[PATCH v3 2/3] hwmon: add Texas Instruments TPS23861 driver

From: Robert Marko
Date: Tue Dec 22 2020 - 09:31:08 EST

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>
---
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

drivers/hwmon/Kconfig | 11 +
drivers/hwmon/Makefile | 1 +
drivers/hwmon/tps23861.c | 603 +++++++++++++++++++++++++++++++++++++++
3 files changed, 615 insertions(+)
create mode 100644 drivers/hwmon/tps23861.c

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index a850e4f0e0bd..3368ecfa7a9c 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1102,6 +1102,17 @@ 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 9db2903b61e5..7493e9d5dc43 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -141,6 +141,7 @@ 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..a321e4700f48
--- /dev/null
+++ b/drivers/hwmon/tps23861.c
@@ -0,0 +1,603 @@
+// 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);
+ if (!data->debugfs_dir)
+ return;
+
+ 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) < 0)
+ 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");
--
2.29.2