hwmon: (it87) Export labels for internal sensors

Some voltage sensors can be wired internally to the IT87xxF chip's own
power supply channels. In that case, we can inform user-space that the
wiring is known by exporting proper labels for these sensors.

Signed-off-by: Jean Delvare <khali@linux-fr.org>

1 files changed, 44 insertions, 2 deletions

diff --git a/drivers/hwmon/it87.c b/drivers/hwmon/it87.c
index 25763d2223b6..f7701295937d 100644
--- a/drivers/hwmon/it87.c
+++ b/drivers/hwmon/it87.c
@@ -259,6 +259,7 @@ struct it87_sio_data {
         u8 revision;
         u8 vid_value;
         u8 beep_pin;
+        u8 internal;    /* Internal sensors can be labeled */
         /* Features skipped based on config or DMI */
         u8 skip_vid;
         u8 skip_fan;
@@ -1194,6 +1195,22 @@ static ssize_t show_vid_reg(struct device *dev, struct device_attribute *attr,
 }
 static DEVICE_ATTR(cpu0_vid, S_IRUGO, show_vid_reg, NULL);
 
+static ssize_t show_label(struct device *dev, struct device_attribute *attr,
+                char *buf)
+{
+        static const char *labels[] = {
+                "+5V",
+                "5VSB",
+                "Vbat",
+        };
+        int nr = to_sensor_dev_attr(attr)->index;
+
+        return sprintf(buf, "%s\n", labels[nr]);
+}
+static SENSOR_DEVICE_ATTR(in3_label, S_IRUGO, show_label, NULL, 0);
+static SENSOR_DEVICE_ATTR(in7_label, S_IRUGO, show_label, NULL, 1);
+static SENSOR_DEVICE_ATTR(in8_label, S_IRUGO, show_label, NULL, 2);
+
 static ssize_t show_name(struct device *dev, struct device_attribute
                          *devattr, char *buf)
 {
@@ -1434,6 +1451,17 @@ static const struct attribute_group it87_group_vid = {
         .attrs = it87_attributes_vid,
 };
 
+static struct attribute *it87_attributes_label[] = {
+        &sensor_dev_attr_in3_label.dev_attr.attr,
+        &sensor_dev_attr_in7_label.dev_attr.attr,
+        &sensor_dev_attr_in8_label.dev_attr.attr,
+        NULL
+};
+
+static const struct attribute_group it87_group_label = {
+        .attrs = it87_attributes_vid,
+};
+
 /* SuperIO detection - will change isa_address if a chip is found */
 static int __init it87_find(unsigned short *address,
         struct it87_sio_data *sio_data)
@@ -1487,6 +1515,9 @@ static int __init it87_find(unsigned short *address,
         pr_info("it87: Found IT%04xF chip at 0x%x, revision %d\n",
                 chip_type, *address, sio_data->revision);
 
+        /* in8 (Vbat) is always internal */
+        sio_data->internal = (1 << 2);
+
         /* Read GPIO config and VID value from LDN 7 (GPIO) */
         if (sio_data->type == it87) {
                 /* The IT8705F doesn't have VID pins at all */
@@ -1540,9 +1571,9 @@ static int __init it87_find(unsigned short *address,
                         pr_notice("it87: Routing internal VCCH to in7\n");
                 }
                 if (reg & (1 << 0))
-                        pr_info("it87: in3 is VCC (+5V)\n");
+                        sio_data->internal |= (1 << 0);
                 if (reg & (1 << 1))
-                        pr_info("it87: in7 is VCCH (+5V Stand-By)\n");
+                        sio_data->internal |= (1 << 1);
 
                 sio_data->beep_pin = superio_inb(IT87_SIO_BEEP_PIN_REG) & 0x3f;
         }
@@ -1600,6 +1631,7 @@ static void it87_remove_files(struct device *dev)
         }
         if (!sio_data->skip_vid)
                 sysfs_remove_group(&dev->kobj, &it87_group_vid);
+        sysfs_remove_group(&dev->kobj, &it87_group_label);
 }
 
 static int __devinit it87_probe(struct platform_device *pdev)
@@ -1725,6 +1757,16 @@ static int __devinit it87_probe(struct platform_device *pdev)
                         goto ERROR4;
         }
 
+        /* Export labels for internal sensors */
+        for (i = 0; i < 3; i++) {
+                if (!(sio_data->internal & (1 << i)))
+                        continue;
+                err = sysfs_create_file(&dev->kobj,
+                                        it87_attributes_label[i]);
+                if (err)
+                        goto ERROR4;
+        }
+
         data->hwmon_dev = hwmon_device_register(dev);
         if (IS_ERR(data->hwmon_dev)) {
                 err = PTR_ERR(data->hwmon_dev);