From: Sung-Chi Li <lschyi@chromium.org>
Register fans connected under EC as thermal cooling devices as well, so
these fans can then work with the thermal framework.
During the driver probing phase, we will also try to register each fan
as a thermal cooling device based on previous probe result (whether the
there are fans connected on that channel, and whether EC supports fan
control). The basic get max state, get current state, and set current
state methods are then implemented as well.
Signed-off-by: Sung-Chi Li <lschyi@chromium.org>
---
Documentation/hwmon/cros_ec_hwmon.rst | 2 +
drivers/hwmon/cros_ec_hwmon.c | 72 +++++++++++++++++++++++++++++++++++
2 files changed, 74 insertions(+)
diff --git a/Documentation/hwmon/cros_ec_hwmon.rst b/Documentation/hwmon/cros_ec_hwmon.rst
index 5b802be120438732529c3d25b1afa8b4ee353305..82c75bdaf912a116eaafa3149dc1252b3f7007d2 100644
--- a/Documentation/hwmon/cros_ec_hwmon.rst
+++ b/Documentation/hwmon/cros_ec_hwmon.rst
@@ -27,3 +27,5 @@ Fan and temperature readings are supported. PWM fan control is also supported if
the EC also supports setting fan PWM values and fan mode. Note that EC will
switch fan control mode back to auto when suspended. This driver will restore
the fan state before suspended.
+If a fan is controllable, this driver will register that fan as a cooling device
+in the thermal framework as well.
diff --git a/drivers/hwmon/cros_ec_hwmon.c b/drivers/hwmon/cros_ec_hwmon.c
index 1139074d3eb003ee72bbe54a954647ced40f6d21..c38c61bba431fe25322793f7dd5db59fcc95daaf 100644
--- a/drivers/hwmon/cros_ec_hwmon.c
+++ b/drivers/hwmon/cros_ec_hwmon.c
@@ -12,6 +12,7 @@
#include <linux/platform_device.h>
#include <linux/platform_data/cros_ec_commands.h>
#include <linux/platform_data/cros_ec_proto.h>
+#include <linux/thermal.h>
#include <linux/types.h>
#include <linux/units.h>
@@ -30,6 +31,11 @@ struct cros_ec_hwmon_priv {
u8 manual_fan_pwm_values[EC_FAN_SPEED_ENTRIES];
};
+struct cros_ec_hwmon_cooling_priv {
+ struct cros_ec_hwmon_priv *hwmon_priv;
+ u8 index;
+};
+
static int cros_ec_hwmon_read_fan_speed(struct cros_ec_device *cros_ec, u8 index, u16 *speed)
{
int ret;
@@ -340,6 +346,38 @@ static const struct hwmon_channel_info * const cros_ec_hwmon_info[] = {
NULL
};
+static int
+cros_ec_hwmon_cooling_get_max_state(struct thermal_cooling_device *cdev,
+ unsigned long *val)
+{
+ *val = 100;
+ return 0;
+}
+
+static int
+cros_ec_hwmon_cooling_get_cur_state(struct thermal_cooling_device *cdev,
+ unsigned long *val)
+{
+ const struct cros_ec_hwmon_cooling_priv *priv = cdev->devdata;
+ u8 raw_val;
+ int ret = cros_ec_hwmon_read_pwm_raw_value(priv->hwmon_priv->cros_ec,
+ priv->index, &raw_val);
+
+ if (ret == 0)
+ *val = raw_val;
+ return ret;
+}
+
+static int
+cros_ec_hwmon_cooling_set_cur_state(struct thermal_cooling_device *cdev,
+ unsigned long val)
+{
+ const struct cros_ec_hwmon_cooling_priv *priv = cdev->devdata;
+
+ return cros_ec_hwmon_set_pwm_raw_value(priv->hwmon_priv, priv->index,
+ val);
+}
+
static const struct hwmon_ops cros_ec_hwmon_ops = {
.read = cros_ec_hwmon_read,
.read_string = cros_ec_hwmon_read_string,
@@ -347,6 +385,12 @@ static const struct hwmon_ops cros_ec_hwmon_ops = {
.is_visible = cros_ec_hwmon_is_visible,
};
+static const struct thermal_cooling_device_ops cros_ec_thermal_cooling_ops = {
+ .get_max_state = cros_ec_hwmon_cooling_get_max_state,
+ .get_cur_state = cros_ec_hwmon_cooling_get_cur_state,
+ .set_cur_state = cros_ec_hwmon_cooling_set_cur_state,
+};
+
static const struct hwmon_chip_info cros_ec_hwmon_chip_info = {
.ops = &cros_ec_hwmon_ops,
.info = cros_ec_hwmon_info,
@@ -421,6 +465,33 @@ cros_ec_hwmon_probe_fan_control_supported(struct cros_ec_hwmon_priv *priv)
priv->fan_control_supported = true;
}
+static void
+cros_ec_hwmon_register_fan_cooling_devices(struct device *dev,
+ struct cros_ec_hwmon_priv *priv)
+{
+ struct cros_ec_hwmon_cooling_priv *cpriv;
+ size_t i;
+
+ if (!priv->fan_control_supported)
+ return;
+
+ for (i = 0; i < EC_FAN_SPEED_ENTRIES; i++) {
+ if (!(priv->usable_fans & BIT(i)))
+ continue;
+
+ cpriv = devm_kzalloc(dev, sizeof(*cpriv), GFP_KERNEL);
+ if (!cpriv)
+ return;
+
+ cpriv->hwmon_priv = priv;
+ cpriv->index = i;
+ devm_thermal_of_cooling_device_register(
+ dev, NULL,
+ devm_kasprintf(dev, GFP_KERNEL, "cros-ec-fan%zu", i),
+ cpriv, &cros_ec_thermal_cooling_ops);
+ }
+}
+
static int cros_ec_hwmon_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
@@ -452,6 +523,7 @@ static int cros_ec_hwmon_probe(struct platform_device *pdev)
cros_ec_hwmon_probe_temp_sensors(dev, priv, thermal_version);
cros_ec_hwmon_probe_fans(priv);
cros_ec_hwmon_probe_fan_control_supported(priv);
+ cros_ec_hwmon_register_fan_cooling_devices(dev, priv);
platform_priv->hwmon_dev = devm_hwmon_device_register_with_info(
dev, "cros_ec", priv, &cros_ec_hwmon_chip_info, NULL);
--
2.49.0.901.g37484f566f-googOn 2025-04-29 16:14:23+0800, Sung-Chi Li via B4 Relay wrote: > From: Sung-Chi Li <lschyi@chromium.org> > > Register fans connected under EC as thermal cooling devices as well, so > these fans can then work with the thermal framework. > > During the driver probing phase, we will also try to register each fan > as a thermal cooling device based on previous probe result (whether the > there are fans connected on that channel, and whether EC supports fan > control). The basic get max state, get current state, and set current > state methods are then implemented as well. There is also HWMON_C_REGISTER_TZ, however it depends on OF. But this patch looks very generic, so maybe it makes sense to implement it in the hwmon core. > Signed-off-by: Sung-Chi Li <lschyi@chromium.org> > --- > Documentation/hwmon/cros_ec_hwmon.rst | 2 + > drivers/hwmon/cros_ec_hwmon.c | 72 +++++++++++++++++++++++++++++++++++ > 2 files changed, 74 insertions(+) <snip>
On Tue, Apr 29, 2025 at 10:45:56PM +0200, Thomas Weißschuh wrote: > On 2025-04-29 16:14:23+0800, Sung-Chi Li via B4 Relay wrote: > > From: Sung-Chi Li <lschyi@chromium.org> > > > > Register fans connected under EC as thermal cooling devices as well, so > > these fans can then work with the thermal framework. > > > > During the driver probing phase, we will also try to register each fan > > as a thermal cooling device based on previous probe result (whether the > > there are fans connected on that channel, and whether EC supports fan > > control). The basic get max state, get current state, and set current > > state methods are then implemented as well. > > There is also HWMON_C_REGISTER_TZ, however it depends on OF. > But this patch looks very generic, so maybe it makes sense to implement > it in the hwmon core. > Hi, the HWMON_C_REGISTER_TZ is for registering a thermal sensor, and here I registered it as thermal cooling devices, so they are different. I followed other hwmon drivers: - gpio-fan.c - aspeed-pwm-tacho.c - max6650.c - qnap-mcu-hwmon.c - ... . These hwmon drivers also manually registered other cooling devices, and that makes sense to me, so I think it is good to just register cooling devices rather than make big changes to hwmon core. > > Signed-off-by: Sung-Chi Li <lschyi@chromium.org> > > --- > > Documentation/hwmon/cros_ec_hwmon.rst | 2 + > > drivers/hwmon/cros_ec_hwmon.c | 72 +++++++++++++++++++++++++++++++++++ > > 2 files changed, 74 insertions(+) > > <snip>
On 2025-04-30 09:51:03+0800, Sung-Chi Li wrote: > On Tue, Apr 29, 2025 at 10:45:56PM +0200, Thomas Weißschuh wrote: > > On 2025-04-29 16:14:23+0800, Sung-Chi Li via B4 Relay wrote: > > > From: Sung-Chi Li <lschyi@chromium.org> > > > > > > Register fans connected under EC as thermal cooling devices as well, so > > > these fans can then work with the thermal framework. > > > > > > During the driver probing phase, we will also try to register each fan > > > as a thermal cooling device based on previous probe result (whether the > > > there are fans connected on that channel, and whether EC supports fan > > > control). The basic get max state, get current state, and set current > > > state methods are then implemented as well. > > > > There is also HWMON_C_REGISTER_TZ, however it depends on OF. > > But this patch looks very generic, so maybe it makes sense to implement > > it in the hwmon core. > > > > Hi, the HWMON_C_REGISTER_TZ is for registering a thermal sensor, and here I > registered it as thermal cooling devices, so they are different. I followed > other hwmon drivers: > > - gpio-fan.c > - aspeed-pwm-tacho.c > - max6650.c > - qnap-mcu-hwmon.c > - ... Indeed, sorry. > . These hwmon drivers also manually registered other cooling devices, and that > makes sense to me, so I think it is good to just register cooling devices rather > than make big changes to hwmon core. The implementation does look like a lot of boilerplate. If Guenter doesn't chime in, let's stick with the current approach. > > > Signed-off-by: Sung-Chi Li <lschyi@chromium.org> > > > --- > > > Documentation/hwmon/cros_ec_hwmon.rst | 2 + > > > drivers/hwmon/cros_ec_hwmon.c | 72 +++++++++++++++++++++++++++++++++++ > > > 2 files changed, 74 insertions(+) > > > > <snip>
On 4/30/25 07:36, Thomas Weißschuh wrote: > On 2025-04-30 09:51:03+0800, Sung-Chi Li wrote: >> On Tue, Apr 29, 2025 at 10:45:56PM +0200, Thomas Weißschuh wrote: >>> On 2025-04-29 16:14:23+0800, Sung-Chi Li via B4 Relay wrote: >>>> From: Sung-Chi Li <lschyi@chromium.org> >>>> >>>> Register fans connected under EC as thermal cooling devices as well, so >>>> these fans can then work with the thermal framework. >>>> >>>> During the driver probing phase, we will also try to register each fan >>>> as a thermal cooling device based on previous probe result (whether the >>>> there are fans connected on that channel, and whether EC supports fan >>>> control). The basic get max state, get current state, and set current >>>> state methods are then implemented as well. >>> >>> There is also HWMON_C_REGISTER_TZ, however it depends on OF. >>> But this patch looks very generic, so maybe it makes sense to implement >>> it in the hwmon core. >>> >> >> Hi, the HWMON_C_REGISTER_TZ is for registering a thermal sensor, and here I >> registered it as thermal cooling devices, so they are different. I followed >> other hwmon drivers: >> >> - gpio-fan.c >> - aspeed-pwm-tacho.c >> - max6650.c >> - qnap-mcu-hwmon.c >> - ... > > Indeed, sorry. > >> . These hwmon drivers also manually registered other cooling devices, and that >> makes sense to me, so I think it is good to just register cooling devices rather >> than make big changes to hwmon core. > > The implementation does look like a lot of boilerplate. > If Guenter doesn't chime in, let's stick with the current approach. > Someone could make the necessary improvements to the hwmon core and clean up the drivers implementing that boilerplate today, but that should be a separate patch series, and this series should not depend on it. Patches welcome ... Thanks, Guenter
On Wed, Apr 30, 2025 at 08:38:06AM -0700, Guenter Roeck wrote: > On 4/30/25 07:36, Thomas Weißschuh wrote: > > On 2025-04-30 09:51:03+0800, Sung-Chi Li wrote: > > > On Tue, Apr 29, 2025 at 10:45:56PM +0200, Thomas Weißschuh wrote: > > > > On 2025-04-29 16:14:23+0800, Sung-Chi Li via B4 Relay wrote: > > > > > From: Sung-Chi Li <lschyi@chromium.org> > > > > > > > > > > Register fans connected under EC as thermal cooling devices as well, so > > > > > these fans can then work with the thermal framework. > > > > > > > > > > During the driver probing phase, we will also try to register each fan > > > > > as a thermal cooling device based on previous probe result (whether the > > > > > there are fans connected on that channel, and whether EC supports fan > > > > > control). The basic get max state, get current state, and set current > > > > > state methods are then implemented as well. > > > > > > > > There is also HWMON_C_REGISTER_TZ, however it depends on OF. > > > > But this patch looks very generic, so maybe it makes sense to implement > > > > it in the hwmon core. > > > > > > > > > > Hi, the HWMON_C_REGISTER_TZ is for registering a thermal sensor, and here I > > > registered it as thermal cooling devices, so they are different. I followed > > > other hwmon drivers: > > > > > > - gpio-fan.c > > > - aspeed-pwm-tacho.c > > > - max6650.c > > > - qnap-mcu-hwmon.c > > > - ... > > > > Indeed, sorry. > > > > > . These hwmon drivers also manually registered other cooling devices, and that > > > makes sense to me, so I think it is good to just register cooling devices rather > > > than make big changes to hwmon core. > > > > The implementation does look like a lot of boilerplate. > > If Guenter doesn't chime in, let's stick with the current approach. > > > > Someone could make the necessary improvements to the hwmon core and clean up the drivers > implementing that boilerplate today, but that should be a separate patch series, and this > series should not depend on it. > > Patches welcome ... > > Thanks, > Guenter > Thank you, I will first complete this series, and see how to improve hwmon core afterwards.
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