| Message ID | 20250317-extend_ec_hwmon_fan-v2-1-13670557afe5@chromium.org (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v2] hwmon: (cros_ec) Add set and get target fan RPM function | expand |
On 2025-03-17 14:40:26+0800, Sung-Chi Li wrote: > The ChromeOS embedded controller (EC) supports closed loop fan speed > control, so add the fan target attribute under hwmon framework, such > that kernel can expose reading and specifying the desired fan RPM for > fans connected to the EC. > > When probing the cros_ec hwmon module, we also check the supported > command version of setting target fan RPM. This commit implements the > version 0 of getting the target fan RPM, which can only read the target > RPM of the first fan. This commit also implements the version 0 and 1 of > setting the target fan RPM, where the version 0 only supports setting > all fan to the same RPM, while version 1 supports setting different RPM > to each fan respectively. Can you explain why this set of command compatibility was chosen? I would have expected to fully support the v1 commands and completely skip v0. > Signed-off-by: Sung-Chi Li <lschyi@chromium.org> > --- > ChromeOS embedded controller (EC) supports closed-loop fan control. We > anticipate to have the fan related control from the kernel side, so this > series register the HWMON_F_TARGET attribute, and implement the read and > write function for setting/reading the target fan RPM from the EC side. > --- > Changes in v2: > > - Squash the read, write, and register of fan target attribute to 1 > commit, as they are the same topic. > - Probe the supported command version from EC for setting the target fan > RPM, and perform the set fan target RPM based on the supported > version. > - Update the used variable type to kernel types (i.e., u32). > - Link to v1: https://lore.kernel.org/r/20250313-extend_ec_hwmon_fan-v1-0-5c566776f2c4@chromium.org > --- > drivers/hwmon/cros_ec_hwmon.c | 130 ++++++++++++++++++++++++++++++++++++++++-- > 1 file changed, 125 insertions(+), 5 deletions(-) > > diff --git a/drivers/hwmon/cros_ec_hwmon.c b/drivers/hwmon/cros_ec_hwmon.c > index 9991c3fa020ac859cbbff29dfb669e53248df885..b118a355f67d7238a6f596cf01a49d5b621b31d6 100644 > --- a/drivers/hwmon/cros_ec_hwmon.c > +++ b/drivers/hwmon/cros_ec_hwmon.c > @@ -21,6 +21,12 @@ struct cros_ec_hwmon_priv { > struct cros_ec_device *cros_ec; > const char *temp_sensor_names[EC_TEMP_SENSOR_ENTRIES + EC_TEMP_SENSOR_B_ENTRIES]; > u8 usable_fans; > + int set_fan_target_rpm_version; > +}; > + > +union ec_params_pwm_set_fan_target_rpm { > + struct ec_params_pwm_set_fan_target_rpm_v0 v0; > + struct ec_params_pwm_set_fan_target_rpm_v1 v1; > }; No need to give this union a name. It is only used once. It doesn't even have to be a union but can be two dedicated on-stack variables. > > static int cros_ec_hwmon_read_fan_speed(struct cros_ec_device *cros_ec, u8 index, u16 *speed) > @@ -36,6 +42,25 @@ static int cros_ec_hwmon_read_fan_speed(struct cros_ec_device *cros_ec, u8 index > return 0; > } > > +static int cros_ec_hwmon_read_fan_target(struct cros_ec_device *cros_ec, > + u8 index, u32 *speed) > +{ > + struct ec_response_pwm_get_fan_rpm r; > + int ret; > + > + // Currently only supports reading the first fan. > + if (index > 0) > + return -EOPNOTSUPP; This needs to be checked in is_visible(), not here. (Or only support v1 and not have the restriction) > + > + ret = cros_ec_cmd(cros_ec, 0, EC_CMD_PWM_GET_FAN_TARGET_RPM, NULL, 0, > + &r, sizeof(r)); > + if (ret < 0) > + return ret; > + > + *speed = r.rpm; Comments from v1 still apply. > + return 0; > +} > + > static int cros_ec_hwmon_read_temp(struct cros_ec_device *cros_ec, u8 index, u8 *temp) > { > unsigned int offset; > @@ -52,6 +77,49 @@ static int cros_ec_hwmon_read_temp(struct cros_ec_device *cros_ec, u8 index, u8 > return 0; > } > > +static int cros_ec_hwmon_set_fan_rpm(struct cros_ec_device *cros_ec, > + int version, u8 index, u16 val) > +{ > + union ec_params_pwm_set_fan_target_rpm req; > + int req_size; > + int ret; > + > + if (version == 0) { > + if (index != 0) > + dev_warn( > + cros_ec->dev, > + "v0 only supports setting all fan to same RPM (cannot just set idx %d), set all to %d\n", > + index, val); How important is v0 in general? > + > + req_size = sizeof(req.v0); > + req.v0.rpm = val; > + } else if (version == 1) { > + req_size = sizeof(req.v1); > + req.v1.rpm = val; > + req.v1.fan_idx = index; > + } else > + return -EOPNOTSUPP; If braces are used in the other branches, also use braces here. Also this case can never happen, remove it. > + > + ret = cros_ec_cmd(cros_ec, version, EC_CMD_PWM_SET_FAN_TARGET_RPM, &req, > + req_size, NULL, 0); > + if (ret < 0) > + return ret; > + return 0; > +} > + > +static int cros_ec_hwmon_write_fan(struct cros_ec_hwmon_priv *priv, u32 attr, > + int channel, long rpm) > +{ > + switch (attr) { > + case hwmon_fan_target: > + return cros_ec_hwmon_set_fan_rpm( > + priv->cros_ec, priv->set_fan_target_rpm_version, > + channel, rpm); > + default: > + return -EOPNOTSUPP; > + } > +} > + > static bool cros_ec_hwmon_is_error_fan(u16 speed) > { > return speed == EC_FAN_SPEED_NOT_PRESENT || speed == EC_FAN_SPEED_STALLED; > @@ -75,6 +143,7 @@ static int cros_ec_hwmon_read(struct device *dev, enum hwmon_sensor_types type, > { > struct cros_ec_hwmon_priv *priv = dev_get_drvdata(dev); > int ret = -EOPNOTSUPP; > + u32 target_rpm; > u16 speed; > u8 temp; > > @@ -91,6 +160,11 @@ static int cros_ec_hwmon_read(struct device *dev, enum hwmon_sensor_types type, > ret = cros_ec_hwmon_read_fan_speed(priv->cros_ec, channel, &speed); > if (ret == 0) > *val = cros_ec_hwmon_is_error_fan(speed); > + } else if (attr == hwmon_fan_target) { > + ret = cros_ec_hwmon_read_fan_target( > + priv->cros_ec, channel, &target_rpm); > + if (ret == 0) > + *val = target_rpm; > } > } else if (type == hwmon_temp) { > if (attr == hwmon_temp_input) { > @@ -130,8 +204,15 @@ static umode_t cros_ec_hwmon_is_visible(const void *data, enum hwmon_sensor_type > const struct cros_ec_hwmon_priv *priv = data; > > if (type == hwmon_fan) { > - if (priv->usable_fans & BIT(channel)) > + if (!(priv->usable_fans & BIT(channel))) > + return 0; > + > + switch (attr) { > + case hwmon_fan_target: > + return 0644; > + default: > return 0444; > + } > } else if (type == hwmon_temp) { > if (priv->temp_sensor_names[channel]) > return 0444; > @@ -140,13 +221,26 @@ static umode_t cros_ec_hwmon_is_visible(const void *data, enum hwmon_sensor_type > return 0; > } > > +static int cros_ec_hwmon_write(struct device *dev, enum hwmon_sensor_types type, > + u32 attr, int channel, long val) > +{ > + struct cros_ec_hwmon_priv *priv = dev_get_drvdata(dev); > + > + switch (type) { > + case hwmon_fan: > + return cros_ec_hwmon_write_fan(priv, attr, channel, val); > + default: > + return -EOPNOTSUPP; > + } > +} > + > static const struct hwmon_channel_info * const cros_ec_hwmon_info[] = { > HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ), > HWMON_CHANNEL_INFO(fan, > - HWMON_F_INPUT | HWMON_F_FAULT, > - HWMON_F_INPUT | HWMON_F_FAULT, > - HWMON_F_INPUT | HWMON_F_FAULT, > - HWMON_F_INPUT | HWMON_F_FAULT), > + HWMON_F_INPUT | HWMON_F_FAULT | HWMON_F_TARGET, > + HWMON_F_INPUT | HWMON_F_FAULT | HWMON_F_TARGET, > + HWMON_F_INPUT | HWMON_F_FAULT | HWMON_F_TARGET, > + HWMON_F_INPUT | HWMON_F_FAULT | HWMON_F_TARGET), > HWMON_CHANNEL_INFO(temp, > HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL, > HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL, > @@ -178,6 +272,7 @@ static const struct hwmon_channel_info * const cros_ec_hwmon_info[] = { > static const struct hwmon_ops cros_ec_hwmon_ops = { > .read = cros_ec_hwmon_read, > .read_string = cros_ec_hwmon_read_string, > + .write = cros_ec_hwmon_write, > .is_visible = cros_ec_hwmon_is_visible, > }; > > @@ -233,6 +328,27 @@ static void cros_ec_hwmon_probe_fans(struct cros_ec_hwmon_priv *priv) > } > } > > +static int cros_ec_hwmon_probe_fan_target_cmd_version(struct cros_ec_hwmon_priv *priv) > +{ > + struct ec_params_get_cmd_versions_v1 params = { > + .cmd = EC_CMD_PWM_SET_FAN_TARGET_RPM, > + }; > + struct ec_response_get_cmd_versions response; > + int ret; > + > + ret = cros_ec_cmd(priv->cros_ec, 1, EC_CMD_GET_CMD_VERSIONS, ¶ms, > + sizeof(params), &response, sizeof(response)); cros_ec_get_cmd_versions(). > + if (ret < 0) { > + dev_err(priv->cros_ec->dev, > + "error getting target fan RPM set command version: %d\n", ret); > + return ret; > + } If neither v0 nor v1 are supported, this will completely prevent the driver from being probed. Is this intentional? > + > + priv->set_fan_target_rpm_version = (response.version_mask & EC_VER_MASK(1)) ? 1 : 0; > + > + return 0; > +} > + > static int cros_ec_hwmon_probe(struct platform_device *pdev) > { > struct device *dev = &pdev->dev; > @@ -260,6 +376,10 @@ 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); > > + ret = cros_ec_hwmon_probe_fan_target_cmd_version(priv); > + if (ret < 0) > + return ret; > + > hwmon_dev = devm_hwmon_device_register_with_info(dev, "cros_ec", priv, > &cros_ec_hwmon_chip_info, NULL); > > > --- > base-commit: 80e54e84911a923c40d7bee33a34c1b4be148d7a > change-id: 20250313-extend_ec_hwmon_fan-a5f59aab2cb3 > > Best regards, > -- > Sung-Chi Li <lschyi@chromium.org> >
On Mon, Mar 17, 2025 at 06:46:32PM +0100, Thomas Weißschuh wrote: > On 2025-03-17 14:40:26+0800, Sung-Chi Li wrote: > > The ChromeOS embedded controller (EC) supports closed loop fan speed > > control, so add the fan target attribute under hwmon framework, such > > that kernel can expose reading and specifying the desired fan RPM for > > fans connected to the EC. > > > > When probing the cros_ec hwmon module, we also check the supported > > command version of setting target fan RPM. This commit implements the > > version 0 of getting the target fan RPM, which can only read the target > > RPM of the first fan. This commit also implements the version 0 and 1 of > > setting the target fan RPM, where the version 0 only supports setting > > all fan to the same RPM, while version 1 supports setting different RPM > > to each fan respectively. > > Can you explain why this set of command compatibility was chosen? > I would have expected to fully support the v1 commands and completely > skip v0. > I thought it would be better to support all current existing functionality. Currently, there are v0 and v1 for setting, and only v0 for getting. However, I think we will only care about v1 for setting (there is only v0 for getting), so combine with another comment for the importance of v0, I think I'll only support setting for v1. > > Signed-off-by: Sung-Chi Li <lschyi@chromium.org> > > --- > > ChromeOS embedded controller (EC) supports closed-loop fan control. We > > anticipate to have the fan related control from the kernel side, so this > > series register the HWMON_F_TARGET attribute, and implement the read and > > write function for setting/reading the target fan RPM from the EC side. > > --- > > Changes in v2: > > > > - Squash the read, write, and register of fan target attribute to 1 > > commit, as they are the same topic. > > - Probe the supported command version from EC for setting the target fan > > RPM, and perform the set fan target RPM based on the supported > > version. > > - Update the used variable type to kernel types (i.e., u32). > > - Link to v1: https://lore.kernel.org/r/20250313-extend_ec_hwmon_fan-v1-0-5c566776f2c4@chromium.org > > --- > > drivers/hwmon/cros_ec_hwmon.c | 130 ++++++++++++++++++++++++++++++++++++++++-- > > 1 file changed, 125 insertions(+), 5 deletions(-) > > > > diff --git a/drivers/hwmon/cros_ec_hwmon.c b/drivers/hwmon/cros_ec_hwmon.c > > index 9991c3fa020ac859cbbff29dfb669e53248df885..b118a355f67d7238a6f596cf01a49d5b621b31d6 100644 > > --- a/drivers/hwmon/cros_ec_hwmon.c > > +++ b/drivers/hwmon/cros_ec_hwmon.c > > @@ -21,6 +21,12 @@ struct cros_ec_hwmon_priv { > > struct cros_ec_device *cros_ec; > > const char *temp_sensor_names[EC_TEMP_SENSOR_ENTRIES + EC_TEMP_SENSOR_B_ENTRIES]; > > u8 usable_fans; > > + int set_fan_target_rpm_version; > > +}; > > + > > +union ec_params_pwm_set_fan_target_rpm { > > + struct ec_params_pwm_set_fan_target_rpm_v0 v0; > > + struct ec_params_pwm_set_fan_target_rpm_v1 v1; > > }; > > No need to give this union a name. It is only used once. > It doesn't even have to be a union but can be two dedicated on-stack > variables. > Only v1 is supported, so I'll remove this union, and there will only be 1 variable on-stack variable. > > > > static int cros_ec_hwmon_read_fan_speed(struct cros_ec_device *cros_ec, u8 index, u16 *speed) > > @@ -36,6 +42,25 @@ static int cros_ec_hwmon_read_fan_speed(struct cros_ec_device *cros_ec, u8 index > > return 0; > > } > > > > +static int cros_ec_hwmon_read_fan_target(struct cros_ec_device *cros_ec, > > + u8 index, u32 *speed) > > +{ > > + struct ec_response_pwm_get_fan_rpm r; > > + int ret; > > + > > + // Currently only supports reading the first fan. > > + if (index > 0) > > + return -EOPNOTSUPP; > > This needs to be checked in is_visible(), not here. > (Or only support v1 and not have the restriction) > Thank you, I was not sure about whether to do it in `is_visible` or the read function. Please note that there is no v1 for getting the specific fan target RPM value. > > + return 0; > > +} > > + > > static int cros_ec_hwmon_read_temp(struct cros_ec_device *cros_ec, u8 index, u8 *temp) > > { > > unsigned int offset; > > @@ -52,6 +77,49 @@ static int cros_ec_hwmon_read_temp(struct cros_ec_device *cros_ec, u8 index, u8 > > return 0; > > } > > > > +static int cros_ec_hwmon_set_fan_rpm(struct cros_ec_device *cros_ec, > > + int version, u8 index, u16 val) > > +{ > > + union ec_params_pwm_set_fan_target_rpm req; > > + int req_size; > > + int ret; > > + > > + if (version == 0) { > > + if (index != 0) > > + dev_warn( > > + cros_ec->dev, > > + "v0 only supports setting all fan to same RPM (cannot just set idx %d), set all to %d\n", > > + index, val); > > How important is v0 in general? > I think v1 covers all functionality for v0, and the intention for having this functionality is to have more control on each fan, so v0 is not that importatn. Along with the comments above, I can drop the support for v0. > > + if (ret < 0) { > > + dev_err(priv->cros_ec->dev, > > + "error getting target fan RPM set command version: %d\n", ret); > > + return ret; > > + } > > If neither v0 nor v1 are supported, this will completely prevent the > driver from being probed. Is this intentional? > Supposedly one of the version should be supported. However, with your reminder, I think missing this functionality should not block this module. As such, I will only log an warning here.
diff --git a/drivers/hwmon/cros_ec_hwmon.c b/drivers/hwmon/cros_ec_hwmon.c index 9991c3fa020ac859cbbff29dfb669e53248df885..b118a355f67d7238a6f596cf01a49d5b621b31d6 100644 --- a/drivers/hwmon/cros_ec_hwmon.c +++ b/drivers/hwmon/cros_ec_hwmon.c @@ -21,6 +21,12 @@ struct cros_ec_hwmon_priv { struct cros_ec_device *cros_ec; const char *temp_sensor_names[EC_TEMP_SENSOR_ENTRIES + EC_TEMP_SENSOR_B_ENTRIES]; u8 usable_fans; + int set_fan_target_rpm_version; +}; + +union ec_params_pwm_set_fan_target_rpm { + struct ec_params_pwm_set_fan_target_rpm_v0 v0; + struct ec_params_pwm_set_fan_target_rpm_v1 v1; }; static int cros_ec_hwmon_read_fan_speed(struct cros_ec_device *cros_ec, u8 index, u16 *speed) @@ -36,6 +42,25 @@ static int cros_ec_hwmon_read_fan_speed(struct cros_ec_device *cros_ec, u8 index return 0; } +static int cros_ec_hwmon_read_fan_target(struct cros_ec_device *cros_ec, + u8 index, u32 *speed) +{ + struct ec_response_pwm_get_fan_rpm r; + int ret; + + // Currently only supports reading the first fan. + if (index > 0) + return -EOPNOTSUPP; + + ret = cros_ec_cmd(cros_ec, 0, EC_CMD_PWM_GET_FAN_TARGET_RPM, NULL, 0, + &r, sizeof(r)); + if (ret < 0) + return ret; + + *speed = r.rpm; + return 0; +} + static int cros_ec_hwmon_read_temp(struct cros_ec_device *cros_ec, u8 index, u8 *temp) { unsigned int offset; @@ -52,6 +77,49 @@ static int cros_ec_hwmon_read_temp(struct cros_ec_device *cros_ec, u8 index, u8 return 0; } +static int cros_ec_hwmon_set_fan_rpm(struct cros_ec_device *cros_ec, + int version, u8 index, u16 val) +{ + union ec_params_pwm_set_fan_target_rpm req; + int req_size; + int ret; + + if (version == 0) { + if (index != 0) + dev_warn( + cros_ec->dev, + "v0 only supports setting all fan to same RPM (cannot just set idx %d), set all to %d\n", + index, val); + + req_size = sizeof(req.v0); + req.v0.rpm = val; + } else if (version == 1) { + req_size = sizeof(req.v1); + req.v1.rpm = val; + req.v1.fan_idx = index; + } else + return -EOPNOTSUPP; + + ret = cros_ec_cmd(cros_ec, version, EC_CMD_PWM_SET_FAN_TARGET_RPM, &req, + req_size, NULL, 0); + if (ret < 0) + return ret; + return 0; +} + +static int cros_ec_hwmon_write_fan(struct cros_ec_hwmon_priv *priv, u32 attr, + int channel, long rpm) +{ + switch (attr) { + case hwmon_fan_target: + return cros_ec_hwmon_set_fan_rpm( + priv->cros_ec, priv->set_fan_target_rpm_version, + channel, rpm); + default: + return -EOPNOTSUPP; + } +} + static bool cros_ec_hwmon_is_error_fan(u16 speed) { return speed == EC_FAN_SPEED_NOT_PRESENT || speed == EC_FAN_SPEED_STALLED; @@ -75,6 +143,7 @@ static int cros_ec_hwmon_read(struct device *dev, enum hwmon_sensor_types type, { struct cros_ec_hwmon_priv *priv = dev_get_drvdata(dev); int ret = -EOPNOTSUPP; + u32 target_rpm; u16 speed; u8 temp; @@ -91,6 +160,11 @@ static int cros_ec_hwmon_read(struct device *dev, enum hwmon_sensor_types type, ret = cros_ec_hwmon_read_fan_speed(priv->cros_ec, channel, &speed); if (ret == 0) *val = cros_ec_hwmon_is_error_fan(speed); + } else if (attr == hwmon_fan_target) { + ret = cros_ec_hwmon_read_fan_target( + priv->cros_ec, channel, &target_rpm); + if (ret == 0) + *val = target_rpm; } } else if (type == hwmon_temp) { if (attr == hwmon_temp_input) { @@ -130,8 +204,15 @@ static umode_t cros_ec_hwmon_is_visible(const void *data, enum hwmon_sensor_type const struct cros_ec_hwmon_priv *priv = data; if (type == hwmon_fan) { - if (priv->usable_fans & BIT(channel)) + if (!(priv->usable_fans & BIT(channel))) + return 0; + + switch (attr) { + case hwmon_fan_target: + return 0644; + default: return 0444; + } } else if (type == hwmon_temp) { if (priv->temp_sensor_names[channel]) return 0444; @@ -140,13 +221,26 @@ static umode_t cros_ec_hwmon_is_visible(const void *data, enum hwmon_sensor_type return 0; } +static int cros_ec_hwmon_write(struct device *dev, enum hwmon_sensor_types type, + u32 attr, int channel, long val) +{ + struct cros_ec_hwmon_priv *priv = dev_get_drvdata(dev); + + switch (type) { + case hwmon_fan: + return cros_ec_hwmon_write_fan(priv, attr, channel, val); + default: + return -EOPNOTSUPP; + } +} + static const struct hwmon_channel_info * const cros_ec_hwmon_info[] = { HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ), HWMON_CHANNEL_INFO(fan, - HWMON_F_INPUT | HWMON_F_FAULT, - HWMON_F_INPUT | HWMON_F_FAULT, - HWMON_F_INPUT | HWMON_F_FAULT, - HWMON_F_INPUT | HWMON_F_FAULT), + HWMON_F_INPUT | HWMON_F_FAULT | HWMON_F_TARGET, + HWMON_F_INPUT | HWMON_F_FAULT | HWMON_F_TARGET, + HWMON_F_INPUT | HWMON_F_FAULT | HWMON_F_TARGET, + HWMON_F_INPUT | HWMON_F_FAULT | HWMON_F_TARGET), HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL, HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL, @@ -178,6 +272,7 @@ static const struct hwmon_channel_info * const cros_ec_hwmon_info[] = { static const struct hwmon_ops cros_ec_hwmon_ops = { .read = cros_ec_hwmon_read, .read_string = cros_ec_hwmon_read_string, + .write = cros_ec_hwmon_write, .is_visible = cros_ec_hwmon_is_visible, }; @@ -233,6 +328,27 @@ static void cros_ec_hwmon_probe_fans(struct cros_ec_hwmon_priv *priv) } } +static int cros_ec_hwmon_probe_fan_target_cmd_version(struct cros_ec_hwmon_priv *priv) +{ + struct ec_params_get_cmd_versions_v1 params = { + .cmd = EC_CMD_PWM_SET_FAN_TARGET_RPM, + }; + struct ec_response_get_cmd_versions response; + int ret; + + ret = cros_ec_cmd(priv->cros_ec, 1, EC_CMD_GET_CMD_VERSIONS, ¶ms, + sizeof(params), &response, sizeof(response)); + if (ret < 0) { + dev_err(priv->cros_ec->dev, + "error getting target fan RPM set command version: %d\n", ret); + return ret; + } + + priv->set_fan_target_rpm_version = (response.version_mask & EC_VER_MASK(1)) ? 1 : 0; + + return 0; +} + static int cros_ec_hwmon_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; @@ -260,6 +376,10 @@ 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); + ret = cros_ec_hwmon_probe_fan_target_cmd_version(priv); + if (ret < 0) + return ret; + hwmon_dev = devm_hwmon_device_register_with_info(dev, "cros_ec", priv, &cros_ec_hwmon_chip_info, NULL);
The ChromeOS embedded controller (EC) supports closed loop fan speed control, so add the fan target attribute under hwmon framework, such that kernel can expose reading and specifying the desired fan RPM for fans connected to the EC. When probing the cros_ec hwmon module, we also check the supported command version of setting target fan RPM. This commit implements the version 0 of getting the target fan RPM, which can only read the target RPM of the first fan. This commit also implements the version 0 and 1 of setting the target fan RPM, where the version 0 only supports setting all fan to the same RPM, while version 1 supports setting different RPM to each fan respectively. Signed-off-by: Sung-Chi Li <lschyi@chromium.org> --- ChromeOS embedded controller (EC) supports closed-loop fan control. We anticipate to have the fan related control from the kernel side, so this series register the HWMON_F_TARGET attribute, and implement the read and write function for setting/reading the target fan RPM from the EC side. --- Changes in v2: - Squash the read, write, and register of fan target attribute to 1 commit, as they are the same topic. - Probe the supported command version from EC for setting the target fan RPM, and perform the set fan target RPM based on the supported version. - Update the used variable type to kernel types (i.e., u32). - Link to v1: https://lore.kernel.org/r/20250313-extend_ec_hwmon_fan-v1-0-5c566776f2c4@chromium.org --- drivers/hwmon/cros_ec_hwmon.c | 130 ++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 125 insertions(+), 5 deletions(-) --- base-commit: 80e54e84911a923c40d7bee33a34c1b4be148d7a change-id: 20250313-extend_ec_hwmon_fan-a5f59aab2cb3 Best regards,