[PATCH] hwmon: (max31790) add fanN_enable

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



The MAX31790 has a tach input enable bit in each fan's configuration
register. This is only enabled by the driver if RPM mode is selected,
but the driver doesn't provide a way to independently enable tachometer
input regardless of the regulator mode.

By adding the fanN_enable sysfs files, we can decouple the tach input
from the regulator mode. Also update the documentation.

Signed-off-by: Justin Ledford <justinledford@xxxxxxxxxx>
---
 Documentation/hwmon/max31790.rst |  1 +
 drivers/hwmon/max31790.c         | 44 +++++++++++++++++++++++++++-----
 2 files changed, 38 insertions(+), 7 deletions(-)

diff --git a/Documentation/hwmon/max31790.rst b/Documentation/hwmon/max31790.rst
index 7b097c3b9b90..33c5c7330efc 100644
--- a/Documentation/hwmon/max31790.rst
+++ b/Documentation/hwmon/max31790.rst
@@ -38,6 +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
+fan[1-6]_enable    RW  enable or disable the tachometer input
 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 7e9362f6dc29..3ae02be4b41e 100644
--- a/drivers/hwmon/max31790.c
+++ b/drivers/hwmon/max31790.c
@@ -118,6 +118,12 @@ static struct max31790_data *max31790_update_device(struct device *dev)
 					goto abort;
 				data->target_count[i] = rv;
 			}
+
+			rv = i2c_smbus_read_byte_data(client,
+					MAX31790_REG_FAN_CONFIG(i));
+			if (rv < 0)
+				goto abort;
+			data->fan_config[i] = rv;
 		}
 
 		data->last_updated = jiffies;
@@ -202,6 +208,9 @@ static int max31790_read_fan(struct device *dev, u32 attr, int channel,
 		}
 		mutex_unlock(&data->update_lock);
 		return 0;
+	case hwmon_fan_enable:
+		*val = !!(data->fan_config[channel] & MAX31790_FAN_CFG_TACH_INPUT_EN);
+		return 0;
 	default:
 		return -EOPNOTSUPP;
 	}
@@ -214,7 +223,7 @@ 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, fan_config;
 	int sr;
 
 	mutex_lock(&data->update_lock);
@@ -243,6 +252,23 @@ static int max31790_write_fan(struct device *dev, u32 attr, int channel,
 					MAX31790_REG_TARGET_COUNT(channel),
 					data->target_count[channel]);
 		break;
+	case hwmon_fan_enable:
+		fan_config = data->fan_config[channel];
+		if (val == 0) {
+			fan_config &= ~MAX31790_FAN_CFG_TACH_INPUT_EN;
+		} else if (val == 1) {
+			fan_config |= MAX31790_FAN_CFG_TACH_INPUT_EN;
+		} else {
+			err = -EINVAL;
+			break;
+		}
+		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;
 		break;
@@ -270,6 +296,10 @@ static umode_t max31790_fan_is_visible(const void *_data, u32 attr, int channel)
 		    !(fan_config & MAX31790_FAN_CFG_TACH_INPUT))
 			return 0644;
 		return 0;
+	case hwmon_fan_enable:
+		if (channel < NR_CHANNEL)
+			return 0644;
+		return 0;
 	default:
 		return 0;
 	}
@@ -423,12 +453,12 @@ 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_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_INPUT | HWMON_F_FAULT,
 			   HWMON_F_INPUT | HWMON_F_FAULT,
-- 
2.37.2.672.g94769d06f0-goog




[Index of Archives]     [Kernel Newbies]     [Security]     [Netfilter]     [Bugtraq]     [Linux FS]     [Yosemite Forum]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Samba]     [Video 4 Linux]     [Device Mapper]     [Linux Resources]

  Powered by Linux