[PATCH 3/3] hwmon: (asus-ec-sensors) add water temperatures for MAXIMUS IX EXTREME
From: Remy Demangeot via B4 Relay
Date: Mon Oct 26 2026 - 05:00:05 EST
From: Remy Demangeot <remy@xxxxxxxxxxxxx>
The MAXIMUS IX EXTREME has a second EC (firmware ID "RGE2-Z270-0109"),
not handled by the ACPI EC driver, at I/O ports 0x68 (data) and 0x6c
(command/status). It uses the standard EC protocol (0x80 read, 0x81
write) and the same bank register (0xff). Its bank 1 holds the water
temperatures: WATER_IN 0x0d, WATER_OUT 0x0b, WATER_IN2 0x13 and
WATER_OUT2 0x11, as signed degrees Celsius with -60 for an absent
probe. Water_In and Water_Out are at the same offsets as on the AMD
400-series boards.
Describe registers of the second EC by setting ASUS_EC2_BANK_FLAG in
the sensor bank. Banks are sorted, so such registers are read last;
the second EC bank is saved and restored like the first one, under the
same hardware access mutex. The I/O ports are only requested for
boards using these sensors.
Add Water_In 2 and Water_Out 2 sensors and enable the four water
temperatures for the board. Readings match HWiNFO 8.54 on the same
machine.
Signed-off-by: Remy Demangeot <remy@xxxxxxxxxxxxx>
---
drivers/hwmon/asus-ec-sensors.c | 145 +++++++++++++++++++++++++++++++++++++---
1 file changed, 136 insertions(+), 9 deletions(-)
diff --git a/drivers/hwmon/asus-ec-sensors.c b/drivers/hwmon/asus-ec-sensors.c
index 11dd7f587530d640b6ccc9b7952dc9da47e11c19..c1969169de6531c11a4c3485eafd54af97874991 100644
--- a/drivers/hwmon/asus-ec-sensors.c
+++ b/drivers/hwmon/asus-ec-sensors.c
@@ -26,7 +26,10 @@
#include <linux/dev_printk.h>
#include <linux/dmi.h>
#include <linux/hwmon.h>
+#include <linux/delay.h>
#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/module.h>
@@ -45,6 +48,21 @@ static char *mutex_path_override;
* group of registers reports (e.g. one of the fans of the fan extension card).
*/
#define ASUS_EC_SELECT_REGISTER 0x43
+
+/*
+ * Some boards have a second EC, not handled by the ACPI EC driver, at these
+ * I/O ports. It uses the standard EC protocol and the same bank register.
+ * Its registers are described by sensors whose bank is ASUS_EC2_BANK(n).
+ */
+#define ASUS_EC2_DATA_PORT 0x68
+#define ASUS_EC2_CMD_PORT 0x6c
+#define ASUS_EC2_BANK_FLAG 0x80
+#define ASUS_EC2_BANK(bank) (ASUS_EC2_BANK_FLAG | (bank))
+#define ASUS_EC2_STATUS_OBF 0x01
+#define ASUS_EC2_STATUS_IBF 0x02
+#define ASUS_EC2_CMD_READ 0x80
+#define ASUS_EC2_CMD_WRITE 0x81
+#define ASUS_EC2_TIMEOUT_US 20000
#define SENSOR_LABEL_LEN 16
/*
@@ -176,6 +194,10 @@ enum ec_sensors {
ec_sensor_fan_ext_1,
ec_sensor_fan_ext_2,
ec_sensor_fan_ext_3,
+ /* "Water_In 2" temperature sensor reading [℃] */
+ ec_sensor_temp_water_in_2,
+ /* "Water_Out 2" temperature sensor reading [℃] */
+ ec_sensor_temp_water_out_2,
};
#define SENSOR_TEMP_CHIPSET BIT(ec_sensor_temp_chipset)
@@ -208,6 +230,8 @@ enum ec_sensors {
#define SENSOR_FAN_EXT_1 BIT(ec_sensor_fan_ext_1)
#define SENSOR_FAN_EXT_2 BIT(ec_sensor_fan_ext_2)
#define SENSOR_FAN_EXT_3 BIT(ec_sensor_fan_ext_3)
+#define SENSOR_TEMP_WATER_IN_2 BIT(ec_sensor_temp_water_in_2)
+#define SENSOR_TEMP_WATER_OUT_2 BIT(ec_sensor_temp_water_out_2)
/*
* The values for temperature sensor readings without physical sensors connected.
@@ -221,7 +245,8 @@ static const s32 environment_temp_sensors =
SENSOR_TEMP_WATER_IN | SENSOR_TEMP_WATER_OUT |
SENSOR_TEMP_WATER_BLOCK_IN | SENSOR_TEMP_WATER_BLOCK_OUT |
SENSOR_TEMP_T_SENSOR_2 | SENSOR_TEMP_SENSOR_EXTRA_1 |
- SENSOR_TEMP_SENSOR_EXTRA_2 | SENSOR_TEMP_SENSOR_EXTRA_3;
+ SENSOR_TEMP_SENSOR_EXTRA_2 | SENSOR_TEMP_SENSOR_EXTRA_3 |
+ SENSOR_TEMP_WATER_IN_2 | SENSOR_TEMP_WATER_OUT_2;
enum board_family {
family_unknown,
@@ -397,6 +422,14 @@ static const struct ec_sensor_info sensors_family_intel_200[] = {
EC_SENSOR_SELECT("EXT_FAN2", hwmon_fan, 2, 0x00, 0x57, 0x0b),
[ec_sensor_fan_ext_3] =
EC_SENSOR_SELECT("EXT_FAN3", hwmon_fan, 2, 0x00, 0x57, 0x0c),
+ [ec_sensor_temp_water_out] =
+ EC_SENSOR("Water_Out", hwmon_temp, 1, ASUS_EC2_BANK(0x01), 0x0b),
+ [ec_sensor_temp_water_in] =
+ EC_SENSOR("Water_In", hwmon_temp, 1, ASUS_EC2_BANK(0x01), 0x0d),
+ [ec_sensor_temp_water_out_2] =
+ EC_SENSOR("Water_Out 2", hwmon_temp, 1, ASUS_EC2_BANK(0x01), 0x11),
+ [ec_sensor_temp_water_in_2] =
+ EC_SENSOR("Water_In 2", hwmon_temp, 1, ASUS_EC2_BANK(0x01), 0x13),
};
static const struct ec_sensor_info sensors_family_intel_300[] = {
@@ -561,7 +594,9 @@ static const struct ec_board_info board_info_maximus_ix_extreme = {
.sensors = SENSOR_TEMP_CHIPSET | SENSOR_TEMP_T_SENSOR |
SENSOR_TEMP_VRM | SENSOR_TEMP_SENSOR_EXTRA_1 |
SENSOR_TEMP_SENSOR_EXTRA_2 | SENSOR_TEMP_SENSOR_EXTRA_3 |
- SENSOR_FAN_EXT_1 | SENSOR_FAN_EXT_2 | SENSOR_FAN_EXT_3,
+ SENSOR_FAN_EXT_1 | SENSOR_FAN_EXT_2 | SENSOR_FAN_EXT_3 |
+ SENSOR_SET_TEMP_WATER | SENSOR_TEMP_WATER_IN_2 |
+ SENSOR_TEMP_WATER_OUT_2,
.mutex_path = ASUS_HW_ACCESS_MUTEX_SB_PCI0_LPCB_SIO1_MUT0,
.family = family_intel_200_series,
};
@@ -1263,15 +1298,84 @@ static int setup_lock_data(struct device *dev)
return 0;
}
+static int asus_ec2_wait(bool want_obf)
+{
+ unsigned int t;
+ u8 status;
+
+ for (t = 0; t < ASUS_EC2_TIMEOUT_US; t += 10) {
+ status = inb(ASUS_EC2_CMD_PORT);
+ if (want_obf ? (status & ASUS_EC2_STATUS_OBF) :
+ !(status & ASUS_EC2_STATUS_IBF))
+ return 0;
+ udelay(10);
+ }
+ return -ETIMEDOUT;
+}
+
+static int asus_ec2_read(u8 index, u8 *val)
+{
+ int status;
+
+ /* drop a stale byte left in the output buffer */
+ if (inb(ASUS_EC2_CMD_PORT) & ASUS_EC2_STATUS_OBF)
+ inb(ASUS_EC2_DATA_PORT);
+ status = asus_ec2_wait(false);
+ if (status)
+ return status;
+ outb(ASUS_EC2_CMD_READ, ASUS_EC2_CMD_PORT);
+ status = asus_ec2_wait(false);
+ if (status)
+ return status;
+ outb(index, ASUS_EC2_DATA_PORT);
+ status = asus_ec2_wait(true);
+ if (status)
+ return status;
+ *val = inb(ASUS_EC2_DATA_PORT);
+ return 0;
+}
+
+static int asus_ec2_write(u8 index, u8 val)
+{
+ int status;
+
+ status = asus_ec2_wait(false);
+ if (status)
+ return status;
+ outb(ASUS_EC2_CMD_WRITE, ASUS_EC2_CMD_PORT);
+ status = asus_ec2_wait(false);
+ if (status)
+ return status;
+ outb(index, ASUS_EC2_DATA_PORT);
+ status = asus_ec2_wait(false);
+ if (status)
+ return status;
+ outb(val, ASUS_EC2_DATA_PORT);
+ return asus_ec2_wait(false);
+}
+
+/* @bank may carry ASUS_EC2_BANK_FLAG to address the second EC */
+static int asus_ec_read_byte(u8 bank, u8 index, u8 *val)
+{
+ if (bank & ASUS_EC2_BANK_FLAG)
+ return asus_ec2_read(index, val);
+ return ec_read(index, val);
+}
+
static int asus_ec_bank_switch(u8 bank, u8 *old)
{
int status = 0;
if (old) {
- status = ec_read(ASUS_EC_BANK_REGISTER, old);
+ status = asus_ec_read_byte(bank, ASUS_EC_BANK_REGISTER, old);
+ if (!status)
+ *old |= bank & ASUS_EC2_BANK_FLAG;
}
if (status || (old && (*old == bank)))
return status;
+ if (bank & ASUS_EC2_BANK_FLAG)
+ return asus_ec2_write(ASUS_EC_BANK_REGISTER,
+ bank & ~ASUS_EC2_BANK_FLAG);
return ec_write(ASUS_EC_BANK_REGISTER, bank);
}
@@ -1279,8 +1383,8 @@ static int asus_ec_block_read(const struct device *dev,
struct ec_sensors_data *ec)
{
int ireg, ibank, status;
- u8 bank, reg_bank, prev_bank, select, prev_select;
- bool select_saved;
+ u8 bank, reg_bank, prev_bank, prev_bank2, select, prev_select;
+ bool select_saved, ec2_used = false;
bank = 0;
status = asus_ec_bank_switch(bank, &prev_bank);
@@ -1299,7 +1403,14 @@ static int asus_ec_block_read(const struct device *dev,
for (ibank = 0; ibank < ec->nr_banks; ibank++) {
if (bank != ec->banks[ibank]) {
bank = ec->banks[ibank];
- if (asus_ec_bank_switch(bank, NULL)) {
+ /* first bank of the second EC: save its bank too */
+ if ((bank & ASUS_EC2_BANK_FLAG) && !ec2_used) {
+ if (asus_ec_bank_switch(bank, &prev_bank2)) {
+ dev_warn(dev, "second EC bank switch failed");
+ break;
+ }
+ ec2_used = true;
+ } else if (asus_ec_bank_switch(bank, NULL)) {
dev_warn(dev, "EC bank switch to %d failed",
bank);
break;
@@ -1312,7 +1423,7 @@ static int asus_ec_block_read(const struct device *dev,
continue;
}
select = register_select(ec->registers[ireg]);
- if (select) {
+ if (select && !(bank & ASUS_EC2_BANK_FLAG)) {
if (!select_saved) {
if (ec_read(ASUS_EC_SELECT_REGISTER,
&prev_select))
@@ -1322,8 +1433,9 @@ static int asus_ec_block_read(const struct device *dev,
if (ec_write(ASUS_EC_SELECT_REGISTER, select))
continue;
}
- ec_read(register_index(ec->registers[ireg]),
- ec->read_buffer + ireg);
+ asus_ec_read_byte(bank,
+ register_index(ec->registers[ireg]),
+ ec->read_buffer + ireg);
}
/* restore the selector while still in its bank */
if (select_saved &&
@@ -1331,6 +1443,9 @@ static int asus_ec_block_read(const struct device *dev,
dev_warn(dev, "EC selector restore failed");
}
+ if (ec2_used && asus_ec_bank_switch(prev_bank2, NULL))
+ dev_warn(dev, "second EC bank restore failed");
+
status = asus_ec_bank_switch(prev_bank, NULL);
return status;
}
@@ -1612,6 +1727,18 @@ static int asus_ec_probe(struct platform_device *pdev)
}
setup_sensor_data(ec_data);
+
+ /* banks are sorted: the second EC, if used, comes last */
+ if (ec_data->nr_banks &&
+ (ec_data->banks[ec_data->nr_banks - 1] & ASUS_EC2_BANK_FLAG)) {
+ if (!devm_request_region(dev, ASUS_EC2_DATA_PORT, 1,
+ dev_name(dev)) ||
+ !devm_request_region(dev, ASUS_EC2_CMD_PORT, 1,
+ dev_name(dev))) {
+ dev_err(dev, "I/O ports of the second EC are busy");
+ return -EBUSY;
+ }
+ }
ec_data->registers = devm_kcalloc(dev, ec_data->nr_registers,
sizeof(*ec_data->registers), GFP_KERNEL);
ec_data->read_buffer = devm_kcalloc(dev, ec_data->nr_registers,
--
2.47.3