From: Patrick Rudolph <patrick.rudolph@xxxxxxxxxxxxx>
Add support for the Maxim Max59x power switch with current/voltage
monitor.
Signed-off-by: Patrick Rudolph <patrick.rudolph@xxxxxxxxxxxxx>
Signed-off-by: Naresh Solanki <Naresh.Solanki@xxxxxxxxxxxxx>
---
drivers/hwmon/Kconfig | 9 ++
drivers/hwmon/Makefile | 1 +
drivers/hwmon/max597x.c | 212 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 222 insertions(+)
create mode 100644 drivers/hwmon/max597x.c
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 5b3b76477b0e..164d980d9de2 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1097,6 +1097,15 @@ config SENSORS_MAX31760
This driver can also be built as a module. If so, the module
will be called max31760.
+config SENSORS_MAX597X
+ tristate "Maxim 597x power switch and monitor"
+ depends on I2C
+ depends on OF
+ select MFD_MAX597X
+ help
+ This driver exposes Maxim 5970/5978 voltage/current monitoring
+ interface.
+
config SENSORS_MAX6620
tristate "Maxim MAX6620 fan controller"
depends on I2C
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 88712b5031c8..720eb7d5fe46 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -142,6 +142,7 @@ obj-$(CONFIG_SENSORS_MAX197) += max197.o
obj-$(CONFIG_SENSORS_MAX31722) += max31722.o
obj-$(CONFIG_SENSORS_MAX31730) += max31730.o
obj-$(CONFIG_SENSORS_MAX31760) += max31760.o
+obj-$(CONFIG_SENSORS_MAX597X) += max597x.o
obj-$(CONFIG_SENSORS_MAX6620) += max6620.o
obj-$(CONFIG_SENSORS_MAX6621) += max6621.o
obj-$(CONFIG_SENSORS_MAX6639) += max6639.o
diff --git a/drivers/hwmon/max597x.c b/drivers/hwmon/max597x.c
new file mode 100644
index 000000000000..d4d8c2faf55c
--- /dev/null
+++ b/drivers/hwmon/max597x.c
@@ -0,0 +1,212 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Device driver for regulators in MAX5970 and MAX5978 IC
+ *
+ * Copyright (c) 2022 9elements GmbH
+ *
+ * Author: Patrick Rudolph <patrick.rudolph@xxxxxxxxxxxxx>
+ */
+
+#include <linux/hwmon.h>
+#include <linux/i2c.h>
+#include <linux/mfd/max597x.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+struct max597x_hwmon {
+ int num_switches, irng[MAX5970_NUM_SWITCHES], mon_rng[MAX5970_NUM_SWITCHES];
+ struct regmap *regmap;
+};
+
+static int max597x_read_reg(struct max597x_hwmon *ddata, int reg, int range, long *val)
+{
+ u8 reg_data[2];
+ int ret;
+
+ ret = regmap_bulk_read(ddata->regmap, reg, ®_data[0], 2);
+ if (ret < 0)
+ return ret;
+
+ *val = (reg_data[0] << 2) | (reg_data[1] & 3);
+ *val = *val * range;
+ /*
+ * From datasheet, the range is fractionally less.
+ * To compensate that, divide with 1033 number.
+ */
+ *val = *val / 1033;
+
+ return 0;
+}
+
+static int max597x_read(struct device *dev, enum hwmon_sensor_types type,
+ u32 attr, int channel, long *val)
+{
+ struct max597x_hwmon *ddata = dev_get_drvdata(dev);
+ int ret;
+
+ switch (type) {
+ case hwmon_curr:
+ switch (attr) {
+ case hwmon_curr_input:
+ ret = max597x_read_reg(ddata, MAX5970_REG_CURRENT_H(channel),
+ ddata->irng[channel], val);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ case hwmon_in:
+ switch (attr) {
+ case hwmon_in_input:
+ ret = max597x_read_reg(ddata, MAX5970_REG_VOLTAGE_H(channel),
+ ddata->mon_rng[channel], val);
+ if (ret < 0)
+ return ret;
+ return 0;
+ default:
+ return -EOPNOTSUPP;
+ }
+ }
+ return -EOPNOTSUPP;
+}
+
+static umode_t max597x_is_visible(const void *data,
+ enum hwmon_sensor_types type,
+ u32 attr, int channel)
+{
+ struct max597x_hwmon *ddata = (struct max597x_hwmon *)data;
+
+ if (channel >= ddata->num_switches)
+ return 0;
+
+ switch (type) {
+ case hwmon_in:
+ switch (attr) {
+ case hwmon_in_input:
+ return 0444;
+ }
+ break;
+ case hwmon_curr:
+ switch (attr) {
+ case hwmon_curr_input:
+ return 0444;
+ }
+ break;
+ default:
+ break;
+ }
+ return 0;
+}
+
+static const struct hwmon_ops max597x_hwmon_ops = {
+ .is_visible = max597x_is_visible,
+ .read = max597x_read,
+};
+
+#define HWMON_CURRENT HWMON_C_INPUT
+#define HWMON_VOLTAGE HWMON_I_INPUT
+
+static const struct hwmon_channel_info *max597x_info[] = {
+ HWMON_CHANNEL_INFO(in, HWMON_VOLTAGE, HWMON_VOLTAGE),
+ HWMON_CHANNEL_INFO(curr, HWMON_CURRENT, HWMON_CURRENT),
+ NULL
+};
+
+static const struct hwmon_chip_info max597x_chip_info = {
+ .ops = &max597x_hwmon_ops,
+ .info = max597x_info,
+};
+
+static int max597x_adc_range(struct regmap *regmap, const int ch,
+ u32 *irng, u32 *mon_rng)
+{
+ unsigned int reg;
+ int ret;
+
+ /* Decode current ADC range */
+ ret = regmap_read(regmap, MAX5970_REG_STATUS2, ®);
+ if (ret)
+ return ret;
+ switch (MAX5970_IRNG(reg, ch)) {
+ case 0:
+ *irng = 100000; /* 100 mV */
+ break;
+ case 1:
+ *irng = 50000; /* 50 mV */
+ break;
+ case 2:
+ *irng = 25000; /* 25 mV */
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ /* Decode current voltage monitor range */
+ ret = regmap_read(regmap, MAX5970_REG_MON_RANGE, ®);
+ if (ret)
+ return ret;
+
+ *mon_rng = MAX5970_MON_MAX_RANGE_UV >> MAX5970_MON(reg, ch);
+ *mon_rng /= 1000; /* uV to mV */
+
+ return 0;
+}
+
+static int max597x_sensor_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct i2c_client *i2c = to_i2c_client(pdev->dev.parent);
+ struct max597x_hwmon *ddata;
+ struct regmap *regmap = dev_get_regmap(pdev->dev.parent, NULL);
+ struct device *hwmon_dev;
+ int err;
+
+ if (!regmap)
+ return -EPROBE_DEFER;
+
+ ddata = devm_kzalloc(dev, sizeof(struct max597x_hwmon), GFP_KERNEL);
+ if (!ddata)
+ return -ENOMEM;
+
+ if (of_device_is_compatible(i2c->dev.of_node, "maxim,max5978"))
+ ddata->num_switches = MAX597x_TYPE_MAX5978;
+ else if (of_device_is_compatible(i2c->dev.of_node, "maxim,max5970"))
+ ddata->num_switches = MAX597x_TYPE_MAX5970;
+ else
+ return -ENODEV;
+
+ ddata->regmap = regmap;
+
+ for (int i = 0; i < ddata->num_switches; i++) {
+ err = max597x_adc_range(regmap, i, &ddata->irng[i], &ddata->mon_rng[i]);
+ if (err < 0)
+ return err;
+ }
+
+ hwmon_dev = devm_hwmon_device_register_with_info(dev,
+ "max597x_hwmon", ddata,
+ &max597x_chip_info, NULL);
+
+ if (IS_ERR(hwmon_dev)) {
+ err = PTR_ERR(hwmon_dev);
+ dev_err(dev, "Unable to register hwmon device, returned %d\n", err);
+ return err;
+ }
+
+ return 0;
+}
+
+static struct platform_driver max597x_sensor_driver = {
+ .probe = max597x_sensor_probe,
+ .driver = {
+ .name = "max597x-hwmon",
+ },
+};
+module_platform_driver(max597x_sensor_driver);
+
+MODULE_AUTHOR("Patrick Rudolph <patrick.rudolph@xxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("MAX5970_hot-swap controller driver");
+MODULE_LICENSE("GPL v2");
base-commit: b4c288cfd2f84c44994330c408e14645d45dee5b
--
2.39.1
