hwmon: add MP5920 driver

Add support for MPS Hot-Swap controller mp5920. This driver exposes
telemetry and limit value readings and writings.

Signed-off-by: Alex Vdovydchenko <xzeol@yahoo.com>
Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/r/20240702115252.981416-3-xzeol@yahoo.com
[groeck: Use min_t() to limit length of displayed model string]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

3 files changed, 100 insertions, 0 deletions

diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
index 338b2e98dc22..a4f02cad92fd 100644
--- a/drivers/hwmon/pmbus/Kconfig
+++ b/drivers/hwmon/pmbus/Kconfig
@@ -380,6 +380,15 @@ config SENSORS_MP5023
 	  This driver can also be built as a module. If so, the module will
 	  be called mp5023.
 
+config SENSORS_MP5920
+	tristate "MPS MP5920"
+	help
+	  If you say yes here you get hardware monitoring support for Monolithic
+	  MP5920.
+
+	  This driver can also be built as a module. If so, the module will
+	  be called mp5920.
+
 config SENSORS_MP5990
 	tristate "MPS MP5990"
 	help
diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile
index 8afc5ba748f6..d00bcc758b97 100644
--- a/drivers/hwmon/pmbus/Makefile
+++ b/drivers/hwmon/pmbus/Makefile
@@ -40,6 +40,7 @@ obj-$(CONFIG_SENSORS_MP2891)	+= mp2891.o
 obj-$(CONFIG_SENSORS_MP2975)	+= mp2975.o
 obj-$(CONFIG_SENSORS_MP2993)	+= mp2993.o
 obj-$(CONFIG_SENSORS_MP5023)	+= mp5023.o
+obj-$(CONFIG_SENSORS_MP5920)	+= mp5920.o
 obj-$(CONFIG_SENSORS_MP5990)	+= mp5990.o
 obj-$(CONFIG_SENSORS_MP9941)	+= mp9941.o
 obj-$(CONFIG_SENSORS_MPQ7932)	+= mpq7932.o
diff --git a/drivers/hwmon/pmbus/mp5920.c b/drivers/hwmon/pmbus/mp5920.c
new file mode 100644
index 000000000000..f6d7527ade7d
--- /dev/null
+++ b/drivers/hwmon/pmbus/mp5920.c
@@ -0,0 +1,90 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Hardware monitoring driver for MP5920 and compatible chips.
+ */
+
+#include <linux/i2c.h>
+#include <linux/minmax.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include "pmbus.h"
+
+static struct pmbus_driver_info mp5920_info = {
+	.pages = 1,
+	.format[PSC_VOLTAGE_IN] = direct,
+	.format[PSC_VOLTAGE_OUT] = direct,
+	.format[PSC_CURRENT_OUT] = direct,
+	.format[PSC_POWER] = direct,
+	.format[PSC_TEMPERATURE] = direct,
+	.m[PSC_VOLTAGE_IN] = 2266,
+	.b[PSC_VOLTAGE_IN] = 0,
+	.R[PSC_VOLTAGE_IN] = -1,
+	.m[PSC_VOLTAGE_OUT] = 2266,
+	.b[PSC_VOLTAGE_OUT] = 0,
+	.R[PSC_VOLTAGE_OUT] = -1,
+	.m[PSC_CURRENT_OUT] = 546,
+	.b[PSC_CURRENT_OUT] = 0,
+	.R[PSC_CURRENT_OUT] = -2,
+	.m[PSC_POWER] = 5840,
+	.b[PSC_POWER] = 0,
+	.R[PSC_POWER] = -3,
+	.m[PSC_TEMPERATURE] = 1067,
+	.b[PSC_TEMPERATURE] = 20500,
+	.R[PSC_TEMPERATURE] = -2,
+	.func[0] = PMBUS_HAVE_VIN  | PMBUS_HAVE_VOUT |
+		PMBUS_HAVE_IOUT | PMBUS_HAVE_POUT |
+		PMBUS_HAVE_TEMP,
+};
+
+static int mp5920_probe(struct i2c_client *client)
+{
+	struct device *dev =  &client->dev;
+	int ret;
+	u8 buf[I2C_SMBUS_BLOCK_MAX];
+
+	if (!i2c_check_functionality(client->adapter,
+				     I2C_FUNC_SMBUS_READ_WORD_DATA))
+		return -ENODEV;
+
+	ret = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, buf);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "Failed to read PMBUS_MFR_MODEL\n");
+
+	if (ret != 6 || strncmp(buf, "MP5920", 6)) {
+		return dev_err_probe(dev, -ENODEV, "Model '%.*s' not supported\n",
+				     min_t(int, ret, sizeof(buf)), buf);
+	}
+
+	return pmbus_do_probe(client, &mp5920_info);
+}
+
+static const struct of_device_id mp5920_of_match[] = {
+	{ .compatible = "mps,mp5920" },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(of, mp5920_of_match);
+
+static const struct i2c_device_id mp5920_id[] = {
+	{ "mp5920" },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(i2c, mp5920_id);
+
+static struct i2c_driver mp5920_driver = {
+	.driver = {
+		.name = "mp5920",
+		.of_match_table = mp5920_of_match,
+	},
+	.probe = mp5920_probe,
+	.id_table = mp5920_id,
+};
+
+module_i2c_driver(mp5920_driver);
+
+MODULE_AUTHOR("Tony Ao <tony_ao@wiwynn.com>");
+MODULE_AUTHOR("Alex Vdovydchenko <xzeol@yahoo.com>");
+MODULE_DESCRIPTION("PMBus driver for MP5920 HSC");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(PMBUS);