[PATCH v3 11/11] hwmon: (amc6821) Add support for pwm1_mode attribute

Guenter Roeck
2024-07-04T17:52:31Z

AMC6821 supports configuring if a fan is DC or PWM controlled.
Add support for the pwm1_mode attribute to make it runtime configurable.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
v3: Fix wrong register used when writing the attribute

v2: New patch

Documentation/hwmon/amc6821.rst | 1 +
drivers/hwmon/amc6821.c | 16 +++++++++++++++-
2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/Documentation/hwmon/amc6821.rst b/Documentation/hwmon/amc6821.rst
index 96e604c5ea8e..dbd544cd1160 100644
--- a/Documentation/hwmon/amc6821.rst
+++ b/Documentation/hwmon/amc6821.rst
@@ -58,6 +58,7 @@ pwm1_enable rw regulator mode, 1=open loop, 2=fan controlled
remote-sensor temperature,
4=fan controlled by target rpm set with
fan1_target attribute.
+pwm1_mode rw Fan duty control mode (0=DC, 1=PWM)
pwm1_auto_channels_temp ro 1 if pwm_enable==2, 3 if pwm_enable==3
pwm1_auto_point1_pwm ro Hardwired to 0, shared for both
temperature channels.
diff --git a/drivers/hwmon/amc6821.c b/drivers/hwmon/amc6821.c
index be3e590aba3d..4e3f8a6e8354 100644
--- a/drivers/hwmon/amc6821.c
+++ b/drivers/hwmon/amc6821.c
@@ -308,6 +308,12 @@ static int amc6821_pwm_read(struct device *dev, u32 attr, long *val)
break;
}
return 0;
+ case hwmon_pwm_mode:
+ err = regmap_read(regmap, AMC6821_REG_CONF2, &regval);
+ if (err)
+ return err;
+ *val = !!(regval & AMC6821_CONF2_TACH_MODE);
+ return 0;
case hwmon_pwm_auto_channels_temp:
err = regmap_read(regmap, AMC6821_REG_CONF1, &regval);
if (err)
@@ -363,6 +369,13 @@ static int amc6821_pwm_write(struct device *dev, u32 attr, long val)
return regmap_update_bits(regmap, AMC6821_REG_CONF1,
AMC6821_CONF1_FDRC0 | AMC6821_CONF1_FDRC1,
mode);
+ case hwmon_pwm_mode:
+ if (val < 0 || val > 1)
+ return -EINVAL;
+ return regmap_update_bits(regmap, AMC6821_REG_CONF2,
+ AMC6821_CONF2_TACH_MODE,
+ val ? AMC6821_CONF2_TACH_MODE : 0);
+ break;
case hwmon_pwm_input:
if (val < 0 || val > 255)
return -EINVAL;
@@ -741,6 +754,7 @@ static umode_t amc6821_is_visible(const void *data,
}
case hwmon_pwm:
switch (attr) {
+ case hwmon_pwm_mode:
case hwmon_pwm_enable:
case hwmon_pwm_input:
return 0644;
@@ -767,7 +781,7 @@ static const struct hwmon_channel_info * const amc6821_info[] = {
HWMON_F_INPUT | HWMON_F_MIN | HWMON_F_MAX |
HWMON_F_TARGET | HWMON_F_PULSES | HWMON_F_FAULT),
HWMON_CHANNEL_INFO(pwm,
- HWMON_PWM_INPUT | HWMON_PWM_ENABLE |
+ HWMON_PWM_INPUT | HWMON_PWM_ENABLE | HWMON_PWM_MODE |
HWMON_PWM_AUTO_CHANNELS_TEMP),
NULL
};
--
2.39.2