus I801 adapter at f040 > + Port1: 56.06 V > + Port2: 0.00 V > + Port3: 0.00 V > + Port4: 0.00 V > + Input: 55.57 V > + Port1: 57.00 mA > + Port2: 0.00 A > + Port3: 0.00 A > + Port4: 0.00 A > + > +Sysfs entries > +------------- > + > +======================= ===================================================================== Did you pass this through "make htmldocs" ? It looks like that should generate errors. > +in[0-3]_input Voltage on ports [1-4] > +in[0-3]_label "Port[1-4]" > +in[0-3]_enable Enable/disable ports [1-4] Suspected attribute abuse. The enable attribute is intended to enable/disable monitoring, not the port. > +in4_input IC input voltage > +in4_label "Input" > +curr[1-4]_input Current on ports [1-4] > +curr[1-4]_label "Port[1-4]" I don't think it is a good idea to use the same labels for current and voltage. > +======================= ===================================================================== > diff --git a/MAINTAINERS b/MAINTAINERS > index c6545eb54..789742390 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -12183,6 +12183,13 @@ S: Maintained > F: Documentation/hwmon/ltc4261.rst > F: drivers/hwmon/ltc4261.c > > +LTC4271 ANALOG DEVICES PoE PSE DRIVER > +M: Lothar Felten <lothar.felten@gmail.com> > +L: linux-hwmon@vger.kernel.org > +S: Maintained > +F: Documentation/hwmon/ltc4271.rst > +F: drivers/hwmon/ltc4271.c > + > LTC4306 I2C MULTIPLEXER DRIVER > M: Michael Hennerich <michael.hennerich@analog.com> > L: linux-i2c@vger.kernel.org > diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig > index 5b3b76477..8254987bc 100644 > --- a/drivers/hwmon/Kconfig > +++ b/drivers/hwmon/Kconfig > @@ -995,6 +995,17 @@ config SENSORS_LTC4261 > This driver can also be built as a module. If so, the module will > be called ltc4261. > > +config SENSORS_LTC4271 > + tristate "Analog Devices LTC4271 PoE PSE" > + depends on I2C > + select REGMAP_I2C > + help > + If you say yes here you get support for Analog Devices LTC4271 > + 802.3at PoE PSE chips. > + > + This driver can also be built as a module. If so, the module > + will be called ltc4271. > + > config SENSORS_LTQ_CPUTEMP > bool "Lantiq cpu temperature sensor driver" > depends on SOC_XWAY > diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile > index 88712b503..8b50361c5 100644 > --- a/drivers/hwmon/Makefile > +++ b/drivers/hwmon/Makefile > @@ -132,6 +132,7 @@ obj-$(CONFIG_SENSORS_LTC4222) += ltc4222.o > obj-$(CONFIG_SENSORS_LTC4245) += ltc4245.o > obj-$(CONFIG_SENSORS_LTC4260) += ltc4260.o > obj-$(CONFIG_SENSORS_LTC4261) += ltc4261.o > +obj-$(CONFIG_SENSORS_LTC4271) += ltc4271.o > obj-$(CONFIG_SENSORS_LTQ_CPUTEMP) += ltq-cputemp.o > obj-$(CONFIG_SENSORS_MAX1111) += max1111.o > obj-$(CONFIG_SENSORS_MAX127) += max127.o > diff --git a/drivers/hwmon/ltc4271.c b/drivers/hwmon/ltc4271.c > new file mode 100644 > index 000000000..a95f5403c > --- /dev/null > +++ b/drivers/hwmon/ltc4271.c > @@ -0,0 +1,449 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +/* > + * Driver for the Analog Devices LTC4271 8/12 port PoE PSE controller > + * > + * The LTC4271 controls 8 ports when paired with the LTC4290 or 12 ports when > + * paired with the LTC4270. > + * The LTC4271 will appear as separate consecutive devices on the I2C bus > + * controlling four ports each. It would be much better to register the additional sets of channels with i2c_new_dummy_device() and manage it from a single device instance. See pmbus/max16601.c for an example on how to do that. > + * > + * Derived from the tps23861 driver by Robert Marko > + * > + * Copyright (C) 2023 Lothar Felten <lothar.felten@gmail.com> > + * > + * Datasheet: https://www.analog.com/en/products/ltc4271.html > + */ > + > +#include <linux/bitfield.h> > +#include <linux/debugfs.h> > +#include <linux/hwmon-sysfs.h> Is this really needed ? What for ? > +#include <linux/hwmon.h> > +#include <linux/i2c.h> > +#include <linux/module.h> > +#include <linux/of_device.h> > +#include <linux/regmap.h> > + > +#define ID 0x1b > +#define FIRMWARE_REVISION 0x41 > +#define VOLTAGE_CURRENT_MASK GENMASK(13, 0) > +#define INPUT_VOLTAGE_LSB 0x2e > +#define PORT_1_CURRENT_LSB 0x30 > +#define PORT_1_VOLTAGE_LSB 0x32 > +#define PORT_2_CURRENT_LSB 0x34 > +#define PORT_2_VOLTAGE_LSB 0x36 > +#define PORT_3_CURRENT_LSB 0x38 > +#define PORT_3_VOLTAGE_LSB 0x3a > +#define PORT_4_CURRENT_LSB 0x3c > +#define PORT_4_VOLTAGE_LSB 0x3e Consider something like #define VOLTAGE_REG(n) (0x2e + ((n) * 4) #define CURRENT_REG(n) (0x30 + ((n) * 4) > +#define PORT_N_CURRENT_LSB_OFFSET 0x04 > +#define PORT_N_VOLTAGE_LSB_OFFSET 0x04 > +#define PORT_1_STATUS 0x0c > +#define PORT_2_STATUS 0x0d > +#define PORT_3_STATUS 0x0e > +#define PORT_4_STATUS 0x0f Consider #define PORT_STATUS(n) (0x0c + (n)) > +#define PORT_STATUS_CLASS_MASK GENMASK(6, 4) > +#define PORT_STATUS_DETECT_MASK GENMASK(2, 0) > +#define PORT_CLASS_UNKNOWN 0 > +#define PORT_CLASS_1 1 > +#define PORT_CLASS_2 2 > +#define PORT_CLASS_3 3 > +#define PORT_CLASS_4 4 > +#define PORT_CLASS_RESERVED 5 > +#define PORT_CLASS_0 6 > +#define PORT_CLASS_OVERCURRENT 7 > +#define PORT_DETECT_UNKNOWN 0 > +#define PORT_DETECT_SHORT 1 > +#define PORT_DETECT_RESERVED 2 > +#define PORT_DETECT_RESISTANCE_LOW 3 > +#define PORT_DETECT_RESISTANCE_OK 4 > +#define PORT_DETECT_RESISTANCE_HIGH 5 > +#define PORT_DETECT_OPEN_CIRCUIT 6 > +#define PORT_DETECT_RESERVED_2 7 > +#define PORT_DETECT_MOSFET_FAULT 8 > +#define PORT_DETECT_LEGACY 9 > +/* Measurement beyond clamp voltage */ > +#define PORT_DETECT_CAPACITANCE_INVALID_BEYOND 10 > +/* Insufficient voltage delta */ > +#define PORT_DETECT_CAPACITANCE_INVALID_DELTA 11 > +#define PORT_DETECT_CAPACITANCE_OUT_OF_RANGE 12 > + > +#define DETECT_CLASS_RESTART 0x18 > +#define POWER_ENABLE 0x19 > +#define LTC4271_NUM_PORTS 4 > + > +#define VOLTAGE_LSB 5835 /* 5.835 mV */ Add note explaining that value is in uV (e.g., 5,835 uV). Specifying the value in uV and documenting it in mV is misleading. Same everywhere below. > +#define SHUNT_RESISTOR_DEFAULT 250000 /* 250 mOhm */ > +#define SHUNT_RESISTOR_250MOHMS 250000 /* 250 mOhm */ > +#define SHUNT_RESISTOR_500MOHMS 500000 /* 500 mOhm */ FWIW, this is even more misleading. The define says "MOHMS" but the values are in uOhm. > +#define CURRENT_LSB_250 122070 /* 122.07 uA */ > +#define CURRENT_LSB_500 61035 /* 61.035 uA */ > + > +struct ltc4271_data { > + struct regmap *regmap; > + u32 shunt_resistor; > + struct i2c_client *client; Drop. See note below. > + struct dentry *debugfs_dir; > +}; > + > +static struct regmap_config ltc4271_regmap_config = { > + .reg_bits = 8, > + .val_bits = 8, > + .use_single_read = true, > + .use_single_write = true, > + .max_register = 0xed, > +}; > + > +static int ltc4271_read_voltage(struct ltc4271_data *data, int channel, > + long *val) > +{ > + __le16 regval; > + long raw_val; > + int err; > + > + if (channel < LTC4271_NUM_PORTS) { > + err = regmap_bulk_read(data->regmap, > + PORT_1_VOLTAGE_LSB + channel * PORT_N_VOLTAGE_LSB_OFFSET, > + ®val, 2); > + } else { > + err = regmap_bulk_read(data->regmap, > + INPUT_VOLTAGE_LSB, > + ®val, 2); > + } It would be much better to model the input port as the first port. > + if (err < 0) > + return err; > + > + raw_val = le16_to_cpu(regval); > + *val = (FIELD_GET(VOLTAGE_CURRENT_MASK, raw_val) * VOLTAGE_LSB) / 1000; > + > + return 0; > +} > + > +static int ltc4271_read_current(struct ltc4271_data *data, int channel, > + long *val) > +{ > + long raw_val, current_lsb; > + __le16 regval; > + > + int err; > + > + if (data->shunt_resistor == SHUNT_RESISTOR_DEFAULT) > + current_lsb = CURRENT_LSB_250; > + else > + current_lsb = CURRENT_LSB_500; > + Consider storing current_lsb in struct ltc4271_data do avoid the conditional. > + err = regmap_bulk_read(data->regmap, > + PORT_1_CURRENT_LSB + channel * PORT_N_CURRENT_LSB_OFFSET, > + ®val, 2); > + if (err < 0) > + return err; > + > + raw_val = le16_to_cpu(regval); > + *val = (FIELD_GET(VOLTAGE_CURRENT_MASK, raw_val) * current_lsb) / 1000000; > + > + return 0; > +} > + > +static int ltc4271_port_disable(struct ltc4271_data *data, int channel) > +{ > + unsigned int regval = 0; > + > + regval |= BIT(channel + 4); Bit values need explanation. > + > + return regmap_write(data->regmap, POWER_ENABLE, regval); > +} > + > +static int ltc4271_port_enable(struct ltc4271_data *data, int channel) > +{ > + unsigned int regval = 0; > + > + regval |= BIT(channel); > + regval |= BIT(channel + 4); > + > + return regmap_write(data->regmap, DETECT_CLASS_RESTART, regval); > +} As mentioned above, suspected attribute abuse. The programming manual is not available to the public. I requested access. but who knows if Analog will grant it. Please note that I won't be able to accept this unless I have confirmation that this controls the sensor(s), not the port. > + > +static umode_t ltc4271_is_visible(const void *data, enum hwmon_sensor_types type, > + u32 attr, int channel) > +{ > + switch (type) { > + case hwmon_in: > + switch (attr) { > + case hwmon_in_input: > + case hwmon_in_label: > + return 0444; > + case hwmon_in_enable: > + return 0200; This must be readable. default: missing. > + } > + case hwmon_curr: > + switch (attr) { > + case hwmon_curr_input: > + case hwmon_curr_label: > + return 0444; default missing (doesn't gcc complain about that ?) > + } default: missing. > + } > + > + return 0; > +} > + > +static int ltc4271_write(struct device *dev, enum hwmon_sensor_types type, > + u32 attr, int channel, long val) > +{ > + struct ltc4271_data *data = dev_get_drvdata(dev); > + > + switch (type) { > + case hwmon_in: > + switch (attr) { > + case hwmon_in_enable: > + if (val == 0) > + return ltc4271_port_disable(data, channel); > + else if (val == 1) > + return ltc4271_port_enable(data, channel); > + else else after return is pointless. > + return -EINVAL; > + } default: missing. > + } > + > + return -EOPNOTSUPP; > +} > + > +static int ltc4271_read(struct device *dev, enum hwmon_sensor_types type, > + u32 attr, int channel, long *val) > +{ > + struct ltc4271_data *data = dev_get_drvdata(dev); > + > + switch (type) { > + case hwmon_in: > + switch (attr) { > + case hwmon_in_input: > + return ltc4271_read_voltage(data, channel, val); > + } > + case hwmon_curr: > + switch (attr) { > + case hwmon_curr_input: > + return ltc4271_read_current(data, channel, val); > + } and again and everywhere. > + } > + > + return -EOPNOTSUPP; > +} > + > +static const char * const ltc4271_port_label[] = { > + "Port1", > + "Port2", > + "Port3", > + "Port4", > + "Input", > +}; > + > +static int ltc4271_read_string(struct device *dev, > + enum hwmon_sensor_types type, > + u32 attr, int channel, const char **str) > +{ > + switch (type) { > + case hwmon_in: > + case hwmon_curr: > + *str = ltc4271_port_label[channel]; > + > + return 0; > + } > + > + return -EOPNOTSUPP; > +} > + > +static const struct hwmon_channel_info *ltc4271_info[] = { > + HWMON_CHANNEL_INFO(in, > + HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL, > + HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL, > + HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL, > + HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL, > + HWMON_I_INPUT | HWMON_I_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), > + NULL > +}; > + > +static const struct hwmon_ops ltc4271_hwmon_ops = { > + .is_visible = ltc4271_is_visible, > + .write = ltc4271_write, > + .read = ltc4271_read, > + .read_string = ltc4271_read_string, > +}; > + > +static const struct hwmon_chip_info ltc4271_chip_info = { > + .ops = <c4271_hwmon_ops, > + .info = ltc4271_info, > +}; > + > +static const char *port_detect_status_string(uint8_t status_reg) > +{ > + switch (FIELD_GET(PORT_STATUS_DETECT_MASK, status_reg)) { > + case PORT_DETECT_UNKNOWN: > + return "Unknown device"; > + case PORT_DETECT_SHORT: > + return "Short circuit"; > + case PORT_DETECT_RESISTANCE_LOW: > + return "Too low resistance"; > + case PORT_DETECT_RESISTANCE_OK: > + return "Valid resistance"; > + case PORT_DETECT_RESISTANCE_HIGH: > + return "Too high resistance"; > + case PORT_DETECT_OPEN_CIRCUIT: > + return "Open circuit"; > + case PORT_DETECT_MOSFET_FAULT: > + return "MOSFET fault"; > + case PORT_DETECT_LEGACY: > + return "Legacy device"; > + case PORT_DETECT_CAPACITANCE_INVALID_BEYOND: > + return "Invalid capacitance, beyond clamp voltage"; > + case PORT_DETECT_CAPACITANCE_INVALID_DELTA: > + return "Invalid capacitance, insufficient voltage delta"; > + case PORT_DETECT_CAPACITANCE_OUT_OF_RANGE: > + return "Valid capacitance, outside of legacy range"; > + case PORT_DETECT_RESERVED: > + case PORT_DETECT_RESERVED_2: > + default: > + return "Invalid"; > + } > +} > + > +static char *port_class_status_string(uint8_t status_reg) > +{ > + switch (FIELD_GET(PORT_STATUS_CLASS_MASK, status_reg)) { > + case PORT_CLASS_UNKNOWN: > + return "Unknown"; > + case PORT_CLASS_0: > + return "0"; > + case PORT_CLASS_1: > + return "1"; > + case PORT_CLASS_2: > + return "2"; > + case PORT_CLASS_3: > + return "3"; > + case PORT_CLASS_4: > + return "4"; > + case PORT_CLASS_OVERCURRENT: > + return "Overcurrent"; > + case PORT_CLASS_RESERVED: > + default: > + return "Invalid"; > + } That makes me wonder if alarm attributes would be appropriate. > +} > + > +static int ltc4271_port_status_show(struct seq_file *s, void *data) > +{ > + struct ltc4271_data *priv = s->private; > + unsigned int i, status; > + > + for (i = 0; i < LTC4271_NUM_PORTS; i++) { > + regmap_read(priv->regmap, PORT_1_STATUS + i, &status); > + > + seq_printf(s, "Port: \t\t%d\n", i + 1); > + seq_printf(s, "Detected: \t%s\n", port_detect_status_string(status)); > + seq_printf(s, "Class: \t\t%s\n", port_class_status_string(status)); > + seq_putc(s, '\n'); > + } > + > + return 0; > +} > + > +DEFINE_SHOW_ATTRIBUTE(ltc4271_port_status); > + > +static void ltc4271_init_debugfs(struct ltc4271_data *data, > + struct device *hwmon_dev) > +{ > + const char *debugfs_name; > + > + debugfs_name = devm_kasprintf(&data->client->dev, GFP_KERNEL, "%s-%s", > + data->client->name, dev_name(hwmon_dev)); pass client as argument. > + if (!debugfs_name) > + return; > + Unnecessary (and undesirable) check. Also, consider creating a single root directory for all LTC4271s in the system. As it is, there will be lots of root directories. Look for various other drivers to see how they implement that. > + data->debugfs_dir = debugfs_create_dir(debugfs_name, NULL); > + > + debugfs_create_file("port_status", > + 0400, > + data->debugfs_dir, > + data, > + <c4271_port_status_fops); > +} > + > +static int ltc4271_probe(struct i2c_client *client) > +{ > + struct device *dev = &client->dev; > + struct ltc4271_data *data; > + struct device *hwmon_dev; > + u32 shunt_resistor; > + > + data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); > + if (!data) > + return -ENOMEM; > + > + data->client = client; > + i2c_set_clientdata(client, data); > + > + data->regmap = devm_regmap_init_i2c(client, <c4271_regmap_config); > + if (IS_ERR(data->regmap)) { > + dev_err(dev, "failed to allocate register map\n"); s/allocate/initialize/ Also consider using dev_err_probe(). > + return PTR_ERR(data->regmap); > + } > + > + if (of_property_read_u32(dev->of_node, "shunt-resistor-micro-ohms", &shunt_resistor)) { Use device_property_read_u32(). > + dev_warn(dev, "assuming default shunt resistor of 250mOhms\n"); > + data->shunt_resistor = SHUNT_RESISTOR_250MOHMS; > + } else if ((shunt_resistor == SHUNT_RESISTOR_250MOHMS) || > + (shunt_resistor == SHUNT_RESISTOR_500MOHMS)) > + data->shunt_resistor = shunt_resistor; Please refrain from unnecessary () in if statements. > + else { > + dev_err(dev, "invalid shunt resistor value: %i. supported values are 250mOhms or 500mOhms\n", > + shunt_resistor/1000); dev_err_probe() > + return -EINVAL; > + } > + > + hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, > + data, <c4271_chip_info, > + NULL); > + if (IS_ERR(hwmon_dev)) > + return PTR_ERR(hwmon_dev); > + > + ltc4271_init_debugfs(data, hwmon_dev); > + > + return 0; > +} > + > +static void ltc4271_remove(struct i2c_client *client) > +{ > + struct ltc4271_data *data = i2c_get_clientdata(client); > + > + debugfs_remove_recursive(data->debugfs_dir); > +} > + > +static const struct i2c_device_id ltc4271_id[] = { > + { "ltc4271", 0 }, > + { } > +}; > +MODULE_DEVICE_TABLE(i2c, ltc4271_id); > + > +static const struct of_device_id __maybe_unused ltc4271_of_match[] = { > + { .compatible = "adi,ltc4271", }, > + { }, > +}; > +MODULE_DEVICE_TABLE(of, ltc4271_of_match); > + > +static struct i2c_driver ltc4271_driver = { > + .class = I2C_CLASS_HWMON, > + .probe_new = ltc4271_probe, s/probe_new/probe/ > + .remove = ltc4271_remove, > + .driver = { > + .name = "ltc4271", > + .of_match_table = of_match_ptr(ltc4271_of_match), Drop of_match_ptr() and _maybe_unused. > + }, > + .id_table = ltc4271_id, > +}; > +module_i2c_driver(ltc4271_driver); > + > +MODULE_LICENSE("GPL"); > +MODULE_AUTHOR("Lothar Felten <lothar.felten@gmail.com>"); > +MODULE_DESCRIPTION("ltc4271 PoE PSE");
diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst index f1fe75f59..0724b04fc 100644 --- a/Documentation/hwmon/index.rst +++ b/Documentation/hwmon/index.rst @@ -124,6 +124,7 @@ Hardware Monitoring Kernel Drivers ltc4245 ltc4260 ltc4261 + ltc4271 max127 max15301 max16064 diff --git a/Documentation/hwmon/ltc4271.rst b/Documentation/hwmon/ltc4271.rst new file mode 100644 index 000000000..e65bc325b --- /dev/null +++ b/Documentation/hwmon/ltc4271.rst @@ -0,0 +1,65 @@ +.. SPDX-License-Identifier: GPL-2.0-or-later + +Kernel driver ltc4271 +====================== + +Supported chips: + * Analog Devices LTC4271 + + Prefix: 'ltc4271' + + Datasheet: https://www.analog.com/en/products/ltc4271.html + +Author: Lothar Felten <lothar.felten@gmail.com> + +Description +----------- + +This driver supports hardware monitoring for Analog Devices LTC4271 PoE PSE. + +LTC4271 is a quad port IEEE802.3at PSE controller with optional I2C control +and monitoring capabilities. + +This driver provides monitoring as well as enabling/disabling the four ports. + +Usage Notes +----------- + +This driver does not probe for I2C devices. You will have to instantiate +devices explicitly, either by adding nodes to the device tree or by loading +the driver manually (see below). + +Example: the following commands will load the driver for the LTC4271 at address +0x20 on I2C bus #3: + + # modprobe ltc4271 + # echo ltc4271 0x20 > /sys/bus/i2c/devices/i2c-3/new_device + +The lm-sensors tool can be use to display the current status + +Example: + # sensors + ltc4271-i2c-3-20 + Adapter: SMBus I801 adapter at f040 + Port1: 56.06 V + Port2: 0.00 V + Port3: 0.00 V + Port4: 0.00 V + Input: 55.57 V + Port1: 57.00 mA + Port2: 0.00 A + Port3: 0.00 A + Port4: 0.00 A + +Sysfs entries +------------- + +======================= ===================================================================== +in[0-3]_input Voltage on ports [1-4] +in[0-3]_label "Port[1-4]" +in[0-3]_enable Enable/disable ports [1-4] +in4_input IC input voltage +in4_label "Input" +curr[1-4]_input Current on ports [1-4] +curr[1-4]_label "Port[1-4]" +======================= ===================================================================== diff --git a/MAINTAINERS b/MAINTAINERS index c6545eb54..789742390 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -12183,6 +12183,13 @@ S: Maintained F: Documentation/hwmon/ltc4261.rst F: drivers/hwmon/ltc4261.c +LTC4271 ANALOG DEVICES PoE PSE DRIVER +M: Lothar Felten <lothar.felten@gmail.com> +L: linux-hwmon@vger.kernel.org +S: Maintained +F: Documentation/hwmon/ltc4271.rst +F: drivers/hwmon/ltc4271.c + LTC4306 I2C MULTIPLEXER DRIVER M: Michael Hennerich <michael.hennerich@analog.com> L: linux-i2c@vger.kernel.org diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig index 5b3b76477..8254987bc 100644 --- a/drivers/hwmon/Kconfig +++ b/drivers/hwmon/Kconfig @@ -995,6 +995,17 @@ config SENSORS_LTC4261 This driver can also be built as a module. If so, the module will be called ltc4261. +config SENSORS_LTC4271 + tristate "Analog Devices LTC4271 PoE PSE" + depends on I2C + select REGMAP_I2C + help + If you say yes here you get support for Analog Devices LTC4271 + 802.3at PoE PSE chips. + + This driver can also be built as a module. If so, the module + will be called ltc4271. + config SENSORS_LTQ_CPUTEMP bool "Lantiq cpu temperature sensor driver" depends on SOC_XWAY diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile index 88712b503..8b50361c5 100644 --- a/drivers/hwmon/Makefile +++ b/drivers/hwmon/Makefile @@ -132,6 +132,7 @@ obj-$(CONFIG_SENSORS_LTC4222) += ltc4222.o obj-$(CONFIG_SENSORS_LTC4245) += ltc4245.o obj-$(CONFIG_SENSORS_LTC4260) += ltc4260.o obj-$(CONFIG_SENSORS_LTC4261) += ltc4261.o +obj-$(CONFIG_SENSORS_LTC4271) += ltc4271.o obj-$(CONFIG_SENSORS_LTQ_CPUTEMP) += ltq-cputemp.o obj-$(CONFIG_SENSORS_MAX1111) += max1111.o obj-$(CONFIG_SENSORS_MAX127) += max127.o diff --git a/drivers/hwmon/ltc4271.c b/drivers/hwmon/ltc4271.c new file mode 100644 index 000000000..a95f5403c --- /dev/null +++ b/drivers/hwmon/ltc4271.c @@ -0,0 +1,449 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Driver for the Analog Devices LTC4271 8/12 port PoE PSE controller + * + * The LTC4271 controls 8 ports when paired with the LTC4290 or 12 ports when + * paired with the LTC4270. + * The LTC4271 will appear as separate consecutive devices on the I2C bus + * controlling four ports each. + * + * Derived from the tps23861 driver by Robert Marko + * + * Copyright (C) 2023 Lothar Felten <lothar.felten@gmail.com> + * + * Datasheet: https://www.analog.com/en/products/ltc4271.html + */ + +#include <linux/bitfield.h> +#include <linux/debugfs.h> +#include <linux/hwmon-sysfs.h> +#include <linux/hwmon.h> +#include <linux/i2c.h> +#include <linux/module.h> +#include <linux/of_device.h> +#include <linux/regmap.h> + +#define ID 0x1b +#define FIRMWARE_REVISION 0x41 +#define VOLTAGE_CURRENT_MASK GENMASK(13, 0) +#define INPUT_VOLTAGE_LSB 0x2e +#define PORT_1_CURRENT_LSB 0x30 +#define PORT_1_VOLTAGE_LSB 0x32 +#define PORT_2_CURRENT_LSB 0x34 +#define PORT_2_VOLTAGE_LSB 0x36 +#define PORT_3_CURRENT_LSB 0x38 +#define PORT_3_VOLTAGE_LSB 0x3a +#define PORT_4_CURRENT_LSB 0x3c +#define PORT_4_VOLTAGE_LSB 0x3e +#define PORT_N_CURRENT_LSB_OFFSET 0x04 +#define PORT_N_VOLTAGE_LSB_OFFSET 0x04 +#define PORT_1_STATUS 0x0c +#define PORT_2_STATUS 0x0d +#define PORT_3_STATUS 0x0e +#define PORT_4_STATUS 0x0f +#define PORT_STATUS_CLASS_MASK GENMASK(6, 4) +#define PORT_STATUS_DETECT_MASK GENMASK(2, 0) +#define PORT_CLASS_UNKNOWN 0 +#define PORT_CLASS_1 1 +#define PORT_CLASS_2 2 +#define PORT_CLASS_3 3 +#define PORT_CLASS_4 4 +#define PORT_CLASS_RESERVED 5 +#define PORT_CLASS_0 6 +#define PORT_CLASS_OVERCURRENT 7 +#define PORT_DETECT_UNKNOWN 0 +#define PORT_DETECT_SHORT 1 +#define PORT_DETECT_RESERVED 2 +#define PORT_DETECT_RESISTANCE_LOW 3 +#define PORT_DETECT_RESISTANCE_OK 4 +#define PORT_DETECT_RESISTANCE_HIGH 5 +#define PORT_DETECT_OPEN_CIRCUIT 6 +#define PORT_DETECT_RESERVED_2 7 +#define PORT_DETECT_MOSFET_FAULT 8 +#define PORT_DETECT_LEGACY 9 +/* Measurement beyond clamp voltage */ +#define PORT_DETECT_CAPACITANCE_INVALID_BEYOND 10 +/* Insufficient voltage delta */ +#define PORT_DETECT_CAPACITANCE_INVALID_DELTA 11 +#define PORT_DETECT_CAPACITANCE_OUT_OF_RANGE 12 + +#define DETECT_CLASS_RESTART 0x18 +#define POWER_ENABLE 0x19 +#define LTC4271_NUM_PORTS 4 + +#define VOLTAGE_LSB 5835 /* 5.835 mV */ +#define SHUNT_RESISTOR_DEFAULT 250000 /* 250 mOhm */ +#define SHUNT_RESISTOR_250MOHMS 250000 /* 250 mOhm */ +#define SHUNT_RESISTOR_500MOHMS 500000 /* 500 mOhm */ +#define CURRENT_LSB_250 122070 /* 122.07 uA */ +#define CURRENT_LSB_500 61035 /* 61.035 uA */ + +struct ltc4271_data { + struct regmap *regmap; + u32 shunt_resistor; + struct i2c_client *client; + struct dentry *debugfs_dir; +}; + +static struct regmap_config ltc4271_regmap_config = { + .reg_bits = 8, + .val_bits = 8, + .use_single_read = true, + .use_single_write = true, + .max_register = 0xed, +}; + +static int ltc4271_read_voltage(struct ltc4271_data *data, int channel, + long *val) +{ + __le16 regval; + long raw_val; + int err; + + if (channel < LTC4271_NUM_PORTS) { + err = regmap_bulk_read(data->regmap, + PORT_1_VOLTAGE_LSB + channel * PORT_N_VOLTAGE_LSB_OFFSET, + ®val, 2); + } else { + err = regmap_bulk_read(data->regmap, + INPUT_VOLTAGE_LSB, + ®val, 2); + } + if (err < 0) + return err; + + raw_val = le16_to_cpu(regval); + *val = (FIELD_GET(VOLTAGE_CURRENT_MASK, raw_val) * VOLTAGE_LSB) / 1000; + + return 0; +} + +static int ltc4271_read_current(struct ltc4271_data *data, int channel, + long *val) +{ + long raw_val, current_lsb; + __le16 regval; + + int err; + + if (data->shunt_resistor == SHUNT_RESISTOR_DEFAULT) + current_lsb = CURRENT_LSB_250; + else + current_lsb = CURRENT_LSB_500; + + err = regmap_bulk_read(data->regmap, + PORT_1_CURRENT_LSB + channel * PORT_N_CURRENT_LSB_OFFSET, + ®val, 2); + if (err < 0) + return err; + + raw_val = le16_to_cpu(regval); + *val = (FIELD_GET(VOLTAGE_CURRENT_MASK, raw_val) * current_lsb) / 1000000; + + return 0; +} + +static int ltc4271_port_disable(struct ltc4271_data *data, int channel) +{ + unsigned int regval = 0; + + regval |= BIT(channel + 4); + + return regmap_write(data->regmap, POWER_ENABLE, regval); +} + +static int ltc4271_port_enable(struct ltc4271_data *data, int channel) +{ + unsigned int regval = 0; + + regval |= BIT(channel); + regval |= BIT(channel + 4); + + return regmap_write(data->regmap, DETECT_CLASS_RESTART, regval); +} + +static umode_t ltc4271_is_visible(const void *data, enum hwmon_sensor_types type, + u32 attr, int channel) +{ + switch (type) { + case hwmon_in: + switch (attr) { + case hwmon_in_input: + case hwmon_in_label: + return 0444; + case hwmon_in_enable: + return 0200; + } + case hwmon_curr: + switch (attr) { + case hwmon_curr_input: + case hwmon_curr_label: + return 0444; + } + } + + return 0; +} + +static int ltc4271_write(struct device *dev, enum hwmon_sensor_types type, + u32 attr, int channel, long val) +{ + struct ltc4271_data *data = dev_get_drvdata(dev); + + switch (type) { + case hwmon_in: + switch (attr) { + case hwmon_in_enable: + if (val == 0) + return ltc4271_port_disable(data, channel); + else if (val == 1) + return ltc4271_port_enable(data, channel); + else + return -EINVAL; + } + } + + return -EOPNOTSUPP; +} + +static int ltc4271_read(struct device *dev, enum hwmon_sensor_types type, + u32 attr, int channel, long *val) +{ + struct ltc4271_data *data = dev_get_drvdata(dev); + + switch (type) { + case hwmon_in: + switch (attr) { + case hwmon_in_input: + return ltc4271_read_voltage(data, channel, val); + } + case hwmon_curr: + switch (attr) { + case hwmon_curr_input: + return ltc4271_read_current(data, channel, val); + } + } + + return -EOPNOTSUPP; +} + +static const char * const ltc4271_port_label[] = { + "Port1", + "Port2", + "Port3", + "Port4", + "Input", +}; + +static int ltc4271_read_string(struct device *dev, + enum hwmon_sensor_types type, + u32 attr, int channel, const char **str) +{ + switch (type) { + case hwmon_in: + case hwmon_curr: + *str = ltc4271_port_label[channel]; + + return 0; + } + + return -EOPNOTSUPP; +} + +static const struct hwmon_channel_info *ltc4271_info[] = { + HWMON_CHANNEL_INFO(in, + HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL, + HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL, + HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL, + HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL, + HWMON_I_INPUT | HWMON_I_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), + NULL +}; + +static const struct hwmon_ops ltc4271_hwmon_ops = { + .is_visible = ltc4271_is_visible, + .write = ltc4271_write, + .read = ltc4271_read, + .read_string = ltc4271_read_string, +}; + +static const struct hwmon_chip_info ltc4271_chip_info = { + .ops = <c4271_hwmon_ops, + .info = ltc4271_info, +}; + +static const char *port_detect_status_string(uint8_t status_reg) +{ + switch (FIELD_GET(PORT_STATUS_DETECT_MASK, status_reg)) { + case PORT_DETECT_UNKNOWN: + return "Unknown device"; + case PORT_DETECT_SHORT: + return "Short circuit"; + case PORT_DETECT_RESISTANCE_LOW: + return "Too low resistance"; + case PORT_DETECT_RESISTANCE_OK: + return "Valid resistance"; + case PORT_DETECT_RESISTANCE_HIGH: + return "Too high resistance"; + case PORT_DETECT_OPEN_CIRCUIT: + return "Open circuit"; + case PORT_DETECT_MOSFET_FAULT: + return "MOSFET fault"; + case PORT_DETECT_LEGACY: + return "Legacy device"; + case PORT_DETECT_CAPACITANCE_INVALID_BEYOND: + return "Invalid capacitance, beyond clamp voltage"; + case PORT_DETECT_CAPACITANCE_INVALID_DELTA: + return "Invalid capacitance, insufficient voltage delta"; + case PORT_DETECT_CAPACITANCE_OUT_OF_RANGE: + return "Valid capacitance, outside of legacy range"; + case PORT_DETECT_RESERVED: + case PORT_DETECT_RESERVED_2: + default: + return "Invalid"; + } +} + +static char *port_class_status_string(uint8_t status_reg) +{ + switch (FIELD_GET(PORT_STATUS_CLASS_MASK, status_reg)) { + case PORT_CLASS_UNKNOWN: + return "Unknown"; + case PORT_CLASS_0: + return "0"; + case PORT_CLASS_1: + return "1"; + case PORT_CLASS_2: + return "2"; + case PORT_CLASS_3: + return "3"; + case PORT_CLASS_4: + return "4"; + case PORT_CLASS_OVERCURRENT: + return "Overcurrent"; + case PORT_CLASS_RESERVED: + default: + return "Invalid"; + } +} + +static int ltc4271_port_status_show(struct seq_file *s, void *data) +{ + struct ltc4271_data *priv = s->private; + unsigned int i, status; + + for (i = 0; i < LTC4271_NUM_PORTS; i++) { + regmap_read(priv->regmap, PORT_1_STATUS + i, &status); + + seq_printf(s, "Port: \t\t%d\n", i + 1); + seq_printf(s, "Detected: \t%s\n", port_detect_status_string(status)); + seq_printf(s, "Class: \t\t%s\n", port_class_status_string(status)); + seq_putc(s, '\n'); + } + + return 0; +} + +DEFINE_SHOW_ATTRIBUTE(ltc4271_port_status); + +static void ltc4271_init_debugfs(struct ltc4271_data *data, + struct device *hwmon_dev) +{ + const char *debugfs_name; + + debugfs_name = devm_kasprintf(&data->client->dev, GFP_KERNEL, "%s-%s", + data->client->name, dev_name(hwmon_dev)); + if (!debugfs_name) + return; + + data->debugfs_dir = debugfs_create_dir(debugfs_name, NULL); + + debugfs_create_file("port_status", + 0400, + data->debugfs_dir, + data, + <c4271_port_status_fops); +} + +static int ltc4271_probe(struct i2c_client *client) +{ + struct device *dev = &client->dev; + struct ltc4271_data *data; + struct device *hwmon_dev; + u32 shunt_resistor; + + data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->client = client; + i2c_set_clientdata(client, data); + + data->regmap = devm_regmap_init_i2c(client, <c4271_regmap_config); + if (IS_ERR(data->regmap)) { + dev_err(dev, "failed to allocate register map\n"); + return PTR_ERR(data->regmap); + } + + if (of_property_read_u32(dev->of_node, "shunt-resistor-micro-ohms", &shunt_resistor)) { + dev_warn(dev, "assuming default shunt resistor of 250mOhms\n"); + data->shunt_resistor = SHUNT_RESISTOR_250MOHMS; + } else if ((shunt_resistor == SHUNT_RESISTOR_250MOHMS) || + (shunt_resistor == SHUNT_RESISTOR_500MOHMS)) + data->shunt_resistor = shunt_resistor; + else { + dev_err(dev, "invalid shunt resistor value: %i. supported values are 250mOhms or 500mOhms\n", + shunt_resistor/1000); + return -EINVAL; + } + + hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, + data, <c4271_chip_info, + NULL); + if (IS_ERR(hwmon_dev)) + return PTR_ERR(hwmon_dev); + + ltc4271_init_debugfs(data, hwmon_dev); + + return 0; +} + +static void ltc4271_remove(struct i2c_client *client) +{ + struct ltc4271_data *data = i2c_get_clientdata(client); + + debugfs_remove_recursive(data->debugfs_dir); +} + +static const struct i2c_device_id ltc4271_id[] = { + { "ltc4271", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, ltc4271_id); + +static const struct of_device_id __maybe_unused ltc4271_of_match[] = { + { .compatible = "adi,ltc4271", }, + { }, +}; +MODULE_DEVICE_TABLE(of, ltc4271_of_match); + +static struct i2c_driver ltc4271_driver = { + .class = I2C_CLASS_HWMON, + .probe_new = ltc4271_probe, + .remove = ltc4271_remove, + .driver = { + .name = "ltc4271", + .of_match_table = of_match_ptr(ltc4271_of_match), + }, + .id_table = ltc4271_id, +}; +module_i2c_driver(ltc4271_driver); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Lothar Felten <lothar.felten@gmail.com>"); +MODULE_DESCRIPTION("ltc4271 PoE PSE");
Driver for Analog Devices LTC4271 PoE PSE controller with I2C interface. The device monitors voltage, current (via shunt resistor) and controls power for each port. Signed-off-by: Lothar Felten <lothar.felten@gmail.com> --- Documentation/hwmon/index.rst | 1 + Documentation/hwmon/ltc4271.rst | 65 +++++ MAINTAINERS | 7 + drivers/hwmon/Kconfig | 11 + drivers/hwmon/Makefile | 1 + drivers/hwmon/ltc4271.c | 449 ++++++++++++++++++++++++++++++++ 6 files changed, 534 insertions(+) create mode 100644 Documentation/hwmon/ltc4271.rst create mode 100644 drivers/hwmon/ltc4271.c