[PATCH 6.19 185/342] hwmon: (pmbus) Mark lowest/average/highest/rated attributes as read-only

Greg Kroah-Hartman
2026-03-31T16:39:16Z

From: Guenter Roeck <linux@roeck-us.net>

[ Upstream commit 805a5bd1c3f307d45ae4e9cf8915ef16d585a54a ]

Writing those attributes is not supported, so mark them as read-only.

Prior to this change, attempts to write into these attributes returned
an error.

Mark boolean fields in struct pmbus_limit_attr and in struct
pmbus_sensor_attr as bit fields to reduce configuration data size.
The data is scanned only while probing, so performance is not a concern.

Fixes: 6f183d33a02e6 ("hwmon: (pmbus) Add support for peak attributes")
Reviewed-by: Sanman Pradhan <psanman@juniper.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/hwmon/pmbus/pmbus_core.c | 48 ++++++++++++++++++++++++++++----
1 file changed, 42 insertions(+), 6 deletions(-)

diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index be6d05def1152..ecd1dddcbe0ff 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -1495,8 +1495,9 @@ static int pmbus_add_label(struct pmbus_data *data,
struct pmbus_limit_attr {
u16 reg; /* Limit register */
u16 sbit; /* Alarm attribute status bit */
- bool update; /* True if register needs updates */
- bool low; /* True if low limit; for limits with compare functions only */
+ bool readonly:1; /* True if the attribute is read-only */
+ bool update:1; /* True if register needs updates */
+ bool low:1; /* True if low limit; for limits with compare functions only */
const char *attr; /* Attribute name */
const char *alarm; /* Alarm attribute name */
};
@@ -1511,9 +1512,9 @@ struct pmbus_sensor_attr {
u8 nlimit; /* # of limit registers */
enum pmbus_sensor_classes class;/* sensor class */
const char *label; /* sensor label */
- bool paged; /* true if paged sensor */
- bool update; /* true if update needed */
- bool compare; /* true if compare function needed */
+ bool paged:1; /* true if paged sensor */
+ bool update:1; /* true if update needed */
+ bool compare:1; /* true if compare function needed */
u32 func; /* sensor mask */
u32 sfunc; /* sensor status mask */
int sreg; /* status register */
@@ -1544,7 +1545,7 @@ static int pmbus_add_limit_attrs(struct i2c_client *client,
curr = pmbus_add_sensor(data, name, l->attr, index,
page, 0xff, l->reg, attr->class,
attr->update || l->update,
- false, true);
+ l->readonly, true);
if (!curr)
return -ENOMEM;
if (l->sbit && (info->func[page] & attr->sfunc)) {
@@ -1707,23 +1708,28 @@ static const struct pmbus_limit_attr vin_limit_attrs[] = {
}, {
.reg = PMBUS_VIRT_READ_VIN_AVG,
.update = true,
+ .readonly = true,
.attr = "average",
}, {
.reg = PMBUS_VIRT_READ_VIN_MIN,
.update = true,
+ .readonly = true,
.attr = "lowest",
}, {
.reg = PMBUS_VIRT_READ_VIN_MAX,
.update = true,
+ .readonly = true,
.attr = "highest",
}, {
.reg = PMBUS_VIRT_RESET_VIN_HISTORY,
.attr = "reset_history",
}, {
.reg = PMBUS_MFR_VIN_MIN,
+ .readonly = true,
.attr = "rated_min",
}, {
.reg = PMBUS_MFR_VIN_MAX,
+ .readonly = true,
.attr = "rated_max",
},
};
@@ -1776,23 +1782,28 @@ static const struct pmbus_limit_attr vout_limit_attrs[] = {
}, {
.reg = PMBUS_VIRT_READ_VOUT_AVG,
.update = true,
+ .readonly = true,
.attr = "average",
}, {
.reg = PMBUS_VIRT_READ_VOUT_MIN,
.update = true,
+ .readonly = true,
.attr = "lowest",
}, {
.reg = PMBUS_VIRT_READ_VOUT_MAX,
.update = true,
+ .readonly = true,
.attr = "highest",
}, {
.reg = PMBUS_VIRT_RESET_VOUT_HISTORY,
.attr = "reset_history",
}, {
.reg = PMBUS_MFR_VOUT_MIN,
+ .readonly = true,
.attr = "rated_min",
}, {
.reg = PMBUS_MFR_VOUT_MAX,
+ .readonly = true,
.attr = "rated_max",
},
};
@@ -1852,20 +1863,24 @@ static const struct pmbus_limit_attr iin_limit_attrs[] = {
}, {
.reg = PMBUS_VIRT_READ_IIN_AVG,
.update = true,
+ .readonly = true,
.attr = "average",
}, {
.reg = PMBUS_VIRT_READ_IIN_MIN,
.update = true,
+ .readonly = true,
.attr = "lowest",
}, {
.reg = PMBUS_VIRT_READ_IIN_MAX,
.update = true,
+ .readonly = true,
.attr = "highest",
}, {
.reg = PMBUS_VIRT_RESET_IIN_HISTORY,
.attr = "reset_history",
}, {
.reg = PMBUS_MFR_IIN_MAX,
+ .readonly = true,
.attr = "rated_max",
},
};
@@ -1889,20 +1904,24 @@ static const struct pmbus_limit_attr iout_limit_attrs[] = {
}, {
.reg = PMBUS_VIRT_READ_IOUT_AVG,
.update = true,
+ .readonly = true,
.attr = "average",
}, {
.reg = PMBUS_VIRT_READ_IOUT_MIN,
.update = true,
+ .readonly = true,
.attr = "lowest",
}, {
.reg = PMBUS_VIRT_READ_IOUT_MAX,
.update = true,
+ .readonly = true,
.attr = "highest",
}, {
.reg = PMBUS_VIRT_RESET_IOUT_HISTORY,
.attr = "reset_history",
}, {
.reg = PMBUS_MFR_IOUT_MAX,
+ .readonly = true,
.attr = "rated_max",
},
};
@@ -1943,20 +1962,24 @@ static const struct pmbus_limit_attr pin_limit_attrs[] = {
}, {
.reg = PMBUS_VIRT_READ_PIN_AVG,
.update = true,
+ .readonly = true,
.attr = "average",
}, {
.reg = PMBUS_VIRT_READ_PIN_MIN,
.update = true,
+ .readonly = true,
.attr = "input_lowest",
}, {
.reg = PMBUS_VIRT_READ_PIN_MAX,
.update = true,
+ .readonly = true,
.attr = "input_highest",
}, {
.reg = PMBUS_VIRT_RESET_PIN_HISTORY,
.attr = "reset_history",
}, {
.reg = PMBUS_MFR_PIN_MAX,
+ .readonly = true,
.attr = "rated_max",
},
};
@@ -1980,20 +2003,24 @@ static const struct pmbus_limit_attr pout_limit_attrs[] = {
}, {
.reg = PMBUS_VIRT_READ_POUT_AVG,
.update = true,
+ .readonly = true,
.attr = "average",
}, {
.reg = PMBUS_VIRT_READ_POUT_MIN,
.update = true,
+ .readonly = true,
.attr = "input_lowest",
}, {
.reg = PMBUS_VIRT_READ_POUT_MAX,
.update = true,
+ .readonly = true,
.attr = "input_highest",
}, {
.reg = PMBUS_VIRT_RESET_POUT_HISTORY,
.attr = "reset_history",
}, {
.reg = PMBUS_MFR_POUT_MAX,
+ .readonly = true,
.attr = "rated_max",
},
};
@@ -2049,18 +2076,22 @@ static const struct pmbus_limit_attr temp_limit_attrs[] = {
.sbit = PB_TEMP_OT_FAULT,
}, {
.reg = PMBUS_VIRT_READ_TEMP_MIN,
+ .readonly = true,
.attr = "lowest",
}, {
.reg = PMBUS_VIRT_READ_TEMP_AVG,
+ .readonly = true,
.attr = "average",
}, {
.reg = PMBUS_VIRT_READ_TEMP_MAX,
+ .readonly = true,
.attr = "highest",
}, {
.reg = PMBUS_VIRT_RESET_TEMP_HISTORY,
.attr = "reset_history",
}, {
.reg = PMBUS_MFR_MAX_TEMP_1,
+ .readonly = true,
.attr = "rated_max",
},
};
@@ -2090,18 +2121,22 @@ static const struct pmbus_limit_attr temp_limit_attrs2[] = {
.sbit = PB_TEMP_OT_FAULT,
}, {
.reg = PMBUS_VIRT_READ_TEMP2_MIN,
+ .readonly = true,
.attr = "lowest",
}, {
.reg = PMBUS_VIRT_READ_TEMP2_AVG,
+ .readonly = true,
.attr = "average",
}, {
.reg = PMBUS_VIRT_READ_TEMP2_MAX,
+ .readonly = true,
.attr = "highest",
}, {
.reg = PMBUS_VIRT_RESET_TEMP2_HISTORY,
.attr = "reset_history",
}, {
.reg = PMBUS_MFR_MAX_TEMP_2,
+ .readonly = true,
.attr = "rated_max",
},
};
@@ -2131,6 +2166,7 @@ static const struct pmbus_limit_attr temp_limit_attrs3[] = {
.sbit = PB_TEMP_OT_FAULT,
}, {
.reg = PMBUS_MFR_MAX_TEMP_3,
+ .readonly = true,
.attr = "rated_max",
},
};
--
2.53.0