hwmon: (adt7475) Add VID support for the ADT7476

The ADT7476 has 5 dedicated pins for VID input, and the +12V input can
optionally be used as a 6th VID pin. Add support for VID input.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Jordan Crouse <jordan@cosmicpenguin.net>
Cc: "Darrick J. Wong" <djwong@us.ibm.com>

3 files changed, 65 insertions, 4 deletions

diff --git a/Documentation/hwmon/adt7475 b/Documentation/hwmon/adt7475
index 03be1e6f69c..0502f2b464e 100644
--- a/Documentation/hwmon/adt7475
+++ b/Documentation/hwmon/adt7475
@@ -70,7 +70,7 @@ ADT7475:
 
 ADT7476:
   * 5 voltage inputs
-  * VID support (not implemented)
+  * VID support
 
 ADT7490:
   * 6 voltage inputs
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 957171c6232..9e640c62ebd 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -207,6 +207,7 @@ config SENSORS_ADT7473
 config SENSORS_ADT7475
         tristate "Analog Devices ADT7473, ADT7475, ADT7476 and ADT7490"
         depends on I2C && EXPERIMENTAL
+        select HWMON_VID
         help
           If you say yes here you get support for the Analog Devices
           ADT7473, ADT7475, ADT7476 and ADT7490 hardware monitoring
diff --git a/drivers/hwmon/adt7475.c b/drivers/hwmon/adt7475.c
index 72c3b754e7b..99abfddedbc 100644
--- a/drivers/hwmon/adt7475.c
+++ b/drivers/hwmon/adt7475.c
@@ -18,6 +18,7 @@
 #include <linux/i2c.h>
 #include <linux/hwmon.h>
 #include <linux/hwmon-sysfs.h>
+#include <linux/hwmon-vid.h>
 #include <linux/err.h>
 
 /* Indexes for the sysfs hooks */
@@ -110,6 +111,7 @@
 
 #define CONFIG5_TWOSCOMP        0x01
 #define CONFIG5_TEMPOFFSET      0x02
+#define CONFIG5_VIDGPIO         0x10    /* ADT7476 only */
 
 /* ADT7475 Settings */
 
@@ -171,6 +173,7 @@ struct adt7475_data {
         u8 bypass_attn;         /* Bypass voltage attenuator */
         u8 has_pwm2:1;
         u8 has_fan4:1;
+        u8 has_vid:1;
         u32 alarms;
         u16 voltage[3][6];
         u16 temp[7][3];
@@ -179,6 +182,9 @@ struct adt7475_data {
         u8 range[3];
         u8 pwmctl[3];
         u8 pwmchan[3];
+
+        u8 vid;
+        u8 vrm;
 };
 
 static struct i2c_driver adt7475_driver;
@@ -864,6 +870,35 @@ static ssize_t set_pwm_at_crit(struct device *dev,
         return count;
 }
 
+static ssize_t show_vrm(struct device *dev, struct device_attribute *devattr,
+                        char *buf)
+{
+        struct adt7475_data *data = dev_get_drvdata(dev);
+        return sprintf(buf, "%d\n", (int)data->vrm);
+}
+
+static ssize_t set_vrm(struct device *dev, struct device_attribute *devattr,
+                       const char *buf, size_t count)
+{
+        struct adt7475_data *data = dev_get_drvdata(dev);
+        long val;
+
+        if (strict_strtol(buf, 10, &val))
+                return -EINVAL;
+        if (val < 0 || val > 255)
+                return -EINVAL;
+        data->vrm = val;
+
+        return count;
+}
+
+static ssize_t show_vid(struct device *dev, struct device_attribute *devattr,
+                        char *buf)
+{
+        struct adt7475_data *data = adt7475_update_device(dev);
+        return sprintf(buf, "%d\n", vid_from_reg(data->vid, data->vrm));
+}
+
 static SENSOR_DEVICE_ATTR_2(in0_input, S_IRUGO, show_voltage, NULL, INPUT, 0);
 static SENSOR_DEVICE_ATTR_2(in0_max, S_IRUGO | S_IWUSR, show_voltage,
                             set_voltage, MAX, 0);
@@ -1007,6 +1042,9 @@ static SENSOR_DEVICE_ATTR_2(pwm3_auto_point2_pwm, S_IRUGO | S_IWUSR, show_pwm,
 static DEVICE_ATTR(pwm_use_point2_pwm_at_crit, S_IWUSR | S_IRUGO,
                    show_pwm_at_crit, set_pwm_at_crit);
 
+static DEVICE_ATTR(vrm, S_IWUSR | S_IRUGO, show_vrm, set_vrm);
+static DEVICE_ATTR(cpu0_vid, S_IRUGO, show_vid, NULL);
+
 static struct attribute *adt7475_attrs[] = {
         &sensor_dev_attr_in1_input.dev_attr.attr,
         &sensor_dev_attr_in1_max.dev_attr.attr,
@@ -1119,6 +1157,12 @@ static struct attribute *in5_attrs[] = {
         NULL
 };
 
+static struct attribute *vid_attrs[] = {
+        &dev_attr_cpu0_vid.attr,
+        &dev_attr_vrm.attr,
+        NULL
+};
+
 static struct attribute_group adt7475_attr_group = { .attrs = adt7475_attrs };
 static struct attribute_group fan4_attr_group = { .attrs = fan4_attrs };
 static struct attribute_group pwm2_attr_group = { .attrs = pwm2_attrs };
@@ -1126,6 +1170,7 @@ static struct attribute_group in0_attr_group = { .attrs = in0_attrs };
 static struct attribute_group in3_attr_group = { .attrs = in3_attrs };
 static struct attribute_group in4_attr_group = { .attrs = in4_attrs };
 static struct attribute_group in5_attr_group = { .attrs = in5_attrs };
+static struct attribute_group vid_attr_group = { .attrs = vid_attrs };
 
 static int adt7475_detect(struct i2c_client *client, int kind,
                           struct i2c_board_info *info)
@@ -1180,6 +1225,8 @@ static void adt7475_remove_files(struct i2c_client *client,
                 sysfs_remove_group(&client->dev.kobj, &in4_attr_group);
         if (data->has_voltage & (1 << 5))
                 sysfs_remove_group(&client->dev.kobj, &in5_attr_group);
+        if (data->has_vid)
+                sysfs_remove_group(&client->dev.kobj, &vid_attr_group);
 }
 
 static int adt7475_probe(struct i2c_client *client,
@@ -1247,11 +1294,14 @@ static int adt7475_probe(struct i2c_client *client,
                         data->has_voltage |= (1 << 0);          /* in0 */
         }
 
-        /* On the ADT7476, the +12V input pin may instead be used as VID5 */
+        /* On the ADT7476, the +12V input pin may instead be used as VID5,
+           and VID pins may alternatively be used as GPIO */
         if (id->driver_data == adt7476) {
                 u8 vid = adt7475_read(REG_VID);
                 if (!(vid & VID_VIDSEL))
                         data->has_voltage |= (1 << 4);          /* in4 */
+
+                data->has_vid = !(adt7475_read(REG_CONFIG5) & CONFIG5_VIDGPIO);
         }
 
         /* Voltage attenuators can be bypassed, globally or individually */
@@ -1304,6 +1354,12 @@ static int adt7475_probe(struct i2c_client *client,
                 if (ret)
                         goto eremove;
         }
+        if (data->has_vid) {
+                data->vrm = vid_which_vrm();
+                ret = sysfs_create_group(&client->dev.kobj, &vid_attr_group);
+                if (ret)
+                        goto eremove;
+        }
 
         data->hwmon_dev = hwmon_device_register(&client->dev);
         if (IS_ERR(data->hwmon_dev)) {
@@ -1314,11 +1370,12 @@ static int adt7475_probe(struct i2c_client *client,
         dev_info(&client->dev, "%s device, revision %d\n",
                  names[id->driver_data], revision);
         if ((data->has_voltage & 0x11) || data->has_fan4 || data->has_pwm2)
-                dev_info(&client->dev, "Optional features:%s%s%s%s\n",
+                dev_info(&client->dev, "Optional features:%s%s%s%s%s\n",
                          (data->has_voltage & (1 << 0)) ? " in0" : "",
                          (data->has_voltage & (1 << 4)) ? " in4" : "",
                          data->has_fan4 ? " fan4" : "",
-                         data->has_pwm2 ? " pwm2" : "");
+                         data->has_pwm2 ? " pwm2" : "",
+                         data->has_vid ? " vid" : "");
         if (data->bypass_attn)
                 dev_info(&client->dev, "Bypassing attenuators on:%s%s%s%s\n",
                          (data->bypass_attn & (1 << 0)) ? " in0" : "",
@@ -1472,6 +1529,9 @@ static struct adt7475_data *adt7475_update_device(struct device *dev)
                         data->pwm[INPUT][i] = adt7475_read(PWM_REG(i));
                 }
 
+                if (data->has_vid)
+                        data->vid = adt7475_read(REG_VID) & 0x3f;
+
                 data->measure_updated = jiffies;
         }