hwmon: (max31790) Add support for fanX_enable attributes

Since pwmX_enable is now fixed and only handles pwm support instead
of also enabling/disabling fan tachometers, we need an explicit means
to do that.

For fan channels 7..12, display the enable status if the channel
is configured for fan speed reporting. The displayed status matches
the value of the companion channel but is read-only.

Cc: Jan Kundrát <jan.kundrat@cesnet.cz>
Cc: Václav Kubernát <kubernat@cesnet.cz>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/Documentation/hwmon/max31790.rst b/Documentation/hwmon/max31790.rst
index 7b097c3b9b908afc45f45e53e4ee6f0509309379..b43aa32813fda88e9dafee3f47dd19ba1d7c5ab0 100644 (file)
--- a/Documentation/hwmon/max31790.rst
+++ b/Documentation/hwmon/max31790.rst
@@ -35,6 +35,9 @@ Sysfs entries
 -------------
 
 ================== === =======================================================
+fan[1-12]_enable   RW  0=disable fan speed monitoring, 1=enable fan speed monitoring
+                       The value is RO for companion channels (7-12). For those
+                       channels, the value matches the value of the primary channel.
 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

diff --git a/drivers/hwmon/max31790.c b/drivers/hwmon/max31790.c
index 67677c43776879721e1149ed8e04799ebac83f26..19651feb40fb2a944d85e823abbf265b74e6e850 100644 (file)
--- a/drivers/hwmon/max31790.c
+++ b/drivers/hwmon/max31790.c
@@ -170,6 +170,9 @@ static int max31790_read_fan(struct device *dev, u32 attr, int channel,
                return PTR_ERR(data);
 
        switch (attr) {
+       case hwmon_fan_enable:
+               *val = !!(data->fan_config[channel % NR_CHANNEL] & MAX31790_FAN_CFG_TACH_INPUT_EN);
+               return 0;
        case hwmon_fan_input:
                sr = get_tach_period(data->fan_dynamics[channel % NR_CHANNEL]);
                rpm = RPM_FROM_REG(data->tach[channel], sr);
@@ -195,12 +198,32 @@ static int max31790_write_fan(struct device *dev, u32 attr, int channel,
        struct i2c_client *client = data->client;
        int target_count;
        int err = 0;
-       u8 bits;
+       u8 bits, config;
        int sr;
 
        mutex_lock(&data->update_lock);
 
        switch (attr) {
+       case hwmon_fan_enable:
+               config = data->fan_config[channel];
+               if (val == 0) {
+                       /* Disabling TACH_INPUT_EN has no effect in RPM_MODE */
+                       if (!(config & MAX31790_FAN_CFG_RPM_MODE))
+                               config &= ~MAX31790_FAN_CFG_TACH_INPUT_EN;
+               } else if (val == 1) {
+                       config |= MAX31790_FAN_CFG_TACH_INPUT_EN;
+               } else {
+                       err = -EINVAL;
+                       break;
+               }
+               if (config != data->fan_config[channel]) {
+                       err = i2c_smbus_write_byte_data(client,
+                                                       MAX31790_REG_FAN_CONFIG(channel),
+                                                       config);
+                       if (!err)
+                               data->fan_config[channel] = config;
+               }
+               break;
        case hwmon_fan_target:
                val = clamp_val(val, FAN_RPM_MIN, FAN_RPM_MAX);
                bits = bits_for_tach_period(val);
@@ -240,6 +263,12 @@ static umode_t max31790_fan_is_visible(const void *_data, u32 attr, int channel)
        u8 fan_config = data->fan_config[channel % NR_CHANNEL];
 
        switch (attr) {
+       case hwmon_fan_enable:
+               if (channel < NR_CHANNEL)
+                       return 0644;
+               if (fan_config & MAX31790_FAN_CFG_TACH_INPUT)
+                       return 0444;
+               return 0;
        case hwmon_fan_input:
        case hwmon_fan_fault:
                if (channel < NR_CHANNEL ||
@@ -404,18 +433,18 @@ static umode_t max31790_is_visible(const void *data,
 
 static const struct hwmon_channel_info *max31790_info[] = {
        HWMON_CHANNEL_INFO(fan,
-                          HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
-                          HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
-                          HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
-                          HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
-                          HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
-                          HWMON_F_INPUT | HWMON_F_TARGET | 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_INPUT | HWMON_F_FAULT,
-                          HWMON_F_INPUT | HWMON_F_FAULT),
+                          HWMON_F_ENABLE | HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
+                          HWMON_F_ENABLE | HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
+                          HWMON_F_ENABLE | HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
+                          HWMON_F_ENABLE | HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
+                          HWMON_F_ENABLE | HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
+                          HWMON_F_ENABLE | HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
+                          HWMON_F_ENABLE | HWMON_F_INPUT | HWMON_F_FAULT,
+                          HWMON_F_ENABLE | HWMON_F_INPUT | HWMON_F_FAULT,
+                          HWMON_F_ENABLE | HWMON_F_INPUT | HWMON_F_FAULT,
+                          HWMON_F_ENABLE | HWMON_F_INPUT | HWMON_F_FAULT,
+                          HWMON_F_ENABLE | HWMON_F_INPUT | HWMON_F_FAULT,
+                          HWMON_F_ENABLE | HWMON_F_INPUT | HWMON_F_FAULT),
        HWMON_CHANNEL_INFO(pwm,
                           HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
                           HWMON_PWM_INPUT | HWMON_PWM_ENABLE,