[PATCH v7 2/2] hwmon: (isl28022) new driver for ISL28022 power monitor

Yikai Tsai
2024-09-25T03:11:56Z

Driver for Renesas ISL28022 power monitor with I2C interface.
The device monitors voltage, current via shunt resistor
and calculated power.

Signed-off-by: Carsten Spieß <mail@carsten-spiess.de>
Signed-off-by: Yikai Tsai <yikai.tsai.wiwynn@gmail.com>
---
Documentation/hwmon/index.rst | 1 +
Documentation/hwmon/isl28022.rst | 63 ++++
MAINTAINERS | 2 +
drivers/hwmon/Kconfig | 11 +
drivers/hwmon/Makefile | 1 +
drivers/hwmon/isl28022.c | 533 +++++++++++++++++++++++++++++++
6 files changed, 611 insertions(+)
create mode 100644 Documentation/hwmon/isl28022.rst
create mode 100644 drivers/hwmon/isl28022.c

diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
index ea3b5be8fe4f..4d15664bc41e 100644
--- a/Documentation/hwmon/index.rst
+++ b/Documentation/hwmon/index.rst
@@ -96,6 +96,7 @@ Hardware Monitoring Kernel Drivers
ir35221
ir38064
ir36021
+ isl28022
isl68137
it87
jc42
diff --git a/Documentation/hwmon/isl28022.rst b/Documentation/hwmon/isl28022.rst
new file mode 100644
index 000000000000..8d4422a2dacd
--- /dev/null
+++ b/Documentation/hwmon/isl28022.rst
@@ -0,0 +1,63 @@
+.. SPDX-License-Identifier: GPL-2.0-or-later
+
+Kernel driver isl28022
+======================
+
+Supported chips:
+
+ * Renesas ISL28022
+
+ Prefix: 'isl28022'
+
+ Addresses scanned: none
+
+ Datasheet: Publicly available at the Renesas website
+
+ https://www.renesas.com/us/en/www/doc/datasheet/isl28022.pdf
+
+Author:
+ Carsten Spieß <mail@carsten-spiess.de>
+
+Description
+-----------
+
+The ISL28022 is a power monitor with I2C interface. The device monitors
+voltage, current via shunt resistor and calculated power.
+
+Usage Notes
+-----------
+
+This driver does not auto-detect devices. You will have to instantiate the
+device explicitly. Please see Documentation/i2c/instantiating-devices.rst for
+details.
+
+The shunt value in micro-ohms, shunt voltage range and averaging can be set
+with device properties.
+Please refer to the Documentation/devicetree/bindings/hwmon/isl,isl28022.yaml
+for bindings if the device tree is used.
+
+The driver supports only shunt and bus continuous ADC mode at 15bit resolution.
+Averaging can be set from 1 to 128 samples (power of 2) on both channels.
+Shunt voltage range of 40, 80, 160 or 320mV is allowed
+The bus voltage range is 60V fixed.
+
+Sysfs entries
+-------------
+
+The following attributes are supported. All attributes are read-only.
+
+======================= =======================================================
+in0_input bus voltage (milli Volt)
+
+curr1_input current (milli Ampere)
+power1_input power (micro Watt)
+======================= =======================================================
+
+Debugfs entries
+---------------
+
+The following attributes are supported. All attributes are read-only.
+
+======================= =======================================================
+shunt_voltage shunt voltage (micro Volt)
+======================= =======================================================
diff --git a/MAINTAINERS b/MAINTAINERS
index 9407481c03a2..a1531c358423 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12080,6 +12080,8 @@ M: Carsten Spieß <mail@carsten-spiess.de>
L: linux-hwmon@vger.kernel.org
S: Maintained
F: Documentation/devicetree/bindings/hwmon/renesas,isl28022.yaml
+F: Documentation/hwmon/isl28022.rst
+F: drivers/hwmon/isl28022.c

ISOFS FILESYSTEM
M: Jan Kara <jack@suse.cz>
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 65ea92529406..ad0f8c0a9535 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -853,6 +853,17 @@ config SENSORS_CORETEMP
sensor inside your CPU. Most of the family 6 CPUs
are supported. Check Documentation/hwmon/coretemp.rst for details.

+config SENSORS_ISL28022
+ tristate "Renesas ISL28022"
+ depends on I2C
+ select REGMAP_I2C
+ help
+ If you say yes here you get support for ISL28022 power monitor.
+ Check Documentation/hwmon/isl28022.rst for details.
+
+ This driver can also be built as a module. If so, the module
+ will be called isl28022.
+
config SENSORS_IT87
tristate "ITE IT87xx and compatibles"
depends on HAS_IOPORT
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 9554d2fdcf7b..4ea6f7c95315 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -103,6 +103,7 @@ obj-$(CONFIG_SENSORS_INA2XX) += ina2xx.o
obj-$(CONFIG_SENSORS_INA238) += ina238.o
obj-$(CONFIG_SENSORS_INA3221) += ina3221.o
obj-$(CONFIG_SENSORS_INTEL_M10_BMC_HWMON) += intel-m10-bmc-hwmon.o
+obj-$(CONFIG_SENSORS_ISL28022) += isl28022.o
obj-$(CONFIG_SENSORS_IT87) += it87.o
obj-$(CONFIG_SENSORS_JC42) += jc42.o
obj-$(CONFIG_SENSORS_K8TEMP) += k8temp.o
diff --git a/drivers/hwmon/isl28022.c b/drivers/hwmon/isl28022.c
new file mode 100644
index 000000000000..d7de8fbfe362
--- /dev/null
+++ b/drivers/hwmon/isl28022.c
@@ -0,0 +1,533 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * isl28022.c - driver for Renesas ISL28022 power monitor chip monitoring
+ *
+ * Copyright (c) 2023 Carsten Spieß <mail@carsten-spiess.de>
+ */
+
+#include <linux/debugfs.h>
+#include <linux/err.h>
+#include <linux/hwmon.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+/* ISL28022 registers */
+#define ISL28022_REG_CONFIG 0x00
+#define ISL28022_REG_SHUNT 0x01
+#define ISL28022_REG_BUS 0x02
+#define ISL28022_REG_POWER 0x03
+#define ISL28022_REG_CURRENT 0x04
+#define ISL28022_REG_CALIB 0x05
+#define ISL28022_REG_SHUNT_THR 0x06
+#define ISL28022_REG_BUS_THR 0x07
+#define ISL28022_REG_INT 0x08
+#define ISL28022_REG_AUX 0x09
+#define ISL28022_REG_MAX ISL28022_REG_AUX
+
+/* ISL28022 config flags */
+/* mode flags */
+#define ISL28022_MODE_SHIFT 0
+#define ISL28022_MODE_MASK 0x0007
+
+#define ISL28022_MODE_PWR_DOWN 0x0
+#define ISL28022_MODE_TRG_S 0x1
+#define ISL28022_MODE_TRG_B 0x2
+#define ISL28022_MODE_TRG_SB 0x3
+#define ISL28022_MODE_ADC_OFF 0x4
+#define ISL28022_MODE_CONT_S 0x5
+#define ISL28022_MODE_CONT_B 0x6
+#define ISL28022_MODE_CONT_SB 0x7
+
+/* shunt ADC settings */
+#define ISL28022_SADC_SHIFT 3
+#define ISL28022_SADC_MASK 0x0078
+
+#define ISL28022_BADC_SHIFT 7
+#define ISL28022_BADC_MASK 0x0780
+
+#define ISL28022_ADC_12 0x0 /* 12 bit ADC */
+#define ISL28022_ADC_13 0x1 /* 13 bit ADC */
+#define ISL28022_ADC_14 0x2 /* 14 bit ADC */
+#define ISL28022_ADC_15 0x3 /* 15 bit ADC */
+#define ISL28022_ADC_15_1 0x8 /* 15 bit ADC, 1 sample */
+#define ISL28022_ADC_15_2 0x9 /* 15 bit ADC, 2 samples */
+#define ISL28022_ADC_15_4 0xA /* 15 bit ADC, 4 samples */
+#define ISL28022_ADC_15_8 0xB /* 15 bit ADC, 8 samples */
+#define ISL28022_ADC_15_16 0xC /* 15 bit ADC, 16 samples */
+#define ISL28022_ADC_15_32 0xD /* 15 bit ADC, 32 samples */
+#define ISL28022_ADC_15_64 0xE /* 15 bit ADC, 64 samples */
+#define ISL28022_ADC_15_128 0xF /* 15 bit ADC, 128 samples */
+
+/* shunt voltage range */
+#define ISL28022_PG_SHIFT 11
+#define ISL28022_PG_MASK 0x1800
+
+#define ISL28022_PG_40 0x0 /* +/-40 mV */
+#define ISL28022_PG_80 0x1 /* +/-80 mV */
+#define ISL28022_PG_160 0x2 /* +/-160 mV */
+#define ISL28022_PG_320 0x3 /* +/-3200 mV */
+
+/* bus voltage range */
+#define ISL28022_BRNG_SHIFT 13
+#define ISL28022_BRNG_MASK 0x6000
+
+#define ISL28022_BRNG_16 0x0 /* 16 V */
+#define ISL28022_BRNG_32 0x1 /* 32 V */
+#define ISL28022_BRNG_60 0x3 /* 60 V */
+
+/* reset */
+#define ISL28022_RESET 0x8000
+
+struct isl28022_data {
+ struct regmap *regmap;
+ u32 shunt;
+ u32 gain;
+ u32 average;
+};
+
+static int isl28022_read_in(struct device *dev, u32 attr, int channel, long *val)
+{
+ struct isl28022_data *data = dev_get_drvdata(dev);
+ unsigned int regval;
+ int err;
+ u16 sign_bit;
+
+ switch (channel) {
+ case 0:
+ switch (attr) {
+ case hwmon_in_input:
+ err = regmap_read(data->regmap,
+ ISL28022_REG_BUS, &regval);
+ if (err < 0)
+ return err;
+ /* driver supports only 60V mode (BRNG 11) */
+ *val = (long)(((u16)regval) & 0xFFFC);
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+ break;
+ case 1:
+ switch (attr) {
+ case hwmon_in_input:
+ err = regmap_read(data->regmap,
+ ISL28022_REG_SHUNT, &regval);
+ if (err < 0)
+ return err;
+ switch (data->gain) {
+ case 8:
+ sign_bit = (regval >> 15) & 0x01;
+ *val = (long)((((u16)regval) & 0x7FFF) -
+ (sign_bit * 32768)) / 100;
+ break;
+ case 4:
+ sign_bit = (regval >> 14) & 0x01;
+ *val = (long)((((u16)regval) & 0x3FFF) -
+ (sign_bit * 16384)) / 100;
+ break;
+ case 2:
+ sign_bit = (regval >> 13) & 0x01;
+ *val = (long)((((u16)regval) & 0x1FFF) -
+ (sign_bit * 8192)) / 100;
+ break;
+ case 1:
+ sign_bit = (regval >> 12) & 0x01;
+ *val = (long)((((u16)regval) & 0x0FFF) -
+ (sign_bit * 4096)) / 100;
+ break;
+ }
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ return 0;
+}
+
+static int isl28022_read_current(struct device *dev, u32 attr, long *val)
+{
+ struct isl28022_data *data = dev_get_drvdata(dev);
+ unsigned int regval;
+ int err;
+
+ switch (attr) {
+ case hwmon_curr_input:
+ err = regmap_read(data->regmap,
+ ISL28022_REG_CURRENT, &regval);
+ if (err < 0)
+ return err;
+ *val = ((long)regval * 1250L * (long)data->gain) /
+ (long)data->shunt;
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ return 0;
+}
+
+static int isl28022_read_power(struct device *dev, u32 attr, long *val)
+{
+ struct isl28022_data *data = dev_get_drvdata(dev);
+ unsigned int regval;
+ int err;
+
+ switch (attr) {
+ case hwmon_power_input:
+ err = regmap_read(data->regmap,
+ ISL28022_REG_POWER, &regval);
+ if (err < 0)
+ return err;
+ *val = ((51200000L * ((long)data->gain)) /
+ (long)data->shunt) * (long)regval;
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ return 0;
+}
+
+static int isl28022_read(struct device *dev, enum hwmon_sensor_types type,
+ u32 attr, int channel, long *val)
+{
+ switch (type) {
+ case hwmon_in:
+ return isl28022_read_in(dev, attr, channel, val);
+ case hwmon_curr:
+ return isl28022_read_current(dev, attr, val);
+ case hwmon_power:
+ return isl28022_read_power(dev, attr, val);
+ default:
+ return -EOPNOTSUPP;
+ }
+ return 0;
+}
+
+static umode_t isl28022_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:
+ return 0444;
+ default:
+ break;
+ }
+ break;
+ case hwmon_curr:
+ switch (attr) {
+ case hwmon_curr_input:
+ return 0444;
+ default:
+ break;
+ }
+ break;
+ case hwmon_power:
+ switch (attr) {
+ case hwmon_power_input:
+ return 0444;
+ default:
+ break;
+ }
+ break;
+ default:
+ break;
+ }
+ return 0;
+}
+
+static const struct hwmon_channel_info *isl28022_info[] = {
+ HWMON_CHANNEL_INFO(in,
+ HWMON_I_INPUT, /* channel 0: bus voltage (mV) */
+ HWMON_I_INPUT), /* channel 1: shunt voltage (mV) */
+ HWMON_CHANNEL_INFO(curr,
+ HWMON_C_INPUT), /* channel 1: current (mA) */
+ HWMON_CHANNEL_INFO(power,
+ HWMON_P_INPUT), /* channel 1: power (µW) */
+ NULL
+};
+
+static const struct hwmon_ops isl28022_hwmon_ops = {
+ .is_visible = isl28022_is_visible,
+ .read = isl28022_read,
+};
+
+static const struct hwmon_chip_info isl28022_chip_info = {
+ .ops = &isl28022_hwmon_ops,
+ .info = isl28022_info,
+};
+
+static bool isl28022_is_writeable_reg(struct device *dev, unsigned int reg)
+{
+ switch (reg) {
+ case ISL28022_REG_CONFIG:
+ case ISL28022_REG_CALIB:
+ case ISL28022_REG_SHUNT_THR:
+ case ISL28022_REG_BUS_THR:
+ case ISL28022_REG_INT:
+ case ISL28022_REG_AUX:
+ return true;
+ }
+
+ return false;
+}
+
+static bool isl28022_is_volatile_reg(struct device *dev, unsigned int reg)
+{
+ switch (reg) {
+ case ISL28022_REG_CONFIG:
+ case ISL28022_REG_SHUNT:
+ case ISL28022_REG_BUS:
+ case ISL28022_REG_POWER:
+ case ISL28022_REG_CURRENT:
+ case ISL28022_REG_INT:
+ case ISL28022_REG_AUX:
+ return true;
+ }
+ return true;
+}
+
+static const struct regmap_config isl28022_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 16,
+ .max_register = ISL28022_REG_MAX,
+ .writeable_reg = isl28022_is_writeable_reg,
+ .volatile_reg = isl28022_is_volatile_reg,
+ .val_format_endian = REGMAP_ENDIAN_BIG,
+ .cache_type = REGCACHE_RBTREE,
+ .use_single_read = true,
+ .use_single_write = true,
+};
+
+static int shunt_voltage_show(struct seq_file *seqf, void *unused)
+{
+ struct isl28022_data *data = seqf->private;
+ unsigned int regval;
+ int err;
+
+ err = regmap_read(data->regmap,
+ ISL28022_REG_SHUNT, &regval);
+ if (err)
+ return err;
+
+ /* print shunt voltage in micro volt */
+ seq_printf(seqf, "%d\n", regval * 10);
+
+ return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(shunt_voltage);
+
+static struct dentry *isl28022_debugfs_root;
+
+static void isl28022_debugfs_remove(void *res)
+{
+ debugfs_remove_recursive(res);
+}
+
+static void isl28022_debugfs_init(struct i2c_client *client, struct isl28022_data *data)
+{
+ char name[16];
+ struct dentry *debugfs;
+
+ scnprintf(name, sizeof(name), "%d-%04hx", client->adapter->nr, client->addr);
+
+ debugfs = debugfs_create_dir(name, isl28022_debugfs_root);
+ debugfs_create_file("shunt_voltage", 0444, debugfs, data, &shunt_voltage_fops);
+
+ devm_add_action_or_reset(&client->dev, isl28022_debugfs_remove, debugfs);
+}
+
+/*
+ * read property values and make consistency checks.
+ *
+ * following values for shunt range and resistor are allowed:
+ * 40 mV -> gain 1, shunt min. 800 micro ohms
+ * 80 mV -> gain 2, shunt min. 1600 micro ohms
+ * 160 mV -> gain 4, shunt min. 3200 micro ohms
+ * 320 mV -> gain 8, shunt min. 6400 micro ohms
+ */
+static int isl28022_read_properties(struct device *dev, struct isl28022_data *data)
+{
+ u32 val;
+ int err;
+
+ err = device_property_read_u32(dev, "shunt-resistor-micro-ohms", &val);
+ if (err == -EINVAL)
+ val = 10000;
+ else if (err < 0)
+ return err;
+ data->shunt = val;
+
+ err = device_property_read_u32(dev, "renesas,shunt-range-microvolt", &val);
+ if (err == -EINVAL)
+ val = 320000;
+ else if (err < 0)
+ return err;
+
+ switch (val) {
+ case 40000:
+ data->gain = 1;
+ if (data->shunt < 800)
+ goto shunt_invalid;
+ break;
+ case 80000:
+ data->gain = 2;
+ if (data->shunt < 1600)
+ goto shunt_invalid;
+ break;
+ case 160000:
+ data->gain = 4;
+ if (data->shunt < 3200)
+ goto shunt_invalid;
+ break;
+ case 320000:
+ data->gain = 8;
+ if (data->shunt < 6400)
+ goto shunt_invalid;
+ break;
+ default:
+ dev_err_probe(dev, "renesas,shunt-range-microvolt invalid value %d\n", val);
+ return -EINVAL;
+ }
+
+ err = device_property_read_u32(dev, "renesas,average-samples", &val);
+ if (err == -EINVAL)
+ val = 1;
+ else if (err < 0)
+ return err;
+ if (val > 128 || hweight32(val) != 1) {
+ dev_err_probe(dev, "renesas,average-samples invalid value %d\n", val);
+ return -EINVAL;
+ }
+ data->average = val;
+
+ return 0;
+
+shunt_invalid:
+ dev_err_probe(dev, "renesas,shunt-resistor-microvolt invalid value %d\n", data->shunt);
+ return -EINVAL;
+}
+
+/*
+ * write configuration and calibration registers
+ *
+ * The driver supports only shunt and bus continuous ADC mode at 15bit resolution
+ * with averaging from 1 to 128 samples (pow of 2) on both channels.
+ * Shunt voltage gain 1,2,4 or 8 is allowed.
+ * The bus voltage range is 60V fixed.
+ */
+static int isl28022_config(struct isl28022_data *data)
+{
+ int err;
+ u16 config;
+ u16 calib;
+
+ config = (ISL28022_MODE_CONT_SB << ISL28022_MODE_SHIFT) |
+ (ISL28022_BRNG_60 << ISL28022_BRNG_SHIFT) |
+ (__ffs(data->gain) << ISL28022_PG_SHIFT) |
+ ((ISL28022_ADC_15_1 + __ffs(data->average)) << ISL28022_SADC_SHIFT) |
+ ((ISL28022_ADC_15_1 + __ffs(data->average)) << ISL28022_BADC_SHIFT);
+
+ calib = data->shunt ? 0x8000 / data->gain : 0;
+
+ err = regmap_write(data->regmap, ISL28022_REG_CONFIG, config);
+ if (err < 0)
+ return err;
+
+ return regmap_write(data->regmap, ISL28022_REG_CALIB, calib);
+}
+
+static int isl28022_probe(struct i2c_client *client)
+{
+ struct device *dev = &client->dev;
+ struct device *hwmon_dev;
+ struct isl28022_data *data;
+ int err;
+
+ if (!i2c_check_functionality(client->adapter,
+ I2C_FUNC_SMBUS_BYTE_DATA |
+ I2C_FUNC_SMBUS_WORD_DATA))
+ return -ENODEV;
+
+ data = devm_kzalloc(dev, sizeof(struct isl28022_data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ err = isl28022_read_properties(dev, data);
+ if (err)
+ return err;
+
+ data->regmap = devm_regmap_init_i2c(client, &isl28022_regmap_config);
+ if (IS_ERR(data->regmap))
+ return PTR_ERR(data->regmap);
+
+ err = isl28022_config(data);
+ if (err)
+ return err;
+
+ isl28022_debugfs_init(client, data);
+
+ hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
+ data, &isl28022_chip_info, NULL);
+ if (IS_ERR(hwmon_dev))
+ return PTR_ERR(hwmon_dev);
+
+ dev_info(dev, "%s: sensor '%s'\n", dev_name(hwmon_dev), client->name);
+ return 0;
+}
+
+static const struct i2c_device_id isl28022_ids[] = {
+ { "isl28022", 0},
+ { /* LIST END */ }
+};
+MODULE_DEVICE_TABLE(i2c, isl28022_ids);
+
+static const struct of_device_id __maybe_unused isl28022_of_match[] = {
+ { .compatible = "renesas,isl28022"},
+ { /* LIST END */ }
+};
+MODULE_DEVICE_TABLE(of, isl28022_of_match);
+
+static struct i2c_driver isl28022_driver = {
+ .class = I2C_CLASS_HWMON,
+ .driver = {
+ .name = "isl28022",
+ },
+ .probe = isl28022_probe,
+ .id_table = isl28022_ids,
+};
+
+static int __init
+isl28022_init(void)
+{
+ int err;
+
+ isl28022_debugfs_root = debugfs_create_dir("isl28022", NULL);
+ err = i2c_add_driver(&isl28022_driver);
+ if (!err)
+ return 0;
+
+ debugfs_remove_recursive(isl28022_debugfs_root);
+ return err;
+}
+
+static void __exit
+isl28022_exit(void)
+{
+ i2c_del_driver(&isl28022_driver);
+ debugfs_remove_recursive(isl28022_debugfs_root);
+}
+
+module_init(isl28022_init);
+module_exit(isl28022_exit);
+
+MODULE_AUTHOR("Carsten Spieß <mail@carsten-spiess.de>");
+MODULE_DESCRIPTION("ISL28022 driver");
+MODULE_LICENSE("GPL");
--
2.25.1