[lm-sensors] [PATCH v3 1/1] hwmon: added support for the max6650 alarm stati

Engelmayer Christian Christian.Engelmayer at frequentis.com
Sun May 24 22:38:15 CEST 2009


From: Christian Engelmayer <christian.engelmayer at frequentis.com>

Exported the alarm stati provided by the MAX6650/MAX6651 fan-speed regulator
and monitor chips via sysfs.

Signed-off-by: Christian Engelmayer <christian.engelmayer at frequentis.com>
---
Tested with the MAX6651 chip. This obsoletes the previously proposed patch
'support for the max6650 GPIO and alarm features' after discussion on sane
gpio handling.

Revised after remarks by Hans de Goede. Changed the alarm attributes to
sensor
device attributes thus eliminating the need for pointer comparison in show
function get_alarm(). Left the alarm behaviour unchanged. In case the sysfs
interface does not prefer 'real time' over 'latched' alarms I prefer to keep
the style used by the device.

Incorporated additional remarks by Hans de Goede. Changed a temporary
variable
from 'u8' to 'int'. Changed the order of alarms within the code from MSB
first
to LSB first as occuring within the registers.

--- drivers/hwmon/max6650.c.orig	2009-05-20 12:36:21.000000000 +0200
+++ drivers/hwmon/max6650.c	2009-05-24 22:13:40.000000000 +0200
@@ -12,7 +12,7 @@
  * also work with the MAX6651. It does not distinguish max6650 and max6651
  * chips.
  *
- * Tha datasheet was last seen at:
+ * The datasheet was last seen at:
  *
  *        http://pdfserv.maxim-ic.com/en/ds/MAX6650-MAX6651.pdf
  *
@@ -98,6 +98,17 @@ I2C_CLIENT_INSMOD_1(max6650);
 #define MAX6650_CFG_MODE_OPEN_LOOP	0x30
 #define MAX6650_COUNT_MASK		0x03
 
+/*
+ * Alarm status register bits
+ */
+
+#define MAX6650_ALRM_MAX	0x01
+#define MAX6650_ALRM_MIN	0x02
+#define MAX6650_ALRM_TACH	0x04
+#define MAX6650_ALRM_GPIO1	0x08
+#define MAX6650_ALRM_GPIO2	0x10
+#define MAX6650_ALRM_MASK	0x1F
+
 /* Minimum and maximum values of the FAN-RPM */
 #define FAN_RPM_MIN 240
 #define FAN_RPM_MAX 30000
@@ -151,6 +162,8 @@ struct max6650_data
 	u8 tach[4];
 	u8 count;
 	u8 dac;
+	u8 alarm_en;
+	u8 alarm;
 };
 
 static ssize_t get_fan(struct device *dev, struct device_attribute *devattr,
@@ -418,6 +431,54 @@ static ssize_t set_div(struct device *de
 	return count;
 }
 
+/*
+ * Get alarm stati:
+ * Possible values:
+ * 0 = no alarm
+ * 1 = alarm
+ */
+
+static ssize_t get_alarm(struct device *dev, struct device_attribute
*devattr,
+			 char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct max6650_data *data = max6650_update_device(dev);
+	struct i2c_client *client = to_i2c_client(dev);
+	u8 mask = 0x00;
+	int alarm = 0;
+
+	switch (attr->index) {
+	case 0:
+		mask = MAX6650_ALRM_MAX;
+		break;
+	case 1:
+		mask = MAX6650_ALRM_MIN;
+		break;
+	case 2:
+		mask = MAX6650_ALRM_TACH;
+		break;
+	case 3:
+		mask = MAX6650_ALRM_GPIO1;
+		break;
+	case 4:
+		mask = MAX6650_ALRM_GPIO2;
+		break;
+	default:
+		return 0;
+	}
+
+	if (data->alarm & mask) {
+		mutex_lock(&data->update_lock);
+		alarm = 1;
+		data->alarm &= ~mask;
+		data->alarm |= i2c_smbus_read_byte_data(client,
+							MAX6650_REG_ALARM);
+		mutex_unlock(&data->update_lock);
+	}
+
+	return sprintf(buf, "%d\n", alarm);
+}
+
 static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, get_fan, NULL, 0);
 static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, get_fan, NULL, 1);
 static SENSOR_DEVICE_ATTR(fan3_input, S_IRUGO, get_fan, NULL, 2);
@@ -426,7 +487,41 @@ static DEVICE_ATTR(fan1_target, S_IWUSR 
 static DEVICE_ATTR(fan1_div, S_IWUSR | S_IRUGO, get_div, set_div);
 static DEVICE_ATTR(pwm1_enable, S_IWUSR | S_IRUGO, get_enable, set_enable);
 static DEVICE_ATTR(pwm1, S_IWUSR | S_IRUGO, get_pwm, set_pwm);
+static SENSOR_DEVICE_ATTR(fan1_max_alarm, S_IRUGO, get_alarm, NULL, 0);
+static SENSOR_DEVICE_ATTR(fan1_min_alarm, S_IRUGO, get_alarm, NULL, 1);
+static SENSOR_DEVICE_ATTR(fan1_fault, S_IRUGO, get_alarm, NULL, 2);
+static SENSOR_DEVICE_ATTR(gpio1_alarm, S_IRUGO, get_alarm, NULL, 3);
+static SENSOR_DEVICE_ATTR(gpio2_alarm, S_IRUGO, get_alarm, NULL, 4);
 
+static mode_t max6650_attrs_visible(struct kobject *kobj, struct attribute
*a,
+				    int n)
+{
+	struct device *dev = container_of(kobj, struct device, kobj);
+	struct max6650_data *data = max6650_update_device(dev);
+
+	/*
+	 * Hide the alarms that have not been enabled by the firmware
+	 */
+
+	if (a == &sensor_dev_attr_fan1_max_alarm.dev_attr.attr) {
+		if (!(data->alarm_en & MAX6650_ALRM_MAX))
+			return 0;
+	} else if (a == &sensor_dev_attr_fan1_min_alarm.dev_attr.attr) {
+		if (!(data->alarm_en & MAX6650_ALRM_MIN))
+			return 0;
+	} else if (a == &sensor_dev_attr_fan1_fault.dev_attr.attr) {
+		if (!(data->alarm_en & MAX6650_ALRM_TACH))
+			return 0;
+	} else if (a == &sensor_dev_attr_gpio1_alarm.dev_attr.attr) {
+		if (!(data->alarm_en & MAX6650_ALRM_GPIO1))
+			return 0;
+	} else if (a == &sensor_dev_attr_gpio2_alarm.dev_attr.attr) {
+		if (!(data->alarm_en & MAX6650_ALRM_GPIO2))
+			return 0;
+	}
+
+	return a->mode;
+}
 
 static struct attribute *max6650_attrs[] = {
 	&sensor_dev_attr_fan1_input.dev_attr.attr,
@@ -437,11 +532,17 @@ static struct attribute *max6650_attrs[]
 	&dev_attr_fan1_div.attr,
 	&dev_attr_pwm1_enable.attr,
 	&dev_attr_pwm1.attr,
+	&sensor_dev_attr_fan1_max_alarm.dev_attr.attr,
+	&sensor_dev_attr_fan1_min_alarm.dev_attr.attr,
+	&sensor_dev_attr_fan1_fault.dev_attr.attr,
+	&sensor_dev_attr_gpio1_alarm.dev_attr.attr,
+	&sensor_dev_attr_gpio2_alarm.dev_attr.attr,
 	NULL
 };
 
 static struct attribute_group max6650_attr_grp = {
 	.attrs = max6650_attrs,
+	.is_visible = max6650_attrs_visible,
 };
 
 /*
@@ -658,6 +759,14 @@ static struct max6650_data *max6650_upda
 		data->count = i2c_smbus_read_byte_data(client,
 							MAX6650_REG_COUNT);
 		data->dac = i2c_smbus_read_byte_data(client,
MAX6650_REG_DAC);
+		data->alarm_en = i2c_smbus_read_byte_data(client,
+
MAX6650_REG_ALARM_EN);
+
+		/* Alarms are cleared on read in case the condition that
+		 * caused the alarm is removed. Keep the value latched here
+		 * for providing the register through different alarm files.
*/
+		data->alarm |= i2c_smbus_read_byte_data(client,
+							MAX6650_REG_ALARM);
 
 		data->last_updated = jiffies;
 		data->valid = 1;





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