* [PATCH AUTOSEL 5.12 60/80] hwmon: (max31790) Report correct current pwm duty cycles
[not found] <20210704230616.1489200-1-sashal@kernel.org>
@ 2021-07-04 23:05 ` Sasha Levin
2021-07-04 23:05 ` [PATCH AUTOSEL 5.12 61/80] hwmon: (max31790) Fix pwmX_enable attributes Sasha Levin
1 sibling, 0 replies; 2+ messages in thread
From: Sasha Levin @ 2021-07-04 23:05 UTC (permalink / raw
To: linux-kernel, stable
Cc: Guenter Roeck, Jan Kundrát, Václav Kubernát,
Václav Kubernát, Sasha Levin, linux-hwmon, linux-doc
From: Guenter Roeck <linux@roeck-us.net>
[ Upstream commit 897f6339893b741a5d68ae8e2475df65946041c2 ]
The MAX31790 has two sets of registers for pwm duty cycles, one to request
a duty cycle and one to read the actual current duty cycle. Both do not
have to be the same.
When reporting the pwm duty cycle to the user, the actual pwm duty cycle
from pwm duty cycle registers needs to be reported. When setting it, the
pwm target duty cycle needs to be written. Since we don't know the actual
pwm duty cycle after a target pwm duty cycle has been written, set the
valid flag to false to indicate that actual pwm duty cycle should be read
from the chip instead of using cached values.
Cc: Jan Kundrát <jan.kundrat@cesnet.cz>
Cc: Václav Kubernát <kubernat@cesnet.cz>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Václav Kubernát <kubernat@ceesnet.cz>
Reviewed-by: Jan Kundrát <jan.kundrat@cesnet.cz>
Link: https://lore.kernel.org/r/20210526154022.3223012-3-linux@roeck-us.net
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
Documentation/hwmon/max31790.rst | 3 ++-
drivers/hwmon/max31790.c | 6 +++---
2 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/Documentation/hwmon/max31790.rst b/Documentation/hwmon/max31790.rst
index f301385d8cef..54ff0f49e28f 100644
--- a/Documentation/hwmon/max31790.rst
+++ b/Documentation/hwmon/max31790.rst
@@ -39,5 +39,6 @@ fan[1-12]_input RO fan tachometer speed in RPM
fan[1-12]_fault RO fan experienced fault
fan[1-6]_target RW desired fan speed in RPM
pwm[1-6]_enable RW regulator mode, 0=disabled, 1=manual mode, 2=rpm mode
-pwm[1-6] RW fan target duty cycle (0-255)
+pwm[1-6] RW read: current pwm duty cycle,
+ write: target pwm duty cycle (0-255)
================== === =======================================================
diff --git a/drivers/hwmon/max31790.c b/drivers/hwmon/max31790.c
index 86e6c71db685..8ad7a45bfe68 100644
--- a/drivers/hwmon/max31790.c
+++ b/drivers/hwmon/max31790.c
@@ -104,7 +104,7 @@ static struct max31790_data *max31790_update_device(struct device *dev)
data->tach[NR_CHANNEL + i] = rv;
} else {
rv = i2c_smbus_read_word_swapped(client,
- MAX31790_REG_PWMOUT(i));
+ MAX31790_REG_PWM_DUTY_CYCLE(i));
if (rv < 0)
goto abort;
data->pwm[i] = rv;
@@ -299,10 +299,10 @@ static int max31790_write_pwm(struct device *dev, u32 attr, int channel,
err = -EINVAL;
break;
}
- data->pwm[channel] = val << 8;
+ data->valid = false;
err = i2c_smbus_write_word_swapped(client,
MAX31790_REG_PWMOUT(channel),
- data->pwm[channel]);
+ val << 8);
break;
case hwmon_pwm_enable:
fan_config = data->fan_config[channel];
--
2.30.2
^ permalink raw reply related [flat|nested] 2+ messages in thread
* [PATCH AUTOSEL 5.12 61/80] hwmon: (max31790) Fix pwmX_enable attributes
[not found] <20210704230616.1489200-1-sashal@kernel.org>
2021-07-04 23:05 ` [PATCH AUTOSEL 5.12 60/80] hwmon: (max31790) Report correct current pwm duty cycles Sasha Levin
@ 2021-07-04 23:05 ` Sasha Levin
1 sibling, 0 replies; 2+ messages in thread
From: Sasha Levin @ 2021-07-04 23:05 UTC (permalink / raw
To: linux-kernel, stable
Cc: Guenter Roeck, Jan Kundrát, Václav Kubernát,
Sasha Levin, linux-hwmon, linux-doc
From: Guenter Roeck <linux@roeck-us.net>
[ Upstream commit 148c847c9e5a54b99850617bf9c143af9a344f92 ]
pwmX_enable supports three possible values:
0: Fan control disabled. Duty cycle is fixed to 0%
1: Fan control enabled, pwm mode. Duty cycle is determined by
values written into Target Duty Cycle registers.
2: Fan control enabled, rpm mode
Duty cycle is adjusted such that fan speed matches
the values in Target Count registers
The current code does not do this; instead, it mixes pwm control
configuration with fan speed monitoring configuration. Worse, it
reports that pwm control would be disabled (pwmX_enable==0) when
it is in fact enabled in pwm mode. Part of the problem may be that
the chip sets the "TACH input enable" bit on its own whenever the
mode bit is set to RPM mode, but that doesn't mean that "TACH input
enable" accurately reflects the pwm mode.
Fix it up and only handle pwm control with the pwmX_enable attributes.
In the documentation, clarify that disabling pwm control (pwmX_enable=0)
sets the pwm duty cycle to 0%. In the code, explain why TACH_INPUT_EN
is set together with RPM_MODE.
While at it, only update the configuration register if the configuration
has changed, and only update the cached configuration if updating the
chip configuration was successful.
Cc: Jan Kundrát <jan.kundrat@cesnet.cz>
Cc: Václav Kubernát <kubernat@cesnet.cz>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Václav Kubernát <kubernat@cesnet.cz>
Reviewed-by: Jan Kundrát <jan.kundrat@cesnet.cz>
Link: https://lore.kernel.org/r/20210526154022.3223012-4-linux@roeck-us.net
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
Documentation/hwmon/max31790.rst | 2 +-
drivers/hwmon/max31790.c | 41 ++++++++++++++++++++------------
2 files changed, 27 insertions(+), 16 deletions(-)
diff --git a/Documentation/hwmon/max31790.rst b/Documentation/hwmon/max31790.rst
index 54ff0f49e28f..7b097c3b9b90 100644
--- a/Documentation/hwmon/max31790.rst
+++ b/Documentation/hwmon/max31790.rst
@@ -38,7 +38,7 @@ Sysfs entries
fan[1-12]_input RO fan tachometer speed in RPM
fan[1-12]_fault RO fan experienced fault
fan[1-6]_target RW desired fan speed in RPM
-pwm[1-6]_enable RW regulator mode, 0=disabled, 1=manual mode, 2=rpm mode
+pwm[1-6]_enable RW regulator mode, 0=disabled (duty cycle=0%), 1=manual mode, 2=rpm mode
pwm[1-6] RW read: current pwm duty cycle,
write: target pwm duty cycle (0-255)
================== === =======================================================
diff --git a/drivers/hwmon/max31790.c b/drivers/hwmon/max31790.c
index 8ad7a45bfe68..76aa96f5b984 100644
--- a/drivers/hwmon/max31790.c
+++ b/drivers/hwmon/max31790.c
@@ -27,6 +27,7 @@
/* Fan Config register bits */
#define MAX31790_FAN_CFG_RPM_MODE 0x80
+#define MAX31790_FAN_CFG_CTRL_MON 0x10
#define MAX31790_FAN_CFG_TACH_INPUT_EN 0x08
#define MAX31790_FAN_CFG_TACH_INPUT 0x01
@@ -271,12 +272,12 @@ static int max31790_read_pwm(struct device *dev, u32 attr, int channel,
*val = data->pwm[channel] >> 8;
return 0;
case hwmon_pwm_enable:
- if (fan_config & MAX31790_FAN_CFG_RPM_MODE)
+ if (fan_config & MAX31790_FAN_CFG_CTRL_MON)
+ *val = 0;
+ else if (fan_config & MAX31790_FAN_CFG_RPM_MODE)
*val = 2;
- else if (fan_config & MAX31790_FAN_CFG_TACH_INPUT_EN)
- *val = 1;
else
- *val = 0;
+ *val = 1;
return 0;
default:
return -EOPNOTSUPP;
@@ -307,23 +308,33 @@ static int max31790_write_pwm(struct device *dev, u32 attr, int channel,
case hwmon_pwm_enable:
fan_config = data->fan_config[channel];
if (val == 0) {
- fan_config &= ~(MAX31790_FAN_CFG_TACH_INPUT_EN |
- MAX31790_FAN_CFG_RPM_MODE);
+ fan_config |= MAX31790_FAN_CFG_CTRL_MON;
+ /*
+ * Disable RPM mode; otherwise disabling fan speed
+ * monitoring is not possible.
+ */
+ fan_config &= ~MAX31790_FAN_CFG_RPM_MODE;
} else if (val == 1) {
- fan_config = (fan_config |
- MAX31790_FAN_CFG_TACH_INPUT_EN) &
- ~MAX31790_FAN_CFG_RPM_MODE;
+ fan_config &= ~(MAX31790_FAN_CFG_CTRL_MON | MAX31790_FAN_CFG_RPM_MODE);
} else if (val == 2) {
- fan_config |= MAX31790_FAN_CFG_TACH_INPUT_EN |
- MAX31790_FAN_CFG_RPM_MODE;
+ fan_config &= ~MAX31790_FAN_CFG_CTRL_MON;
+ /*
+ * The chip sets MAX31790_FAN_CFG_TACH_INPUT_EN on its
+ * own if MAX31790_FAN_CFG_RPM_MODE is set.
+ * Do it here as well to reflect the actual register
+ * value in the cache.
+ */
+ fan_config |= (MAX31790_FAN_CFG_RPM_MODE | MAX31790_FAN_CFG_TACH_INPUT_EN);
} else {
err = -EINVAL;
break;
}
- data->fan_config[channel] = fan_config;
- err = i2c_smbus_write_byte_data(client,
- MAX31790_REG_FAN_CONFIG(channel),
- fan_config);
+ if (fan_config != data->fan_config[channel]) {
+ err = i2c_smbus_write_byte_data(client, MAX31790_REG_FAN_CONFIG(channel),
+ fan_config);
+ if (!err)
+ data->fan_config[channel] = fan_config;
+ }
break;
default:
err = -EOPNOTSUPP;
--
2.30.2
^ permalink raw reply related [flat|nested] 2+ messages in thread
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[not found] <20210704230616.1489200-1-sashal@kernel.org>
2021-07-04 23:05 ` [PATCH AUTOSEL 5.12 60/80] hwmon: (max31790) Report correct current pwm duty cycles Sasha Levin
2021-07-04 23:05 ` [PATCH AUTOSEL 5.12 61/80] hwmon: (max31790) Fix pwmX_enable attributes Sasha Levin
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