Re: [PATCH v5 2/3] hwmon: add Texas Instruments TPS23861 driver

From: Guenter Roeck
Date: Thu Feb 11 2021 - 23:33:53 EST

On Thu, Jan 21, 2021 at 02:44:33PM +0100, Robert Marko wrote:
> Add basic monitoring support as well as port on/off control for Texas
> Instruments TPS23861 PoE PSE IC.
>
> Signed-off-by: Robert Marko <robert.marko@xxxxxxxxxx>
> Cc: Luka Perkov <luka.perkov@xxxxxxxxxx>
> Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>

Applied.

Thanks,
Guenter

> ---
> Changes in v4:
> * Add documentation
> * Correct of_property_read_u32() return check
> * Drop useless and incorrect debugfs return check
>
> Changes in v3:
> * Leave only standard values in hwmon hwmon
> * Drop custom sysfs entries
> * Use debugfs to provide non standard debug information
> * Add temperature label
> * Use hwmon_in_enable to enable/disable ports
>
> Changes in v2:
> * Convert to devm_hwmon_device_register_with_info()
> * Change license
>
> Documentation/hwmon/index.rst | 1 +
> Documentation/hwmon/tps23861.rst | 41 +++
> drivers/hwmon/Kconfig | 11 +
> drivers/hwmon/Makefile | 1 +
> drivers/hwmon/tps23861.c | 601 +++++++++++++++++++++++++++++++
> 5 files changed, 655 insertions(+)
> create mode 100644 Documentation/hwmon/tps23861.rst
> create mode 100644 drivers/hwmon/tps23861.c
>
> diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
> index fcb870ce6286..2c94f0b524dd 100644
> --- a/Documentation/hwmon/index.rst
> +++ b/Documentation/hwmon/index.rst
> @@ -178,6 +178,7 @@ Hardware Monitoring Kernel Drivers
> tmp401
> tmp421
> tmp513
> + tps23861
> tps40422
> tps53679
> twl4030-madc-hwmon
> diff --git a/Documentation/hwmon/tps23861.rst b/Documentation/hwmon/tps23861.rst
> new file mode 100644
> index 000000000000..46d121ff3f31
> --- /dev/null
> +++ b/Documentation/hwmon/tps23861.rst
> @@ -0,0 +1,41 @@
> +.. SPDX-License-Identifier: GPL-2.0-only
> +
> +Kernel driver tps23861
> +======================
> +
> +Supported chips:
> + * Texas Instruments TPS23861
> +
> + Prefix: 'tps23861'
> +
> + Datasheet: https://www.ti.com/lit/gpn/tps23861
> +
> +Author: Robert Marko <robert.marko@xxxxxxxxxx>
> +
> +Description
> +-----------
> +
> +This driver supports hardware monitoring for Texas Instruments TPS23861 PoE PSE.
> +
> +TPS23861 is a quad port IEEE802.3at PSE controller with optional I2C control
> +and monitoring capabilities.
> +
> +TPS23861 offers three modes of operation: Auto, Semi-Auto and Manual.
> +
> +This driver only supports the Auto mode of operation providing monitoring
> +as well as enabling/disabling the four ports.
> +
> +Sysfs entries
> +-------------
> +
> +======================= =====================================================================
> +in[0-3]_input Voltage on ports [1-4]
> +in[0-3]_label "Port[1-4]"
> +in4_input IC input voltage
> +in4_label "Input"
> +temp1_input IC die temperature
> +temp1_label "Die"
> +curr[1-4]_input Current on ports [1-4]
> +in[1-4]_label "Port[1-4]"
> +in[0-3]_enable Enable/disable ports [1-4]
> +======================= =====================================================================
> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> index 1ecf697d8d99..e2a3aeed0628 100644
> --- a/drivers/hwmon/Kconfig
> +++ b/drivers/hwmon/Kconfig
> @@ -1136,6 +1136,17 @@ config SENSORS_TC654
> This driver can also be built as a module. If so, the module
> will be called tc654.
>
> +config SENSORS_TPS23861
> + tristate "Texas Instruments TPS23861 PoE PSE"
> + depends on I2C
> + select REGMAP_I2C
> + help
> + If you say yes here you get support for Texas Instruments
> + TPS23861 802.3at PoE PSE chips.
> +
> + This driver can also be built as a module. If so, the module
> + will be called tps23861.
> +
> config SENSORS_MENF21BMC_HWMON
> tristate "MEN 14F021P00 BMC Hardware Monitoring"
> depends on MFD_MENF21BMC
> diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
> index 09a86c5e1d29..583ca5dbd838 100644
> --- a/drivers/hwmon/Makefile
> +++ b/drivers/hwmon/Makefile
> @@ -144,6 +144,7 @@ obj-$(CONFIG_SENSORS_MAX31790) += max31790.o
> obj-$(CONFIG_SENSORS_MC13783_ADC)+= mc13783-adc.o
> obj-$(CONFIG_SENSORS_MCP3021) += mcp3021.o
> obj-$(CONFIG_SENSORS_TC654) += tc654.o
> +obj-$(CONFIG_SENSORS_TPS23861) += tps23861.o
> obj-$(CONFIG_SENSORS_MLXREG_FAN) += mlxreg-fan.o
> obj-$(CONFIG_SENSORS_MENF21BMC_HWMON) += menf21bmc_hwmon.o
> obj-$(CONFIG_SENSORS_MR75203) += mr75203.o
> diff --git a/drivers/hwmon/tps23861.c b/drivers/hwmon/tps23861.c
> new file mode 100644
> index 000000000000..c2484f15298b
> --- /dev/null
> +++ b/drivers/hwmon/tps23861.c
> @@ -0,0 +1,601 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2020 Sartura Ltd.
> + *
> + * Driver for the TI TPS23861 PoE PSE.
> + *
> + * Author: Robert Marko <robert.marko@xxxxxxxxxx>
> + */
> +
> +#include <linux/bitfield.h>
> +#include <linux/debugfs.h>
> +#include <linux/delay.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 TEMPERATURE 0x2c
> +#define INPUT_VOLTAGE_LSB 0x2e
> +#define INPUT_VOLTAGE_MSB 0x2f
> +#define PORT_1_CURRENT_LSB 0x30
> +#define PORT_1_CURRENT_MSB 0x31
> +#define PORT_1_VOLTAGE_LSB 0x32
> +#define PORT_1_VOLTAGE_MSB 0x33
> +#define PORT_2_CURRENT_LSB 0x34
> +#define PORT_2_CURRENT_MSB 0x35
> +#define PORT_2_VOLTAGE_LSB 0x36
> +#define PORT_2_VOLTAGE_MSB 0x37
> +#define PORT_3_CURRENT_LSB 0x38
> +#define PORT_3_CURRENT_MSB 0x39
> +#define PORT_3_VOLTAGE_LSB 0x3a
> +#define PORT_3_VOLTAGE_MSB 0x3b
> +#define PORT_4_CURRENT_LSB 0x3c
> +#define PORT_4_CURRENT_MSB 0x3d
> +#define PORT_4_VOLTAGE_LSB 0x3e
> +#define PORT_4_VOLTAGE_MSB 0x3f
> +#define PORT_N_CURRENT_LSB_OFFSET 0x04
> +#define PORT_N_VOLTAGE_LSB_OFFSET 0x04
> +#define VOLTAGE_CURRENT_MASK GENMASK(13, 0)
> +#define PORT_1_RESISTANCE_LSB 0x60
> +#define PORT_1_RESISTANCE_MSB 0x61
> +#define PORT_2_RESISTANCE_LSB 0x62
> +#define PORT_2_RESISTANCE_MSB 0x63
> +#define PORT_3_RESISTANCE_LSB 0x64
> +#define PORT_3_RESISTANCE_MSB 0x65
> +#define PORT_4_RESISTANCE_LSB 0x66
> +#define PORT_4_RESISTANCE_MSB 0x67
> +#define PORT_N_RESISTANCE_LSB_OFFSET 0x02
> +#define PORT_RESISTANCE_MASK GENMASK(13, 0)
> +#define PORT_RESISTANCE_RSN_MASK GENMASK(15, 14)
> +#define PORT_RESISTANCE_RSN_OTHER 0
> +#define PORT_RESISTANCE_RSN_LOW 1
> +#define PORT_RESISTANCE_RSN_OPEN 2
> +#define PORT_RESISTANCE_RSN_SHORT 3
> +#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(7, 4)
> +#define PORT_STATUS_DETECT_MASK GENMASK(3, 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_CLASS_MISMATCH 8
> +#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
> +/* Measurment 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 POE_PLUS 0x40
> +#define OPERATING_MODE 0x12
> +#define OPERATING_MODE_OFF 0
> +#define OPERATING_MODE_MANUAL 1
> +#define OPERATING_MODE_SEMI 2
> +#define OPERATING_MODE_AUTO 3
> +#define OPERATING_MODE_PORT_1_MASK GENMASK(1, 0)
> +#define OPERATING_MODE_PORT_2_MASK GENMASK(3, 2)
> +#define OPERATING_MODE_PORT_3_MASK GENMASK(5, 4)
> +#define OPERATING_MODE_PORT_4_MASK GENMASK(7, 6)
> +
> +#define DETECT_CLASS_RESTART 0x18
> +#define POWER_ENABLE 0x19
> +#define TPS23861_NUM_PORTS 4
> +
> +#define TEMPERATURE_LSB 652 /* 0.652 degrees Celsius */
> +#define VOLTAGE_LSB 3662 /* 3.662 mV */
> +#define SHUNT_RESISTOR_DEFAULT 255000 /* 255 mOhm */
> +#define CURRENT_LSB_255 62260 /* 62.260 uA */
> +#define CURRENT_LSB_250 61039 /* 61.039 uA */
> +#define RESISTANCE_LSB 110966 /* 11.0966 Ohm*/
> +#define RESISTANCE_LSB_LOW 157216 /* 15.7216 Ohm*/
> +
> +struct tps23861_data {
> + struct regmap *regmap;
> + u32 shunt_resistor;
> + struct i2c_client *client;
> + struct dentry *debugfs_dir;
> +};
> +
> +static struct regmap_config tps23861_regmap_config = {
> + .reg_bits = 8,
> + .val_bits = 8,
> +};
> +
> +static int tps23861_read_temp(struct tps23861_data *data, long *val)
> +{
> + unsigned int regval;
> + int err;
> +
> + err = regmap_read(data->regmap, TEMPERATURE, &regval);
> + if (err < 0)
> + return err;
> +
> + *val = (regval * TEMPERATURE_LSB) - 20000;
> +
> + return 0;
> +}
> +
> +static int tps23861_read_voltage(struct tps23861_data *data, int channel,
> + long *val)
> +{
> + unsigned int regval;
> + int err;
> +
> + if (channel < TPS23861_NUM_PORTS) {
> + err = regmap_bulk_read(data->regmap,
> + PORT_1_VOLTAGE_LSB + channel * PORT_N_VOLTAGE_LSB_OFFSET,
> + &regval, 2);
> + } else {
> + err = regmap_bulk_read(data->regmap,
> + INPUT_VOLTAGE_LSB,
> + &regval, 2);
> + }
> + if (err < 0)
> + return err;
> +
> + *val = (FIELD_GET(VOLTAGE_CURRENT_MASK, regval) * VOLTAGE_LSB) / 1000;
> +
> + return 0;
> +}
> +
> +static int tps23861_read_current(struct tps23861_data *data, int channel,
> + long *val)
> +{
> + unsigned int current_lsb;
> + unsigned int regval;
> + int err;
> +
> + if (data->shunt_resistor == SHUNT_RESISTOR_DEFAULT)
> + current_lsb = CURRENT_LSB_255;
> + else
> + current_lsb = CURRENT_LSB_250;
> +
> + err = regmap_bulk_read(data->regmap,
> + PORT_1_CURRENT_LSB + channel * PORT_N_CURRENT_LSB_OFFSET,
> + &regval, 2);
> + if (err < 0)
> + return err;
> +
> + *val = (FIELD_GET(VOLTAGE_CURRENT_MASK, regval) * current_lsb) / 1000000;
> +
> + return 0;
> +}
> +
> +static int tps23861_port_disable(struct tps23861_data *data, int channel)
> +{
> + unsigned int regval = 0;
> + int err;
> +
> + regval |= BIT(channel + 4);
> + err = regmap_write(data->regmap, POWER_ENABLE, regval);
> +
> + return err;
> +}
> +
> +static int tps23861_port_enable(struct tps23861_data *data, int channel)
> +{
> + unsigned int regval = 0;
> + int err;
> +
> + regval |= BIT(channel);
> + regval |= BIT(channel + 4);
> + err = regmap_write(data->regmap, DETECT_CLASS_RESTART, regval);
> +
> + return err;
> +}
> +
> +static umode_t tps23861_is_visible(const void *data, enum hwmon_sensor_types type,
> + u32 attr, int channel)
> +{
> + switch (type) {
> + case hwmon_temp:
> + switch (attr) {
> + case hwmon_temp_input:
> + case hwmon_temp_label:
> + return 0444;
> + default:
> + return 0;
> + }
> + case hwmon_in:
> + switch (attr) {
> + case hwmon_in_input:
> + case hwmon_in_label:
> + return 0444;
> + case hwmon_in_enable:
> + return 0200;
> + default:
> + return 0;
> + }
> + case hwmon_curr:
> + switch (attr) {
> + case hwmon_curr_input:
> + case hwmon_curr_label:
> + return 0444;
> + default:
> + return 0;
> + }
> + default:
> + return 0;
> + }
> +}
> +
> +static int tps23861_write(struct device *dev, enum hwmon_sensor_types type,
> + u32 attr, int channel, long val)
> +{
> + struct tps23861_data *data = dev_get_drvdata(dev);
> + int err;
> +
> + switch (type) {
> + case hwmon_in:
> + switch (attr) {
> + case hwmon_in_enable:
> + if (val == 0)
> + err = tps23861_port_disable(data, channel);
> + else if (val == 1)
> + err = tps23861_port_enable(data, channel);
> + else
> + err = -EINVAL;
> + break;
> + default:
> + return -EOPNOTSUPP;
> + }
> + break;
> + default:
> + return -EOPNOTSUPP;
> + }
> +
> + return err;
> +}
> +
> +static int tps23861_read(struct device *dev, enum hwmon_sensor_types type,
> + u32 attr, int channel, long *val)
> +{
> + struct tps23861_data *data = dev_get_drvdata(dev);
> + int err;
> +
> + switch (type) {
> + case hwmon_temp:
> + switch (attr) {
> + case hwmon_temp_input:
> + err = tps23861_read_temp(data, val);
> + break;
> + default:
> + return -EOPNOTSUPP;
> + }
> + break;
> + case hwmon_in:
> + switch (attr) {
> + case hwmon_in_input:
> + err = tps23861_read_voltage(data, channel, val);
> + break;
> + default:
> + return -EOPNOTSUPP;
> + }
> + break;
> + case hwmon_curr:
> + switch (attr) {
> + case hwmon_curr_input:
> + err = tps23861_read_current(data, channel, val);
> + break;
> + default:
> + return -EOPNOTSUPP;
> + }
> + break;
> + default:
> + return -EOPNOTSUPP;
> + }
> +
> + return err;
> +}
> +
> +static const char * const tps23861_port_label[] = {
> + "Port1",
> + "Port2",
> + "Port3",
> + "Port4",
> + "Input",
> +};
> +
> +static int tps23861_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 = tps23861_port_label[channel];
> + break;
> + case hwmon_temp:
> + *str = "Die";
> + break;
> + default:
> + return -EOPNOTSUPP;
> + }
> +
> + return 0;
> +}
> +
> +static const struct hwmon_channel_info *tps23861_info[] = {
> + HWMON_CHANNEL_INFO(chip,
> + HWMON_C_REGISTER_TZ),
> + HWMON_CHANNEL_INFO(temp,
> + HWMON_T_INPUT | HWMON_T_LABEL),
> + 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 tps23861_hwmon_ops = {
> + .is_visible = tps23861_is_visible,
> + .write = tps23861_write,
> + .read = tps23861_read,
> + .read_string = tps23861_read_string,
> +};
> +
> +static const struct hwmon_chip_info tps23861_chip_info = {
> + .ops = &tps23861_hwmon_ops,
> + .info = tps23861_info,
> +};
> +
> +static char *tps23861_port_operating_mode(struct tps23861_data *data, int port)
> +{
> + unsigned int regval;
> + int mode;
> +
> + regmap_read(data->regmap, OPERATING_MODE, &regval);
> +
> + switch (port) {
> + case 1:
> + mode = FIELD_GET(OPERATING_MODE_PORT_1_MASK, regval);
> + break;
> + case 2:
> + mode = FIELD_GET(OPERATING_MODE_PORT_2_MASK, regval);
> + break;
> + case 3:
> + mode = FIELD_GET(OPERATING_MODE_PORT_3_MASK, regval);
> + break;
> + case 4:
> + mode = FIELD_GET(OPERATING_MODE_PORT_4_MASK, regval);
> + break;
> + default:
> + mode = -EINVAL;
> + }
> +
> + switch (mode) {
> + case OPERATING_MODE_OFF:
> + return "Off";
> + case OPERATING_MODE_MANUAL:
> + return "Manual";
> + case OPERATING_MODE_SEMI:
> + return "Semi-Auto";
> + case OPERATING_MODE_AUTO:
> + return "Auto";
> + default:
> + return "Invalid";
> + }
> +}
> +
> +static char *tps23861_port_detect_status(struct tps23861_data *data, int port)
> +{
> + unsigned int regval;
> +
> + regmap_read(data->regmap,
> + PORT_1_STATUS + (port - 1),
> + &regval);
> +
> + switch (FIELD_GET(PORT_STATUS_DETECT_MASK, regval)) {
> + 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 *tps23861_port_class_status(struct tps23861_data *data, int port)
> +{
> + unsigned int regval;
> +
> + regmap_read(data->regmap,
> + PORT_1_STATUS + (port - 1),
> + &regval);
> +
> + switch (FIELD_GET(PORT_STATUS_CLASS_MASK, regval)) {
> + case PORT_CLASS_UNKNOWN:
> + return "Unknown";
> + case PORT_CLASS_RESERVED:
> + 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_MISMATCH:
> + return "Mismatch";
> + default:
> + return "Invalid";
> + }
> +}
> +
> +static char *tps23861_port_poe_plus_status(struct tps23861_data *data, int port)
> +{
> + unsigned int regval;
> +
> + regmap_read(data->regmap, POE_PLUS, &regval);
> +
> + if (BIT(port + 3) & regval)
> + return "Yes";
> + else
> + return "No";
> +}
> +
> +static int tps23861_port_resistance(struct tps23861_data *data, int port)
> +{
> + u16 regval;
> +
> + regmap_bulk_read(data->regmap,
> + PORT_1_RESISTANCE_LSB + PORT_N_RESISTANCE_LSB_OFFSET * (port - 1),
> + &regval,
> + 2);
> +
> + switch (FIELD_GET(PORT_RESISTANCE_RSN_MASK, regval)) {
> + case PORT_RESISTANCE_RSN_OTHER:
> + return (FIELD_GET(PORT_RESISTANCE_MASK, regval) * RESISTANCE_LSB) / 10000;
> + case PORT_RESISTANCE_RSN_LOW:
> + return (FIELD_GET(PORT_RESISTANCE_MASK, regval) * RESISTANCE_LSB_LOW) / 10000;
> + case PORT_RESISTANCE_RSN_SHORT:
> + case PORT_RESISTANCE_RSN_OPEN:
> + default:
> + return 0;
> + }
> +}
> +
> +static int tps23861_port_status_show(struct seq_file *s, void *data)
> +{
> + struct tps23861_data *priv = s->private;
> + int i;
> +
> + for (i = 1; i < TPS23861_NUM_PORTS + 1; i++) {
> + seq_printf(s, "Port: \t\t%d\n", i);
> + seq_printf(s, "Operating mode: %s\n", tps23861_port_operating_mode(priv, i));
> + seq_printf(s, "Detected: \t%s\n", tps23861_port_detect_status(priv, i));
> + seq_printf(s, "Class: \t\t%s\n", tps23861_port_class_status(priv, i));
> + seq_printf(s, "PoE Plus: \t%s\n", tps23861_port_poe_plus_status(priv, i));
> + seq_printf(s, "Resistance: \t%d\n", tps23861_port_resistance(priv, i));
> + seq_putc(s, '\n');
> + }
> +
> + return 0;
> +}
> +
> +DEFINE_SHOW_ATTRIBUTE(tps23861_port_status);
> +
> +static void tps23861_init_debugfs(struct tps23861_data *data)
> +{
> + data->debugfs_dir = debugfs_create_dir(data->client->name, NULL);
> +
> + debugfs_create_file("port_status",
> + 0400,
> + data->debugfs_dir,
> + data,
> + &tps23861_port_status_fops);
> +}
> +
> +static int tps23861_probe(struct i2c_client *client)
> +{
> + struct device *dev = &client->dev;
> + struct tps23861_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, &tps23861_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))
> + data->shunt_resistor = shunt_resistor;
> + else
> + data->shunt_resistor = SHUNT_RESISTOR_DEFAULT;
> +
> + hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
> + data, &tps23861_chip_info,
> + NULL);
> + if (IS_ERR(hwmon_dev))
> + return PTR_ERR(hwmon_dev);
> +
> + tps23861_init_debugfs(data);
> +
> + return 0;
> +}
> +
> +static int tps23861_remove(struct i2c_client *client)
> +{
> + struct tps23861_data *data = i2c_get_clientdata(client);
> +
> + debugfs_remove_recursive(data->debugfs_dir);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id __maybe_unused tps23861_of_match[] = {
> + { .compatible = "ti,tps23861", },
> + { },
> +};
> +MODULE_DEVICE_TABLE(of, tps23861_of_match);
> +
> +static struct i2c_driver tps23861_driver = {
> + .probe_new = tps23861_probe,
> + .remove = tps23861_remove,
> + .driver = {
> + .name = "tps23861",
> + .of_match_table = of_match_ptr(tps23861_of_match),
> + },
> +};
> +module_i2c_driver(tps23861_driver);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_AUTHOR("Robert Marko <robert.marko@xxxxxxxxxx>");
> +MODULE_DESCRIPTION("TI TPS23861 PoE PSE");